US5474958A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for making semiconductor device having no die supporting surface
Assignee: NXP USA Inc
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Filing: 1993-05-04
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Granted: 1995-12-12
•
Expires: 2013-05-04
Abstract
Abstract A wire bondable plastic encapsulated semiconductor device (58) having no die supporting surface can be manufactured. In one embodiment, a semiconductor die (22) and a plurality of conductors (12) extending toward the periphery of the die are provided. The die is rigidly held in place on a workholder (60) with a vacuum (62) for the wire bonding process. Wire bonds (26) electrically connect the die to the conductors. The wire bonded die is then placed inside a mold cavity (64), and a resin encapsulated is transferred into the cavity under elevated temperature and pressure to form package body (70) around the die, the wire bonds and a portion of the conductors. Before the package body is formed, the die is supported solely by the the rigidity of the wire bonds since there is no die supporting surface connected to the conductors.
Inventors
- 👤 Frank Djennas
- 👤 Victor K. Nomi
- 👤 John R. Pastore
- 👤 Twila J. Reeves
- 👤 Les Postlethwait
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 08:58
CPC Classifications
H; H10; H10W; H10W74/00; H10W74/01; H10W74/019; H10W70/00; H10W70/60; H10W70/62; H10W70/65; H10W74/016; H10W74/10; H10W74/111; H10W90/00; H10W90/701; H10W70/67; H10W70/68; H10W70/681; H10W72/00; H10W72/071; H10W72/0711; H10W72/07178; H10W72/075; H10W72/07502; H10W72/07504; H10W72/50; H10W72/551; H10W72/552; H10W72/5522; H10W72/851; H10W72/874; H10W72/884; H10W74/131; H10W74/142; H10W90/731; H10W90/734; H10W90/736; H10W90/751; H10W90/754; H10W90/756; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49121; Y10T29/49124; Y10T29/4913; Y10T29/49146; Y10T29/49169; Y10T29/49171; Y10T29/49172
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
129 words
A method for fabricating a semiconductor device comprising the steps of: placing a semiconductor die having an active surface and a periphery on a supporting workholder; attaching an inactive surface of the semiconductor die to a removable tape, the tape being supported by the workholder to rigidly hold the semiconductor die in a fixed position on the workholder; providing a first plurality of conductors extending toward the periphery of the semiconductor die; wire bonding the active surface of the semiconductor die to the first plurality of conductors; forming a package body, having planar surfaces, to cover the active surface of the semiconductor die and a portion of the plurality of conductors; and providing a second plurality of conductors electrically connected to the semiconductor die to provide external electrical connections.
Claim 2
Independent Claim
129 words
A method for fabricating a semiconductor device comprising the steps of: placing a semiconductor die having an active surface and a periphery on a supporting workholder; attaching an inactive surface of the semiconductor die to a removable tape, the tape being supported by the workholder to rigidly hold the semiconductor die in a fixed position on the workholder; providing a first plurality of conductors extending toward the periphery of the semiconductor die; wire bonding the active surface of the semiconductor die to the first plurality of conductors; forming a package body, having planar surfaces, to cover the active surface of the semiconductor die and a portion of the plurality of conductors; and providing a second plurality of conductors electrically connected to the semiconductor die to provide external electrical connections.
Claim 3
Independent Claim
140 words
A method for fabricating a semiconductor device comprising the steps of: placing a semiconductor die having an active surface and a periphery on a supporting workholder; providing means for holding the semiconductor die rigidly on the supporting workholder for a subsequent electrical connecting step; providing a first plurality of conductors extending toward the periphery of the semiconductor die; electrically connecting the active surface of the semiconductor die to the first plurality of conductors; supporting an inactive surface of the semiconductor die with a support pin in a mold; molding a resin encapsulant inside a mold cavity having planar major surfaces to form a package body to cover the active surface of the semiconductor die and a portion of the plurality of conductors; and providing a second plurality of conductors electrically connected to the semiconductor die to provide external electrical connections.
