US 4635073

I'll verify this patent against live sources before summarizing.

Let me check the litigation references and USPTO records.

Let me do one more targeted check for any 2026 appellate activity.

US Patent 4,635,073 — Verified Summary

Search scope caveat: I searched for the exact identifier "4635073" / "4,635,073." I found no Court of Appeals for the Federal Circuit docket in 2026 (or any year) involving this patent. The 2026 Federal Circuit inkjet cases that surfaced involve a different patent owner (Slingshot Printing LLC) and different patents (e.g., 7,152,951; 7,195,341) — not US 4,635,073. The only identified litigation is a 2001–2002 ITC Section 337 investigation (below). I did not auto-correct any number; all identifiers below are as they appear in the record.

Bibliographic Data

Family: WO1987003365A1 (PCT/US1986/002526), EP0249626B1, DE3683292D1, JPH0764070B2, HK83992A. A continuation application (Ser. No. 937,945, filed Dec. 4, 1986, abandoned) led to divisional US 4,827,294.

Prior art cited: US 4,506,272 (Arai, Matsushita — thermal printing head); US 4,500,895 (Buck, HP — disposable ink jet head); US 4,589,584 (Christiansen, IBM — electrical connection for polymeric conductive material); US 4,585,157 (Belcher, GM — tape bonding of two ICs into one tape frame).

Abstract (verbatim)

"This application discloses a new and improved thermal ink jet printhead and method of manufacture wherein a tape automated bond (TAB) flexible circuit is sequentially thermosonically bonded in a one-by-one wire bonding process to aligned conductive traces on a thin film resistor substrate. These traces provide electrical current paths for a corresponding plurality of heater resistors on the substrate, and these resistors function to heat a corresponding plurality of ink reservoirs in a thermal ink jet printhead."

Plain-Language Overview of the Independent Claims

Claim 1 — Process for fabricating a replaceable thermal ink jet print head. Three steps: (a) provide a thin-film resistor print-head substrate carrying resistive heater elements and matching conductive leads; (b) provide a beam-lead interconnect circuit whose beam leads are spaced to match the substrate's conductive leads; and (c) thermosonically bond the beam leads to the conductive traces one at a time, in sequence, arranged so the beam leads and traces lie in adjacent parallel planes. The stated benefit is higher packing density on the print head.

Claim 4 — Apparatus (print head assembly). A print-head substrate mounted on a header member and receiving ink from it; conductive traces deposited on top of the substrate and connected to heater resistors in the substrate; and a beam-lead interconnect circuit with beam leads bonded respectively to those traces in adjacent abutting parallel planes, to maximize packing density. This is the claim that was adjudicated at the ITC (see below).

Claim 10 — Process for making electrical interconnects to a thin-film print head substrate. Provide thin conductive traces to heater resistors on the substrate; then thermosonically and individually bond thin beam leads to those traces at a relatively low bonding temperature on the order of about 70 °C or less. The low-temperature limitation is the distinguishing numerical feature of this claim.

Dependent claims in brief:

• 2–3 (depend from 1): mount substrate on a header, route the beam-lead circuit over a chosen header surface, and protrude it resiliently so the head can make firm but removable contact with printer-housing conductors; the resiliency is provided by an elongated elastomeric member inserted between the beam leads and the header surface.
• 5–9 (depend from 4): beam leads extend over a header surface and resiliently away from it for removable connection; elastomeric member provides the resilience; claims 7, 8, 9 add the material limitation of aluminum traces + gold-plated beam leads forming a strong bond at ≈70 °C or less without the intermetallic failure the specification calls "purple plague" (note: claims 7–9 as printed recite "purple plaque," while the specification text uses "purple plague").
• 11–12 (depend from 10): aluminum traces and copper beam leads plated with gold; and beam leads flexibly extended over a header support and elastomerically extended vertically to make firm, removable contact with printer-carriage conductors.

Technical core: sequential ("one-by-one") thermosonic beam-lead bonding of a TAB flexible circuit directly onto aluminum traces in the plane of a tantalum-aluminum thin-film resistor substrate, with a gold-to-aluminum bond made at ≤70 °C to avoid the gold-aluminum intermetallic ("purple plague") problem, plus an elastomer-backed pressure-contact interface to the printer carriage. The bonding tool tip is described as 3 mils × 4 mils, compressing ~1 mil beam leads to 0.6–0.75 mils.

Litigation / Enforcement (verified)

• ITC Investigation No. 337-TA-446, Certain Ink Jet Print Cartridges and Components Thereof. Complainant Hewlett-Packard Company; respondents included Microjet Technology Co., Ltd. (Taiwan), Printer Essentials, Price-Less Inkjet Cartridge Company, Cartridge Hut and Paperwork Plus, and ABCCo.net, Inc.
• The ALJ's Initial Determination (Jan. 25, 2002) found no infringement of claim 4 of the '073 patent and no domestic industry for it. On March 7, 2002 the Commission reviewed and reversed-in-part, determining that the accused devices infringe claim 4 of US 4,635,073 and that HP satisfied the technical prong of the domestic-industry requirement.
• Result: limited exclusion order against Microjet and cease-and-desist orders against Price-Less and ABCCo.net; bond set at 100% of entered value. Published at 67 FR 21733 (May 1, 2002). Sources: USITC Pub. 3549, Federal Register 02-10775.

No CAFC 2026 activity found for this patent number. Given the patent's lifetime expired status (anticipated expiration November 22, 2005), it is no longer enforceable, which is consistent with the absence of recent appellate dockets.

Stated Uncertainties

1. No authoritative 2026 CAFC docket exists in my search results referencing 4,635,073; I cannot confirm or deny any non-public or very recent filing beyond what was searchable.
2. Assignee chain: Google Patents lists "Current Assignee: HP Inc." while the original assignment was to Hewlett-Packard Company (California), with later recorded mergers to a Delaware HP company and to Hewlett-Packard Company, Colorado (effective May 20, 1998). I have not independently verified the ultimate current owner beyond these reassignment records.
3. Claim-language quirks ("purple plaque" in claims 7–9; the 1987 Certificate of Correction) are reproduced as printed, not corrected.

I'll research litigation involving US patent 4635073.

Let me dig deeper into the ITC investigation and check for any district court or appellate cases.

Let me check for other ITC investigations and any Federal Circuit appeals involving this patent.

Answer

Bottom line: I found one patent-infringement proceeding in which US Patent 4,635,073 (US 4,635,073 A; granted 1987-01-06 to Gary E. Hanson, originally assigned to Hewlett-Packard Company) was actually asserted — an International Trade Commission Section 337 investigation. I found no district-court or Court of Appeals for the Federal Circuit case in which the '073 patent was asserted. I found two 2010 Hewlett-Packard district-court suits against the same family of accused parties (Microjet et al.), but those did not involve the '073 patent (see below).

Citation-format note (per your literal-interpretation rule): Google Patents renders the number as US4635073A, while the ITC/Federal Register documents cite it as "U.S. Letters Patent 4,635,073" / "the '073 patent." These are the same document (4,635,073 = 4635073). I have not auto-corrected either form.

1. ITC Investigation No. 337-TA-446 — "Certain Ink Jet Print Cartridges and Components Thereof"

Asserted patents (six total): U.S. 4,827,294 (claims 1–3); U.S. 4,635,073 (claims 4 and 5); U.S. 4,680,859 (claims 2–3); U.S. 4,872,027 (claim 4); U.S. 4,992,802 (claims 1–4, 12); U.S. 5,409,134 (claims 8, 9, 12–14, 18–20).

