Browse Prior Art Database

Mold Wall Shaped to Produce Flat Meniscus

IP.com Disclosure Number: IPCOM000109483D
Original Publication Date: 1992-Aug-01
Included in the Prior Art Database: 2005-Mar-24
Document File: 1 page(s) / 40K

Publishing Venue

IBM

Related People

Buchwalter, SL: AUTHOR [+5]

Abstract

Disclosed is a design for an open gravity-levelled mold that produces a flat surface despite the presence of a non-perpendicular wetting angle between the mold wall and the molding material.

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Mold Wall Shaped to Produce Flat Meniscus

      Disclosed is a design for an open gravity-levelled mold that
produces a flat surface despite the presence of a non-perpendicular
wetting angle between the mold wall and the molding material.

      The problem is to encapsulate electronic components using a
gravity-levelled open mold in such a way that there is no positive
meniscus formed.  The molded surface is to be flat without protruding
edges.  If the wetting angle between the encapsulation material and
the mold material is less than ninety degrees, the meniscus formed
produces upwardly protruding edges.

      The solution to the problem is to slant the wall of the mold in
such a manner that the slant angle of the wall is equal to the
wetting angle formed.  The result is a flat surface.  Alternatively,
the mold may have vertical walls up to a level just below that of the
filling level of the mold.  From this point to a point above the
filling level, the walls are slanted at an angle equal to the wetting
angle in order to produce the desired effect.

      Disclosed anonymously.