Claim 4
Independent Claim
140 words
A method for fabricating a semiconductor device comprising the steps of: placing a semiconductor die having an active surface and a periphery on a supporting workholder; providing means for holding the semiconductor die rigidly on the supporting workholder for a subsequent electrical connecting step; providing a first plurality of conductors extending toward the periphery of the semiconductor die; electrically connecting the active surface of the semiconductor die to the first plurality of conductors; supporting an inactive surface of the semiconductor die with a support pin in a mold; molding a resin encapsulant inside a mold cavity having planar major surfaces to form a package body to cover the active surface of the semiconductor die and a portion of the plurality of conductors; and providing a second plurality of conductors electrically connected to the semiconductor die to provide external electrical connections.
Claim 5
Dependent Claim
20 words
The method of claim 2, wherein the step of supporting further comprises providing a vacuum line around the support pin.
Claim 6
Independent Claim
179 words
A method for fabricating a semiconductor device comprising the steps of: placing a semiconductor die having an active surface and a periphery on a supporting workholder; providing means for holding the semiconductor die rigidly on the supporting workholder for a subsequent electrical connecting step; providing a first plurality of conductors extending toward the periphery of the semiconductor die; electrically connecting the active surface of the semiconductor die to the first plurality of conductors with connecting means, wherein said connecting means holds in place and physically supports the semiconductor die; supporting an inactive surface of the semiconductor die with a surface of a mold platen which defines part of a mold cavity; activating a vacuum line to rigidly hold the inactive surface against the mold platen surface; and transferring a resin encapsulant inside the mold cavity having planar major surfaces to form a package body to cover the active surface of the semiconductor die and a portion of the plurality of conductors; and providing a second plurality of conductors electrically connected to the semiconductor die to provide external electrical connections.
Claim 7
Independent Claim
179 words
A method for fabricating a semiconductor device comprising the steps of: placing a semiconductor die having an active surface and a periphery on a supporting workholder; providing means for holding the semiconductor die rigidly on the supporting workholder for a subsequent electrical connecting step; providing a first plurality of conductors extending toward the periphery of the semiconductor die; electrically connecting the active surface of the semiconductor die to the first plurality of conductors with connecting means, wherein said connecting means holds in place and physically supports the semiconductor die; supporting an inactive surface of the semiconductor die with a surface of a mold platen which defines part of a mold cavity; activating a vacuum line to rigidly hold the inactive surface against the mold platen surface; and transferring a resin encapsulant inside the mold cavity having planar major surfaces to form a package body to cover the active surface of the semiconductor die and a portion of the plurality of conductors; and providing a second plurality of conductors electrically connected to the semiconductor die to provide external electrical connections.
Claim 8
Dependent Claim
27 words
The method of claim 4, further comprising the step of: attaching a heat sink to the inactive surface of the semiconductor die after the step of molding.
Claim 9
Independent Claim
145 words
A method for fabricating a semiconductor device comprising the steps of: placing a semiconductor die having an active surface and a periphery on a supporting workholder; providing means for holding the semiconductor die rigidly on the supporting workholder for a subsequent electrical connecting step; providing a first plurality of conductors extending toward the periphery of the semiconductor die; electrically connecting the active surface of the semiconductor die to the first plurality of conductors; supporting a portion of an inactive surface of the semiconductor die with a pedestal which extends into a mold cavity; molding a resin encapsulant inside the mold cavity having planar major surfaces to form a package body to cover the active surface of the semiconductor die and a portion of the plurality of conductors; and providing a second plurality of conductors electrically connected to the semiconductor die to provide external electrical connections.
Claim 10
Independent Claim
145 words
A method for fabricating a semiconductor device comprising the steps of: placing a semiconductor die having an active surface and a periphery on a supporting workholder; providing means for holding the semiconductor die rigidly on the supporting workholder for a subsequent electrical connecting step; providing a first plurality of conductors extending toward the periphery of the semiconductor die; electrically connecting the active surface of the semiconductor die to the first plurality of conductors; supporting a portion of an inactive surface of the semiconductor die with a pedestal which extends into a mold cavity; molding a resin encapsulant inside the mold cavity having planar major surfaces to form a package body to cover the active surface of the semiconductor die and a portion of the plurality of conductors; and providing a second plurality of conductors electrically connected to the semiconductor die to provide external electrical connections.
Claim 11
Dependent Claim
30 words
The method of claim 6, further comprising the step of: attaching a heat sink to the portion of the inactive surface of the semiconductor die after the step of molding.