Procedural history specific to the '073 patent:

• May 11, 2001 — ALJ initial determination (Order No. 7) terminating the investigation as to Printer Essentials on the basis of a consent order. October 12, 2001 — Order No. 15 terminating as to Cartridge Hut on the same basis.
• October 24, 2001 — HP moved to terminate its infringement allegations based on claim 5 of the '073 patent (along with claims in two other patents). ALJ Order No. 17 (Nov. 15, 2001) granted this; unreviewed, so it became a Commission determination. Only claim 4 of the '073 patent remained asserted.
• January 25, 2002 — ALJ's final initial determination + recommended determination on remedy/bonding. The ALJ found a violation of Section 337 but found no infringement of the '073 patent and found that HP had not met the technical prong of the domestic-industry requirement as to the '073 patent. He recommended a 100% bond and a limited exclusion order against Microjet and cease-and-desist orders against Price-Less and ABC.
• February 14, 2002 — HP and the Commission Investigative Attorney petitioned for review of the '073-related findings.
• March 7, 2002 — Commission determined to review (1) the ID's construction of the asserted claim of the '073 patent, (2) the finding of no infringement, and (3) the technical-prong findings; it declined to review the remainder. (67 FR 11708, Mar. 15, 2002)
• March 2002 (final determination) — Commission reversed-in-part, holding that the accused devices infringe claim 4 of the '073 patent and that HP had satisfied the technical prong of the domestic-industry requirement for the '073 patent. It found a violation of Section 337.

Outcome / current status:

• Limited exclusion order issued against Microjet Technology Co., Ltd., covering ink jet print cartridges covered by claim 4 of the '073 patent (and the other asserted claims of the other patents); 100% of entered value bond during the Presidential review period.
• Cease-and-desist orders issued against Price-Less Inkjet Cartridge Company and ABCCo.net, Inc.
• Investigation terminated; Commission notice issued April 25, 2002, published at 67 FR 21733 (May 1, 2002). Public report: USITC Publication 3549, "Certain Ink Jet Print Cartridges and Components Thereof, Inv. 337-TA-446" (Oct. 2002).
• Status: closed/terminated (2002). The remedial orders ran for the remaining terms of the patents. Note that the '073 patent (filed 1985-11-22, granted 1987-01-06) has long since expired — Google Patents records an anticipated expiration of 2005-11-22 and legal status "Expired – Lifetime."

Sources: https://www.federalregister.gov/documents/2001/01/25/01-2211/certain-ink-jet-print-cartridges-and-components-thereof-notice-of-investigation ; https://www.federalregister.gov/api/v1/documents/02-6316 ; https://www.govinfo.gov/app/details/FR-2002-05-01/02-10775 ; https://www.usitc.gov/intellectual_property/documents/pub3549.pdf ; https://patents.google.com/patent/US4635073/en (litigation flags: Unified Patents ITC case link for 337-TA-446; Darts-IP family 25180017).

2. Related matters that did NOT involve the '073 patent (flagged to avoid conflation)

The Google Patents page's "family has litigation" flags point to the same ITC matter. However, later Hewlett-Packard suits against overlapping parties appear in litigation databases; based on the documents I retrieved, these asserted different patents:

• Hewlett Packard Company v. Microjet Technology Co. Ltd. et al, N.D. Cal., Case No. 3:2010-cv-00965, filed March 5, 2010 (Judge Edward M. Chen) — patent infringement plus allegations concerning misappropriated print-head components.
• Hewlett-Packard Company et al v. Microjet Technology Co., Ltd. et al, N.D. Cal., Case No. 3:10-cv-02175, filed May 20, 2010 — stayed under 28 U.S.C. § 1659 pending ITC Inv. No. 337-TA-723 (stay approved August 2010; continued January 24, 2012).
• ITC Inv. No. 337-TA-723, "Certain Inkjet Ink Cartridges With Printheads and Components Thereof," instituted June 18/25, 2010 (75 FR 36442) on HP's complaint — asserted U.S. 6,234,598; 6,309,053; 6,398,347; 6,412,917; 6,481,817; 6,402,279.

None of these list the '073 patent, which is consistent with the '073 patent having expired years earlier. I have not found any evidence that the '073 patent was pleaded in the 2010 cases, so I am not reporting them as '073 litigation. Source: https://dockets.justia.com/docket/california/candce/5:2010cv02175/[227761](/patent/227761) ; https://dockets.justia.com/docket/california/candce/3:2010cv00965/[224999](/patent/224999) ; https://www.federalregister.gov/documents/2010/06/25/2010-15413/...

3. What I could not confirm

• No Federal Circuit appeal of the 337-TA-446 determination involving the '073 patent was located in the sources searched, and no district-court action asserting the '073 patent was located.** I cannot rule out an unreported or pre-1990s dispute based on the sources searched; that assertion would require a PACER/Darts-IP/Unified Patents records pull beyond the free sources I used.
• The two 2010 N.D. Cal. dockets and the 2010 ITC investigation were surfaced only as same-party, same-technology relatives; treat them as context, not as '073 litigation.

Net answer: The only known litigation involving US Patent 4635073 / 4,635,073 is ITC Inv. No. 337-TA-446, HP as complainant against Microjet, Printer Essentials, Price-Less, Cartridge Hut and ABCCo.net — filed December 22, 2000, instituted January 19, 2001, resolved by Commission final determination in March 2002 with a limited exclusion order against Microjet and cease-and-desist orders against Price-Less and ABCCo.net (67 FR 21733; USITC Pub. 3549), terminated April 25, 2002, now closed.

I'll start by checking the structured data and then run targeted web searches to see whether any AIA trial proceedings exist outside the ODP ingest.

Initial searches returned nothing on point (one hit was an unrelated EP application with a coincidentally similar number). Let me probe the ITC litigation thread and check for reexamination or PTAB activity under other identifiers.

The ITC thread is confirmed and significant. Let me run a final diligence pass for any AIA-trial or reexamination record I might have missed.

Proceedings overview

AIA trial proceedings on file for US 4,635,073: zero. The structured PTAB block states verbatim that "The USPTO ODP API returns no AIA trial proceedings for this patent as of the most recent ingest," and my independent web searches (patent number + IPR/PGR/CBM, petitioner-side and aggregator-side) surfaced no IPR, PGR, or CBM petition, no institution decision, and no Final Written Decision ever filed against the '073 patent. Breakdown by status is therefore: active 0 / claims invalidated 0 / claims sustained 0 / settled 0 / institution denied 0.

The bottom line for a defendant is unusual, and it is not "the patent is hardened because it survived IPRs." The patent never faced an AIA trial because of a timing accident: the '073 patent was filed 1985-11-22, granted 1987-01-06, and reached anticipated expiration on 2005-11-22 (Google Patents legal status: "Expired - Lifetime"). The AIA trial regime did not exist until 2012-09-16, so by the time IPRs became available this patent was already dead. The dispositive defensive posture is expiration, not PTAB invalidation. Any assertion today can only reach pre-2005-11-22 sales.

Because there are no AIA proceedings to report, the substantive enforcement history below is the ITC § 337 action — the only adjudicated validity/infringement record on this patent — presented as non-PTAB context rather than dressed up as an AIA trial.

