US3768986A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Laminated lead frame and method of producing same
Assignee: MICRO SCIENCE ASS
•
Filing: 1971-10-08
•
Granted: 1973-10-30
•
Expires: 1991-10-08
Abstract
Abstract A lead frame structure for a semiconductive device package is fabricated by laminating two preformed thin sheets, the lower sheet having a fully developed set of closely spaced inner lead tips and the upper sheet having leads which terminate short of the tips. The laminated lead frame has the thickness required for handling, assembly and use. The cavity formed by the foreshortened lead tips of the upper sheet is adopted to contain beam-lead or flip-chip devices bonded directly to the lead tips of the lower sheet. The very thin lower sheet makes possible closer lead spacing than was heretofore possible with either photoetching or stamping techniques.
Inventors
- 👤 R Ramos
- 👤 R Haas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:48
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/40; H10W70/421; H10W70/442; Y; Y10; Y10S; Y10S428/00; Y10S428/922; Y10S428/923; Y10S428/924; Y10S428/926; Y10T; Y10T428/00; Y10T428/12; Y10T428/12188; Y10T428/12194; Y10T428/12229; Y10T428/1234; Y10T428/12361; Y10T428/12389
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
33 words
The lead frame assembly as claimed in claim 1, wherein the thickness of said lower sheet is small enough to allow the formation of said lead tips of a desired size and spacing.
Claim 2
Dependent Claim
26 words
The lead frame assembly as claimed in claim 2, wherein the thickness of said upper sheet is sufficient to provide said frame with required structural strength.
Claim 3
Dependent Claim
33 words
The lead frame assembly as claimed in claim 3, wherein the overall thickness of said assembly is about 0.010 in., and the thickness of said upper sheet is at least about 0.005 in.
Claim 4
Dependent Claim
25 words
The lead frame assembly as claimed in claim 1, and additionally comprising a coating of bond-facilitating metal on the upper surface of said lower sheet.
Claim 5
Independent Claim
115 words
The method of fabricating a lead frame assembly for use in a semiconductive device package comprising; forming a first, flat lead frame element including an array of lead members having inner tips disposed so as to accommodate said device, said lead members being held within said frame by integral web means; forming a second, flat lead frame element similar in plan to said first element but with an enlarged opening in place of said inner tips; and laminating said first and second elements together on major surfaces thereof with similar lead members in registration, said opening in said second element forming a recess above said inner tips for at least partial containment of said device.
Claim 6
Dependent Claim
30 words
The method as claimed in claim 6, wherein said second element is formed from stock thin enough to allow said inner tips to be of a desired size and spacing.
Claim 7
Dependent Claim
25 words
The method as claimed in claim 6, wherein said second element is formed from stock thick enough to provide said frame with required structural strength.
Claim 8
Dependent Claim
23 words
The method as claimed in claim 7, wherein said first element is formed by photoetching said array and said webs in said stock.
Claim 9
Dependent Claim
43 words
The method as claimed in claim 6, wherein said laminating is carried out by coating the surface of said second element to be joined to said first element with a suitable bonding material, and heating and pressing said elements together to effect lamination.
Claim 10
Dependent Claim
25 words
The method as claimed in claim 4, wherein the surface of said first element laminated to said second element has a bond-facilitating metal coated thereon.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-29 | 1977-04-30 | 1977-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-29 | 1981-04-30 | 1981-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-29 | 1985-04-30 | 1985-10-30 | $7700.00 | Window Closed / Lapsed |