US5483098A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drop-in heat sink package with window frame flag
Assignee: Motorola Solutions Inc
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Filing: 1994-10-18
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Granted: 1996-01-09
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Expires: 2014-10-18
Abstract
Abstract A molded semiconductor device (24) having greater resistance to package cracking during board mounting in addition to increased thermal performance is provided wherein the device has a reduced semiconductor die to flag interface and a drop-in heat sink. The semiconductor die (12) is mounted on a leadframe (16) having a flag (15) with an opening to expose a substantial portion of the inactive surface (14) of the die (12). Decreasing the interfacial contact area between the die (12) and the flag (15) reduces the risk of package cracking during board mounting by limiting the area where delamination typically occurs. An encapsulant (22) forms a package body which encompasses an opening (23) to expose a substantial portion of the inactive surface (14) of the semiconductor die (12). A heat sink (26) is inserted into the opening (23), directly coupling the heat sink (26) to the die (12), after the semiconductor package is mounted onto a printed circuit board.
Inventors
- 👤 Bennett A. Joiner, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 20:19
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/40; H10W70/461; H10W70/01; H10W70/04; H10W40/00; H10W40/70; H10W40/77; H10W40/778; H10W70/045; H10W70/411; H10W70/464; H10W72/00; H10W72/50; H10W72/551; H10W72/552; H10W72/5522; H10W72/5524; H10W72/5525; H10W74/00; H10W74/10; H10W74/131; H10W74/142; H10W90/00; H10W90/701; H10W90/751; H10W90/756
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
221 words
The semiconductor device comprising: a semiconductor die having an active surface, an inactive surface, and a periphery, wherein the semiconductor die has a plurality of bonding pads on the active surface; a leadframe having a plurality of leads and a mounting surface with a die opening, the die opening being smaller than the semiconductor die, a first portion of the inactive surface of the semiconductor die being directly bonded to the mounting surface of the leadframe above the die opening thereby exposing a second portion of the inactive surface of the semiconductor die, whereby an interfacial area between the inactive surface of the semiconductor die and the mounting surface of the leadframe is limited to the first portion of the inactive surface; a plurality of conductive wires electrically coupling the plurality of bonding pads on the active surface of the semiconductor die to the plurality of leads of the leadframe; and a molded package body around the periphery, over the active surface, and over the first portion of the inactive surface of the semiconductor die, the wires, and the leadframe, wherein the package body has an opening molded therein so that the second portion of the inactive surface of the semiconductor die remains uncovered, wherein said opening has a tapered sidewall to allow insertion of a heat spreader without external pressure.
Claim 2
Dependent Claim
221 words
The semiconductor device comprising: a semiconductor die having an active surface, an inactive surface, and a periphery, wherein the semiconductor die has a plurality of bonding pads on the active surface; a leadframe having a plurality of leads and a mounting surface with a die opening, the die opening being smaller than the semiconductor die, a first portion of the inactive surface of the semiconductor die being directly bonded to the mounting surface of the leadframe above the die opening thereby exposing a second portion of the inactive surface of the semiconductor die, whereby an interfacial area between the inactive surface of the semiconductor die and the mounting surface of the leadframe is limited to the first portion of the inactive surface; a plurality of conductive wires electrically coupling the plurality of bonding pads on the active surface of the semiconductor die to the plurality of leads of the leadframe; and a molded package body around the periphery, over the active surface, and over the first portion of the inactive surface of the semiconductor die, the wires, and the leadframe, wherein the package body has an opening molded therein so that the second portion of the inactive surface of the semiconductor die remains uncovered, wherein said opening has a tapered sidewall to allow insertion of a heat spreader without external pressure.
Claim 3
Dependent Claim
31 words
The semiconductor device according to claim 1 wherein the leadframe comprises a leadframe having a surface treatment selected from a group consisting of: plating, organic coating, oxidation, and UV ozone cleaning.
Claim 4
Dependent Claim
41 words
The semiconductor device according to claim 1 further comprising an insertable thermally conductive heat spreader attached to the inactive surface of the semiconductor die through said opening in the package body wherein the heat spreader is not encapsulated by the encapsulant.
