US6735857B2
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of mounting a BGA
Assignee: Toshiba Corp
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Filing: 2001-08-17
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Granted: 2004-05-18
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Expires: 2021-08-17
Abstract
Abstract Solder paste is applied beforehand onto through-hole upper lands (or solder) of a printed circuit board and attachment is effected by inserting solder joined to the BGA-side pads into the holes of the through-hole upper lands; solder and solder paste are then melted by heating, causing them to flow into the through-holes and to wet and spread out upon the through-hole bottom face lands, thereby effecting a soldered joint with the BGA-side pads and through-hole upper lands securely attached, and forming solder fillets. In this way, the quality of the solder joints can be ascertained by an ordinary external inspection method.
Inventors
- 👤 Yuji Saito
- 👤 Kozo Fukuzawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 11:25
CPC Classifications
H; H05; H05K; H05K1/00; H05K1/02; H05K1/0201; H05K1/0203; H05K1/0204; H05K1/0206; H05K3/00; H05K3/30; H05K3/32; H05K3/34; H05K3/341; H05K3/3431; H05K3/3436; H05K1/0266; H05K1/0269; H05K2201/00; H05K2201/09; H05K2201/09209; H05K2201/095; H05K2201/09572; H05K2201/10; H05K2201/10613; H05K2201/10621; H05K2201/10734; H05K2201/10954; H05K2201/10969; H05K2203/00; H05K2203/04; H05K2203/0455; H05K3/3465; H05K3/3485; H05K3/40; H05K3/42; H10; H10W; H10W74/00; H10W90/00; H10W90/701; H10W90/751; H10W90/754; Y; Y02; Y02P; Y02P70/00; Y02P70/50; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49124; Y10T29/4913; Y10T29/49144; Y10T29/49147; Y10T29/49149; Y10T29/49155; Y10T29/49165; Y10T29/49174; Y10T29/49179
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
192 words
A ball grid array mounting method, in which a ball grid array is soldered onto a printed circuit board comprising: (a) applying solder paste beforehand onto at least one of a plurality of lands of a printed circuit board which are in a position of through-holes of said printed circuit board and a plurality of solder balls of said ball grid array which are connected with pads of said ball grid array; (b) attaching and superimposing said through-holes of said printed circuit board and said solder balls of said ball grid array; (c) melting said solder bails and said solder paste by heating both said ball grid array and said printed circuit board, to flow into said through-holes, to be led into through-hole bottom face lands which said solder balls and said solder paste wet and where said solder balls and said solder paste spread out; and (d) sticking and effecting said pads of said ball grid array securely together with said lands of said printed circuit board, which are in the positions of said through-holes of said printed circuit board, whereby solder fillets are formed on said through-hole bottom face lands.
Claim 2
Dependent Claim
192 words
A ball grid array mounting method, in which a ball grid array is soldered onto a printed circuit board comprising: (a) applying solder paste beforehand onto at least one of a plurality of lands of a printed circuit board which are in a position of through-holes of said printed circuit board and a plurality of solder balls of said ball grid array which are connected with pads of said ball grid array; (b) attaching and superimposing said through-holes of said printed circuit board and said solder balls of said ball grid array; (c) melting said solder bails and said solder paste by heating both said ball grid array and said printed circuit board, to flow into said through-holes, to be led into through-hole bottom face lands which said solder balls and said solder paste wet and where said solder balls and said solder paste spread out; and (d) sticking and effecting said pads of said ball grid array securely together with said lands of said printed circuit board, which are in the positions of said through-holes of said printed circuit board, whereby solder fillets are formed on said through-hole bottom face lands.
Claim 3
Dependent Claim
83 words
The ball grid array mounting method according to claim 1 , wherein a total amount of solder obtained by adding a solder and a solder paste required for solder joining of said ball grid array pads and said lands of said printed circuit board which are in the positions of said through-holes of said printed circuit board is an amount greater than a through-hole volume and less than said through-hole volume plus a solder volume of hemispheres on said through-hole bottom face lands.
Claim 4
Dependent Claim
48 words
The BGA mounting method according to claim 1 , wherein a ground layer pattern is provided in a position of said printed circuit board corresponding to a position of a silicon chip of said BGA, and said BGA body and said ground layer pattern are securely stuck together.
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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) | 2007-05-18 | 2007-11-17 | 2008-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2011-05-18 | 2011-11-17 | 2012-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2015-05-18 | 2015-11-17 | 2016-05-18 | $7700.00 | Window Closed / Lapsed |