Method for producing semiconductor device

• US 9,468,993 B2
• Filed: 09/12/2012
• Issued: 10/18/2016
• Est. Priority Date: 09/15/2011
• 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: Miyasaka, Toshiyuki, Tamai, Yuta
• Primary Examiner(s): Fan, Michele
• Application Number:
  US14/239,014
• Publication Number:
  US 20140203420A1
• Time in Patent Office: 1,497 Days
• US Class Current: 1/1
• CPC Class Codes: B23K 26/20 Bonding soldering by means of radiant energy B23K1/005; joining of preformed plastics parts by heating using laser beam B29C65/16
• 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 2224/291 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 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/33181 On opposite sides of the body
• CPC Class Codes: H01L 2224/37099 Material
• CPC Class Codes: H01L 2224/40095 Kinked
• CPC Class Codes: H01L 2224/40101 Connecting bonding areas at the same height, e.g. horizontal bond
• CPC Class Codes: H01L 2224/40137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2224/73263 Layer and strap connectors
• CPC Class Codes: H01L 2224/83801 Soldering or alloying
• CPC Class Codes: H01L 2224/83815 Reflow soldering
• CPC Class Codes: H01L 2224/84214 using a laser
• CPC Class Codes: H01L 2224/84801 Soldering or alloying
• CPC Class Codes: H01L 23/047 the other leads being parallel to the base
• CPC Class Codes: H01L 23/24 solid or gel at the normal operating temperature of the device H01L23/3135 takes precedence
• CPC Class Codes: H01L 23/3735 Laminates or multilayers, e.g. direct bond copper ceramic substrates
• CPC Class Codes: H01L 23/49568 specifically adapted to facilitate heat dissipation
• CPC Class Codes: H01L 23/49811 Additional leads joined to the metallisation on the insulating substrate, e.g. pins, bumps, wires, flat leads H01L23/49827 takes precedence
• 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 24/40 : of an individual strap connector
• CPC Class Codes: H01L 24/73 : Means for bonding being of different types provided for in two or more of groups H01L24/10, H01L24/18, H01L24/26, H01L24/34, H01L24/42, H01L24/50, H01L24/63, H01L24/71
• CPC Class Codes: H01L 24/83 : using a layer connector
• CPC Class Codes: H01L 24/84 : using a strap connector
• CPC Class Codes: H01L 25/072 : the devices being arranged next to each other
• CPC Class Codes: H01L 25/18 : the devices being of types provided for in two or more different subgroups of the same main group of groups H01L27/00 - H01L33/00, or in a single subclass of H10K, H10N
• 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 2924/014 : Solder alloys
• 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 2924/15788 : Glasses, e.g. amorphous oxides, nitrides or fluorides

Abstract

A method for producing a semiconductor device includes laser welding to bond an upper terminal and a lower terminal as internal wiring members of the semiconductor device. When the upper terminal is fixed to the lower terminal by the laser welding, a gap between an upper surface of the lower terminal and a lower surface of the upper terminal is equal to or more than 20 μm and equal to or less than 400 μm.

Claims

1. A method for producing a semiconductor device, comprising:

forming a step portion on a rear surface of an upper terminal,

close contacting the rear surface of the upper terminal where the step portion is not formed, to an upper surface of a lower terminal to thereby set a gap at the step portion between the upper surface of the lower terminal and the rear surface of the upper terminal to equal to or more than 20 μ

m and equal to or less than 400 μ

m, said gap being laterally open between the lower terminal and the upper terminal without being closed, said lower and upper terminals being internal wiring members of the semiconductor device, and

radiating a laser beam to a surface of the upper terminal immediately above the step portion to laser-weld the upper terminal directly to the lower terminal while keeping the gap between the upper terminal and the lower terminal.

2. The method for producing the semiconductor device according to claim 1, wherein forming the step portion on the rear surface of the upper terminal comprises thinning one end portion of the upper terminal.

3. The method for producing the semiconductor device according to claim 2, wherein in thinning the one end portion of the upper terminal, the step portion is formed to have an open end and a closed end having an inclined surface after close contacting the rear surface of the upper terminal where the step portion is not formed to the upper surface of the lower terminal.

4. The method for producing the semiconductor device according to claim 3, wherein thinning the one end portion of the upper terminal includes cutting or crushing the one end portion of the upper terminal.