US6196871B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for adjusting differential thermal expansion between an electrical socket and a circuit board
Assignee: Hon Hai Precision Industry Co Ltd
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Filing: 1999-04-26
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Granted: 2001-03-06
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Expires: 2019-04-26
Abstract
Abstract The present invention relates to a method for adjusting differential thermal expansion between an electrical socket and a circuit board by means of secure and accurate interconnection of an adjusting device therebetween before a heating step. The adjusting device is made of an adhesive fusible material and fixed to the housing for absorbing most of the fracture stress exerted on the solder balls and for eliminating a misalignment between the electrical socket and the circuit board during the heating step. The adjusting device can be designed according to practical requirements to be a number of adjusting posts, an adjusting frame, or an adjusting chip.
Inventors
- 👤 Ming-Lun Szu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:26
CPC Classifications
H; H01; H01R; H01R43/00; H01R43/02; H01R43/0256; H01R43/0263; H05; H05K; H05K3/00; H05K3/30; H05K3/303; H05K2201/00; H05K2201/01; H05K2201/0104; H05K2201/0129; H05K2201/06; H05K2201/068; H05K2201/10; H05K2201/10227; H05K2201/10325; H05K2203/00; H05K2203/16; H05K2203/167; H05K3/305; H05K3/32; H05K3/34; H05K3/341; H05K3/3431; H05K3/3436; Y; Y02; Y02P; Y02P70/00; Y02P70/50
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
243 words
A method for mounting a ball-grid-array (BGA) electrical socket to a circuit board, said electrical socket and circuit board having different coefficients of thermal expansion (CTE), said method comprising the steps of: (a) manufacturing an electrical socket and a circuit board, a plurality of contacts received in the electrical socket, a plurality of contact pads formed on the circuit board corresponding to the contacts of the electrical socket, a plurality of holes defined in the electrical socket surrounding the contacts, and a plurality of positioning holes defined in the circuit board and corresponding to the holes of the electrical socket; (b) planting a plurality of solder balls onto the corresponding contacts of the electrical socket; (c) disposing a plurality of posts made of adhesive fusible material into the holes of the electrical socket and the positioning holes of the circuit board; and (d) subjecting the electrical socket and the circuit board to a heat treatment process to cause the solder balls of the electrical socket to be soldered to the contact pads of the circuit board and the posts to melt and then solidify to fix the electrical socket to the circuit board, said posts absorbing most of fracture stress exerted on the solder balls by the socket and the circuit board due to the different CTEs of the electrical socket and the circuit board thereby preventing misalignment between the contacts of the electrical socket and the contact pads of the circuit board.
Claim 2
Independent Claim
243 words
A method for mounting a ball-grid-array (BGA) electrical socket to a circuit board, said electrical socket and circuit board having different coefficients of thermal expansion (CTE), said method comprising the steps of: (a) manufacturing an electrical socket and a circuit board, a plurality of contacts received in the electrical socket, a plurality of contact pads formed on the circuit board corresponding to the contacts of the electrical socket, a plurality of holes defined in the electrical socket surrounding the contacts, and a plurality of positioning holes defined in the circuit board and corresponding to the holes of the electrical socket; (b) planting a plurality of solder balls onto the corresponding contacts of the electrical socket; (c) disposing a plurality of posts made of adhesive fusible material into the holes of the electrical socket and the positioning holes of the circuit board; and (d) subjecting the electrical socket and the circuit board to a heat treatment process to cause the solder balls of the electrical socket to be soldered to the contact pads of the circuit board and the posts to melt and then solidify to fix the electrical socket to the circuit board, said posts absorbing most of fracture stress exerted on the solder balls by the socket and the circuit board due to the different CTEs of the electrical socket and the circuit board thereby preventing misalignment between the contacts of the electrical socket and the contact pads of the circuit board.
Claim 3
Dependent Claim
16 words
The method as claimed in claim 1 , wherein the posts are made of thermoplastic material.
