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EP0432361A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Strain relief flip-chip integrated circuit assembly with test fixturing

Assignee: HP Inc
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Filing: 1990-08-08
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Granted: —
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Expires: 2010-08-08
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Abstract

Abstract A multi-chip, self-aligning, integrated circuit flip-chip assembly (300) using flexible connection assemblies (400) for its attachment is enclosed in an integrated circuit package (100). The connection assembly (400) contains connection pillars (376) which are attached to die (104) and carrier wafer (102) by means of flexible membranes (370) covering cavities (368). Each pillar consists of two opposing connection posts, (222) of die (104) and (216) of carrier wafer (102), joined by solder bump (228). A post is formed by etching a ring into the dielectric around predefined metal islands (342 or 226, 346, 348 and 350) provided by the process, which are interconnected by vias (354, 356 and 358) respectively to form conductive core (374). The conductive path established between first layer metal interconnects (342) and (226) via connection pillars (376) furnishes the electrical interface between chip and carrier in the flip chip arrangement. Flexure of the membranes allowed by the air filled cavities enables connection pillars (376) to tilt, so as to relieve the assembly of shear strain when subjected to differential thermal expansion. A membrane prober (500), using test metal bumps (582) in place of solder joints (228) but which is otherwise identical to flip-­chip assembly (300), can be interfaced with a tester to perform conventional vector testing of individual chips (104) or complete multi-chip assemblies. Alternatively, test assemblies with metal bumps can be configured as "system-emulators" for testing individual production chips, by providing a test environment that accurately represents the full system. This test method dispenses with the many technical drawbacks and high costs associated with conventional vector testing, including the loading by the low tester impedance.

Inventors

  • 👤 Dirk J. Bartelink

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-08 14:39
CPC Classifications
H; H10; H10W; H10W72/00; H10W72/20; H10W72/071; H10W72/072; H10W72/07231; H10W72/07236; H10W72/251; H10W72/252

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 130 words
An integrated circuit assembly (300) comprising: an integrated circuit carrier (102); at least one integrated circuit chip (104) in a flip-chip arrangement relative to said carrier; a connection pillar (376) electrically and mechanically connecting said carrier and said chip, said connection pillar having an axis defining an axial direction, said pillar spacing said chip and said carrier in said axial direction; and flexible attachment means for attaching said pillar to at least one element of the set consisting of said carrier and said chip so that said pillar can move in said axial direction and tilt with respect to said axial direction; whereby, when said carrier and said chip undergo differential thermal expansion said pillar moves to reduce shear strain in planes orthogonal to said axial direction along said pillar.
Claim 2
Dependent Claim 130 words
An integrated circuit assembly (300) comprising: an integrated circuit carrier (102); at least one integrated circuit chip (104) in a flip-chip arrangement relative to said carrier; a connection pillar (376) electrically and mechanically connecting said carrier and said chip, said connection pillar having an axis defining an axial direction, said pillar spacing said chip and said carrier in said axial direction; and flexible attachment means for attaching said pillar to at least one element of the set consisting of said carrier and said chip so that said pillar can move in said axial direction and tilt with respect to said axial direction; whereby, when said carrier and said chip undergo differential thermal expansion said pillar moves to reduce shear strain in planes orthogonal to said axial direction along said pillar.
Claim 3
Dependent Claim 37 words
The assembly of Claim 1 wherein said connection pillar comprises a first post (222) attached to said carrier, a second post (216) attached to said chip, and a solder bump (228) attaching said first and second posts.
Claim 4
Dependent Claim 26 words
The assembly of Claim 1 or 2 wherein said flexible attachment means provides for flexibly attaching said pillar to both of said carrier and said chip.
Claim 5
Dependent Claim 35 words
The assembly of Claim 1, 2 or 3 wherein said flexible attachment means includes a cavity (368) formed in said element and a flexible membrane (370) formed over said cavity and attaching to said pillar.
Claim 6
Independent Claim 66 words
A method of fabricating an integrated assembly (300), said method comprising: attaching a pillar (376) to an integrated circuit (102) and an integrated circuit chip (104) in a flip-chip arrangement so that said carrier and said chip are spaced by said pillar, said attaching involving a flexible joint between said pillar and at least one element of the set consisting of said carrier and said chip.
Claim 7
Independent Claim 66 words
A method of fabricating an integrated assembly (300), said method comprising: attaching a pillar (376) to an integrated circuit (102) and an integrated circuit chip (104) in a flip-chip arrangement so that said carrier and said chip are spaced by said pillar, said attaching involving a flexible joint between said pillar and at least one element of the set consisting of said carrier and said chip.
Claim 8
Independent Claim 68 words
A method of fabricating an integrated circuit assembly (300), said method comprising the steps of: forming cavities (368) in an integrated circuit chip (104) and an integrated circuit carrier (102); forming membranes (370) over said cavities; forming posts (222 and 216) over respective said membranes; and soldering at least one of said posts formed on said carrier to at least one of said posts formed on said chip.
Claim 9
Independent Claim 68 words
A method of fabricating an integrated circuit assembly (300), said method comprising the steps of: forming cavities (368) in an integrated circuit chip (104) and an integrated circuit carrier (102); forming membranes (370) over said cavities; forming posts (222 and 216) over respective said membranes; and soldering at least one of said posts formed on said carrier to at least one of said posts formed on said chip.
Claim 10
Independent Claim 118 words
A method of fabricating a membrane prober assembly (500), said method comprising the steps of: forming a cavity (368) in an integrated circuit chip (104); forming a membrane (370) over said cavity; forming a post (216) over said membrane of said chip; forming a cavity (568) in an integrated circuit test carrier (502); forming a membrane (570) over said cavity of said test carrier; forming a post (522) over said membrane of said test carrier; forming a test post (584) consisting of said post of said test carrier and a test bump (582); and engaging at least one of said posts formed on said chip with at least one of said test posts formed on said test carrier.
Claim 11
Independent Claim 118 words
A method of fabricating a membrane prober assembly (500), said method comprising the steps of: forming a cavity (368) in an integrated circuit chip (104); forming a membrane (370) over said cavity; forming a post (216) over said membrane of said chip; forming a cavity (568) in an integrated circuit test carrier (502); forming a membrane (570) over said cavity of said test carrier; forming a post (522) over said membrane of said test carrier; forming a test post (584) consisting of said post of said test carrier and a test bump (582); and engaging at least one of said posts formed on said chip with at least one of said test posts formed on said test carrier.

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