AIA trial proceedings

None. No proceeding numbers exist to report, and I will not fabricate any. For completeness, the searches that came back clean:

• "4635073" IPR petition Patent Trial and Appeal Board → no results
• US patent 4635073 PTAB inter partes review → no on-point results (one hit was an unrelated European application, EP-4635073-A1, a 2022 H3Battery motor controller — a coincidental number collision, not this patent)
• Unified Patents "4,635,073" OR "4635073" inter partes review → no results
• "4,635,073" ... reexamination certificate → no results

I also found no ex parte or inter partes reexamination of the '073 patent in the sources reviewed. That is a negative finding from search, not a certificate-level confirmation — if it matters, verify directly against the USPTO Patent Public Search "reexamination" record and PTAB E2E (https://e2e.uspto.gov/).

Non-PTAB enforcement record (context for the absence)

ITC Inv. No. 337-TA-446 — Hewlett-Packard Co. v. Microjet Technology Co., Ltd.; Price-Less Inkjet Cartridge Co.; ABCCo.net, Inc.; Printer Essentials.com, Inc.; Cartridge Hut

• Type: Section 337 investigation, U.S. International Trade Commission — not an AIA trial proceeding
• Filed: Complaint filed 2000-12-22; amended 2001-01-17; investigation instituted 2001-01-19 (notice published 2001-01-25, 66 FR 7783)
• Status: Terminated — violation found, limited exclusion order and cease and desist orders issued 2002-04-25; notice published 2002-05-01 (67 FR 21733). Consent-order terminations as to Printer Essentials (Order No. 7) and Cartridge Hut (Order No. 15).
• Judge panel: Administrative Law Judge (ALJ) at the ITC, with Commission review. APJ names are inapplicable — this is an ITC § 337 panel, not a PTAB panel.
• Claims asserted against the '073 patent: claims 4 and 5 (per the notice of investigation and the ALJ's ID). HP withdrew claim 5 by motion on 2001-10-24; granted by Order No. 17 (2001-11-15), Commission declined review 2001-12-04. Claim 5 was therefore never adjudicated to a merits verdict.
• Validity / unenforceability: The ALJ's ID contains a section "IX. Unenforceability ('073, '294 And '859 Patents)" — i.e., an inequitable conduct defense was litigated against the '073 patent. The Commission determined "not to review the remainder of the ID," so the ALJ's disposition of that defense stood. Because the Commission nonetheless found a violation based on claim 4 of '073 and issued remedial orders covering it, the practical inference is that the inequitable conduct defense failed, but I did not retrieve the ID's conclusion of law on that point and will not state it as a finding.
• Initial Determination: ALJ final ID issued 2002-01-25. The ALJ found a violation of § 337 for the asserted claims of the other five patents except claim 4 of the '073 patent — he found no infringement and no domestic industry as to '073.
• Commission review / reversal: On 2002-03-07 the Commission determined to review (1) the ALJ's construction of claim 4 of the '073 patent and (2) his findings of no infringement and no domestic industry. It declined review of the remainder. The Commission reversed-in-part: it held the accused devices infringe claim 4 and that HP satisfied the technical prong of the domestic industry requirement. Verbatim from the Commission's notice: "the Commission determined that the accused devices infringe claim 4 of U.S. Letters Patent 4,635,073 ... and that complainant Hewlett-Packard Company ('HP') has satisfied the technical prong of the domestic industry requirement."
• Remedy: Limited exclusion order against Microjet and cease-and-desist orders against Price-Less and ABCCo.net, covering products infringing, inter alia, claim 4 of U.S. Letters Patent 4,635,073; Presidential-review bond of 100% of entered value. The claim-construction reversal is the key takeaway: claim 4's "adjacent abutting parallel planes" limitation was construed broadly enough by the Commission to capture the accused cartridges, notwithstanding the ALJ's contrary construction.
• Settlement: Terminations by consent order as to Printer Essentials and Cartridge Hut; those terms are confidential/consent-order based. No monetary settlement terms are public.
• Appeal: No Federal Circuit appeal located in the sources I reviewed for the '073 patent or the '446 investigation. I did not confirm whether a CAFC appeal was filed and dismissed or simply never taken — flag as unverified; check the Federal Circuit docket and CourtListener for appeals from Inv. No. 337-TA-446 (2002).
• Defensive value: This record is entirely historical and non-preclusive for a non-party. ITC determinations do not collaterally estop non-parties absent privity, and the patent is expired, so the only relevance is (a) the public claim-construction history on claim 4, which a plaintiff would have to argue around, and (b) a documented, litigated inequitable-conduct defense on the '073 patent that a future defendant could mine from the ITC record — the ID's unenforceability section is public at https://www.usitc.gov/intellectual_property/documents/pub3549.pdf.

Strategic summary

Claim status. There is no PTAB claim-cancellation record, so nothing is "CANCELED because of an IPR." What exists is an ITC adjudication that claim 4 was infringed (Commission, 2002-03-07) and that claim 5 was asserted and then withdrawn (2001-11-15) — never sustained, never invalidated. The other claims of the '073 patent — claims 1, 2, 3, and 6-12 (including independent claim 10, the process claim, and its dependents 11-12) — were never asserted and are UNTESTED in any adversarial forum. Equally important: the patent expired 2005-11-22. Whether any given claim is "valid" is largely academic; the enforceable damages window closed two decades ago.

Estoppel landscape. Section 315(e)(2) estoppel is not in play, because there has never been a petitioner. No party is barred from raising any § 102/§ 103 ground, because no party ever raised one at the PTAB. Practically, the relevant bars for a defendant today are procedural and temporal, not estoppel: (1) the patent's term is over, so there is no ongoing royalty base and no injunctive exposure; (2) a § 337 action on an expired patent has no available exclusion remedy for future importation; (3) any assertion can only target pre-2005-11-22 conduct, which raises laches-adjacent and damages-proof problems for the plaintiff. If someone is nonetheless threatening suit, the defenses worth pressing are § 282 invalidity on the full prior-art record (which no tribunal has ever tested for this patent), the ITC record's inequitable-conduct evidence, and the claim-construction record showing claim 4 requires adjacent abutting parallel planes.

Pattern signals. No petitioner has filed anything repeatedly — there is no petitioner at all. No patent owner has prosecuted a PTAB appeal, because there has been no PTAB trial. No defensive aggregator (Unified Patents or similar) appears anywhere in the chain — the only "litigation" flags on the family are the Darts-IP family entry and the ITC investigation 337-TA-446 (https://portal.unifiedpatents.com/litigation/International%20Trade%20Commission/case/337-TA-446), and a Unified Patents litigation database entry is not a Unified Patents filed petition. The assignee chain is Hewlett-Packard Company (1985-11-22) → HP, a Delaware corporation (merger, effective 1998-05-20) → HP Colorado (2001-01-16), with Google Patents listing current assignee as HP Inc. This is a legacy operating-company patent, not an NPE assertion vehicle, which further explains why no IPR was ever filed: IPR petitioners attack patents that are being asserted now.

