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US4493145A Expired / Lapsed US ⏱️ 0.0 years remaining

Integrated circuit device having easily cleaned region between mother board and chip carriers mounted thereon

Assignee: Fujitsu Ltd
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Filing: 1983-10-19
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Granted: 1985-01-15
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Expires: 2003-10-19
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Abstract

Abstract An integrated circuit device for realizing high integration density wherein a small size package called chip carrier (1) comprising a semiconductor integrated circuit element and providing connecting area at the perimeter of the rear side of said package is mounted onto a wiring board called mother board (2) providing connecting area corresponding to the connecting area of said small size package at the upper surface, characterized in that, contamination or dust existing in the gap between the upper surface of the mother board (2) and rear side of the chip carrier (1) can easily flow out and can be removed, thus improving reliability, by providing a through hole (7) at the chip carrier mounting area on said mother board (2).

Inventors

  • 👤 Norio Honda

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-04 19:20
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/22; H05K3/26; H05K1/00; H05K1/18; H05K1/181; H05K3/30; H05K3/32; H05K3/34; H05K3/341; H05K3/3431; H05K3/3442; H05K1/02; H05K1/14; H05K1/141; H05K2201/00; H05K2201/09; H05K2201/09009; H05K2201/09072; H05K2201/10; H05K2201/10227; H05K2201/1034; H05K2201/10613; H05K2201/10621; H05K2201/10727; H05K2203/00; H05K2203/07; H05K2203/0779; H05K2203/0783; Y; Y02; Y02P; Y02P70/00; Y02P70/50; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49124; Y10T29/4913; Y10T29/49144

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 94 words
A method for making an integrated circuit device, comprising the steps of: forming solder pads on the bottom side of a chip carrier; forming corresponding solder pads on the top side of a mother board; positioning the chip carrier on the mother board so that the solder pads of the chip carrier are adjacent the corresponding solder pads of the mother board; heating the solder pads to melt the solder and join the corresponding solder pads; and circulating solvent between the chip carrier and the mother board through an opening in the mother board.
Claim 2
Independent Claim 94 words
A method for making an integrated circuit device, comprising the steps of: forming solder pads on the bottom side of a chip carrier; forming corresponding solder pads on the top side of a mother board; positioning the chip carrier on the mother board so that the solder pads of the chip carrier are adjacent the corresponding solder pads of the mother board; heating the solder pads to melt the solder and join the corresponding solder pads; and circulating solvent between the chip carrier and the mother board through an opening in the mother board.
Claim 3
Dependent Claim 32 words
The method of claim 1, wherein the step of circulating solvent through an opening in the mother board is accomplished by dipping the mother board into a circulating solution of organic solvent.
Claim 4
Dependent Claim 29 words
The method of claim 1, wherein the step of circulating solvent through an opening in the mother board is accomplished by exposing the mother board to organic solvent fumes.

References Cited (Backward Citations)

US3794886A Cited
US3777220A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1988-01-15 1988-07-16 1989-01-15 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1992-01-15 1992-07-16 1993-01-15 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1996-01-15 1996-07-16 1997-01-15 $7700.00 Window Closed / Lapsed

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