Claims
- 1. A method for forming solder contact on contacts areas of ball grid array semiconductor devices, comprising the steps of:pre heating a semiconductor substrate; applying an adhesive solder paste to a sheet of solder material; punching from said sheet of solder material directly onto contact areas on a semiconductor substrate a plurality of solder forms; such that said paste holds the solder forms in place; and then reflowing the solder forms by the application of heat to form solder contacts on the semiconductor substrate.
- 2. The method according to claim 1, wherein the reflow of the solder is done in a N2 atmosphere.
- 3. The method according to claim 1, wherein a solder flux is applied to the contact areas prior to punching the solder forms onto the substrate.
- 4. The method according to claim 1, wherein the substrate is preheated to a temperature in the range of 150 to 225 degrees C.
- 5. The method according to claim 1, wherein the solder sheet is of solder selected from 63/37 SnPb or 90/10 Sn/Pb solder composition.
- 6. The method according to claim 1, wherein the substrate and solder forms are subjected to a reflow for a period of 3½ minutes to 5½ minutes.
Parent Case Info
This application claim benefit to provisional application Ser. No. 60/082,312 Nov. 27, 1996 and claim benefit to provisional application Ser. No. 60/033,160 Dec. 13, 1996.
US Referenced Citations (6)
Provisional Applications (2)
|
Number |
Date |
Country |
|
60/082312 |
Nov 1996 |
US |
|
60/033160 |
Dec 1996 |
US |