Patent EP0813356A1 successfully refreshed from Google Patents.
EP0813356A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Hold-down collar for attachment of IC substrates and elastomeric material to PCBs
Assignee: Sun Microsystems Inc
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Filing: 1997-06-11
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Granted: —
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Expires: 2017-06-11
Abstract
Abstract A land grid array package (21) or a ball grid array package is electrically connected by means of an elastomeric type layer (26) containing alternating elements of conductive and non-conductive silicone, to a printed wire board (31) or motherboard. A hold-down collar (36) engages the peripheral edges (24) of the package (21) and snaps into holes (33) in the board (31) in such manner as to create pressure on the elastomeric layer (26), causing the layer (26) to compress and create through-going electrical paths between exposed lands (22) or conductive elements on the bottom of the package (21) and exposed conductive elements (32) on the wiring board (31). In one embodiment, solder balls adhere to the exposed conductive elements on the bottom of the package. In this embodiment the collar is initially in two pieces which are fitted together to engage both the top and bottom edges of the substrate.
Inventors
- 👤 Erich H. Selna
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 05:33
CPC Classifications
H; H05; H05K; H05K7/00; H05K7/02; H05K7/12; H05K3/00; H05K3/30; H05K3/32; H05K3/325
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
191 words
In combination an IC package (21) having an array of a plurality of conductive members (22) in a first array on its lower surface and having peripheral top edges (24), a layer (26) of soft elastomeric material formed with a plurality of conductive and non-conductive vertical elements beneath said package (21), a printed wire board (31) below said layer (26) having a plurality of conductive lands (32) in a second array on its upper surface, said board (31) underlying said layer (26) and being formed with hold-down collar engaging means (33), a hold-down collar (36) having in-turned flanges (37) engaging said top edges (24) of said package (21), legs (39) extending downward relative to said flanges (37) and having board-engaging means (41) cooperable with said collar-engaging means (33) to apply downward force to said flanges (37) and secure said collar (36) to said board (31), said collar (36) being vertically dimensioned so that when said collar (36) is secured to said board (31) said layer (26) is compressed and conductive elements (22) are exposed to establish electrical circuits between pluralities of said members (22) and corresponding pluralities of said lands (32).
Claim 2
Dependent Claim
23 words
The combination of claim 1, in which said layer (26) is formed with apertures (27), said legs (39) passing through said apertures (27).
Claim 3
Dependent Claim
27 words
The combination of claim 1 or 2, in which said package comprises a substrate (21) and encapsulating material (23) on an upper surface of said substrate (21).
Claim 4
Dependent Claim
38 words
The combination of any of the preceding claims, in which said board engaging means comprise prongs (41) on said legs (39) and said collar engaging means comprise apertures (33) in said board (31 to receive said prongs (41).
Claim 5
Dependent Claim
39 words
The combination of any of the preceding claims, in which each said conductive member (22) comprises a second land (22a) on the underside of said package (21a) and a ball of solder (46) adhered to said second land (22a).
Claim 6
Dependent Claim
36 words
The combination of any of the preceding claims, in which said collar (36, 36a) comprises a vertical skirt (38, 38a) depending from said flanges (37, 37a), said legs (39, 39a) depending from said skirt (38, 38a).
Claim 7
Dependent Claim
38 words
The combination of claim 6, in which said collar (36a) further combines second in-turned flanges (48) spaced below said first-mentioned flanges (37a) a distance substantially equal to the thickness of said package (21a) at said top edges (24a).
Claim 8
Dependent Claim
32 words
The combination of claim 7 in which said second in-turned flanges (48) have a thickness less than the distance between the underside of package (21a) and the upper surface of layer (26a).
Claim 9
Dependent Claim
52 words
The combination of claim 7 or 8, in which said collar (36a) is initially formed in at least two pieces and re-assembled together surrounding said package (21a), said first-mentioned flanges (37a) engaging said package (21a) above said top edges (24a) and said second flanges (48) engaging the bottom of said package (21a).
Claim 10
Dependent Claim
27 words
The combination of any of claims 6 to 9, in which said package (21, 21a), said layer (26, 26a) and said collar (36, 36a) are substantially rectangular.
Claim 11
Dependent Claim
48 words
A hold-down collar (36) for attaching an IC package and an underlying layer (26) of elastomeric material to a printed wire board (31) comprising an in-turned flange (37), legs (39) extending downward relative to said flange (37) and printed wire board engaging means (41) on said legs (39).
Claim 12
Dependent Claim
25 words
The collar of claim 11, which further comprises a vertical skirt (38) depending from said flange (37), said legs (39) depending from said skirt (38).
Claim 13
Dependent Claim
21 words
The collar of claim 11, in which said board engaging means comprises prongs (41) adjacent lower ends of said legs (39).
Claim 14
Dependent Claim
19 words
The collar of claim 11, which further comprises a second in-turned flange (48) spaced below said first-mentioned flange (37).
Claim 15
Dependent Claim
19 words
The collar of claim 14, which collar (36a) is initially formed in at least two pieces and re-assembled together.
Claim 16
Dependent Claim
16 words
The collar of claim 11, in which said flange (37, 37a) is substantially rectangular a horizontal.
References Cited (Backward Citations)
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