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:
Nov. 17, 1992
Filed:
Nov. 15, 1990
Charles F Miller, Anaheim Hills, CA (US);
Kenneth L Biggs, Orange, CA (US);
Other;
Abstract
A method and apparatus for attaching semiconductor dice to substrates includes a novel die-grasping apparatus and technique which employs a tweezer-like clamping device which has one fixed leg. The second leg of the clamping device is movable laterally towards the fixed leg by means of a linear actuator coupled to the movable leg through a spring. Lateral spacing between the linear actuator and the movable leg is adjustable, allowing the spring to be prestressed to a precisely adjustable value, thereby resulting in a precisely pre-adjustable side-gripping force on the lateral sides of a semiconductor chip or die, ensuring that the fragile die will not be broken by the grasping action. The preferred embodiment employs a micro-manipulator to precisely position a die in place on a molten solder pre-form on a substrate, and a vacuum probe for first placing the pre-form on the substrate. Also included in the preferred embodiment is a load cell responsive to a pre-determined normal force on a die in initiating lateral oscillation of the die in contact with the liquified pre-form. This 'scrubbing' action improving the quality of the bond formed between the die and substrate when the solder re-solidifies.