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Method for a dualistic BGA contact system

IP.com Disclosure Number: IPCOM000021247D
Publication Date: 2004-Jan-07
Document File: 3 page(s) / 78K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for a dualistic ball grid array (BGA) contact system. Benefits include improved yield, improved support for future technology, improved ease of manufacturing, and improved test and programming environments.

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Method for a dualistic BGA contact system

Disclosed is a method for a dualistic ball grid array (BGA) contact system. Benefits include improved yield, improved support for future technology, improved ease of manufacturing, and improved test and programming environments.

Background

         To contact an ultra-thin solder ball on ultra-thin stacked chip scale packages (UTSCSP), the industry uses vertical motion contact probes. This probing methodology applies a force vertically against a package, resulting in a high latching force. The latches push the package into the contacts. The force applied to the package increases with the number of contacts in the socket.

         Conventional burn-in sockets use either a pure vertical motion or a horizontal motion.

         Socket contact technology that uses horizontal force (such as tweezer contacts) cannot reliably grip solder balls with less than a 0.2-mm standoff and vertical probing methods must be used. However, vertical probing methods can generate too much force.

General description

         The disclosed method is a component used in the more complex assembly of a burn-in socket. The burn-in socket houses a mechanism for controlling the application of contact force to the solder ball of any BGA package. These mechanisms include a contact (probe), biasing grid (slider), latch, and other standard mechanisms of an open-top burn-in socket.

         A solder ball is engaged by a vertical probe and force is applied to the side of the ball.

         The disclosed method combines both the vertical and horizontal actuation of the contact to obtain the optimal contact force for the specific purpose of reducing the vertical load to a BGA package with very thin solder balls with a standoff of less than 0.2 mm.

Advantages

         The disclosed method provides advantages, including:

•         Improved yield due to reducing the risk of package damage by applying normal contact force at a shallow angle to the horizontal of the package

•         Impr...