Low temperature hermetic sealing method having passivation layer

• US 20030104651A1
• Filed: 11/14/2002
• Published: 06/05/2003
• Est. Priority Date: 12/04/2001
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Woon-bae, Shin, Hyung-jae, Cho, Chang-ho, Kang, Seung-goo
• Granted Patent: US 7,065,867 B2
• Time in Patent Office: Days
• US Class Current: 438/106
• CPC Class Codes: B81C 1/00269 Bonding of solid lids or wafers to the substrate
• CPC Class Codes: H01L 21/50 Assembly of semiconductor devices using processes or apparatus not provided for in a single one of the subgroups H01L21/06 - H01L21/326, e.g. sealing of a cap to a base of a container
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/45015 being circular
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/85399 Material
• CPC Class Codes: H01L 23/10 characterised by the material or arrangement of seals between parts, e.g. between cap and base of the container or between leads and walls of the container
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 24/97 the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01004 Beryllium [Be]
• CPC Class Codes: H01L 2924/01005 Boron [B]
• CPC Class Codes: H01L 2924/01006 Carbon [C]
• CPC Class Codes: H01L 2924/01013 Aluminum [Al]
• CPC Class Codes: H01L 2924/01024 Chromium [Cr]
• CPC Class Codes: H01L 2924/01027 Cobalt [Co]
• CPC Class Codes: H01L 2924/01029 Copper [Cu]
• CPC Class Codes: H01L 2924/0103 : Zinc [Zn]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01046 : Palladium [Pd]
• CPC Class Codes: H01L 2924/01047 : Silver [Ag]
• CPC Class Codes: H01L 2924/01049 : Indium [In]
• CPC Class Codes: H01L 2924/01051 : Antimony [Sb]
• CPC Class Codes: H01L 2924/01075 : Rhenium [Re]
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01082 : Lead [Pb]
• CPC Class Codes: H01L 2924/01322 : Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/09701 : Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/12042 : LASER
• CPC Class Codes: H01L 2924/15153 : the die mounting substrate comprising a recess for hosting the device
• CPC Class Codes: H01L 2924/15165 : Monolayer substrate
• CPC Class Codes: H01L 2924/15312 : being a pin array, e.g. PGA
• CPC Class Codes: H01L 2924/16152 : Cap comprising a cavity for hosting the device, e.g. U-shaped cap
• CPC Class Codes: H01L 2924/16195 : Flat cap [not enclosing an internal cavity]
• CPC Class Codes: H01L 2924/163 : Connection portion, e.g. seal
• CPC Class Codes: H01L 2924/207 : Diameter ranges
• CPC Class Codes: Y10T 29/49002 : Electrical device making
• CPC Class Codes: Y10T 29/4913 : Assembling to base an electrical component, e.g., capacitor, etc.
• CPC Class Codes: Y10T 29/49144 : by metal fusion
• CPC Class Codes: Y10T 29/49146 : with encapsulating, e.g., potting, etc.
• CPC Class Codes: Y10T 29/49789 : Obtaining plural product pieces from unitary workpiece
• CPC Class Codes: Y10T 29/49794 : Dividing on common outline

Abstract

A hermetic sealing method, which is capable of preventing oxidation of a micro-electromechanical system (MEMS) and sealing the MEMS at a low temperature. A low temperature hermetic sealing method having a passivation layer includes depositing a junction layer, a wetting layer, and a solder layer on a prepared lid frame, depositing a first protection layer for preventing oxidation on the solder layer and forming a lid, preparing a package base on which a device is disposed, and in which a metal layer and a second protection layer are formed around the device, and assembling the lid and the package base, heating, and sealing them. The protection layer is laminated on the solder layer that is formed by the lid, thereby preventing oxidation without using a flux. The low temperature hermetic sealing method having a passivation layer is suitable for sealing a device, such as the MEMS, which is sensitive to heat, water and other by-products.

Claims

1. A low temperature hermetic sealing method having a passivation layer, the method comprising:

depositing a junction layer, a wetting layer, and a solder layer on a prepared lid frame;

depositing a first protection layer for preventing oxidation on the solder layer and forming a lid;

preparing a package base on which a device is disposed, and in which a metal layer and a second protection layer are formed around the device; and

assembling, heating, and sealing the lid and the package base.

2. The method of claim 1, wherein the lid frame is formed of one selected from glass, quartz, Si, ceramic, and Kovar.

3. The method of claim 1, wherein the junction layer is formed of one selected from Cr, Ti, and an alloy of Cr and Ti.

4. The method of claim 1, wherein the wetting layer is formed of one selected from Ni, Cu, and an alloy of Ni and Cu.

5. The method of claim 1, wherein the solder layer is formed of at least one selected from In, Sn, Bi, Ag, and Zn.

6. The method of claim 1, wherein the first protection layer is formed of Au.

7. A low temperature hermetic sealing method having a passivation layer, the method comprising:

laminating a junction layer, a wetting layer, and a solder layer on a wafer and forming a lid wafer;

depositing a first protection layer for preventing oxidation on the solder layer;

manufacturing micro-electromechanical system (MEMS) devices on a package base wafer;

depositing a metal layer and a second protection layer on the package base wafer;

assembling the lid wafer and the package base wafer so that the lid wafer and the package base wafer are opposite to each other;

heating the lid wafer and the package base wafer so that the first protection layer is absorbed into the solder layer;

sealing the lid wafer and the package base wafer; and

dicing the sealed wafer in units of the MEMS devices.

8. The method of claim 7, wherein the first protection layer is formed of Au.