Browse Prior Art Database

Method for Plating Unequal Length Contact Tabs

IP.com Disclosure Number: IPCOM000041010D
Original Publication Date: 1987-May-01
Included in the Prior Art Database: 2005-Feb-02
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Broadie, RW: AUTHOR [+2]

Abstract

It is often desirable to have circuit card contact tabs of unequal length so as to permit one contact to always make contact first and break contact last as the card is inserted or removed. When plating such variable length contact tabs, it is not pos- sible to use the prior art continuous electrical bus at the edge of the card which is later cut off as part of final production. This disclosure places plating bus conductor in an area away from the edge of the card. The bus connections are then removed by drilling or milling.

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Method for Plating Unequal Length Contact Tabs

It is often desirable to have circuit card contact tabs of unequal length so as to permit one contact to always make contact first and break contact last as the card is inserted or removed. When plating such variable length contact tabs, it is not pos- sible to use the prior art continuous electrical bus at the edge of the card which is later cut off as part of final production. This disclosure places plating bus conductor in an area away from the edge of the card. The bus connections are then removed by drilling or milling.

Figure 1 shows a prior art card 11 having contact tabs 15, 16, 17 which are plated using plating bus 13 as a common elec- trode. After the plating process, the card is cut along dotted line 18 to remove the bus and provide electrical isolation between the contact tabs 12. When card contact tabs are to be of differing lengths, as on card 21 in Figure 2, it is not possible to use the technique shown in Figure 1 for providing an electro- plating bus connection. Instead, each tab is connected to its adjacent tabs on internal areas of the card. For example, tab 22 is connected to tabs 25, 26, and 27 by metal areas forming part of plating bus 23. After the tabs have been electroplated, the external connection to bus 23 is milled away along dotted line 28. Internal connections provided by bus 23 are either drilled out as at 29, or cut out along a surface as at 30 by a surface milling cutter. In this way...