Claim 5
Dependent Claim
26 words
The semiconductor device according to claim 3 wherein the thermally conductive heat spreader is coupled to the inactive surface of the semiconductor die with an adhesive.
Claim 6
Dependent Claim
27 words
The semiconductor device according to claim 3 wherein the thermally conductive heat spreader is coupled to the inactive surface of the semiconductor die with a thermal grease.
Claim 7
Dependent Claim
153 words
A semiconductor device comprising: a semiconductor die having an active surface, an inactive surface, and a periphery, wherein the semiconductor die has a plurality of bonding pads on the active surface; a flagless leadframe having a plurality of leads, a number of the plurality of leads being directly mounted on the active surface of the semiconductor die and along the periphery thereof, the plurality of leads being selectively electrically coupled to the plurality of bonding pads on the active surface of the semiconductor die, and exposing the inactive surface of the semiconductor die; and a molded package body around the semiconductor die including the periphery and the active surface, and the leadframe, wherein the package body has an opening so that at least a substantial portion of the inactive surface of the semiconductor die remains uncovered, wherein said opening has a tapered sidewall to allow insertion of a heat spreader without external pressure.
Claim 8
Dependent Claim
153 words
A semiconductor device comprising: a semiconductor die having an active surface, an inactive surface, and a periphery, wherein the semiconductor die has a plurality of bonding pads on the active surface; a flagless leadframe having a plurality of leads, a number of the plurality of leads being directly mounted on the active surface of the semiconductor die and along the periphery thereof, the plurality of leads being selectively electrically coupled to the plurality of bonding pads on the active surface of the semiconductor die, and exposing the inactive surface of the semiconductor die; and a molded package body around the semiconductor die including the periphery and the active surface, and the leadframe, wherein the package body has an opening so that at least a substantial portion of the inactive surface of the semiconductor die remains uncovered, wherein said opening has a tapered sidewall to allow insertion of a heat spreader without external pressure.
Claim 9
Dependent Claim
31 words
The semiconductor device according to claim 6 wherein the leadframe comprises a leadframe having a surface treatment selected from a group consisting of: plating, organic coating, oxidation, and UV ozone cleaning.
Claim 10
Dependent Claim
41 words
The semiconductor device according to claim 6 further comprising an insertable thermally conductive heat spreader attached to the inactive surface of the semiconductor die through said opening in the package body wherein the heat spreader is not encapsulated by the encapsulant.
Claim 11
Dependent Claim
25 words
The semiconductor according to claim 8 wherein the thermally conductive heat spreader is coupled to the inactive surface of the semiconductor die with an adhesive.
Claim 12
Dependent Claim
27 words
The semiconductor device according to claim 8 wherein the thermally conductive heat spreader is coupled to the inactive surface of the semiconductor die with a thermal grease.
Claim 13
Dependent Claim
163 words
A semiconductor device comprising: a semiconductor die having an active surface, an inactive surface, and a periphery, wherein the semiconductor die has a plurality of bonding pads on the active surface; a flagless leadflame having a plurality of leads which are directly mounted on a first portion of the inactive surface of the semiconductor die and along the periphery thereof, the flagless leadframe exposing a second portion of the inactive surface of the semiconductor die, the plurality of leads selectively electrically coupled to the plurality of bonding pads on the active surface of the semiconductor die; and a molded package body around the semiconductor die including the periphery, the active surface, and the first portion of the inactive surface, and the leadframe, wherein the package body has an opening molded therein so that the second portion of the inactive surface of the semiconductor die remains uncovered, wherein said opening has a tapered sidewall to allow insertion of a heat spreader without external pressure.
Claim 14
Dependent Claim
163 words
A semiconductor device comprising: a semiconductor die having an active surface, an inactive surface, and a periphery, wherein the semiconductor die has a plurality of bonding pads on the active surface; a flagless leadflame having a plurality of leads which are directly mounted on a first portion of the inactive surface of the semiconductor die and along the periphery thereof, the flagless leadframe exposing a second portion of the inactive surface of the semiconductor die, the plurality of leads selectively electrically coupled to the plurality of bonding pads on the active surface of the semiconductor die; and a molded package body around the semiconductor die including the periphery, the active surface, and the first portion of the inactive surface, and the leadframe, wherein the package body has an opening molded therein so that the second portion of the inactive surface of the semiconductor die remains uncovered, wherein said opening has a tapered sidewall to allow insertion of a heat spreader without external pressure.
