Auto Detection and alignment of guided wire lead of solder ball profile for the purpose of hot bump pull testing
Publication Date: 2011-Apr-21
The IP.com Prior Art Database
Described is a self- aligning fixture and process associated with hot bump pull testing. This fixture can then be sold as an add-on feature to the existing testing equipment.
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Hot bump pull test has emerged to be an attractive alternative to the traditional ball shear method for characterizing the attachment strength of solder interconnection and pad cratering mainly due to the introduction of Pb-free solder systems. Since it is a relatively new development, there is no alignment related tool available to test these interconnects.
This disclosure is designed as an add-on for the current hot bump pull test load cell from
Dage. It consists of an optical camera, software, and an alignment window. To operate the device, the user first adjusts the alignment window to fully encompass the solder ball and fixes the copper pin in the holder to ensure it does not move relative to the alignment window.
the camera is activated and a picture of the solder ball is captured. The software then analyzes the picture to measure solder ball size and center location. The alignment window is then adjusted either by hand or automated motor to frame the solder ball and ensure the copper wire is directly in the center. After achieving proper alignment, the hot bump pull test can be run as normal. An additional embodiment of this invention involves the use of a touch or laser sensor to determine the height of the copper wire during placement. The sensor could extend from a portion of the alignment window to touch the surface of the card near the solder ball. The data would then be fed to the software to measure the height of the pin. Thus, ensuring co...