Ball Grid Array and Column Grid Array Module Solder Paste Fixtures / Handlers
Original Publication Date: 1994-Jun-01
Included in the Prior Art Database: 2005-Mar-27
Isaacs, PD: AUTHOR [+3]
Disclosed is a Ball Grid Array (BGA) and a Column Grid Array (CGA) module fixture to facilitate solder paste screening with ease of handling.
Ball Grid Array and Column Grid Array Module Solder Paste
Fig. 1 displays the following:
A BGA and CGA module solder paste fixture/handler
B Module solder stencil template
C BGA or CGA module cavity
D BGA or CGA module retainer
E Module retainer spring
F Locating holes
G Material removed for weight reduction
a Ball Grid Array (BGA) and a Column Grid Array
(CGA) module fixture to facilitate solder paste screening with ease
BGA and CGA module solder paste fixtures have the following features:
o The fixtures
utilize the BGA/CGA Module solder stencil template
with the following advantages:
- The template supports the solder paste
stencil to prevent
sagging of the stencil to all for more consistent screening
of solder paste.
- The template thickness supports the stencil
in such a way
that the solder volume that is actually screened correlates
to the solder volume that would be screened with a much
thicker stencil without the corresponding problem of plugging
the stencil openings that are associated with thicker
- The thickness of, and the opening in, the
stencil and the
thickness of the template are optimized to provide the proper
solder paste volume.
- The template provides support such that the
volume of solder
paste deposited has a much tighter variance in volume
distribution and the solder paste deposit is better defined.
- The ratio of the template opening and
remaining web between
holes is optimized to adequately support the solder paste
stencil and small enough not to remove or smear solder paste
when the module and template are separated.
- The template prevents the solder stencil
from touching the
solder balls or solder columns and therefore also prevents
the stencil from damaging the solder balls or solder columns
Fig. 2 displays the following:
A Module solder stencil template...