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Lamination of Large Cores to Form Multilayer Printed Circuits

IP.com Disclosure Number: IPCOM000087690D
Original Publication Date: 1977-Mar-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 2 page(s) / 24K

Publishing Venue

IBM

Related People

Haining, FW: AUTHOR [+2]

Abstract

The standard practice for forming large cores is illustrated in Fig. 1. Oversized cores are made, and then blank composites are cut only after the cores have been laminated into the composites. The cores are placed in registration on two pins located to accept the locating holes 11 and 13 along one edge of the core. Sheets of prepreg are placed between the cores and in between stacks of cores and the foil copper on both sides of the stack. Then, after lamination to form the composites, the composites are blanked out to the desired, reduced size and simultaneously V-notch locations are placed in the reduced size panels.

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Lamination of Large Cores to Form Multilayer Printed Circuits

The standard practice for forming large cores is illustrated in Fig. 1. Oversized cores are made, and then blank composites are cut only after the cores have been laminated into the composites. The cores are placed in registration on two pins located to accept the locating holes 11 and 13 along one edge of the core. Sheets of prepreg are placed between the cores and in between stacks of cores and the foil copper on both sides of the stack. Then, after lamination to form the composites, the composites are blanked out to the desired, reduced size and simultaneously V-notch locations are placed in the reduced size panels. Thus, there are two sizes and two registration systems involved in preparing the composite, with the two pin-locating holes 11 and 13 being trimmed off in the blanking operation, thereby irretrievably losing the first registration system.

The proposed approach (Fig. 2) uses a core of the desired size with V- notches 15, 17, 19, 20 and 21 as the only size and location system. Two holes 23 and 25 are placed in the panel for pin location during composite lamination and for cleaning out the V-notches after lamination.

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