Integrated circuit package
View Patent ↗Embodiments of the present disclosure are directed towards a method of assembling an integrated circuit package. In embodiments the method may include providing a wafer having an unpatterned passivation layer to prevent corrosion of metal conductors embedded in the wafer. The method may further include laminating a dielectric material on the passivation layer to form a dielectric layer and selectively removing dielectric material to form voids in the dielectric layer. These voids may reveal portions of the passivation layer disposed over the metal conductors. The method may then involve removing the portions of the passivation layer to reveal the metal conductors. Other embodiments may be described and/or claimed.
1. A method of assembling an integrated circuit package comprising:
providing a wafer having an unpatterned passivation layer that is disposed on and in direct contact with a metal conductor embedded in the wafer;
disposing a dielectric material on the passivation layer to form a dielectric layer;
forming a via in the dielectric layer to expose a portion of the passivation layer disposed over the metal conductors; and
removing the portions of the passivation layer that is exposed by the forming of the via, to reveal the metal conductor, including using the dielectric layer as a mask to form a void in the passivation layer that comprises the exposed portion of the passivation layer, wherein an edge of a remainder of the passivation layer is to align with an edge of the via in the dielectric layer.
2. The method of claim 1 , wherein the metal conductor comprises copper, wherein the method further comprises applying a wet etch process to the metal conductor to remove copper oxide formed thereon.
3. The method of claim 2 , wherein the wet etch process involves applying phosphoric acid and hydrogen peroxide.
4. The method of claim 1 , wherein disposing a dielectric material further comprises: spin-coating of the dielectric material on the passivation layer; and
curing the dielectric material to harden the dielectric material.
5. The method of claim 1 , wherein forming a via in the dielectric layer comprises using either a photolithography process or a laser drilling process.
6. The method of claim 1 , wherein removing the portions of the passivation layer further comprises applying a plasma treatment to the portions of the passivation layer to create openings in the passivation layer that reveal the metal conductor.
7. The method of claim 1 , further comprising:
depositing a barrier material on the dielectric layer and the metal conductors to create a barrier layer; and
depositing a seed material on the barrier layer to create a seed layer.
8. The method of claim 7 , further comprising:
depositing a resist material on the seed layer to form a resist layer; and
selectively removing portions of the resist material to form voids in the resist material that reveal the seed layer.
9. The method of claim 8 , further comprising:
depositing a redistribution layer (RDL) or an under bump metallization (UBM) layer in the voids of the resist material.
10. The method of claim 9 , further comprising:
depositing solder onto the RDL or UBM layer to form a solder ball.