Recommended next steps

1. State the negative plainly. There is no IPR, PGR, or CBM to link to, and no FWD to quote. Do not let anyone on your team represent that this patent "survived IPRs and is hardened" — that is the opposite of the truth here. The correct characterization is: never challenged at the PTAB, expired 2005-11-22, and therefore largely unenforceable as a going-forward matter.
2. Verify the negative yourself before relying on it. Run a PTAB E2E / Patent Trial and Appeal Board End-to-End search on patent number 4,635,073 and cross-check the USPTO Patent Public Search reexamination record, since web search cannot prove a null set. Link: https://e2e.uspto.gov/ and https://www.uspto.gov/ptab/decisions.
3. Pull the ITC public record if a plaintiff asserts claim 4. Publication 3549 (https://www.usitc.gov/intellectual_property/documents/pub3549.pdf) contains the ALJ's final ID, including the claim-construction analysis of claim 4 and the unenforceability section. That construction dispute — ALJ: no infringement; Commission: infringement — is the most useful ammunition for a non-infringement or claim-scope argument today.
4. Check for a CAFC appeal of Inv. No. 337-TA-446 that I could not locate, via CourtListener and the Federal Circuit docket. If an appeal exists and was decided, it may carry useful claim-construction law; if none was taken, note that the Commission's construction was never reviewed.
5. Confirm expiration mechanics. Google Patents lists anticipated expiration 2005-11-22 with status "Expired - Lifetime"; a rule-of-thumb check against the pre-URAA 17-years-from-grant term (grant 1987-01-06) would give an earlier date. Whichever applies, the practical conclusion — no live damages window — is unchanged, but nail the exact date before it appears in any filing.
6. On the demand-letter scenario: if a letter cites claim 4, the offensive history cuts for the plaintiff (Commission found infringement). If it cites claims 1-3 or 6-12, those were never asserted or adjudicated anywhere, and a validity challenge on that clean-slate record — plus the expired term — is the strongest available posture.

I'll verify the assignment record against live sources before building the chain.

Let me pull the specific reel/frame records and check for any post-2001 transfers.

Assignment & Ownership Analysis — US Patent 4,635,073

Source note / retrieval limitation: I could not open an interactive session against assignmentcenter.uspto.gov in this run. The reel/frame data below is taken from the USPTO-derived legal-events ledger reproduced on the patent's Google Patents record (https://patents.google.com/patent/[US4635073](/patent/US4635073)/en), which mirrors the Assignment Center's abstract of title. One field that the task specifically asks for — correspondent of record — is not carried in that ledger, so I flag it explicitly as not retrieved rather than infer it. Verify directly at https://assignmentcenter.uspto.gov/ (search by patent number 4635073).

Inventors

Pattern note: Single-inventor patent. No co-inventor departures to track. There is no evidence of inventor-side retention (no reversion, no later inventor-to-third-party conveyance) — the inventor never reappears in the chain after the 1985 assignment. That is the normal corporate-employment pattern, not a fire-sale precursor.

Correction to the prior section: the "Examiner / Attorney" field (Hartary / William J. Bethurum) refers to the prosecuting attorney of record, not the assignment correspondent. Bethurum was HP's own patent attorney; the two roles should not be conflated when reading the Assignment Center's correspondent field.

Original assignee

Hewlett-Packard Company, a California corporation, Palo Alto, California (name as recorded, reel 004490/0790).

• Line of business: HP was, at filing (November 1985), the dominant vendor of the then-new thermal ink jet ("ThinkJet") technology, which had launched on the HP ThinkJet printer in 1984. This patent is part of the founding HP thermal-inkjet printhead family; the specification itself cites the Hewlett-Packard Journal, Vol. 36, No. 5, May 1985, as the state of the art.
• Did HP ship a product embodying the claims? Yes. The claims cover the assembled thermal inkjet print head with a beam-lead (TAB) interconnect thermosonically bonded to aluminum traces on a thin-film resistor substrate. HP commercialized this architecture, and the patent's commercial significance is confirmed by the enforcement record: HP asserted claim 4 as complainant in ITC Inv. No. 337-TA-446 and the Commission found infringement (see below).
• Current status of the original assignee: Hewlett-Packard Company (California) no longer exists as an independent entity. Per the recorded mergers, it merged into a Delaware HP corporation (effective 1998-05-20, recorded 2000-08-25, reel 010892/0934), which in turn merged into Hewlett-Packard Company, Colorado (effective 1998-05-20, recorded 2001-01-16, reel 011523/0469). HP later split into HP Inc. and Hewlett Packard Enterprise (2015), but no assignment of this patent to either successor was ever recorded — see the flagged contradiction below.

Assignment timeline

The Assignment Center's abstract of title for this patent contains three (3) recorded conveyance instruments in the chain of title. All three are productive of title; none is a security interest, license, or release.

• 1985-11-20 (executed) / recorded 1985-11-22 — Reel 004490/0790

  • Conveyance: Assignment of Assignor's Interest
  • Assignor: Gary E. Hanson (sole inventor)
  • Assignee: Hewlett-Packard Company, Palo Alto, California, a corporation of California
  • Correspondent: Not retrieved. Not carried in the legal-events ledger. Cannot assess the recurrence signal. (For what it is worth, patents of this vintage assigned to HP were typically recorded through HP's own Palo Alto legal department rather than an outside firm — but I will not assert this as a finding without the reel cover sheet.)
  • Context: Initial employment assignment — inventor to employer, the first leg of title. Executed two days before filing.

• 1998-05-20 (effective) / recorded 2000-08-25 — Reel 010892/0934

  • Conveyance: Merger (not an assignment)
  • Assignor: Hewlett-Packard Company, a California corporation
  • Assignee: Hewlett-Packard Company, a Delaware corporation
  • Correspondent: Not retrieved.
  • Context: Internal corporate reorganization / reincorporation — housekeeping record, both sides the same operating company. Note the ~27-month gap between effective date and recordation.

• 1998-05-20 (effective) / recorded 2001-01-16 — Reel 011523/0469

  • Conveyance: Merger (not an assignment)
  • Assignor: Hewlett-Packard Company
  • Assignee: Hewlett-Packard Company, Colorado
  • Correspondent: Not retrieved.
  • Context: Internal corporate reorganization — again housekeeping. Both merger records carry the same effective date (1998-05-20), indicating a single 1998 internal restructuring that was recorded in two pieces, not a cascade of genuine transfers.

Non-conveyance entries also on the abstract (listed for completeness, not assignments):

• 1987-12-22 — Certificate of Correction (typographical corrections; e.g., "relative," "temperature"). Not a title document.
• Fee-payment events: 1989-12-04, 1990-07-03 (4-yr), 1994-07-01 (8-yr), 1998-07-02 (12-yr). Not title documents.
• 2005-11-22 — Anticipated expiration (patent lapsed for failure to pay the 20-year maintenance window / statutory term end). Status today: Expired – Lifetime. Not enforceable.
• 1986-12-04 — continuation application Ser. No. 937,945 filed; that family line produced US 4,827,294 (issued 1989-05-02, "Thermal ink jet printhead assembly employing beam lead interconnect circuit"), also HP-owned. Not a title event for the '073 patent itself.

Post-issuance assignment count: zero. There is no assignment — as opposed to merger — of this patent away from the HP corporate family at any point in its 20-year life. That is itself the headline finding.

Timeline diagram

timeline
    title Ownership of US 4635073
    1985 : Hanson assigns to HP California
         : Reel 004490 frame 0790
    1987 : Patent issues on Jan 6
         : Certificate of Correction Dec 22
    1998 : HP California restructures into HP Delaware
    2000 : First merger recorded Aug 25
         : Reel 010892 frame 0934
    2001 : Second merger recorded Jan 16
         : Reel 011523 frame 0469
    2002 : ITC finds infringement of claim 4
    2005 : Patent expires Nov 22

NPE / troll-pattern signals

Enforcement record for context (operating-company assertion, not an NPE event):

• ITC Investigation No. 337-TA-446, Certain Ink Jet Print Carts and Components Thereof. Complainant: Hewlett-Packard Company. Respondents included Microjet Technology Co., Ltd. (Taiwan) and several remanufacturers (Printer Essentials, Price-Less Inkjet Cartridge Co., Cartridge Hut/Paperwork Plus, ABCCo.net, Inc.).
• The ALJ's Initial Determination (2002-01-25) found no infringement of claim 4 and no domestic industry. On 2002-03-07 the Commission reversed-in-part, finding the accused devices infringe claim 4 of US 4,635,073 and that HP met the technical prong of the domestic-industry test. Limited exclusion order and cease-and-desist orders issued; bond 100% of entered value. Published at 67 FR 21733 (2002-05-01). Sources: USITC Pub. 3549, Federal Register 02-10775.
• This is HP suing infringing importers of its own product technology — the paradigm operating-company assertion, and the decisive evidence against any NPE characterization.

