Sequential fabrication of vertical conductive interconnects in capped chips

• US 8,143,095 B2
• Filed: 12/28/2005
• Issued: 03/27/2012
• Est. Priority Date: 03/22/2005
• Status: Expired due to Fees

• Current Assignee: Tessera, Inc. (Adeia Inc.)
• Original Assignee: Tessera, Inc. (Adeia Inc.)
• Inventors: Honer, Kenneth Allen
• Primary Examiner(s): Landau, Matthew
• Assistant Examiner(s): Crawford, Latanya N
• Application Number:
  US11/319,836
• Publication Number:
  US 20070145564A1
• Time in Patent Office: 2,281 Days
• Field of Search: 438/51, 438/55, 257/E21.499, 257/E21.511, 257/E23.067, 257/E23.085
• US Class Current: 438/106
• CPC Class Codes: B81B 2207/095 through the lid
• CPC Class Codes: B81C 1/00301 Connecting electric signal lines from the MEMS device with external electrical signal lines, e.g. through vias
• CPC Class Codes: H01L 2224/05568 the whole external layer protruding from the surface
• CPC Class Codes: H01L 2224/05573 Single external layer
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/06135 Covering only the peripheral area of the surface to be connected, i.e. peripheral arrangements
• CPC Class Codes: H01L 2224/11334 using preformed bumps
• CPC Class Codes: H01L 2224/1148 Permanent masks, i.e. masks left in the finished device, e.g. passivation layers
• CPC Class Codes: H01L 2224/11901 with repetition of the same manufacturing step
• CPC Class Codes: H01L 2224/13022 the bump connector being at least partially embedded in the surface
• CPC Class Codes: H01L 2224/13076 being mutually engaged together, e.g. through inserts
• CPC Class Codes: H01L 2224/13099 Material
• CPC Class Codes: H01L 2224/131 with a principal constituent of the material being a metal or a metalloid, e.g. boron [B], silicon [Si], germanium [Ge], arsenic [As], antimony [Sb], tellurium [Te] and polonium [Po], and alloys thereof
• CPC Class Codes: H01L 2224/13111 Tin [Sn] as principal constituent
• CPC Class Codes: H01L 2224/13144 Gold [Au] as principal constituent
• CPC Class Codes: H01L 2224/1357 Single coating layer
• CPC Class Codes: H01L 2224/81011 Chemical cleaning, e.g. etching, flux
• CPC Class Codes: H01L 24/11 Manufacturing methods for bumps on insulating substrates H01L21/4853
• CPC Class Codes: H01L 24/742 Apparatus for manufacturing bump connectors
• CPC Class Codes: H01L 2924/00013 Fully indexed content
• 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 2924/0101 : Neon [Ne]
• CPC Class Codes: H01L 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01018 : Argon [Ar]
• CPC Class Codes: H01L 2924/01022 : Titanium [Ti]
• CPC Class Codes: H01L 2924/01023 : Vanadium [V]
• 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 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01047 : Silver [Ag]
• CPC Class Codes: H01L 2924/01074 : Tungsten [W]
• 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 2924/01087 : Francium [Fr]
• CPC Class Codes: H01L 2924/01322 : Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/09701 : Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/3011 : Impedance
• CPC Class Codes: H03H 9/1092 : the enclosure being defined by a cover cap mounted on an element forming part of the surface acoustic wave [SAW] device on the side of the IDT's

Abstract

A method is provided of forming a capped chip which includes a conductive interconnect exposed through an opening in the cap. A cap having openings extending between outer and inner surfaces is aligned and joined to a chip. A mass of fusible conductive material is positioned through a first such opening onto a first such bond pad of the chip. The positioned mass is heated to bond the mass to the first bond pad. The steps of positioning and heating the mass form at least a portion of a conductive interconnect extending from the first bond pad at least partially through the first opening.

