Method of making a ceramic combo lid with selective and edge metallizations
A frame lid for use with a semiconductor package is disclosed. First, a mask is applied to a top surface of the lid and over a central area of the top surface to define a peripheral area. Next, a seal ring is formed by metallizing the peripheral area and the sidewall of the plate. The mask can then be removed obtain the frame lid. Next, a solder preform can be attached to the seal ring. This reduces pullback and shrinkage of the metallized layer, while lowering the manufacturing cost and process times.
1. A method of making a frame lid assembly comprising:
providing a plate with a top surface, a bottom surface opposite the top surface and a sidewall that joins the top and bottom surface together, wherein the plate is made from a non-metallic material;
applying a mask to the top surface of the plate over a central area of the top surface of the plate to define a peripheral area on the top surface;
forming a seal ring by metallizing the peripheral area and the sidewall of the plate;
attaching a solder preform to the seal ring; and
removing the mask to obtain the frame lid, wherein the central area of the top surface of the plate is not metallized.
2. The method of claim 1 , wherein the plate is made from glass or a ceramic selected from the group consisting of alumina (Al 2 O 3 ), beryllia (BeO), aluminum nitride (AlN), zirconia toughened alumina (ZTA), SiC, and Si 3 N 4 .
3. The method of claim 1 , wherein the seal ring is formed from a set of sublayers.
4. The method of claim 1 , wherein the plate has a thickness of about 0.5 millimeter to about 1 millimeter.
5. The method of claim 1 , wherein the plate is formed from a non-magnetic material.
6. The method of claim 1 , wherein the peripheral area is from about 20% to about 35% of the surface area of the top surface of the plate.
7. The method of claim 1 , wherein the seal ring is formed from a metal selected from the group consisting of silver, palladium, platinum, nickel, gold, titanium, tungsten-copper-nickel, palladium-gold-tin, and alloys thereof.
8. The method of claim 1 , wherein the seal ring is formed from a non-magnetic metal.
9. The method of claim 1 , wherein the seal ring on the peripheral area has a width of about 0.5 mm to about 1 mm.
10. The method of claim 1 , wherein the seal ring on the peripheral area has a thickness of about 1 micrometer (μm) to about 40 μm.
11. The method of claim 1 , wherein the plate is in the shape of a disk or a rectangular prism.
12. The method of claim 1 , further comprising tack welding the solder preform to the seal ring.
13. The method of claim 1 , wherein the solder preform has a melting temperature of from about 200° C. to about 350° C.
14. The method of claim 1 , wherein the solder preform is formed from a gold-tin alloy, a lead-based alloy, or a lead-free alloy.
15. The method of claim 1 , wherein the mask is made of a metal.
16. The method of claim 1 , wherein the metallizing is performed by sputter deposition.