Claim 15
Dependent Claim
31 words
The semiconductor device according to claim 11 wherein the leadframe comprises a leadframe having a surface treatment selected from a group consisting of: plating, organic coating, oxidation, and UV ozone cleaning.
Claim 16
Dependent Claim
41 words
The semiconductor device according to claim 11 further comprising an insertable thermally conductive heat spreader attached to the inactive surface of the semiconductor die through said opening in the package body wherein the heat spreader is not encapsulated by the encapsulant.
Claim 17
Dependent Claim
26 words
The semiconductor device according to claim 13 wherein the thermally conductive heat spreader is coupled to the inactive surface of the semiconductor die with an adhesive.
Claim 18
Dependent Claim
27 words
The semiconductor device according to claim 13 wherein the thermally conductive heat spreader is coupled to the inactive surface of the semiconductor die with a thermal grease.
Claim 19
Independent Claim
195 words
A method of manufacturing a semiconductor device comprising the steps of: providing a semiconductor die having an active surface, an inactive surface, and a periphery; providing a leadframe having an integral die mounting area and a plurality of leads; mounting the semiconductor die directly onto the die mounting area wherein the die mounting area intimately supports a first portion of the inactive surface around the periphery of the semiconductor die, exposing a second portion of the inactive surface of the semiconductor die, whereby an interfacial area between the inactive surface of the semiconductor die and the mounting surface of the leadframe is limited to the first portion of the inactive surface; electrically coupling the semiconductor die to the plurality of leads of the leadframe; and molding a package body around the periphery, over the active surface, and over the first portion of the inactive surface of the semiconductor die, and the leadframe, with means for forming an opening in the package body during molding so that the second portion of the inactive surface of the semiconductor die remains uncovered, wherein said opening has tapered sidewalls to allow insertion of a heat spreader without external pressure.
Claim 20
Independent Claim
195 words
A method of manufacturing a semiconductor device comprising the steps of: providing a semiconductor die having an active surface, an inactive surface, and a periphery; providing a leadframe having an integral die mounting area and a plurality of leads; mounting the semiconductor die directly onto the die mounting area wherein the die mounting area intimately supports a first portion of the inactive surface around the periphery of the semiconductor die, exposing a second portion of the inactive surface of the semiconductor die, whereby an interfacial area between the inactive surface of the semiconductor die and the mounting surface of the leadframe is limited to the first portion of the inactive surface; electrically coupling the semiconductor die to the plurality of leads of the leadframe; and molding a package body around the periphery, over the active surface, and over the first portion of the inactive surface of the semiconductor die, and the leadframe, with means for forming an opening in the package body during molding so that the second portion of the inactive surface of the semiconductor die remains uncovered, wherein said opening has tapered sidewalls to allow insertion of a heat spreader without external pressure.
Claim 21
Dependent Claim
39 words
The method of manufacturing a semiconductor device according to claim 16 wherein the step of providing a leadframe further comprises performing a leadframe surface treatment selected from a group consisting of: plating, organic coating, oxidation, and UV ozone cleaning.
Claim 22
Dependent Claim
52 words
The method of manufacturing a semiconductor device according to claim 16 further comprising the step of attaching a thermally conductive heat spreader to the inactive surface of the semiconductor die through said opening in the package body after the step of molding, wherein the heat spreader is not encapsulated by the encapsulant.
Claim 23
Dependent Claim
42 words
The method of manufacturing a semiconductor device according to claim 18 wherein the step of attaching a thermally conductive heat spreader to the inactive surface of the semiconductor die comprises applying an adhesive for coupling the heat spreader to the inactive surface.
Claim 24
Dependent Claim
42 words
The method of manufacturing a semiconductor device according to claim 18 wherein the step of attaching a thermally conductive heat spreader to the inactive surface of the semiconductor die comprises applying a thermal grease between the heat spreader and the inactive surface.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-01-08 | 1999-07-10 | 2000-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-01-08 | 2003-07-10 | 2004-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-01-08 | 2007-07-10 | 2008-01-09 | $7700.00 | Window Closed / Lapsed |