Surface finish structure of multi-layer substrate and manufacturing method thereof
A surface finish structure of multi-layer substrate and manufacturing method thereof. The surface finish structure of the present invention includes a bond pad layer, at least one cover metal layer and a solder mask. The cover metal layer covers the bond pad layer. The solder mask has a hole to expose the cover metal layer. The present invention can form the cover metal layer to cover the bond pad layer and then forms the solder mask. Thereafter, the hole is made to the solder mask at the position of the cover metal layer to expose thereof. Because the bond pad layer is embedded in a dielectric layer of the multi-layer substrate, adhesion intensity between the bond pad layer and the dielectric layer can be enhanced. Meanwhile, contact of the bond pad layer with the solder can be prevented with the cover metal layer.
1. A surface finish structure of a multi-layer substrate, comprising:
a bond pad layer, embedded in a dielectric layer, wherein there is no height difference between adjacent lateral edges of the bond pad layer and the dielectric layer;
at least one cover metal layer, covering the bond pad layer; and
a solder mask, having a hole to expose the cover metal layer, wherein the solder mask covers a portion of the cover metal layer.
2. The surface finish structure of claim 1 , wherein a material of the dielectric layer is polyimide.
3. The surface finish structure of claim 1 , wherein a material of the bond pad layer is copper.
4. The surface finish structure of claim 1 , wherein a material of the cover metal layer is nickel.
5. The surface finish structure of claim 1 , wherein a material of the cover metal layer is gold.
6. The surface finish structure of claim 1 , wherein an interface adhesion enhancing process is implemented between the dielectric layer and the bond pad layer to increase adhesion intensity therebetween.
7. A surface fmish structure of a multi-layer substrate, comprising:
a bond pad layer, embedded in a dielectric layer, wherein there is no height difference between adjacent lateral edges of the bond pad layer and the dielectric layer;
at least one cover metal layer, covering the bond pad layer; and
a solder mask, covering a portion of the cover metal layer.
8. The surface finish structure of claim 7 , wherein an interface adhesion enhancing process is implemented between the dielectric layer and the bond pad layer to increase adhesion intensity therebetween.
9. The surface finish structure of claim 7 , wherein a material of the dielectric layer is polyimide.
10. The surface finish structure of claim 7 , wherein a material of the bond pad layer is copper.
11. The surface finish structure of claim 7 , wherein a material of the cover metal layer is nickel.
12. The surface finish structure of claim 7 , wherein a material of the cover metal layer is gold.
13. A method of manufacturing a surface fmish structure of a multi-layer substrate, comprising steps of:
forming a bond pad layer on a carrier surface and forming a dielectric layer, and then separating the bond pad layer and the dielectric layer from the carrier surface to embed the bond pad layer into the dielectric layer;
forming at least one cover metal layer on a surface of the bond pad layer and the cover metal layer covers the bond pad layer completely;
coating a solder mask on one surface of the multi-layer substrate having the bond pad layer; and
making a hole to the solder mask at a position of the cover metal layer to expose thereof.
14. The manufacturing method of claim 13 , wherein the solder mask covers a portion of the cover metal layer.
15. The manufacturing method of claim 13 , wherein an area of the hole comprises a whole area of the cover metal layer.
16. A method of manufacturing a surface finish structure of a multi-layer substrate, comprising steps of:
coating a solder mask;
making a hole to the solder mask at a position of a bond pad layer embedded in a surface of a dielectric layer of the multi-layer substrate, wherein there is no height difference between adjacent lateral edges of the bond pad layer and the dielectric layer; and
forming at least one cover metal layer on a surface of the bond pad layer to cover the bond pad layer.
17. The manufacturing method of claim 16 , wherein the solder mask covers a portion of the bond pad layer.
18. The manufacturing method of claim 16 , wherein an area of the hole comprises a whole area of the bond pad layer.
19. The manufacturing method of claim 16 , further comprising steps of forming the bond pad layer on a carrier surface and forming the dielectric layer, and then separating the bond pad layer and the dielectric layer from the carrier surface to embed the bond pad layer into the dielectric layer before the step of coating the solder mask.
20. The manufacturing method of claim 16 , wherein the solder mask is formed on a carrier surface.
21. The manufacturing method of claim 20 , further comprising steps of forming the bond pad layer on the solder mask and forming the dielectric layer to embed the bond pad layer into the dielectric layer after the step of forming the solder mask.
22. The manufacturing method of claim 20 , further comprising a step of separating the solder mask from the carrier surface before the step of making the hole to the solder mask.