Claims

1. A method of forming a capped chip including a conductive interconnect extending vertically through a cap thereof, the method comprising:

providing a cap having an outer surface, an inner surface opposite said outer surface, and a plurality of through holes extending between said outer and inner surfaces;

aligning and joining said cap to a chip having a front face, a device region at said front face and a plurality of bond pads disposed at said front face, such that said inner surface of said cap faces said front face of said chip and said plurality of through holes each expose at least a region of a corresponding one of said plurality of bond pads;

positioning a mass of fusible conductive material through a first through hole of said plurality of through holes onto a first bond pad of said plurality of bond pads;

heating said positioned mass of fusible conductive material such that said mass flows, entirely covers the region of said first bond pad that is exposed by said first through hole, and thereby bonds to said first bond pad, said steps of positioning and heating said mass of fusible conductive material forming at least a portion of a conductive interconnect extending from said first bond pad at least partially through said first through hole;

positioning a further mass of said fusible conductive material in contact with said bonded mass;

heating said further mass until said further mass bonds with said bonded mass, thereby increasing a height of said conductive interconnect above said first bond pad,

wherein said step of aligning and joining said cap to said chip includes providing a sealing medium between said front face of said chip and said inner surface of said cap, wherein said sealing medium separates said device region from said plurality of bond pads, and

said step of positioning said mass of fusible conductive material includes dispensing a ball-shaped mass of said fusible conductive material, and said fusible conductive material includes at least one material selected from the group consisting of solder, tin and a eutectic composition; and

prior to aligning and joining said cap to said chip, forming wettable layers surrounding said plurality of bond pads and on walls of said plurality of through holes, wherein said step of heating said positioned mass wets said first bond pad and wets a first wall of said first through hole.

2. A method of forming a capped chip including a conductive interconnect extending vertically through a cap thereof, the method comprising:

providing a cap having an outer surface, an inner surface opposite said outer surface, and a plurality of through holes extending between said outer and inner surfaces;

aligning and joining said cap to a chip having a front face, a device region at said front face and a plurality of bond pads disposed at said front face, such that said inner surface of said cap faces said front face of said chip and said plurality of through holes each expose at least a region of a corresponding one of said plurality of bond pads;

positioning a mass of fusible conductive material through a first through hole of said plurality of through holes onto a first bond pad of said plurality of bond pads;

heating said positioned mass of fusible conductive material such that said mass flows, entirely covers the region of said first bond pad that is exposed by said first through hole, and thereby bonds to said first bond pad, said steps of positioning and heating said mass of fusible conductive material forming at least a portion of a conductive interconnect extending from said first bond pad at least partially through said first through hole;

positioning a further mass of said fusible conductive material in contact with said bonded mass; and

heating said further mass until said further mass bonds with said bonded mass, thereby increasing a height of said conductive interconnect above said first bond pad,

wherein said mass is a first mass, and said step of positioning said mass includes simultaneously positioning a second mass of said fusible conductive material through a second through hole of said plurality of through holes onto a second bond pad of said plurality of bond pads, and said step of heating said mass includes simultaneously heating said positioned second mass of fusible conductive material, such that said second mass bonds to said second bond pad to form at least a portion of a second conductive interconnect extending from said second bond pad at least partially through said second through hole, and

said step of positioning said second mass includes dispensing said fusible conductive material in a second nominal volume exceeding a first nominal volume of said first mass by more than 20%.

3. The method as claimed in claim 2, wherein said steps of positioning and heating said first mass, and positioning and heating said second mass are performed sequentially at a time when said chip remains attached to other chips in form of at least a portion of a wafer.

4. The method as claimed in claim 2, further comprising, performing the following steps in sequential order for each i^th bond pad of said plurality of bond pads, after heating said second mass to bond said second mass to said second bond pad,

positioning an i^th mass of fusible conductive material through an i^th through hole of said plurality of through holes onto said i^th bond pad;

and

heating said i^th mass such that said heated i^th mass bonds to said i^th bond pad, said steps of positioning and heating said i^th mass forms at least a portion of an i^th conductive interconnect extending from said i^th bond pad at least partially through said i^th through hole.

5. The method as claimed in claim 2, wherein said second nominal volume is dispensed in said step of positioning said second mass by an apparatus which positions and heats said first nominal volume, said second nominal volume being determined by adjusting said apparatus according to at least one of a width of said second through hole and a vertical separation distance between said inner surface of said cap and said front surface of said chip at said second through hole.