United States Patent   Patent Number: 5,201,451
Desai et al.  Date of Patent: Apr. 13,1993
 METHOD AND APPARATUS FOR MOUNTING A FLEXIBLE FILM SEMICONDUCTOR CHIP CARRIER ON A CIRCUITIZED SUBSTRATE
 Inventors: Kishor V. Desai, Vestal; Nelson P.
Franchak, Binghamton; Robert H.
Katyl, Vestal; Harold Kohn,
Endwell; Endwell; Tamar A. Sholtes,
Endicott, all of N.Y.; Vilakkudi G.
Veeraraghavan, Lexington, Ky.;
Charles G. Woychik, Endicott, N.Y.
 Assignee: International Business Machines
Corp., Annonk, N.Y.
 Appl. No.: 727,047
 Filed: Jul. 9,1991
Related U.S. Application Data
 Division of Ser. No. 644,528, Jan. 23, 1991, which is a division of Ser. No. 365,326, Jun. 13, 1989, Pat. No. 5,159,535, which is a continuation of Ser. No. 24,499, Mar. 11, 1987, abandoned.
 Int.C1.5 B23K 37/00
 U.S. CI 228/5.5; 228/44.7
 Field of Search 228/44.7, 106, 180.2,
228/212, 5.5; 269/903, 43
 References Cited
U.S. PATENT DOCUMENTS
3,948,429 4/1976 Davies et al 219/85.16
4,255,644 3/1981 Delonne 219/85.16
4,300,715 11/1981 Keizer et al 219/85.16
4,371,912 2/1983 Guzik 228/180.2
4,607,779 8/1986 Burns 228/106
4.638.937 1/1987 Belanger 228/5.5
4.638.938 1/1987 Yarne et al 228/180.2
Method and apparatus are disclosed for mounting a flexible film semiconductor chip carrier on a second level electronic package. The resulting electronic packaging structure includes electrically conductive spacers, such as solder balls or solder coated copper balls, which electrically interconnect outer lead bonding pads on the flexible film semiconductor chip carrier and corresponding bonding pads on the second level electronic package, and which physically support the flexible film of the semiconductor chip carrier substantially in a plane above the surface of the second level electronic package. This electronic packaging structure is made using a special assembly fixture comprising a base plate, a pressure insert with a resilient member, and a top plate. The flexible film semiconductor chip carrier with the spacers attached thereto is placed over the resilient member of the pressure insert which is clamped together with the second level electronic package between the top and base plates Then, this assembly is heated to reflow the solder of the spacers, and the assembly fixture is disassembled,; leaving the flexible film semiconductor chip carrier mounted on the second level electronic package with the flexible film of the carrier having a planar geometry as desired.
7 Claims, 4 Drawing Sheets