MC Substrate Process for Optimum Chip Joining Yields
Original Publication Date: 1978-Feb-01
Included in the Prior Art Database: 2005-Feb-20
In metallized ceramic (MC) substrates there has been a problem of solder pads on the substrate not wetting during the chip-joining process. Due to the nature of the tinning process and multisize pads on the substrate, the height of the solder on the substrate pads is not uniform. When the chip is placed on the substrate for chip joining, all the pads on the chip do not come in contact with the pads on the substrate. Therefore, not all the pads on the chip reflow with the pads on the substrate.