Laser welding method, laser welding jig, and semiconductor device

• US 9,399,268 B2
• Filed: 10/30/2014
• Issued: 07/26/2016
• Est. Priority Date: 12/19/2013
• Status: Active Grant

• Current Assignee: Fuji Electric Company Limited (Fuji Electric Systems Company Limited)
• Original Assignee: Fuji Electric Company Limited (Fuji Electric Systems Company Limited)
• Inventors: Tamai, Yuta
• Primary Examiner(s): Trinh, Hoa B
• Application Number:
  US14/528,537
• Publication Number:
  US 20150179539A1
• Time in Patent Office: 635 Days
• Field of Search: 257/734, 257/739, 257/747, 257/752, 257/753, 257/666, 257/668, 257/670, 257/672, 257/676
• US Class Current: 1/1
• CPC Class Codes: B23K 2101/34 Coated articles , e.g. plated or painted; Surface treated articles
• CPC Class Codes: B23K 2101/35 Surface treated articles
• CPC Class Codes: B23K 2101/42 Printed circuits
• CPC Class Codes: B23K 2103/08 Non-ferrous metals or alloys
• CPC Class Codes: B23K 2103/10 Aluminium or alloys thereof
• CPC Class Codes: B23K 2103/12 Copper or alloys thereof
• CPC Class Codes: B23K 2103/16 Composite materials , e.g. fibre reinforced
• CPC Class Codes: B23K 2103/172 wherein at least one of the layers is non-metallic
• CPC Class Codes: B23K 2103/50 Inorganic material, e.g. metals, not provided for in B23K2103/02 – B23K2103/26
• CPC Class Codes: B23K 26/0006 taking account of the properties of the material involved B23K26/32, B23K26/40 take precedence
• CPC Class Codes: B23K 26/037 by pressing on the workpiece, e.g. pressing roller foot
• CPC Class Codes: B23K 26/0622 by shaping pulses
• CPC Class Codes: B23K 26/206 Laser sealing
• CPC Class Codes: B23K 26/211 with interposition of special material to facilitate connection of the parts
• CPC Class Codes: B23K 26/22 Spot welding
• CPC Class Codes: B23K 26/32 taking account of the properties of the material involved
• CPC Class Codes: H01L 21/4846 Leads on or in insulating or insulated substrates, e.g. metallisation H01L21/4821 takes precedence; metallisation of ceramics in general C04B41/51; printed circuits H05K3/00
• CPC Class Codes: H01L 2224/291 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 2224/29101 the principal constituent melting at a temperature of less than 400°C
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/32245 : the item being metallic
• CPC Class Codes: H01L 2224/33181 : On opposite sides of the body
• CPC Class Codes: H01L 2224/37124 : Aluminium [Al] as principal constituent
• CPC Class Codes: H01L 2224/37138 : the principal constituent melting at a temperature of greater than or equal to 950°C and less than 1550°C
• CPC Class Codes: H01L 2224/37147 : Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2224/3718 : Molybdenum [Mo] as principal constituent
• CPC Class Codes: H01L 2224/37184 : Tungsten [W] as principal constituent
• CPC Class Codes: H01L 2224/37187 : Ceramics, e.g. crystalline carbides, nitrides or oxides glass ceramics H01L2224/37188
• CPC Class Codes: H01L 2224/3754 : Coating
• CPC Class Codes: H01L 2224/37638 : the principal constituent melting at a temperature of greater than or equal to 950°C and less than 1550°C
• CPC Class Codes: H01L 2224/37655 : Nickel [Ni] as principal constituent
• CPC Class Codes: H01L 2224/37663 : the principal constituent melting at a temperature of greater than 1550°C
• CPC Class Codes: H01L 2224/40137 : the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2224/40499 : Material of the auxiliary connecting means
• CPC Class Codes: H01L 2224/48227 : connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/73265 : Layer and wire connectors
• CPC Class Codes: H01L 2224/75261 : Laser
• CPC Class Codes: H01L 2224/7555 : Mechanical means, e.g. for planarising, pressing, stamping
• CPC Class Codes: H01L 2224/83224 : using a laser
• CPC Class Codes: H01L 2224/834 : 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 2224/83801 : Soldering or alloying
• CPC Class Codes: H01L 2224/83895 : between electrically conductive surfaces, e.g. copper-copper direct bonding, surface activated bonding
• CPC Class Codes: H01L 23/049 : the other leads being perpendicular to the base
• CPC Class Codes: H01L 23/3735 : Laminates or multilayers, e.g. direct bond copper ceramic substrates
• CPC Class Codes: H01L 24/00 : Arrangements for connecting or disconnecting semiconductor or solid-state bodies; Methods or apparatus related thereto
• CPC Class Codes: H01L 24/29 : of an individual layer connector
• CPC Class Codes: H01L 24/32 : of an individual layer connector
• CPC Class Codes: H01L 24/33 : of a plurality of layer connectors
• CPC Class Codes: H01L 24/37 : of an individual strap connector
• CPC Class Codes: H01L 24/40 : of an individual strap connector
• CPC Class Codes: H01L 24/75 : Apparatus for connecting with bump connectors or layer connectors
• CPC Class Codes: H01L 24/83 : using a layer connector
• CPC Class Codes: H01L 24/84 : using a strap connector
• CPC Class Codes: H01L 24/92 : Specific sequence of method steps
• 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 2924/00012 : Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/01005 : Boron [B]
• CPC Class Codes: H01L 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01014 : Silicon [Si]
• CPC Class Codes: H01L 2924/01015 : Phosphorus [P]
• CPC Class Codes: H01L 2924/01028 : Nickel [Ni]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01042 : Molybdenum [Mo]
• CPC Class Codes: H01L 2924/01046 : Palladium [Pd]
• CPC Class Codes: H01L 2924/01074 : Tungsten [W]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/013 : Alloys
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/04642 : SiC
• CPC Class Codes: H01L 2924/1203 : Rectifying Diode
• CPC Class Codes: H01L 2924/12042 : LASER
• CPC Class Codes: H01L 2924/13055 : Insulated gate bipolar transistor [IGBT]
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/19107 : off-chip wires
• CPC Class Codes: H01L 2924/40102 : being pulsed

