circuit
Full Member level 2
wire bonding pcb
hello, i am looking at an application where in I have a chip in the silicon die form which needs to be wire bonded to the very small pcb (around 3 mm x 5 mm) and then I need to take the signals out to a different board using a flex cable.
The board hosting the chip has to be rigid and cannot be flex. the problem i am facing is, the chip has its pads ( all along one ege) with dimension 81 um x 81 um and the edge - edge pad distance is 3 um ( center to center is 84um). Now I heard that the pads on the board is preferred to be directly under the die so that wire bond can be straight wire. now this means the pads on the board will be separated by 3 um edge-to-edge which is not acceptable for any pcb manufacturer. I checked with many pcb manufacturers and they are willing to go as far as 3 mil ( track space/width). when they say 3 mil spacing everything is edge to edge ?
Now my question is, do you have any suggestions for wire bonding companies in the US. and what are the requirements on the pads on the board. can i move the pads away from the chip so that somehow i can make everything 3/4 mils spacing (the person who was supposed to do the wire bonding said he prefers the pads to be underneath the silicon). or is there a different technology that is there to work at such fine pitch devices ? thanks in advance.....
hello, i am looking at an application where in I have a chip in the silicon die form which needs to be wire bonded to the very small pcb (around 3 mm x 5 mm) and then I need to take the signals out to a different board using a flex cable.
The board hosting the chip has to be rigid and cannot be flex. the problem i am facing is, the chip has its pads ( all along one ege) with dimension 81 um x 81 um and the edge - edge pad distance is 3 um ( center to center is 84um). Now I heard that the pads on the board is preferred to be directly under the die so that wire bond can be straight wire. now this means the pads on the board will be separated by 3 um edge-to-edge which is not acceptable for any pcb manufacturer. I checked with many pcb manufacturers and they are willing to go as far as 3 mil ( track space/width). when they say 3 mil spacing everything is edge to edge ?
Now my question is, do you have any suggestions for wire bonding companies in the US. and what are the requirements on the pads on the board. can i move the pads away from the chip so that somehow i can make everything 3/4 mils spacing (the person who was supposed to do the wire bonding said he prefers the pads to be underneath the silicon). or is there a different technology that is there to work at such fine pitch devices ? thanks in advance.....