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Process for Precision Punching of Multi-Layer Laminates

IP.com Disclosure Number: IPCOM000112849D
Original Publication Date: 1994-Jun-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 40K

Publishing Venue

IBM

Related People

Haskell, R: AUTHOR [+4]

Abstract

Disclosed here is a process to Punch Precision Diameter Holes in a Multi-Layer Laminate such as a printed circuit board but not limited to printed circuit boards. These holes are primarily used as a means of locating and registering the laminate in fixturing devices. The process contains two steps whereby a rough diameter hole is prepunched in the laminate, shown as a 0.125 inch diameter hole in Fig. 1B but not limited to that specific diameter. The second step of the operation is to optically locate the laminate with respect to a set of larger diameter precision punches and shave out the prepunched hole, shown in Fig. 1B as a 0.1585 inch diameter but not limited to that diameter.

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Process for Precision Punching of Multi-Layer Laminates

      Disclosed here is a process to Punch Precision Diameter Holes
in a Multi-Layer Laminate such as a printed circuit board but not
limited to printed circuit boards.  These holes are primarily used as
a means of locating and registering the laminate in fixturing
devices.  The process contains two steps whereby a rough diameter
hole is prepunched in the laminate, shown as a 0.125 inch diameter
hole in Fig.  1B but not limited to that specific diameter.  The
second step of the operation is to optically locate the laminate with
respect to a set of larger diameter precision punches and shave out
the prepunched hole, shown in Fig. 1B as a 0.1585 inch diameter but
not limited to that diameter.  Optically locating punch machines that
can precisely locate the laminate to be punched are commonly
available in the printed circuit board industry.  The shaved hole
exhibits an extremely consistent diameter top to bottom through the
laminate.  The shear portion of the hole wall increases from near 30%
for a single one time punch operation as seen in Fig. 1A to near 100%
for the new punch process as seen in Fig. 1B.  In practice this
technique has produced holes with the following diameter tolerances.

               Expected Diameter             0.1585  inch

               Average Measured Diameter     0.1585  inch

               Standard Deviation       ...