Laser ablation for wire bonding on organic solderability preservative surface
A printed circuit board is disclosed. The printed circuit board includes: a substrate layer; a copper layer disposed on the substrate layer; and an organic solderability preservative (OSP) layer disposed on the copper layer. The OSP layer defines one or more laser treated OSP surfaces.
1. A method comprising:
providing a substrate layer;
providing a copper layer disposed on the substrate layer;
providing an organic solderability preservative (OSP) layer disposed on the copper layer;
exposing a surface of the copper layer by applying a laser beam from a laser on the OSP layer, the applied laser beam removing an amount of the copper layer such that a thickness of the copper layer under the exposed surface is less than a thickness of the copper layer that is under the OSP layer; and
providing a connection between a component and the exposed surface of the copper layer.
2. The method of claim 1 , wherein the OSP layer has a thickness between about 100 and 500 nanometer.
3. The method of claim 1 , wherein the connection comprises a bondwire wire bonded to the exposed surface of the copper layer.
4. The method of claim 3 , wherein the bondwire is one of an aluminium bondwire, a copper bondwire, a silver bondwire, a gold bondwire, and aluminium coated copper wire.
5. The method of claim 1 , wherein the laser beam comprises one of a fiber laser and a continuous wave laser.
6. The method of claim 1 , wherein the laser beam comprises a fiber laser.
7. The method of claim 1 , wherein the laser beam comprises a continuous wave laser.