Abstract

In a laser welding method, a gap between first and second members to be welded is made at most 300 μm by pressing the second member against the first member with claws that are pressing parts of a laser welding jig, and the second member to be welded at a place between the claws is irradiated by laser light to laser-weld the first member and the second member. In a semiconductor device, the gap between the first member and the second member at the portion of laser-welding is at most 300 μm.

Claims

1. A semiconductor device comprising:

a ceramic insulated substrate;

a front surface conductor pattern fixed on a front surface of the ceramic insulated substrate;

a semiconductor chip electrically connected to the front surface conductor pattern;

a first member electrically connected to the semiconductor chip; and

a second member laser-welded to the first member at at least one portion to electrically connect thereto;

wherein a gap between the first member and the second member at the portion of laser-welding is at most 300 μ

m.

2. The semiconductor device according to claim 1, wherein the first and second members are further welded at another portion, and

a distance between an outer periphery of the one portion of laser welding and an outer periphery of the another portion of laser welding is at most 2 mm.

3. The semiconductor device according to claim 1, wherein the first member has a thickness of at least 0.5 mm and the second member has a thickness of at most 1 mm.

4. The semiconductor device according to claim 1, wherein the first member and the second member are planar at least at the one portion of the laser welding.

5. The semiconductor device according to claim 1, wherein each of the first and second member has an engaging part for positioning the first member and the second member, and

the portion of the laser welding is different from the engaging part.

6. The semiconductor device according to claim 1, further comprising a sealing material for sealing the ceramic insulated substrate, the front surface conductor pattern, the semiconductor chip, and a part of the first member,

wherein the one portion of the laser welding is not sealed with the sealing material.