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Alignment Technique by Cu Etching for Solder Attaching Chips To TAB

IP.com Disclosure Number: IPCOM000120449D
Original Publication Date: 1991-Apr-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 1 page(s) / 34K

Publishing Venue

IBM

Related People

Ameen, JG: AUTHOR [+4]

Abstract

As Tape Automated Bonding (TAB) Technology becomes more dense, solder attaching of the chips to the TAB tape becomes very desirable. To accomplish this, a method of aligning and attaching the chip to TAB film has been developed and is defined below. 1. The thin film tape is designed to have three or more leads that occupy the area of two leads. Four sharp points are etched into these leads (Figure 1) to align and hold the chip in position for soldering. 2. The chip is placed into the three or more depressions. Using a preset load, the chip is pressed so that the supported leads slightly nick the solder ball. The other leads are deflected by the other solder balls to guarantee contact. Flux will also help hold the leads in place. 3. The solder is reflowed using a thermode, oven, or vapor phase process. 4.

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Alignment Technique by Cu Etching for Solder Attaching Chips To TAB

      As Tape Automated Bonding (TAB) Technology becomes more dense,
solder attaching of the chips to the TAB tape becomes very desirable.
To accomplish this, a method of aligning and attaching the chip to
TAB film has been developed and is defined below.
   1.   The thin film tape is designed to have three or more leads
that occupy the area of two leads.  Four sharp points are etched into
these leads (Figure 1) to align and hold the chip in position for
soldering.
   2.   The chip is placed into the three or more depressions.  Using
a preset load, the chip is pressed so that the supported leads
slightly nick the solder ball. The other leads are deflected by the
other solder balls to guarantee contact.  Flux will also help hold
the leads in place.
   3.   The solder is reflowed using a thermode, oven, or vapor phase
process.
   4.   The chip is then encapsulated by methods commonly employed in
the industry.

      Disclosed anonymously.