Claim 4
Dependent Claim
213 words
An electrical socket for electrically connecting a modular chip and a circuit board, comprising: an insulative housing forming a mating face for connecting to the modular chip, a jointing face for connecting to the circuit board, a plurality of engaging slots and holes defined between the mating face and the jointing face, the holes being located around the edges of the housing; a plurality of matrix type contacts received in the corresponding engaging slots and a plurality of solder balls planted on bottom ends of the contacts, the contacts being adapted to be soldered to the circuit board after undergoing a heating procedure; and a plurality of adjusting posts made of adhesive fusible material and fixed in the holes of the housing, at least a portion of each adjusting post extending outside of the housing and being adapted to be fixed to the circuit board after undergoing the heating procedure, the adjusting posts circumferentially enclosing the contacts of the electrical socket in a limited space and absorbing most of the fracture stress exerted on the solder balls by the socket and the circuit board when the socket is mounted to the circuit board and subject to a thermal load, thereby preventing misalignment between the contacts of the electrical socket and the circuit board.
Claim 5
Dependent Claim
213 words
An electrical socket for electrically connecting a modular chip and a circuit board, comprising: an insulative housing forming a mating face for connecting to the modular chip, a jointing face for connecting to the circuit board, a plurality of engaging slots and holes defined between the mating face and the jointing face, the holes being located around the edges of the housing; a plurality of matrix type contacts received in the corresponding engaging slots and a plurality of solder balls planted on bottom ends of the contacts, the contacts being adapted to be soldered to the circuit board after undergoing a heating procedure; and a plurality of adjusting posts made of adhesive fusible material and fixed in the holes of the housing, at least a portion of each adjusting post extending outside of the housing and being adapted to be fixed to the circuit board after undergoing the heating procedure, the adjusting posts circumferentially enclosing the contacts of the electrical socket in a limited space and absorbing most of the fracture stress exerted on the solder balls by the socket and the circuit board when the socket is mounted to the circuit board and subject to a thermal load, thereby preventing misalignment between the contacts of the electrical socket and the circuit board.
Claim 6
Dependent Claim
18 words
The socket as claimed in claim 3 , wherein the adjusting posts are made of a thermoplastic material.
Claim 7
Independent Claim
182 words
A method for mounting an electrical socket to a circuit board, comprising the following steps: preparing an adjusting device made of thermoplastic material; preparing a circuit board having a corresponding plurality of contact pads and a positioning hole; preparing an electrical socket having a hole and a corresponding plurality of ball-grid-array (BGA) contacts with corresponding solder balls attached thereto, bringing the adjusting device to be received in the hole of the electrical socket, and positioning the socket together with the adjusting device to the circuit board to cause the contacts of the socket to contact the pads, and the adjusting device to engage the positioning hole of the circuit board; heating the socket together with circuit board to a temperature melting the solder balls and the adjusting device; solidifying the adjusting device so that it fixedly connects the socket and the circuit board together whereby a large portion of fracture stress which would be exerted on the solder balls during thermal loading due to different coefficients of thermal expansion of the socket and the circuit board is absorbed by the adjusting device.
Claim 8
Independent Claim
182 words
A method for mounting an electrical socket to a circuit board, comprising the following steps: preparing an adjusting device made of thermoplastic material; preparing a circuit board having a corresponding plurality of contact pads and a positioning hole; preparing an electrical socket having a hole and a corresponding plurality of ball-grid-array (BGA) contacts with corresponding solder balls attached thereto, bringing the adjusting device to be received in the hole of the electrical socket, and positioning the socket together with the adjusting device to the circuit board to cause the contacts of the socket to contact the pads, and the adjusting device to engage the positioning hole of the circuit board; heating the socket together with circuit board to a temperature melting the solder balls and the adjusting device; solidifying the adjusting device so that it fixedly connects the socket and the circuit board together whereby a large portion of fracture stress which would be exerted on the solder balls during thermal loading due to different coefficients of thermal expansion of the socket and the circuit board is absorbed by the adjusting device.
References Cited (Backward Citations)
US4206542A
Cited
US4774760A
Cited
US4873397A
Cited
US4836792A
Cited
US5046953A
Cited
US5046957A
Cited
US5417577A
Cited
US5462454A
Cited
US5800209A
Cited
US5492479A
Cited
US5834848A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-03-05 | 2004-09-04 | 2005-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-03-05 | 2008-09-04 | 2009-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-03-05 | 2012-09-04 | 2013-03-06 | $7700.00 | Window Closed / Lapsed |