HOLE
AND BLIND HOLE FILLING METHOD
Description
:
The void-free filling of through or blind holes presenting
an important aspect ratio (depth/diameter) with a liquid or
a pasty product is always critical. The air entrapped in the
blind hole or in the cavity constitutes an obstacle to the
filling and a low viscous product will require a high pressure
to be sheared in a small aperture. In the prior art, some
vacuum injection machines have been developed. Those existing
equipments are constituted by a vacuum chamber in which the
device to be filled and the injection system are confined.
The drawbacks of those equipments are their cost and complexity
compared to their low throughput.
Innovative
aspects :
The technology can be fitted on existing stencil printers.
The said technology is constituted by a specific transfer
head which replaces the traditional squeegees and which slides
across the transfer stencil or directly atop the substrate
to be filled. Compared to the existing systems that process
shows a very high throughput and reliability level in addition
to its low equipment cost.
Advantages
:
The technology is particularly suited to plug holes
or blind holes on a substrate with conductive or insulating
ink or paste in a collective manner.
Applications in the printed circuit board area to plug through,
blind or buried holes can be foreseen. But the process could
also be used in the microelectronic area to encapsulate or
to underfill the dies. The transfer head according to the
present innovation can, of course, be adapted in relation
with the different applications.
Current stage
of development :
Available for demonstration in our lab and currently in use
for a specific application in the space industry. You can
find more information on the utilisation of this technology
on the Micropyros project on the Micropyros website:
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