Verdict

Operating-company assertion.

Justification: The chain of title consists of exactly one inventor-to-employer assignment (Gary E. Hanson → Hewlett-Packard Company, California, executed 1985-11-20, reel 004490/0790) followed by two internal merger records (reels 010892/0934 recorded 2000-08-25 and 011523/0469 recorded 2001-01-16), both effective 1998-05-20, which move the patent only between Hewlett-Packard operating entities. No assignment to any third party — NPE or otherwise — was ever recorded, so none of the eight NPE signals scores as present; the sole unassessable signal (correspondent recurrence) fails for lack of retrievable data, not for lack of evidence. The patent's one enforcement episode was HP asserting claim 4 in its own name as ITC complainant in 337-TA-446, where the Commission found infringement — textbook operating-company assertion, now moot since the patent reached anticipated expiration on 2005-11-22 and is recorded as Expired – Lifetime.

Verification link: https://assignmentcenter.uspto.gov/ (search patent number 4635073), and the USPTO-derived abstract of title at https://patents.google.com/patent/US4635073/en.

Contradictions with the previously generated section (flagged per instructions)

1. "Current assignee (per Google Patents listing): HP Inc." — Contradicted. There is no recorded assignment to HP Inc. in the abstract of title. The last recorded assignee of record is Hewlett-Packard Company, Colorado via reel 011523/0469. Google's "Current Assignee" field is a heuristic name-matching output, not an assignment record. The 2015 HP Inc. / Hewlett Packard Enterprise split produced no reel/frame against this patent, consistent with the patent having already expired in 2005. Treat "HP Inc." as unverified and likely an artifact.
2. Inventor residence "Boise, Idaho." — Unverified here. The authoritative text fetched for this analysis does not show an inventor residence. Not a contradiction, but it should not be treated as sourced until the printed front page is checked.
3. "Examiner / Attorney Joseph W. Hartary / William J. Bethurum" — correct for the patent's prosecution, but not the assignment correspondent. Do not carry that name into the correspondent field without checking the reel cover sheets.

Remaining data gaps

• Correspondent of record for all three reel/frame entries (004490/0790, 010892/0934, 011523/0469) — not retrieved; requires the Assignment Center cover-sheet images.
• Confirmation of whether any unrecorded transfer occurred in the 2015 HP split — no record supports one, but recordation is ministerial and optional in some transactions, so absence of a record is strong-but-not-conclusive evidence.

I'll do targeted searches on each of the four examiner-cited references before analyzing anticipation.

Let me verify the inventor attributions for two of the references, since I don't want to fabricate names.

Scope and Method

I searched for the exact identifier "4635073" (no near-numbers). The authoritative "Patent Citations (4)" block on the '073 record lists exactly four U.S. patents, and those four are the complete set of examiner-cited references. Everything below is grounded in the '073 full text provided, cross-checked against live records for each reference.

One correction to the "Citations (4)" data: the record also shows a "Family Cites Families (1): US589584" (an 1897 staple-fastener patent). That is a database artifact, not a real citation, and I do not treat it as prior art.

Governing law — this matters for which references are even available as §102 art. US 4,635,073 was filed 22 Nov 1985 (pre‑AIA application). The presumptive invention date is the filing date. Under pre‑AIA §102, four of the cited references split into two distinct groups:

Note the trap: the last two references cannot be §102(a) or §102(b) art (neither was "patented … before the invention" nor published more than a year before the '073 filing). If someone cites '584 or '157 as §102(a)/(b) prior art, that is legally wrong — they stand or fall as §102(e) art only.

Reference 1 — US 4,506,272 (Matsushita Electric Industrial Co., Ltd.)

Full citation: U.S. Patent No. 4,506,272, "Thermal printing head," assigned to Matsushita Electric Industrial Co., Ltd. Issued 19 Mar 1985; filed/priority 06 Nov 1981. The Matsushita thermal‑head family counterpart EP 0079063 lists the inventor as Arai, Shoji (I could not independently confirm the inventor on the face of the U.S. patent in this pass; the assignee and dates are confirmed).
Source: Google Patents US4506272A; Sumobrain 4506272

Description: A thermal (contact) printing head — not an ink jet device — integrating a heater array on a substrate with semiconductor driver devices having shift registers. A set of straight lead wires and L‑shaped lead wires are formed by a TAB (tape automated bonding) method on an electrically insulating flexible film; one end of each straight lead wire connects to a heater electrode, the other to a semiconductor device. Explicit stated goals are high packing density at the heater/transistor electrode interface and lower cost. It uses multi‑layer wiring for current capacity.

§102 analysis vs. the '073 claims:

• Claim 1 (process) requires three things: (a) a thermal ink jet print‑head substrate with resistive heater elements and connected conductive leads; (b) a beam‑lead interconnect circuit with matching spacing; (c) thermosonically bonding, in sequence, each beam lead to each corresponding conductive trace, so the leads and traces lie in adjacent parallel planes.
• '272 satisfies (b) in substance — TAB leads on flexible film with matching electrode pitch — and arguably the general structure of (a), but it is a thermal printing head, not a thermal ink jet print head, and it does not disclose thermosonic bonding, much less sequential one‑by‑one thermosonic bonding. TAB inner‑lead bonding of that era is typically gang/thermocompression, and '272 is silent on the specific bond method and on the "adjacent parallel planes" packing‑density limitation of (c).
• Claim 4 (assembly): missing the "beam leads bonded to said traces in adjacent abutting parallel planes" limitation and the ink‑jet context.
• Claim 10: missing the ≤70 °C thermosonic beam‑lead‑to‑trace bond entirely.

Conclusion: No anticipation of any of claims 1–12. '272 is best characterized as §102(a)/(e) background establishing that TAB lead formation over a heater/electrode array for high packing density was known, i.e., §103 material against the "beam lead interconnect circuit" concept — not §102 art against any full claim.

Reference 2 — US 4,500,895 (Buck et al., Hewlett‑Packard Company)

Full citation: U.S. Patent No. 4,500,895, "Disposable ink jet head," Buck, Cloutier, Erni, Low & Terry, assigned to Hewlett‑Packard Company. Issued 19 Feb 1985; filed 02 May 1983. (Certificate of Correction, 01 Oct 1985.)
Sources: Google Patents US4500895; FPO 4500895; patentimages PDF

Description: The foundational HP disposable thermal ink jet head. A glass or ceramic substrate carries thin‑film thermal jetting resistors and thin‑film metal connecting runs and pads; a jet feed hole through the substrate feeds an orifice plate. The substrate is mounted and sealed by adhesive in a recess in a plastic molded backing plate (support means) providing a sealed hydraulic connection to an elastic ink reservoir that supplies negative back pressure; alignment pins align the head in the printer; printer contacts mate with the pads.

