Lid and method for sealing a non-magnetic package

Patent metadata

Field	Value
Publication number	US-2016122183-A1
Application number	US-201414529410-A
Country	US
Kind code	A1
Filing date	Oct 31, 2014
Priority date	Oct 31, 2014
Publication date	May 5, 2016
Grant date	—

Abstract

A non-magnetic lid for sealing a hermetic package. The lid includes a molybdenum substrate having a sputtered adhesion layer and a copper seed layer. The lid also includes a plated palladium solder base layer, and has gold/tin solder preforms attached to a sealing surface of the lid.

First claim

What is claimed is:

1 . A metallic non-magnetic lid for sealing a hermetic package, comprising:
a molybdenum substrate; a sputtered adhesion layer; a copper seed layer; a palladium solder base layer; and gold/tin solder preforms attached at a sealing surface of the lid.

2 . The non-magnetic lid as claimed in claim 1 , wherein the adhesion layer includes Ti.

3 . The non-magnetic lid as claimed in claim 2 , wherein the substrate received at least one of chemical etching, mechanical etching, or back-sputtering prior to sputtering the adhesion layer.

4 . The non-magnetic lid as claimed in claim 1 , wherein the solder base layer is plated between about 1000 angstrom to about 2 μm thick.

5 . The non-magnetic lid as claimed in claim 1 , wherein the solder base layer is at least about 1 micron thick.

6 . The non-magnetic lid as claimed in claim 5 , wherein the solder base layer is no more than about 6 micron thick.

7 . The non-magnetic lid as claimed in claim 1 , further comprising over the solder base layer an electroplated gold coating to about 1000 angstrom −2 μm thick.

8 . The non-magnetic lid as claimed in claim 1 , wherein the palladium coated lid was vacuum baked, prior to attaching the gold/tin preforms.

9 . The non-magnetic lid as claimed in claim 8 , wherein the lid was vacuum baked to achieve less than about 6 ppm H concentration in the palladium solder base layer.

10 . The non-magnetic lid as claimed in claim 1 , having at its outside edges a corner radius of about 30 mil.

11 . The non-magnetic lid as claimed in claim 1 , wherein the adhesion layer is at least about 500 angstrom thick.

12 . The non-magnetic lid as claimed in claim 1 , wherein the adhesion layer is about 2000 angstrom thick.

13 . The non-magnetic lid as claimed in claim 1 , wherein the seed layer is at least about 1000 angstrom thick.

14 . The non-magnetic lid as claimed in claim 1 , wherein the seed layer is about 2000 angstrom thick.

15 . The non-magnetic lid as claimed in claim 14 , wherein the seed layer is no more than about 6000 angstrom thick.

16 . The non-magnetic lid as claimed in claim 1 , wherein the adhesion layer includes one or more materials selected from the group consisting of: titanium, tantalum, or chromium.

17 . The non-magnetic lid as claimed in claim 1 , wherein the adhesion layer includes titanium.

18 . The non-magnetic lid as claimed in claim 1 , wherein the adhesion layer, the seed layer, and the solder base layer cover at least a sealing surface of the substrate and an edge of the substrate that bounds the sealing surface.

19 . The non-magnetic lid as claimed in claim 18 , wherein the adhesion layer, the seed layer, and the solder base layer uniformly cover the substrate.

20 . A method for making a lid for sealing a non-magnetic hermetic package, said method comprising:
forming a lid-shaped substrate from a molybdenum blank; sputtering onto the substrate an adhesion layer that includes one or more materials selected from the group consisting of: titanium, tantalum, or chromium; sputtering onto the adhesion layer a copper seed layer; electroplating onto the seed layer a palladium solder base layer; and attaching a gold/tin solder preform at a sealing surface of the lid.

21 . The method as claimed in claim 20 , further comprising at least one of back sputtering, chemically etching, or mechanically etching the substrate prior to sputtering the adhesion layer.

22 . The method as claimed in claim 20 , further comprising vacuum baking the lid prior to attaching the gold/tin solder preform.

23 . The method as claimed in claim 20 , wherein the adhesion layer consists essentially of titanium.

24 . A method for making a non-magnetic hermetic package comprising:
bonding a sensitive component within an interior cavity defined by non-magnetic walls that have a sealing edge defined by a non-magnetic metallic seal ring ; and sealing to the sealing edge a non-magnetic lid, wherein the non-magnetic lid has a sealing surface that includes a gold/tin solder preform, which is sealed to the sealing edge.

25 . The method as claimed in claim 24 , wherein the lid includes a molybdenum substrate.

26 . The method as claimed in claim 25 , wherein the lid includes a sputtered adhesion layer that includes titanium, tantalum, or chromium.

27 . The method as claimed in claim 26 , wherein the lid includes a copper seed layer.

28 . The method as claimed in claim 27 , wherein the lid includes a palladium solder base layer.

29 . A metallic non-magnetic lid for sealing a hermetic package, comprising:
a molybdenum substrate; a physical vapor deposited adhesion layer; a copper seed layer; a palladium solder base layer; and gold/tin solder preforms attached at a sealing surface of the lid.

Assignees

• Gen Electric

Inventors

• Kapusta Christopher
• Aimi Marco Francesco

Classifications

• B81B7/0058 Primary

  for protecting against damages due to external chemical or mechanical influences, e.g. shocks or vibrations · CPC title

• B23K2101/40

  Semiconductor devices · CPC title

• B81C2203/0172

  Seals · CPC title

• B81C1/00269 Primary

  Bonding of solid lids or wafers to the substrate · CPC title

• C23C28/023 Primary

  only coatings of metal elements only · CPC title