Browse Prior Art Database

Solder-Bump Process by Multi-Source

IP.com Disclosure Number: IPCOM000106150D
Original Publication Date: 1993-Oct-01
Included in the Prior Art Database: 2005-Mar-20
Document File: 2 page(s) / 53K

Publishing Venue

IBM

Related People

Miyamoto, R: AUTHOR [+2]

Abstract

Disclosed is a process for the deposition of solder-bump metals by using multi-source set in evaporator (FIG.1). Multi-source (some kinds of metals) is simultaneously evaporated by RF induction heating to create solder-bump on the wafer.

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Solder-Bump Process by Multi-Source

      Disclosed is a process for the deposition of solder-bump metals
by using multi-source set in evaporator (FIG.1).  Multi-source (some
kinds of metals) is simultaneously evaporated by RF induction heating
to create solder-bump on the wafer.

Not only does this process bring the possibility of various
bump-metal com-position, but it can realize the reduction of 'reflow
process' for bump m-etals mixture because the bump does not have the
boundary (by each melting temperature) of each metal (FIG.2).

The actual use of this proposed process (evaporator) for example is
as follows.

   1.  When two sources are used.
      (a) Appropriate volume of Lead and Tin are prepared in
          the two melting pots respectively.  Each metal is
          simultaneously evaporated by RF induction heater
          under the following evaporation-rate.   The metal
          composition of the finished bump is a solder-bump
          (97%Lead/3%Tin) and the bump melting temperature is
        around 315 degree C.

      Evaporation-rate, Lead : Tin = 97 : 3 (wt%)

     (b) Lead and Tin are prepared in the two melting pots,
         and each metal is evaporated by RF induction heater
         in the same manner (a) which is mentioned above.
         But, when the evaporation-rate is changed as
         follows in the middle of the process, the finished
...