Title: Stress-free hall-cell package

Abstract: A thin stress-free hall-cell package includes a semiconductor hall-cell chip that is completely enveloped by a resilient cushioning material which is in turn held within a cup. The cup is attached to or is a part of at least one of the metal leads. Wires connect the leads to terminal-pads on the chip through the resilient cushioning material. The method for making the package includes providing support for the cup by one or more of the leads, placing the chip in the cup, dispensing a silicone resin into the cup and heat curing the resin. The package is completed with encapsulation of the cup and adjacent lead ends by a hard resin. The cup advantageously has a hole in its bottom such that a chip placed thereover is held in position for wire bonding by evacuating the hole from underneath by means of a vacuum system. A hot pin is then inserted in the hole to elevate the chip, the pin is retracted to be about flush with the inside of the cup bottom and liquid resin dispersed therein and completely envelops the chip. The resin cures locally about the hot pin. The pin is removed and the resin is completely cured in an oven.

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Other info:

Inventors: Eysermans, Hubert (Wichita Falls, TX, US)

Application Number: 591684
Filing Date: 1975-06-30
Publication_date: 1977-09-13
Assignee: Sprague Electric Company (North Adams, MA)
Primary Class(es): 361/813 174/52.2, 257/702, 257/788, 361/812
Other Classes:
US Patent Ref:

2906931	Sep, 1959	Armstrong	357/72.
2915684	Dec, 1959	Halla et al.	357/26.
3441813	Apr, 1969	Takatsuka et al.	357/72.
3568012	Mar, 1971	Ernst et al.	357/72.
3659164	Apr, 1972	Gaylor	357/72.
3689864	Sep, 1972	Ishihama et al.	174/52.
3706840	Dec, 1972	Moyle	29/588.
3742599	Jul, 1973	Desmond et al.	357/72.
3778685	Dec, 1973	Kennedy	357/72.
3820237	Jun, 1974	Effer	29/588.

Other Refs:
Primary Examiner: Smith, Jr., David
Assistant Examiner:
Attorney: Connolly and Hutz