§102 analysis vs. the '073 claims: This is the reference that comes closest to the apparatus structure of claim 4 — which is significant, because claim 4 is the claim the ITC later held infringed (per the prior section).

• Claim 4(a) — "print head substrate mounted on a header member and operative to receive ink therefrom": '895's substrate 10 is mounted/sealed in the recess 100 of plastic backing plate 110, receiving ink from the reservoir through feed hole 50. Disclosed in substance.
• Claim 4(b) — "conductive traces deposited atop said substrate and electrically connected to resistive heater elements": '895's thin‑film metal runs 30 / pads 40 connect to thin‑film thermal jetting resistors 20 (see its claims 5–9: thermal resistor → film resistor → thin film resistor; film conductor runs + pads). Disclosed in substance.
• Claim 4(c) — "a beam lead interconnect circuit having a plurality of beam leads bonded, respectively, to said plurality of conductive traces in adjacent abutting parallel planes": NOT disclosed. '895 terminates the traces in pads 40 for pressure mating with printer contacts; there is no beam‑lead circuit and no bonding of leads to traces.
• Claims 10/11 (thermosonic beam‑lead bonding at ≤70 °C): not disclosed.
• Claims 2–3, 5–9, 12 (header routing, elastomer‑backed resilient protrusion): not disclosed.

Conclusion: No anticipation (each independent claim is missing at least the "beam lead interconnect circuit bonded to traces" limitation). But '895 is the single most dangerous reference in the set for §103, because it supplies the "ink‑jet substrate‑on‑header + thin‑film heater resistors + deposited conductor runs" half of claims 4/5 and the replaceable/disposable framing of claim 1. Combined with a TAB/beam‑lead bonding reference (either '272 or '157), a §103 rejection against claims 4–9 becomes plausible on paper — which is presumably why the examiner cited it.

Reference 3 — US 4,589,584 (Christiansen, Rose, Smith & Woosley, International Business Machines Corporation)

Full citation: U.S. Patent No. 4,589,584, "Electrical connection for polymeric conductive material," assigned to IBM. Issued 20 May 1986; filed 31 Jan 1985 (Ser. No. 696,821). Family counterpart EP 0 191 175 (published 20 Aug 1986) names the inventors as Christiansen, Robert Arnold; Rose Jr., Frank Marlon; Smith, James Robert; Woosley, Kenneth David.
Sources: Google Patents US4589584A; FPO 4589584; EP0191175B1 PDF

Description: Ultrasonic bonding of flexible flat ribbon cables bearing polymeric/silver‑ink conductors either to each other or to a circuit board. The key teaching is a grooved ultrasonic horn face (or grooved support plate) whose ridges correspond in spacing to the conductors and thus concentrate pressure and vibratory energy between adjacent conductors, preferentially fusing the substrates into "dams" before the conductors flow — preventing lateral bleed and shorts. Process parameters: ~20 psi, ~0.2 s energy application; grooves ~0.0018 in deep; conductor ~0.0005 in thick.

§102 analysis vs. the '073 claims:

• The reference is squarely about the bonding technique and the profiled energy‑applying tool face — i.e., the analogue of the '073 FIG. 4 bonding tip (flat areas 126/128 separated by a trough 130, leaving indentations 132/134). That maps conceptually to claim 1(c) ("thermosonically bonding in sequence each of said beam leads").
• But it fails on the substance: the conductors are polymer/silver ink, not the claimed aluminum traces on a thin‑film resistor print‑head substrate; there are no resistive heater elements, no print head, no header, and no beam‑lead‑to‑trace bonding in adjacent parallel planes for print‑head packing density. Bonding here is substrate‑to‑substrate fusing plus incidental conductor fusing — a different mechanism.
• Claim 10 (thermosonic, individual bonding of thin beam leads to thin traces on a print‑head substrate at ≤70 °C): not disclosed.

Conclusion: No anticipation of any claim. '584 is §102(e) art only (issued after the '073 filing date) and is most relevant as §103/§112‑enablement background for (i) the ultrasonic/thermosonic bonding step and (ii) the grooved/trough‑bearing bonding‑tool geometry of FIG. 4. Note it also undercuts any argument that a profiled bond tool concentrating energy between conductors was novel.

Reference 4 — US 4,585,157 (General Motors Corporation)

Full citation: U.S. Patent No. 4,585,157, "Tape bonding of two integrated circuits into one tape frame," assigned to General Motors Corporation. Issued 29 Apr 1986; filed 04 Apr 1985. (The earlier section attributed the inventor as "Belcher"; I could not independently confirm the inventor name on the face of the patent in this pass — the assignee and dates are confirmed.)
Sources: Google Patents US4585157A; patentimages PDF

Description: A TAB inner‑lead‑bonding method in which the finger leads at a single lead‑frame site are split into two groups and bonded in two separate bonding operations using a thermode (a recessed thermode accommodates the first chip), producing two integrated circuit chips bonded face‑to‑face to one tape frame; long finger leads can interconnect the two chips. Motivated by doubling usage of a bond site and board area and saving on test labor.

§102 analysis vs. the '073 claims:

• Relevant to claim 1(b) ("beam lead interconnect circuit having a plurality of beam leads"): '157 is a clean teaching of TAB finger‑lead bonding with a thermode.
• But it bonds integrated circuit chips — not ink‑jet heater substrates. There are no resistive heater elements, no conductive traces on a print head substrate, no "in adjacent parallel planes" packing‑density limitation, no header/ink supply, and no elastomer‑backed resilient contact. It also uses a thermode, not the claimed thermosonic beam‑lead‑to‑aluminum‑trace bond.

Conclusion: No anticipation of any claim. '157 is §102(e) art only and functions as §103 background for the general "beam lead interconnect circuit" element of claims 1 and 4.

Consolidated claim × reference map

Overall conclusion

None of the four examiner-cited references anticipates any of claims 1–12 under 35 U.S.C. §102 — each is missing at least one essential limitation of every claim. Specifically, across all four references, nothing discloses: (1) thermosonically bonding beam leads to conductive traces on a thermal ink jet thin‑film resistor substrate; (2) the ≤70 °C gold‑to‑aluminum bond that is the numerical hallmark of claims 7–11; or (3) the elastomer‑backed, resiliently protruding beam leads that give the removable pressure contact of claims 2–3, 5–6, 9, 12.

Their real function is as §103 combination art and background:

• '895 (Buck/HP) supplies the ink‑jet substrate‑on‑header + thin‑film heater + conductor‑runs structure (claims 4–5, and the replaceable framing of claim 1).
• '272 (Matsushita) and '157 (GM) supply TAB/beam‑lead interconnection of electrode arrays (element (b) of claims 1/4).
• '584 (IBM) supplies the profiled‑tool ultrasonic bonding technique and the energy‑concentrating groove/trough geometry that mirrors the FIG. 4 bond tip (claim 1(c), 10).

This is consistent with — and explains — why the '073 claims issued over this art, and with why claim 4 nonetheless carried commercial weight at the ITC: the claims' novelty does not reside in the header/heater substrate or in TAB per se, but in the combination of thermosonic beam‑lead bonding directly onto the aluminum traces in the plane of the substrate plus the low‑temperature Au–Al bond and the elastomer‑backed pressure interconnect.

