...
US005302801A
United States Patent [19] [ii] Patent Number: 5,302,801
Kanda et al. [45] Date of Patent: Apr. 12,1994
[54] LASER BONDING APPARATUS
[75] Inventors: Makoto Kanda; Masaharu Yoshida,
both of Fukuoka, Japan
[73] Assignee: Mitsubishi Denki Kabushiki Kaisha,
Tokyo, Japan
[21] Appl. No.: 66,259
[22] Filed: May 25,1993
Related U.S. Application Data
[62] Division of Ser. No. 780,495, Oct. 22, 1991, Pat. No. 5,250,781.
[30] Foreign Application Priority Data
Nov. 16, 1990 [JP] Japan 2-312194
[51] Int. CI.* B23K 26/00
[52] U.S. Q 219/121.63; 219/121.84
[58] Field of Search 219/121.63, 121.64,
219/121.84
[56] References Cited
U.S. PATENT DOCUMENTS
3,304,403 2/1967 Harper 219/121.63
3,383.491 5/1967 Munchergan 219/121.63
3,463,898 8/1969 Takaoka et al 219/121.63
4,906,812 3/1990 Nied et al 219/121.63
5,194,710 3/1993 McDaniel et al 219/121.63
5,227,604 7/1993 Freedman 219/121.63
FOREIGN PATENT DOCUMENTS
3238350A1 7/1982 Fed. Rep. of Germany . 3701013C2 3/1987 Fed. Rep. of Germany .
A bonding apparatus comprises a base (16) for supporting a printed circuit board (7), an atmosphere cover (1) which has a concavity (lc) covering a semiconductor device (5) mounted on the printed circuit board (7) and which is formed of laser light transmitting material, driving means (If) for moving the atmosphere cover (1) upwards and downwards related to the base (16), pressing means (2) and (3) provided in the atmosphere cover (1) for pressing the semiconductor device (5) toward the printed circuit board (7), and laser heating means (9) for bonding a lead terminal (6) of the semiconductor device (5) with a junction (la) of the printed circuit board (7). The laser heating means (9) irradiates laser light (9a) through the atmosphere cover (1) to bonding agent (8) applied between a junction (6a) of the lead terminal (6) of the semiconductor device (5) and the junction (7a) of the printed circuit board (7), and heats and fuses the bonding agent (8) to bond both the junctions without touching the junctions thereof. Also, inside the atmosphere cover (1), atmosphere gas supplying means (Id), (le), (If) and (Ig) are provided for supplying atmosphere gas, (4) which is employed for preventing oxidation in the bonding.
7 Claims, 3 Drawing Sheets
