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US5101263A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semiconductor device and method for manufacturing the same
Assignee: Hitachi Ltd
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Filing: 1990-06-21
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Granted: 1992-03-31
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Expires: 2010-06-21
Abstract
Abstract In a plastic encapsulated semiconductor device, a part of wire piece may break down due to thermal fatigue, which positioned adjacent to a bonding portion of the wire piece connected to a chip. This is caused by that wire piece moves relative to plastic encapsulating the chip and the wire piece, and a strain in the wire piece due to thermal deformation of the device concentrates on one portion of the wire piece. Accordingly, a rugged portion is formed on a surface of a part of wire piece subjected to a breakdown to thermal fatigue. The plastic bites recesses of the rugged portion to prevent the wire piece from moving relative to the plastic, thereby preventing the wire piece from breaking down due to thermal fatigue.
Inventors
- 👤 Makoto Kitano
- 👤 Chikako Kitabayashi
- 👤 Asao Nishimura
- 👤 Hideo Miura
- 👤 Akihiro Yaguchi
- 👤 Sueo Kawai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 15:50
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/40; H10W70/464; H10W70/465; H10W72/00; H10W72/01; H10W72/015; H10W72/01551; H10W72/071; H10W72/0711; H10W72/07141; H10W72/075; H10W72/07511; H10W72/07521; H10W72/07551; H10W72/07553; H10W72/07555; H10W72/50; H10W72/531; H10W72/533; H10W72/536; H10W72/5363; H10W72/551; H10W72/552; H10W72/5522; H10W72/5525; H10W72/59; H10W74/00; H10W90/00; H10W90/701; H10W90/751; H10W90/756
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
179 words
A plastic encapsulated semiconductor device comprising: a chip having a plurality of electrodes; a lead frame on which said chip is mounted; a plurality of wire pieces each having a ball bonding portion in the form of a bulb at a connecting end thereof, said wire pieces being connected to the respective electrodes of said chip by means of the respective ball bonding portions, each of said wire pieces being provided with a rugged surface having recess portions at a part thereof spaced above the top of the bulb of its ball bonding portion by a distance of at least about 0.2 mm so that the recess portions are located in areas of the wire pieces where the yield stress of the wire pieces has not been substantially reduced by heat during ball bonding, and wherein a depth of the recess portions of said rugged surface is at least 8% of a diameter of the associated wire piece; and plastic for encapsulating said aforementioned members, said plastic filling said recess portions of the rugged surfaces of said wire pieces.
Claim 2
Dependent Claim
179 words
A plastic encapsulated semiconductor device comprising: a chip having a plurality of electrodes; a lead frame on which said chip is mounted; a plurality of wire pieces each having a ball bonding portion in the form of a bulb at a connecting end thereof, said wire pieces being connected to the respective electrodes of said chip by means of the respective ball bonding portions, each of said wire pieces being provided with a rugged surface having recess portions at a part thereof spaced above the top of the bulb of its ball bonding portion by a distance of at least about 0.2 mm so that the recess portions are located in areas of the wire pieces where the yield stress of the wire pieces has not been substantially reduced by heat during ball bonding, and wherein a depth of the recess portions of said rugged surface is at least 8% of a diameter of the associated wire piece; and plastic for encapsulating said aforementioned members, said plastic filling said recess portions of the rugged surfaces of said wire pieces.
Claim 3
Dependent Claim
31 words
A semiconductor device according to claim 1, wherein said recess portions in each of said wire pieces are located in a predetermined arrangement in the surface of the associated wire piece.
Claim 4
Dependent Claim
17 words
A semiconductor device according to claim 1, wherein said rugged surfaces of said wire pieces comprise dimples.
Claim 5
Dependent Claim
31 words
A semiconductor device according to claim 1, wherein a depth of the recess portions of said rugged surface is between 8% and 12% of a diameter of the associated wire piece.
Claim 6
Dependent Claim
187 words
A plastic encapsulated semiconductor device comprising: a chip having a plurality of electrodes; a lead frame on which said chip is mounted; a plurality of wire pieces each having a ball bonding portion in the form of a bulb at a connecting end thereof, said wire pieces being connected to the respective electrodes of said chip by means of the respective ball bonding portions, each of said wire pieces being provided with a rugged surface having recess portions at a part thereof spaced above the top of the bulb of its ball bonding portion by a distance of at least about 0.2 mm so that the recess portions are located in areas of the wire pieces where the yield stress of the wire pieces has not been substantially reduced by heat during ball bonding, and wherein a depth of the recess portions of said rugged surface is at least 8% of a diameter of the associated wire piece; and plastic for encapsulating said aforementioned members, said plastic filling said recess portions of the rugged surfaces of said wire pieces, wherein said wire pieces are made of gold.
Claim 7
Dependent Claim
187 words
A plastic encapsulated semiconductor device comprising: a chip having a plurality of electrodes; a lead frame on which said chip is mounted; a plurality of wire pieces each having a ball bonding portion in the form of a bulb at a connecting end thereof, said wire pieces being connected to the respective electrodes of said chip by means of the respective ball bonding portions, each of said wire pieces being provided with a rugged surface having recess portions at a part thereof spaced above the top of the bulb of its ball bonding portion by a distance of at least about 0.2 mm so that the recess portions are located in areas of the wire pieces where the yield stress of the wire pieces has not been substantially reduced by heat during ball bonding, and wherein a depth of the recess portions of said rugged surface is at least 8% of a diameter of the associated wire piece; and plastic for encapsulating said aforementioned members, said plastic filling said recess portions of the rugged surfaces of said wire pieces, wherein said wire pieces are made of gold.
Claim 8
Dependent Claim
31 words
A semiconductor device according to claim 3, wherein said recess portions in each of said wire pieces are located in a predetermined arrangement in the surface of the associated wire piece.
Claim 9
Dependent Claim
17 words
A semiconductor device according to claim 5, wherein said rugged surfaces of said wire pieces comprise dimples.
Claim 10
Dependent Claim
31 words
A semiconductor device according to claim 5, wherein a depth of the recess portions of said rugged surface is between 8% and 12% of a diameter of the associated wire piece.
References Cited (Backward Citations)
JPS5219971A
Cited
DE2824607A1
Cited
JPS5422770A
Cited
JPS59104147A
Cited
EP0142447A2
Cited
JPS61210646A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-03-31 | 1995-09-30 | 1996-03-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-03-31 | 1999-09-30 | 2000-03-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-03-31 | 2003-09-30 | 2004-03-31 | $7700.00 | Window Closed / Lapsed |