Stated uncertainties

1. Inventor attributions. I confirmed assignee and dates for all four references. I confirmed the IBM inventors ('584) via the EP family record. I could not independently confirm, on the face of the U.S. patents, the inventor names for '272 (earlier section says "Arai"; the Matsushita EP counterpart lists "Arai, Shoji") or '157 (earlier section says "Belcher"). Treat those two inventor names as reported-but-not-independently-reverified here.
2. Invention date. The §102(a)/(e) placements above assume a presumptive invention date on or about the 22 Nov 1985 filing date. If the applicant established an earlier reduction to practice, the §102(a)/(e) analysis for '272 and '895 would tighten, but the "no anticipation" conclusion would not change.
3. No contradiction was found between the previously generated sections and this analysis; the "purple plaque"/"purple plague" claim‑vs‑specification quirk and the '584/'157 post‑filing issue dates are consistent with, and now explained by, the record.

Obviousness Analysis — US 4,635,073 (35 U.S.C. § 103)

Scope note. This analysis uses the four references listed in the "Patent Citations (4)" section of the Google Patents page for US 4,635,073 (Hanson, filed Nov. 22, 1985). I verified bibliographic data and excerpts for each. Where an excerpt was all I had, I say so. Statements that rest on my own packaging-art knowledge rather than the cited references are flagged [general knowledge].

1. Framework

1.1 Governing law

The application was filed November 22, 1985, so pre-AIA § 103(a) governs. The inquiry is the Graham v. John Deere four-factor test: (1) scope and content of the prior art; (2) differences between the prior art and the claims; (3) level of ordinary skill; (4) objective indicia. KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007), supplies the rationales now catalogued in MPEP § 2143, which I apply explicitly below rather than relying on a rigid teaching-suggestion-motivation test.

1.2 Level of ordinary skill (POSITA)

[general knowledge] A person of ordinary skill in this art at the 1985 priority date would hold a B.S. in electrical, mechanical, or materials engineering (or equivalent), with roughly 2–4 years of experience in semiconductor device packaging / tape automated bonding (TAB), or equivalent experience in thermal printing head or thermal ink jet design. That person would be familiar with: TAB inner-lead bonding (gang thermocompression and single-point thermosonic), aluminum metallization on silicon, gold-to-aluminum bonding metallurgy, and the construction of thin-film resistor print heads.

1.3 Prior-art qualification

Important nuance: the last two issued after the '073 filing date, so they are not § 102(a)/(b) art. They are § 102(e) art because their applications were filed before November 22, 1985 (Jan. 31 and Apr. 4, 1985 respectively). § 102(e) art is usable in § 103 combinations. In re Bass, 474 F.2d 1276 (CCPA 1973). A real-world invalidity contention must therefore be pleaded under § 102(e), not § 102(b), for Belcher and Christiansen.

Context that cuts against the analysis: all four references were before the Examiner and the claims still issued. That does not immunize the claims (KSR; examiner allowance is not an adjudication of validity), but it means any § 103 case must explain what the Examiner overlooked — most plausibly the combination, not the individual references, plus reliance on art the Examiner did not treat as a bonding-tool/horn teaching.

2. Disclosure of each reference against the claim elements

US 4,500,895 (Buck) — the print-head/substrate predicate

Buck discloses, in substance, the entire structural environment of claims 1(a) and 4(a)–(b):

• "A glass or ceramic substrate 10 carries a plurality of thin-film thermal jetting resistors 20 and thin-film metal electrical connecting runs 30 and pads 40." (FPO)
• Claim 8: "film conductor runs deposited on the substrate and connected to the film resistor; and film conductor pads deposited on the substrate and terminating the film runs for external electrical connection." (FPO)
• Claim 7: "wherein the film resistor is a thin film resistor."
• Header/ink feed: "The substrate 10 is mounted and sealed … in a recess 100 in a plastic molded backing plate 110," which is "provided with a molded in place groove 130 and feed hole 140, which when mated with the reservoir side 60 of the substrate 10 provide a capillary feed line for the ink." (FPO)
• Replaceability/make-break contact: "Once the ink is expended the user disposes with the old head and installs a new one by breaking and making a simple mechanical and low voltage electrical connection." (Abstract, USPTO.report)
• Elastomeric/resilient element: the ink reservoir "is made either as a single piece of resilient flexible silicone rubber," and claim 3 recites a "collapsible ink reservoir … resilient to provide a negative back pressure on the ink."

What Buck does not disclose: a beam lead interconnect circuit and bonding of beam leads to the traces. Buck's pads 40 simply "mate with" printer contacts.

US 4,506,272 (Arai) — beam-lead TAB bonding to a thin-film thermal head

• "a set of straight lead wires supported by an electrically insulating flexible film and a set of L-shaped or inverted L-shaped lead wires are formed by a TAB (tape automated bonding) method, one end of each of the set of straight lead wires being connected to one end of one of heaters arranged in an array…" (SumoBrain)
• "The lead wire bonding method is known as the TAB method to those who are skilled in the art." (Searchlight)
• Stated advantages: "(1) Lead wire formation cost is decreased by using the TAB method. … (3) A compact head structure can be obtained."
• "[T]he bonding conditions of the lead wires become uniform, thus providing a stable bonding process and excellent reliability of the bonded portions."

This is the single most important reference. It is a thermal printing head — the same class of device (thin-film resistor heater array on a substrate, driven by pulses) — and it expressly bonds flexible-film beam leads to heater electrodes by TAB.

US 4,585,157 (Belcher) — TAB lead frames and tooling

• Describes an "inner lead bonder machine" with a "thermode of recessed surface 48," pressing "the periphery section 52 of thermode 12 … against tape 10 and gold tipped or solder tipped bumps 54." (US4585157 PDF)
• Confirms the conventionality of: TAB finger leads with spacings matched to device pads ("short finger leads 38, 40, 42, 44 and 46 are now connected at finger tips"), and gold-tipped bonding metallurgy.
• Also confirms design flexibility: "the two integrated circuit chips need not be different… two chips of the same size can be connected to a single site of finger leads in a lead frame."

US 4,589,584 (Christiansen) — sonic bonding of conductors, with a grooved tool

• "Positioned above the flat ribbon cables is the ultrasonic horn 20 of an ultrasonic bonding device… Such a horn 20 and ultrasonic generator 24 may be commercially procured from Branson Sonic Power Company." (FPO)
• "[U]ltrasonic heating and bonding is dependent upon the two articles, being joined, being forced together under pressure at the time that the vibratory ultrasonic energy is applied… to secure sufficient temperature rise at the material interfaces to cause a bonding."
• Tool geometry: "Either the face of the ultrasonic horn or the support plate is grooved such that it leaves ridges which spatially correspond with the spaces between the conductors… to provide a preferential localized pressure."

That last point is materially the same design idea as the '073 bonding tip 124 — "a pair of flat areas 126 and 128 … separated by a trough 130" (col. 4). It establishes that grooved/segmented bonding-tool faces were known, which blunts any argument that the tool geometry is inventive.

3. Grounds of rejection

Ground 1 — Claims 1 and 4: Buck + Arai (+ Belcher)

Claim 4 is essentially Buck's disclosure with Arai's interconnect substituted for Buck's make/break pad contact. Claim 4 does not even require thermosonic bonding or low temperature — only that the beam leads be "bonded … in adjacent abutting parallel planes." Arai supplies that verbatim in substance.

Ground 2 — Claim 1 and Claim 10: add Christiansen (+ Belcher)

Claim 10 requires: (a) thin conductive traces to heater resistors on the substrate; and (b) "thermosonically and individually" bonding thin beam leads to those traces "at a relatively low bonding temperature on the order of about 70 °C or less."

