US3859718A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for the assembly of semiconductor devices
Assignee: Texas Instruments Inc
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Filing: 1973-01-02
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Granted: 1975-01-14
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Expires: 1993-01-02
Abstract
Abstract A dual-in-line plastic package for an integrated circuit is assembled with the use of a thermal stress-resistant thin-film interconnect pattern on a flexible insulator film. All electrical connections to the semiconductor chip are made simultaneously by bonding directly to the thin-film interconnect pattern. Each segment of the interconnect pattern is then connected simultaneously to a simplified external lead frame, by means of a novel soldering technique. The assembly is then ready for plastic encapsulation and final trimming. By supplying both the flexible interconnect pattern and the external lead frame in continuous coils or reels, a high degree of handling simplicity, speed and accuracy is achieved with a maximum opportunity for automation, to produce a low work content product.
Inventors
- 👤 Terry Wayne Noe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:05
CPC Classifications
H; H10; H10W; H10W72/00; H10W72/071; H10W72/01; H10W72/0198; H10P; H10P72/00; H10P72/04; H10P72/0446; H10W70/00; H10W70/40; H10W70/421; H10W70/438; H10W70/453; H10W70/464; H10W70/468; H10W72/077; H10W72/50; H05; H05K; H05K1/00; H05K1/02; H05K1/09; H10W72/073; H10W72/07331; H10W72/07336; H10W74/00; H10W90/00; H10W90/701; H10W90/731; H10W90/736
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
221 words
In a process for the fabrication of integrated circuit assemblies, wherein a plurality of semiconductor chips are attached to a strip of flexible dielectric film having a corresponding plurality of conductive interconnect patterns supported thereon, the improved method of attaching the interconnect patterns to an external lead frame strip, including a plurality of lead frame units integrally joined, comprising the steps of: coating the appropriate portions of the lead frame strip and the interconnect patterns with a suitable low-melting metal or alloy; placing in alignment (1) the to-be-bonded portions of one of said interconnect patterns, (2) the corresponding portions of a lead frame unit, (3) a bonding tool maintained at a temperature above the melting temperature of said low-melting or alloy, (4) a punching means shaped to mate with the bonding tool, and (5) a shearing means shaped to mate with said punching means; severing said one interconnect pattern from said strip of flexible dielectric film by causing an engagement of said punching means with said shearing means; and then bonding said interconnect pattern to the lead frame by bringing said punch means and bonding tool in close proximity whereby the interconnect pattern and the lead frame are sandwiched therebetween at a temperature and for a time sufficient to temporarily reflow the low-melting metal or alloy and thereby complete the bond.
Claim 2
Dependent Claim
221 words
In a process for the fabrication of integrated circuit assemblies, wherein a plurality of semiconductor chips are attached to a strip of flexible dielectric film having a corresponding plurality of conductive interconnect patterns supported thereon, the improved method of attaching the interconnect patterns to an external lead frame strip, including a plurality of lead frame units integrally joined, comprising the steps of: coating the appropriate portions of the lead frame strip and the interconnect patterns with a suitable low-melting metal or alloy; placing in alignment (1) the to-be-bonded portions of one of said interconnect patterns, (2) the corresponding portions of a lead frame unit, (3) a bonding tool maintained at a temperature above the melting temperature of said low-melting or alloy, (4) a punching means shaped to mate with the bonding tool, and (5) a shearing means shaped to mate with said punching means; severing said one interconnect pattern from said strip of flexible dielectric film by causing an engagement of said punching means with said shearing means; and then bonding said interconnect pattern to the lead frame by bringing said punch means and bonding tool in close proximity whereby the interconnect pattern and the lead frame are sandwiched therebetween at a temperature and for a time sufficient to temporarily reflow the low-melting metal or alloy and thereby complete the bond.
Claim 3
Dependent Claim
50 words
The method of claim 1 further including the repetitive steps of sequentially aligning and separating successive portions of said flexible film from the film strip, each successive film portion having supported thereon one interconnect pattern, then bonding, advancing said film strip, advancing said lead frame strip, and repeating the operation.
Claim 4
Dependent Claim
24 words
The method of claim 1 wherein said flexible film supported interconnect pattern comprises a pattern of rolled copper film supported by a polyimide film.
Claim 5
Dependent Claim
19 words
The method of claim 3 wherein said copper film and said polyimide film are laminated with a polyamide adhesive.
Claim 6
Dependent Claim
45 words
The method of claim 1 wherein said external lead frame comprises a solder plated copper strip having a plurality of mirror image sets of leads extending lengthwise of the strip and terminating with tips having a width approximately equal to the spacing between the tips.
Claim 7
Dependent Claim
139 words
In the fabrication and assembly of a semiconductor device, wherein a semiconductor chip is attached to a thin-film interconnect pattern supported by a portion of a flexible dielectric film strip, and wherein said portion of the film strip is separated from the strip for bonding said interconnect pattern to a lead frame, the improved method for so separating and so bonding comprising the steps of: pressing a punch member and a shearing die in contact with opposite sides of said portion of the film strip, in mated relationship, thereby punching out the said portion of the strip; then bringing said punch member, with the punched-out portiOn of said film in place thereon, in contact with said lead frame and in contact with a bonding tool aligned therewith to complete said bonding of the interconnect patttern to the lead frame.
Claim 8
Dependent Claim
139 words
In the fabrication and assembly of a semiconductor device, wherein a semiconductor chip is attached to a thin-film interconnect pattern supported by a portion of a flexible dielectric film strip, and wherein said portion of the film strip is separated from the strip for bonding said interconnect pattern to a lead frame, the improved method for so separating and so bonding comprising the steps of: pressing a punch member and a shearing die in contact with opposite sides of said portion of the film strip, in mated relationship, thereby punching out the said portion of the strip; then bringing said punch member, with the punched-out portiOn of said film in place thereon, in contact with said lead frame and in contact with a bonding tool aligned therewith to complete said bonding of the interconnect patttern to the lead frame.
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) | 1978-01-13 | 1978-07-15 | 1979-01-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-13 | 1982-07-15 | 1983-01-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-13 | 1986-07-15 | 1987-01-14 | $7700.00 | Window Closed / Lapsed |