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Punch for Circuit Board Materials

IP.com Disclosure Number: IPCOM000091541D
Original Publication Date: 1968-Mar-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 42K

Publishing Venue

IBM

Related People

Byrnes, HP: AUTHOR [+2]

Abstract

Drawings A, B, and C show a device for punching holes in circuit board materials such as epoxy-glass weaves. Drawing D shows a cross-section of the punching action through a circuit board material. In order to implement punching action, the punch can be mounted as the tip of a conventional punch or can be used as a projectile shot from a high-velocity projector.

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Punch for Circuit Board Materials

Drawings A, B, and C show a device for punching holes in circuit board materials such as epoxy-glass weaves. Drawing D shows a cross-section of the punching action through a circuit board material. In order to implement punching action, the punch can be mounted as the tip of a conventional punch or can be used as a projectile shot from a high-velocity projector.

The punch is shaped with a frustum of a cone portion 1 attached to cylindrical portion 2 where the cylindrical portion diameter OD is greater than the cone portion diameter ID. The OD is .043 inch and the ID is .040 inch for example. For a .010 inch hole, the OD is that dimension which in turn is approximately 10% to 20% greater than the ID. Cone portion 1 has a neck which meets concave openings 4 in portion 2 along plane 6-6'. The neck diameter is less than the ID diameter. Openings 4 form a cutting edge 5 along the perimeter of portion 2 at the plane 6-6'.

Drawing D shows punching through a circuit board. The punching action of cone portion 1 leaves an initial hole with a relatively rough surface 8. The cutting or punching action of the cylinder via the knife-edge 5 shaves down surface 8 forming the final OD dimension with a smooth surface 9. Because of the reduced diameter of the portion 1 neck, clearance room between surface 8 and that neck exists. The clearance room collects the circuit board material shaved by knife- edge 5 and prevents that material from abrasively...