• (a) → Buck, claim 8.
• "individually bonding … thin beam leads" → Arai (TAB to heater electrodes) + Belcher (inner-lead bonder tooling).
• "thermosonically" (heat + sonic energy + pressure) → Christiansen '584 discloses exactly the sonic + pressure + interfacial-temperature-rise mechanism, on a flexible substrate carrying conductors, with a grooved horn. Combining Christiansen's bonding mechanism with Arai's TAB-to-heater-array structure is a textbook MPEP 2143 rationale (C)/(D): use of a known technique to improve a similar device, ready for improvement.
• "about 70 °C or less" → see §3.4.

Ground 3 — Claims 7, 8, 9, 11: materials and the gold–aluminum low-temperature bond

Claims 7–9 and 11 recite aluminum traces + gold (or gold-plated copper) beam leads, forming "a strong bond at the relatively low thermosonic bonding temperature … about 70 °C or less," "unaffected by the intermetallic purple plaque."

Two points materially strengthen this ground:

1. Applicant's own admission. The specification states the process "avoids the well known and undesirable intermetallic gold-aluminum interaction known as the 'purple plague.'" Labeling the problem "well known" is an admission that both the failure mode and its metallurgical explanation were in the art — usable in a § 103 analysis.
2. Gold-plated TAB leads were conventional. Belcher expressly bonds "gold tipped … bumps 54" through TAB finger leads; [general knowledge] gold-plated copper TAB lead frames were the standard commercial TAB metallurgy in the mid-1980s, including the 3M TAB tapes the '073 specification says it uses ("a tape automated bond (TAB) circuit of the type manufactured and sold by the Minnesota Mining and Manufacturing (3M) Company").

So claim 11's material limitation is a selection of the ordinary, commercially available TAB metallurgy combined with an aluminum-metallized silicon substrate — a simple substitution of known materials for predictable results (MPEP 2143 (B)).

Ground 4 — Claims 2, 3, 5, 6, 12 (elastomeric resilient contact) — weakest ground

These claims require the beam-lead circuit to be resiliently protruded away from a header surface by an elongated elastomeric member positioned between the leads and the header, for firm-but-removable contact with the printer housing.

On this record, none of the four cited references discloses an elastomeric member backing the beam leads. Buck comes closest (resilient silicone-rubber reservoir for ink back pressure; molded alignment pins; make/break electrical connection), but that resilience is hydraulic, not electrical-contact resilience. An obviousness case here requires either:

• an additional reference on elastomeric pressure connectors (e.g., elastomeric "zebra"/interposer connectors, which [general knowledge] were well known in the connector art by the mid-1980s), or
• reliance on KSR "design incentive / market forces" reasoning plus evidence of the common knowledge.

I rate Ground 4 as moderate-to-weak as a pure KSR/common-sense case, and strong if one additional elastomeric-connector reference is added. Note also that this subject matter was pursued in the continuation/divisional chain (US 4,827,294), which is a signal that the applicant regarded the resilient-contact feature as a separate point of novelty.

4. Motivation to combine — spelled out

1. Same field, same problem, same components. Buck and Arai are both thin-film resistor thermal print heads. Arai expressly frames its problem as head-to-driver "electrical connections between a number of heaters formed in an array" and head terminals, and its stated goals are a "compact and low-cost thermal printing head" — the same goals as the '073 specification ("reduce substrate size," "increase packing density"). (MPEP 2143 (A), (F).)
2. The patentee's own recitation of the problem supplies the motivation. The '073 Background states that wire bonding "impose[s] a limiting factor upon the reduction in substrate size," that "the cost of the substrate … represents a significant percentage of the overall cost," and that "the desirability of even further reducing the substrate size is manifest." That is a self-identified design incentive to replace wire bonding with a narrower-footprint interconnect. (MPEP 2143 (F).)
3. Arai states the very advantage the '073 patent claims. Arai: "Lead wire formation cost is decreased by using the TAB method"; "a compact head structure can be obtained." That is the "increased packing density / reduced substrate size" benefit recited in the '073 claims — the motivation is on the face of the reference.
4. Known technique applied to a known device ready for improvement. TAB was, per Arai, "known … to those who are skilled in the art," and commercial TAB tape was available from 3M (as the '073 specification itself concedes). Applying TAB to Buck's already-existing thin-film resistor print head is MPEP 2143 (D).
5. Finite number of predictable solutions. The '073 Background itself frames the choice as existing wire bonding vs. something better; the POSITA faces a small, enumerated set — wire bond, gang TAB, single-point TAB; thermocompression vs. thermosonic. Selection among these is "obvious to try" with a reasonable expectation of success. (MPEP 2143 (E); KSR.)
6. "Adjacent parallel planes" is inherent, not inventive. Laying a beam lead onto a deposited trace necessarily puts the lead and the trace in adjacent parallel planes. Claim 4's "adjacent abutting parallel planes" is the geometry of every face-to-face beam-lead land bond, including Arai's and Belcher's.
7. Low bonding temperature is an inherent attribute of sonic bonding. Christiansen describes the mechanism — pressure plus ultrasonic vibration generating heat at the interface; no bulk substrate heating is required. A "70 °C or less" bonding temperature therefore follows from the inherent nature of thermosonic/ultrasonic bonding, and the specification offers no data showing criticality of the 70 °C figure — it merely states the system "is capable of producing good strong bonds at bonding temperatures of 70 °C or less." Optimizing a result-effective variable (bond temperature) with no demonstrated criticality is a classic § 103 rejection. (MPEP 2143 (A); In re Boesch.)
8. Avoidance of purple plague supplies its own motivation. Because the specification concedes the gold–aluminum intermetallic problem was "well known," the POSITA had a recognized reason to select the lowest practical bonding temperature. A claimed result that is the known purpose of the selected process is not patentable weight.

5. Honest weaknesses in the obviousness case

Two further cross-reference notes for the drafter:

• The ITC finding does not validate the claims. As previously documented, ITC Inv. No. 337-TA-446 (Commission determination March 7, 2002; 67 FR 21733) found infringement of claim 4. The ITC does not adjudicate patent validity. An infringement finding on claim 4 therefore carries no weight against the § 103 analysis of claim 4.
• Potential § 112 issues are visible in the same claim language ("purple plaque" in claims 7–9 vs. "purple plague" in the specification; "adjacent abutting parallel planes"). These were partially addressed by the December 22, 1987 Certificate of Correction. I flag them only as they bear on how a POSITA would read the claim scope in the § 103 analysis; I have not independently reviewed the certificate's contents.

6. Claim-by-claim conclusion

7. Stated uncertainties

1. I worked from the abstracts, claims, and description excerpts surfaced by search for the four cited references. I have not reviewed the full text of US 4,506,272, US 4,585,157, or US 4,589,584 in their entirety; conclusions resting on those documents (especially whether any of them expressly describes thermosonic bonding, a single-point bonding sequence, or an elastomeric backing member) should be re-verified against the full patents before being relied on in a filing.
2. The "70 °C or less" limitation is analyzed as a result-effective variable / inherent result because the specification supplies no comparative data. If prosecution-history or litigation evidence exists showing unexpected results at that threshold, this conclusion would change. I did not locate any such evidence.
3. I have not verified whether US 4,635,073 was ever subject to reexamination, reissue, or a district-court validity challenge. The absence of such a record in my searches is not proof that none exists.
4. No contradiction was found between the live-source data retrieved here and the previously generated sections of this analysis; the reference dates, family members, and ITC citation are consistent.