Browse Prior Art Database

Removal of Semiconductor Chip from Substrate

IP.com Disclosure Number: IPCOM000073414D
Original Publication Date: 1970-Dec-01
Included in the Prior Art Database: 2005-Feb-22
Document File: 2 page(s) / 40K

Publishing Venue

IBM

Related People

Rogers, CT: AUTHOR [+2]

Abstract

This method and apparatus removes a semiconductor chip from a module substrate in a simple manner without damaging adjoining chips or the module substrate.

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Removal of Semiconductor Chip from Substrate

This method and apparatus removes a semiconductor chip from a module substrate in a simple manner without damaging adjoining chips or the module substrate.

In order to remove chip 10 from module substrate 12, a heating tool, for example, the tip of a soldering iron 14 having a cavity 16, is placed over the chip. The outer projecting edges around the cavity are lined with an elastic heat resistant material, such as, silicon rubber 18 to prevent leakage of molten solder. Prior to placing the heating tool 14 over the chip a solder preform 20 is placed in the cavity. The assembly is then heated, for example, by heating the soldering iron or by passing the assembly through a belt furnace so as to heat it to a temperature above the melting point of the solder 20 and the metallurgical connection 22 which joins the chip to the module substrate. Since the density of the silicon chip is less than that of the solder 20, the chip floats on the solder surface as illustrated in the second sequence of diagrams. Finally, the module is tilted, as shown in the final sequence of illustrations, so as to dump the chip which is floating on the surface of the solder 20. The semiconductor chips without the surplus solder remain in place as they are held by the surface tension of their liquid solder joints.

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