The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 27, 1987
Filed:
Jul. 26, 1985
Yoshinori Enomoto, Kawasaki, JP;
Hideo Monma, Kawasaki, JP;
Shunzo Ohta, Aizuwakamatsu, JP;
Takeshi Sasaki, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A circuit for checking the integrity of interconnections between chips in a chip-on-chip type IC device is fabricated in respective portions on the lower and upper chips in peripheral areas thereof intermediate the inner logic circuit of each chip and the corresponding bonding pads. Selection circuits connected between the inner logic circuit signal terminals and the corresponding bonding pads of the chip are switched by control signals to be isolated and permit normal operation of the chip or to a checking mode to isolate the inner logic circuit and permit transmission of test signals through the interconnections. The test signals received through the interconnections are compared with the test signals as transmitted to determine the integrity of the individual interconnections. The disclosed apparatus and method provide for testing of the integrity of interconnections defining single direction signal paths of individual interconnections, as between the upper and lower chips, and for selectively bidirectional transmission through the individual interconnections.