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EP0478240A2
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EP
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Insulated lead frame for integrated circuits and method of manufacture thereof
Assignee: Texas Instruments Inc
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Filing: 1991-09-20
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Granted: —
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Expires: 2011-09-20
Abstract
Abstract An insulated lead frame is disclosed. The preferred embodiment contains a lead over chip lead frame (25) having an aluminum oxide insulator (30) on portions of the power supply busses (28) where no electrical connections will be made. The aluminum oxide (30) may be easily deposited by an arc deposition process such as by plasma deposition. A mask prohibits the aluminum oxide from coating the places on the power supply busses where electrical connection, such as by wire bond, will be made. Wire bonds crossing over the power supply busses (28) as they connect bond pads (23) to the lead fingers (27) of the lead frame (25) are therefore less likely to short to the insulated power supply busses (28). A semiconductor packaged device having an aluminum oxide coating to the underside of the chip support pad is also disclosed. The aluminum oxide coating promotes adhesion between the chip support pad and the encapsulant, that is typically plastic, thereby preventing the chance of delamination and package cracking.
Inventors
- 👤 Katherine G. Heinen
- 👤 Henry F. Breit
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 04:30
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/40; H10W70/411; H10W70/415; H10W70/456; H10W70/458; H10W72/00; H10W72/90; H10W74/00; H10W74/10; H10W74/111; H10W74/127; H10W72/50; H10W72/531; H10W72/536; H10W72/541; H10W72/5449; H10W72/551; H10W72/552; H10W72/5522; H10W72/5524; H10W72/59; H10W72/851; H10W72/853; H10W72/865; H10W72/874; H10W72/884; H10W72/931; H10W72/932; H10W72/934; H10W72/941; H10W72/944; H10W72/9445; H10W72/951; H10W72/952; H10W90/00; H10W90/701; H10W90/731; H10W90/736; H10W90/751; H10W90/756
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
53 words
An insulated power supply bus for a semiconductor circuit, comprising: a strip of metal sheet stock; a dielectric adhered to the strip of metal sheet stock; and an apperture in the dielectric to expose the strip of metal sheet stock so that electrical connection from a semiconductor circuit may be made to it.
Claim 2
Dependent Claim
14 words
The insulated power supply bus of claim 1 wherein the dielectric is an oxide.
Claim 3
Dependent Claim
14 words
The insulated power supply bus of claim 2 wherein the oxide is aluminum oxide.
Claim 4
Dependent Claim
16 words
The insulated power supply bus of claim 3 wherein the aluminum oxide is plasma arc deposited.
Claim 5
Dependent Claim
16 words
The insulated power supply bus of claim 3 wherein the aluminum oxide is flame spray deposited.
Claim 6
Dependent Claim
55 words
An insulated lead frame comprising: a first plurality of conductive lead fingers; a second plurality of conductive lead fingers; a power supply bus lying between the first and second pluralities of conductive lead fingers; and an insulator covering selected portions of the power supply bus, the portions selected having no electrical connection made to them.
Claim 7
Dependent Claim
13 words
The insulated lead frame of claim 6 wherein the insulator is aluminum oxide.
Claim 8
Dependent Claim
15 words
The insulated lead frame of claim 7 wherein the aluminum oxide is plasma arc deposited.
Claim 9
Dependent Claim
15 words
The insulated lead frame of claim 7 wherein the aluminum oxide is flame spray deposited.
Claim 10
Dependent Claim
56 words
The insulated lead frame of claim 7 further comprising: a second power supply bus lying between the first and second pluralities of conductive lead fingers, adjacent to the first power supply bus; and an aluminum oxide insulator covering selected portions of the second power supply bus, the portions selected having no electrical connection made to them.
Claim 11
Dependent Claim
128 words
An encapsulated semiconductor device, comprising: a semiconductor die having terminals thereon disposed within an encapsulating material; a lead frame having a plurality of lead fingers and a power supply bus connected to one of the plurality of lead fingers disposed within the encapsulating material, and having portions of the plurality of lead fingers extending out of the encapsulating material; a means for connecting some of the plurality of lead fingers to some of the plurality of terminals of the semiconductor die that crosses over the power supply bus and is disposed within the encapsulant; and a dielectric coating on the power supply bus where the means for connecting some of the plurality of lead fingers to some of the plurality of terminals crosses over the power supply bus.
Claim 12
Dependent Claim
14 words
The encapsulated semiconductor device of claim 11 wherein the dielectric coating is aluminum oxide.
Claim 13
Dependent Claim
25 words
The encapsulated semiconductor device of claim 12 wherein the dielectric coating of aluminum oxide is between the range of about 0.0005 to 0.05 inches thick.
Claim 14
Dependent Claim
15 words
The encapsulated semiconductor device of claim 12 wherein the aluminum oxide has a roughened surface.
Claim 15
Dependent Claim
22 words
The encapsulated semiconductor device of claim 14 wherein the roughened surface of the aluminum oxide has a RMS of about 130 micrometers.
Claim 16
Dependent Claim
17 words
The encapsualted semiconductor device of claim 12 wherein the aluminum oxide is arc deposited by plasma deposition.
Claim 17
Dependent Claim
18 words
The encapsulated semiconductor device of claim 12 wherein the aluminum oxide is arc deposited by flame spray deposition.
Claim 18
Dependent Claim
33 words
The encapsulated semiconductor device of claim 12 wherein wire bonds comprise the means for connecting some of the plurality of lead fingers to some of the plurality of terminals of the semiconductor die.
Claim 19
Independent Claim
70 words
A method of insulating a lead frame having a power supply bus disposed near a plurality of lead fingers, comprising the steps of: selecting portions of the power supply bus by determining where wire bonds will cross the power supply bus as they connect various of the plurality of lead fingers to an integrated semiconductor circuit; and arc depositing aluminum oxide onto the selected portions of the power supply buss.
Claim 20
Dependent Claim
15 words
The method of claim 19 wherein the arc depositing step is by plasma arc deposition.
Claim 21
Dependent Claim
15 words
The method of claim 19 wherein the arc depositing step is by flame spray deposition.
Claim 22
Dependent Claim
74 words
A semiconductor device, comprising: a semiconductor circuit with a terminal thereon; a lead finger; a strip of metal lying between the terminal of the semiconductor circuit and the lead fingers; a connecting means for connecting the terminal of the semiconductor circuit to the lead finger, that crosses the strip of metal; and a coating on the strip of metal where the connecting means crosses to insulate the strip of metal from the connecting means.
References Cited (Backward Citations)
No citation records indexed.
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