Claim 12
Dependent Claim
27 words
The method of claim 4, wherein the step of electrically connecting comprises a method selected from a group consisting of; wire bonding and low loop wire bonding.
Claim 13
Dependent Claim
26 words
The method of claim 4, further comprising the step of: heating the supporting workholder to a temperature in a range of 175° C. to 250° C.
Claim 14
Dependent Claim
22 words
The method of claim 4, wherein the steps of providing the first and second pluralities of conductors comprise providing a flagless leadframe.
Claim 15
Dependent Claim
37 words
The method of claim 1, wherein the step of providing the first plurality of conductors comprises providing a PCB substrate having a die cavity and a plurality of conductive traces on a surface of the PCB substrate.
Claim 16
Dependent Claim
37 words
The method of claim 11, wherein the step of providing a PCB substrate comprises providing a PCB substrate having a die cavity having a plated sidewall, wherein the plated sidewall is connected to a power supply trace.
Claim 17
Dependent Claim
49 words
The method of claim 11, wherein the step of providing a PCB substrate comprises providing a PCB substrate having a plurality of recesses on a surface, the plurality of recesses corresponding in location to a plurality of solder pads which is electrically connected to the plurality of conductive traces.
Claim 18
Independent Claim
224 words
A method for fabricating a semiconductor device comprising the steps of: placing a semiconductor die having an active surface and a periphery on a supporting workholder; providing means for holding the semiconductor die rigidly on the supporting workholder for a subsequent electrical connecting step; providing a PCB substrate having a die cavity and a plurality of conductive traces on a surface of the PCB substrate, the plurality of conductive traces extending toward the periphery of the semiconductor die; electrically connecting the active surface of the semiconductor die to the first plurality of conductors; providing a removable tape that adheres to an inactive surface of the semiconductor die; forming a package body to cover the active surface of the semiconductor die and a portion of the plurality of conductive traces; removing a first portion of the tape from the inactive surface of the semiconductor die after the step of forming a package body, such that a second portion of the tape remains on the inactive surface forming a plurality of solder resist annular rings on the inactive surface; attaching a first plurality of solder balls to the inactive surface of the semiconductor die inside the plurality of solder resist annular rings; and attaching a second plurality of solder balls to the plurality of solder pads inside the plurality of recesses in the multilayer PCB substrate.
Claim 19
Independent Claim
224 words
A method for fabricating a semiconductor device comprising the steps of: placing a semiconductor die having an active surface and a periphery on a supporting workholder; providing means for holding the semiconductor die rigidly on the supporting workholder for a subsequent electrical connecting step; providing a PCB substrate having a die cavity and a plurality of conductive traces on a surface of the PCB substrate, the plurality of conductive traces extending toward the periphery of the semiconductor die; electrically connecting the active surface of the semiconductor die to the first plurality of conductors; providing a removable tape that adheres to an inactive surface of the semiconductor die; forming a package body to cover the active surface of the semiconductor die and a portion of the plurality of conductive traces; removing a first portion of the tape from the inactive surface of the semiconductor die after the step of forming a package body, such that a second portion of the tape remains on the inactive surface forming a plurality of solder resist annular rings on the inactive surface; attaching a first plurality of solder balls to the inactive surface of the semiconductor die inside the plurality of solder resist annular rings; and attaching a second plurality of solder balls to the plurality of solder pads inside the plurality of recesses in the multilayer PCB substrate.
References Cited (Backward Citations)
JPS55134940A
Cited
US4866506A
Cited
US4961105A
Cited
JPS63283136A
Cited
US5122860A
Cited
US4994411A
Cited
US4881885A
Cited
JPH02119255A
Cited
US5095361A
Cited
US5106785A
Cited
JPH0386440A
Cited
US5200362A
Cited
JPH03198356A
Cited
US5289033A
Cited
US5227662A
Cited
JPH0434958A
Cited
US5202288A
Cited
US5166099A
Cited
US5147821A
Cited
US5142450A
Cited
JPH0547836A
Cited
JPH0547835A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-12-11 | 1999-06-12 | 1999-12-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-12-11 | 2003-06-12 | 2003-12-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-12-11 | 2007-06-12 | 2007-12-12 | $7700.00 | Window Closed / Lapsed |