Circuit device and manufacturing method thereof

• US 7,446,406 B2
• Filed: 03/27/2006
• Issued: 11/04/2008
• Est. Priority Date: 03/30/2005
• Status: Expired due to Fees

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Wakita, Shigeru, Mizuno, Takahito, Yamamoto, Ren
• Primary Examiner(s): Smith; Zandra
• Assistant Examiner(s): Green; Telly D
• Application Number:
  US11/388,987
• Publication Number:
  US 20060220216A1
• Time in Patent Office: 953 Days
• Field of Search: 438/106, 438/122, 257/734, 257/678, 257/691, 257/703, 257/707, 257/730, 257/731, 257/E23.098, 257/E25.031
• US Class Current: 257/703
• CPC Class Codes: H01L 2224/32225 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 2224/451 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 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2224/48139 with an intermediate bond, e.g. continuous wire daisy chain
• CPC Class Codes: H01L 2224/49111 the connectors connecting two common bonding areas, e.g. Litz or braid wires
• CPC Class Codes: H01L 2224/49113 the connectors connecting different bonding areas on the semiconductor or solid-state body to a common bonding area outside the body, e.g. converging wires
• CPC Class Codes: H01L 2224/49175 Parallel arrangements
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 23/5385 Assembly of a plurality of insulating substrates
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 24/49 of a plurality of wire connectors
• CPC Class Codes: H01L 25/072 the devices being arranged next to each other
• 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 2924/01078 Platinum [Pt]
• CPC Class Codes: H01L 2924/13055 Insulated gate bipolar transistor [IGBT]
• CPC Class Codes: H01L 2924/207 Diameter ranges
• CPC Class Codes: H05K 1/0263 High current adaptations, e.g. printed high current conductors or using auxiliary non-printed means; Fine and coarse circuit patterns on one circuit board H05K1/0293 takes precedence
• CPC Class Codes: H05K 1/0306 : Inorganic insulating substrates, e.g. ceramic, glass
• CPC Class Codes: H05K 1/09 : Use of materials for the conductive, e.g. metallic pattern
• CPC Class Codes: H05K 2201/10272 : Busbars, i.e. thick metal bars mounted on the PCB as high-current conductors metal strips H05K2201/1028
• CPC Class Codes: H05K 2203/0285 : Using ultrasound, e.g. for cleaning, soldering or wet treatment
• CPC Class Codes: H05K 3/0061 : onto a metallic substrate, e.g. a heat sink heat sinks for electric apparatus H05K7/20
• CPC Class Codes: H05K 3/243 : characterised by selective plating, e.g. for finish plating of pads selective plating for making the circuit pattern H05K3/108, H05K3/182
• CPC Class Codes: H05K 3/328 : by welding
• CPC Class Codes: Y10T 29/49126 : Assembling bases

Abstract

A circuit device includes a ceramic substrate, an Al wiring layer provided on the ceramic substrate, and a semiconductor device and a bus bar which are electrically connected to the wiring layer. On part of the wiring layer, a Ni layer is plated. Thus a coated region in which the wiring layer is coated with nickel having solder wetability superior to aluminum and an exposing region in which the wiring layer is exposed as viewed from above the ceramic substrate are provided. The semiconductor device is connected onto the Ni layer within the coated region through solder. The bus bar is ultrasonically bonded to the wiring layer within the exposing region as viewed from above the ceramic substrate. Thus, the circuit device including the semiconductor device and the bus bar that are bonded to the ceramic substrate by sufficient bonding strength and its manufacturing method are provided.

Claims

1. A circuit device in which a functional device and an externally leading conductor are mounted, comprising:

a substrate;

a wiring layer provided on the substrate and electrically connected to the functional device and to the externally leading conductor; and

a coating metal layer formed on a part of the wiring layer to provide a coated region in which the wiring layer is coated and an exposing region in which the wiring layer is exposed;

wherein the functional device is connected onto the coating metal layer within the coated region through solder, and

the externally leading conductor is bonded directly to a part of the wiring layer within the exposing region.

2. The circuit device according to claim 1, wherein the wiring layer is made of aluminum.

3. The circuit device according to claim 2, wherein the coating metal layer is made of metal having solder wetability superior to aluminum.

4. The circuit device according to claim 3, wherein the coating metal layer is made of nickel or copper.

5. The circuit device according to claim 1, wherein the externally leading conductor is bonded to the wiring layer within the exposing region by ultrasonic bonding.

6. A method of manufacturing a circuit device in which a functional device and an externally leading conductor are mounted, the method comprising the steps of:

partially forming a coating metal layer onto a wiring layer formed on a substrate, thereby providing a coated region in which the wiring layer is coated and an exposing region in which the wiring layer is exposed;

connecting the functional device onto the coating metal layer within the coated region through solder; and

bonding the externally leading conductor directly to a portion of the wiring layer within the exposing region.

7. The manufacturing method of the circuit device, according to claim 6, wherein the wiring layer is made of aluminum.

8. The manufacturing method of the circuit device, according to claim 7, wherein the coating metal layer is made of metal having solder wetability superior to aluminum.

9. The manufacturing method of the circuit device, according to claim 8, the coating metal layer is made of nickel or copper.

10. The manufacturing method of the circuit device, according to claim 6, wherein the externally leading conductor is bonded onto the wiring layer within the exposing region by ultrasonic bonding.