Microelectronic component mounting with deformable shell terminals

• US 5,971,253 A
• Filed: 12/27/1996
• Issued: 10/26/1999
• Est. Priority Date: 07/31/1995
• Status: Expired due to Term

• Current Assignee: Tessera, Inc. (Adeia, Inc.)
• Original Assignee: Tessera, Inc. (Adeia, Inc.)
• Inventors: Karavakis, Konstantine, Gilleo, Kenneth B.
• Primary Examiner(s): Ryan, Patrick
• Assistant Examiner(s): STONER, KILEY SHAWN
• Application Number:
  US08/777,307
• Time in Patent Office: 1,033 Days
• Field of Search: 228/180.22, 228/189, 228/56.3, 228/104, 438/119, 438/612, 438/613, 438/614, 438/615, 438/616, 438/617, 257/737, 257/738, 257/747, 257/748, 257/773, 174/261, 174/260, 361/762, 361/767, 361/768, 361/771
• US Class Current: 228/180.22
• CPC Class Codes: H01L 23/49827 Via connections through the substrates, e.g. pins going through the substrate, coaxial cables H01L23/49822, H01L23/49833, H01L23/4985, H01L23/49861 take precedence
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2924/3011 Impedance
• CPC Class Codes: H05K 3/3436 having an array of bottom contacts, e.g. pad grid array or ball grid array components

Abstract

A microelectronic element assembly such as a semiconductor chip assembly uses a connection component incorporating a dielectric sheet with electrically conductive elements therein. Each electrically conductive element may include a flexible shell. The flexible shells can be formed to assure reliable engagement with mating contact pads.

Claims

1. A method of making a semiconductor chip assembly comprising the steps of:

(a) providing a plurality of deformable electrically conductive elements, each including a thin, flexible metallic shell extending over at least a portion of the surface of the conductive element, and mounting said conductive elements to contacts on a chip so that the metallic shells are exposed;

then

(b) connecting the chip to a substrate by metallurgically bonding the conductive elements to contact pads on the substrate.

2. A method of making a semiconductor chip assembly comprising the steps of:

(a) providing a plurality of deformable electrically conductive elements, each including a thin, flexible metallic shell extending over at least a portion of the surface of the conductive element, and mounting said conductive elements to contacts on a chip so that the metallic shells are exposed;

then

(b) connecting the chip to a substrate by bonding the conductive elements to contact pads on the substrate; and

(c) testing the chip prior to said connecting step by forcibly engaging contact pads with the exposed metallic shells and applying test signals to the chip through the engaged probes and shells, at least some of said shells being deformed during said engagement step.

3. A method of making a semiconductor chip assembly comprising the steps of:

(a) providing a plurality of deformable electrically conductive elements, each including a thin, flexible metallic shell extending over at least a portion of the surface of the conductive element, and mounting said conductive elements to contacts on a chip so that the metallic shells are exposed;

then

(b) connecting the chip to a substrate by bonding the conductive elements to contact pads on the substrate; and

(c) testing the chip prior to said connecting step by forcibly engaging contact pads with the exposed metallic shells and applying test signals to the chip through the engaged probes and shells, at least some of said shells being deformed during said engagement step, wherein each said shell is in the form of a hollow spheroid.

4. A method as claimed in claim 3 wherein each said conductive element includes a polymeric material within the spheroidal shell.

5. A method as claimed in claim 3 wherein each said hollow spheroid is empty.

6. A method as claimed in claim 3 wherein said step of mounting the conductive elements to the contacts on the chip includes the step of forming a metallurgical bond between the shells and the contacts of the chip before said testing step.

7. A method as claimed in claim 6 wherein said step of forming a metallurgical bond is performed by soldering, brazing, diffusion bonding, or eutectic bonding.

8. A method as claimed in claim 3 wherein said step of mounting said conductive elements on said chip includes the step of placing a dielectric sheet having a first surface, a second surface and holes extending between said surfaces in a pattern corresponding to the pattern of contacts on said chip onto the chip so that one hole is aligned with each said contact.

9. A method as claimed in claim 8 wherein said spheroidal shells are disposed within the holes of said sheet before the sheet is placed onto the chip.

10. A method as claimed in claim 9 wherein each spheroidal shell protrudes from the first surface of the sheet, whereby each spheroidal shell bears on one said contact of the chip when the sheet is placed onto the chip.

11. A method of making a semiconductor chip assembly comprising the steps of:

(a) providing a plurality of deformable electrically conductive elements, each including a thin, flexible metallic shell extending over at least a portion of the surface of the conductive element, and mounting said conductive elements to contacts on a chip so that the metallic shells are exposed;

then

(b) connecting the chip to a substrate by bonding the conductive elements to contact pads on the substrate; and

(c) testing the chip prior to said connecting step by forcibly engaging contact pads with the exposed metallic shells and applying test signals to the chip through the engaged probes and shells, at least some of said shells being deformed during said engagement step wherein each said conductive element includes a mass of an electrically conductive bonding material, said mounting step being performed so as to position the mass of bonding material of each conductive element between the shell of such conductive element and the contact of the chip.

12. A method as claimed in claim 11 wherein said mounting step includes the step of providing each said mass of conductive material in a flowable condition and depositing each said shell onto one such mass.

13. A method as claimed in claim 11 wherein said mounting step includes the step of providing a sheet having oppositely-directed first and second surfaces and having holes in a predetermined pattern corresponding to the pattern of contacts on said chip extending between said first and second surfaces, and having a mass of soft conductive material disposed within each said hole, and placing said sheet on the chip so that the first surface of the sheet faces toward the chip and so that the soft conductive material in each said hole touches one said contact.

14. A method as claimed in claim 13 wherein said sheet has one said shell disposed in each said hole and exposed at the second surface prior to said step of placing the sheet on the chip.

15. A method as claimed in claim 13 further comprising the step of curing said soft conductive material to form a permanent electrical connection between each contact and the associated shell.

16. A method as claimed in claim 11 wherein each said mass of electrically conductive material includes an electrically conductive, polymer-containing composition.

17. A method of making a semiconductor chip assembly comprising the steps of:

(a) providing a plurality of deformable electrically conductive elements, each including a thin, flexible metallic shell extending over at least a portion of the surface of the conductive element, and mounting said conductive elements to contacts on a chip so that the metallic shells are exposed;

then

(b) connecting the chip to a substrate by metallurgically bonding the conductive elements to contact pads on the substrate; and

then

(c) injecting a dielectric encapsulant between the chip and the substrate.

18. A method as claimed in claim 17 further comprising curing the encapsulant to form a permanent environmental seal between the chip and the substrate.

19. A method as claimed in claim 18 wherein said cured encapsulant forms an elastomer or a gel.