Patent US6146924A successfully refreshed from Google Patents.
US6146924A
Expired / Lapsed
US
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Magnetic insert into mold cavity to prevent resin bleeding from bond area of pre-mold (open cavity) plastic chip carrier during molding process
Assignee: Vanguard International Semiconductor Corp
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Filing: 1999-08-06
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Granted: 2000-11-14
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Expires: 2019-08-06
Abstract
Abstract A new method is provided for the creation of a pre-molded chip carrier. The invention teaches putting magnetic inserts into the upper mold. The magnetic inserts attract the lead fingers that are inserted into the upper mold during the process of filling the cavity with a compound pressing the lead fingers tightly against the surface of the magnet. The possibility of mold compound spilling over the lead fingers and forming resin depositions on the surface of the lead fingers is thereby voided.
Inventors
- 👤 Daniel Chang
- 👤 Chengder Huang
- 👤 Pei-Haw Tsao
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 21:52
CPC Classifications
H; H10; H10W; H10W74/00; H10W74/01; H10W74/016; H10W90/00; H10W90/701; H10W90/751; H10W90/756
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
102 words
A method of forming a pre-molded plastic chip carrier, comprising the steps of: forming a lower mold said lower mold containing a lower mold cavity; forming an upper mold said upper mold containing an upper mold cavity; inserting magnets into said upper mold; attaching a die pad and conducting lead fingers to said upper mold; mating said lower mold with said upper mold thereby creating a complete mold assemblage with a complete mold cavity; injecting a molding compound into said complete mold cavity; curing said injected molding compound; and removing said lower and upper mold thereby freeing said pre-molded plastic chip carrier.
Claim 2
Independent Claim
102 words
A method of forming a pre-molded plastic chip carrier, comprising the steps of: forming a lower mold said lower mold containing a lower mold cavity; forming an upper mold said upper mold containing an upper mold cavity; inserting magnets into said upper mold; attaching a die pad and conducting lead fingers to said upper mold; mating said lower mold with said upper mold thereby creating a complete mold assemblage with a complete mold cavity; injecting a molding compound into said complete mold cavity; curing said injected molding compound; and removing said lower and upper mold thereby freeing said pre-molded plastic chip carrier.
Claim 3
Dependent Claim
73 words
The method of claim 1 wherein said lower mold when matched and mated with said upper mold meets all design requirements imposed by environmental and electrical requirements that are in force for adequate, reliable and cost effective mounting of semiconductor chips on the surface of said pre-molded plastic chip carrier wherein furthermore the cavities for the creation of said pre-molded plastic chip carrier are created in the top surface of said lower mold.
Claim 4
Dependent Claim
124 words
The method of claim 1 wherein said forming an upper mold comprises: designing said upper mold such that when matched and mated with said lower mold said upper mold meets all design requirements imposed by environmental and electrical requirements that are in force for adequate, reliable and cost effective mounting of semiconductor chips on the surface of said pre-molded plastic chip carrier; providing cavities for the creation of said pre-molded plastic chip carrier said cavities to be created in the lower surface of said upper mold; and providing additional cavities said cavities to be in the lower surface of said upper mold said lower surface being the surface of said upper mold that matches and mates with the upper surface of said lower mold.
Claim 5
Dependent Claim
83 words
The method of claim 3 wherein said additional cavities are of a profile such that bodies of metal or any other configuration of components that have magnetic properties of attracting or rejecting other metal can be inserted into said additional cavities whereby furthermore the locations of said additional cavities match and mate with the locations where the die pad and lead fingers of lines that connect said die to surrounding points of electrical contact must be positioned within said pre-molded plastic chip carrier.
Claim 6
Dependent Claim
48 words
The method of claim 4 whereby said magnetic properties of attracting or rejecting other metal can be controlled in a manner that is independent of and external to said lower and upper mold such that said attracting or rejecting other metal can be activated or can be negated.
Claim 7
Dependent Claim
59 words
The method of claim 1 wherein said inserting magnets into said upper mold is inserting magnets of metal or any other configuration of components that have magnetic properties of attracting or rejecting other metal into said additional cavities in said upper mold thereby inserting die pad magnets for said die pad and lead finger magnets for said lead fingers.
Claim 8
Dependent Claim
76 words
The method of claim 1 wherein said attaching a die pad is attaching the die pad such that the geometric center of the die pad essentially coincides with the geometric center of said upper mold whereby the plane of said die pad is parallel to the lower plane of said upper mold whereby furthermore the location of said die pad matches and mates with the die pad magnet that has been inserted into the upper mold.
Claim 9
Dependent Claim
49 words
The method of claim 1 wherein said attaching conducting lead fingers to said upper mold is attaching a plurality of conducting lines around the periphery of said upper mold whereby said lead fingers match and mate with the lead finger magnets that have been inserted into said upper mold.
Claim 10
Dependent Claim
67 words
The method of claim 1 wherein said mating said lower mold with said upper mold is aligning the geometric center of said die pad mounted in the lower surface of the upper mold with the geometric center of the upper surface of the lower mold furthermore bringing the lower surface of the upper mold in direct and intimate contact with the upper surface of the lower mold.
Claim 11
Dependent Claim
47 words
The method of claim 1 with the additional step of providing wire bond connections between the die that is mounted on the surface of the pre-molded chip carrier and the lead fingers that have been provided for this purpose on the surface of the pre-molded chip carrier.
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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) | 2003-11-14 | 2004-05-15 | 2004-11-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-11-14 | 2008-05-15 | 2008-11-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-11-14 | 2012-05-15 | 2012-11-14 | $7700.00 | Window Closed / Lapsed |