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Punch Design for Magnetic Punch

IP.com Disclosure Number: IPCOM000036716D
Original Publication Date: 1989-Oct-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 2 page(s) / 56K

Publishing Venue

IBM

Related People

Long, DC: AUTHOR [+2]

Abstract

A modification has been proposed for the punch heads used for punching green sheets used in multilayer ceramic (MLC) semiconductor devices. The proposal calls for coining of the normally flat punchhead which results in an extended operating life and improved performance of the punch.

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Punch Design for Magnetic Punch

A modification has been proposed for the punch heads used for punching green sheets used in multilayer ceramic (MLC) semiconductor devices. The proposal calls for coining of the normally flat punchhead which results in an extended operating life and improved performance of the punch.

A magnetic punch operating satisfactorily when punching thin green sheets experienced difficulty when used with thicker sheets. Drive power was increased because of the thicker sheets, and this damaged the normally flat disk head, as shown in Fig. 1, and caused the head to be bent, as shown in Fig. 2. With the disk bent, the magnetic coupling between it and the drive coil 1 (Fig. 3) of the punch is drastically reduced, resulting in a loss of punching power. The bent disk would also result in damage to the green sheet adjacent to the hole just punched because of reduced air damping.

A modification was made to the copper disk head by coining the existing punch disk head to produce a depression in it, as shown in

(Image Omitted)

Fig. 4. This configuration effectively increases the strength of the disk without increasing its mass. The impact of the die upon the disc, which effects the coining, also acts to work hard on the copper metal. As shown in Fig. 3, the coined punch head 2 now makes better contact with the shim stock 3, which separates the cooling system 4 from the punch head, because the shim stock bulges slightly due to the combined forces of the...