Simple Method of Chip Positioning on Polyimide Film Chip Carrier
Original Publication Date: 1988-Mar-01
Included in the Prior Art Database: 2005-Feb-14
A chip positioning device allows the registration of the chip's controlled collapse chip connectors (C4) to the pads of a polyimide film chip carrier and, by the use of flux as an adhesive, holds the chip in the correct position until the solder is reflowed in a reflow oven. The device works as described in the following. The chip 1 (Fig. 1) with attached C4 connectors 2 is placed on a compressible material, typically foam rubber 3, with the C4 connectors facing up. A spacing gasket 4 with a hole in its center is placed on foam rubber 3 such that gasket 4 encloses the chip 1. A polyimide film chip carrier 5 is coated with a thin layer of flux 6 over carrier pads 7 and placed flux side towards the chip 1. The chip 1 and the polyimide film chip carrier 5 are aligned under a microscope, the result being seen in Fig. 2.