SEMICONDUCTOR DEVICE WITH WELDED LEADS AND METHOD OF MANUFACTURING THE SAME

• US 20090008775A1
• Filed: 06/27/2008
• Published: 01/08/2009
• Est. Priority Date: 07/05/2007
• Status: Active Grant

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: NEC Electronics Corporation (Renesas Electronics Corporation)
• Inventors: TAKAHASHI, Kouhei, TANAKA, Takekazu
• Granted Patent: US 8,299,620 B2
• Time in Patent Office: Days
• US Class Current: 257/737
• CPC Class Codes: H01L 2224/05624 Aluminium [Al] as principal constituent
• CPC Class Codes: H01L 2224/05639 Silver [Ag] as principal constituent
• CPC Class Codes: H01L 2224/05644 Gold [Au] as principal constituent
• CPC Class Codes: H01L 2224/05647 Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2224/05655 Nickel [Ni] as principal constituent
• CPC Class Codes: H01L 2224/05669 Platinum [Pt] as principal constituent
• CPC Class Codes: H01L 2224/2919 with a principal constituent of the material being a polymer, e.g. polyester, phenolic based polymer, epoxy
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/37124 Aluminium [Al] as principal constituent
• CPC Class Codes: H01L 2224/37147 Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2224/40245 the item being metallic
• 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 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48464 the other connecting portion not on the bonding area also being a ball bond, i.e. ball-to-ball
• CPC Class Codes: H01L 2224/73221 Strap and wire connectors
• CPC Class Codes: H01L 2224/73263 Layer and strap connectors
• CPC Class Codes: H01L 2224/83205 Ultrasonic bonding
• CPC Class Codes: H01L 2224/83801 Soldering or alloying
• CPC Class Codes: H01L 2224/84205 : Ultrasonic bonding
• CPC Class Codes: H01L 2224/84214 : using a laser
• CPC Class Codes: H01L 2224/8485 : using a polymer adhesive, e.g. an adhesive based on silicone, epoxy, polyimide, polyester
• CPC Class Codes: H01L 2224/85214 : using a laser
• CPC Class Codes: H01L 23/49524 : the additional leads being a tape carrier or flat leads
• CPC Class Codes: H01L 23/49562 : for devices being provided for in H01L29/00
• CPC Class Codes: H01L 24/32 : of an individual layer connector
• 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 24/48 : of an individual wire connector
• CPC Class Codes: H01L 24/80 : Methods for connecting semiconductor or other solid state bodies using means for bonding being attached to, or being formed on, the surface to be connected
• CPC Class Codes: H01L 24/83 : using a layer connector
• CPC Class Codes: H01L 24/84 : using a strap connector
• CPC Class Codes: H01L 24/85 : using a wire connector wire bonding in general B23K20/004
• 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 2924/00011 : Not relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/01004 : 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 2924/01015 : Phosphorus [P]
• CPC Class Codes: H01L 2924/01028 : Nickel [Ni]
• 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 2924/0105 : Tin [Sn]
• CPC Class Codes: H01L 2924/01073 : Tantalum [Ta]
• 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 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/0665 : Epoxy resin
• CPC Class Codes: H01L 2924/1301 : Thyristor
• CPC Class Codes: H01L 2924/1305 : Bipolar Junction Transistor [BJT]
• CPC Class Codes: H01L 2924/13055 : Insulated gate bipolar transistor [IGBT]
• CPC Class Codes: H01L 2924/1306 : Field-effect transistor [FET]
• CPC Class Codes: H01L 2924/13091 : Metal-Oxide-Semiconductor Field-Effect Transistor [MOSFET]
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/19043 : being a resistor
• CPC Class Codes: H01L 2924/2076 : equal to or larger than 100 microns

Abstract

A semiconductor device and a manufacturing method for preventing mechanical and thermal damage to the semiconductor chip. A laser beam welds a first connection pad formed on a first external lead to a first electrode formed on the surface of the semiconductor chip. A first connection hole is formed in the first connection pad, and the first connection hole overlaps the first connection electrode. A laser beam irradiates an area including the first connection hole, and the first connection pad in a portion around the first connection hole is melted to form a melting section, that is welded to the first connection electrode to easily form a semiconductor device with more excellent electrical characteristics.

Claims

1. A semiconductor device comprising:

a semiconductor chip containing a first connection electrode formed on a top surface thereof; and

a first external lead including a first connection pad formed with a first connection hole,

wherein the first connection hole overlaps the first connection electrode, and a melting section of the first connection pad is welded to the first connection electrode in a portion around the first connection hole.

2. The semiconductor device according to claim 1, wherein the material of the first connection electrode is a material that does not melt when a portion of the first connection pad has started to melt.

3. The semiconductor device according to claim 1, wherein the first connection electrode includes an underlayer and a melt prevention layer formed above that underlayer.

4. The semiconductor device according to claim 1, wherein the first connection pad contains a base material and a melt accelerator layer formed on a top surface of the base material.

5. The semiconductor device according to claim 1, further comprises a bump electrode, wherein the first connection hole overlaps the bump electrode as substitute for the first connection electrode, and the melting section of the first connection pad is welded to the bump electrode.

6. The semiconductor device according to claim 5, wherein a portion of the bump electrode and a portion of the first connection pad melt and form the melting section.

7. The semiconductor device according to claim 5, wherein the bump electrode includes a base material, and melt prevention layer formed on a surface of the base material.

8. The semiconductor device according to claim 1, further comprises a first connection clip formed with a connection hole, wherein the first connection clip and the connection hole function as a substitute for the first connection pad and the first connection hole, respectively.

9. The semiconductor device according to claim 8, wherein

a second connection hole is further formed in the first connection clip;

the second connection hole overlaps the first external lead; and

the first connection clip is welded to the first external lead in a portion around the second connection hole.

10. The semiconductor device according to claim 8, wherein the first connection clip is electrically connected by conductive paste to the first external lead.

11. A semiconductor device according to claim 1, further comprising:

a second external lead including a second connection pad where a third connection hole is formed, and

a third external lead,

wherein the semiconductor chip includes a vertical MOSFET containing the first connection electrode serving as the source electrode, a second connection electrode serving as a gate electrode on the top surface, and a drain electrode formed on a rear surface opposite to the top surface,

wherein the third external lead connects electrically to the drain electrode, and

wherein the third connection hole overlaps the second connection electrode, and a melting section of the second connection pad is welded to the second connection electrode in a portion around the third connection hole.

12. The semiconductor device according to claim 11, further comprises another bump electrode, wherein the third connection hole overlaps the another bump electrode as a substitute for the second connection electrode, and the melting section of the second connection pad is welded to the another bump electrode.

13. A manufacturing method for a semiconductor device comprising:

preparing a semiconductor chip with a first connection electrode formed on a top surface thereof;

preparing a first external lead including a first connection pad formed with a first connection hole;

overlapping the first connection hole with the first connection electrode; and

irradiating a laser beam onto an area including the first connection hole, and welding the first connection pad to the first connection electrode in a portion around the first connection hole.

14. The manufacturing method for semiconductor device according to claim 13, wherein a light source of the laser beam is a YAG laser.

15. The manufacturing method for a semiconductor device according to claim 13, wherein the method uses a material that does not melt the first connection electrode, when starting to melt a portion of the first connection pad.

16. The manufacturing method for a semiconductor device according to claim 13, further comprises forming a bump electrode on the first connection electrode, wherein the first connection hole is overlapped with the bump electrode as a substitute for the first connection electrode, and the first connection pad is welded to the bump electrode as a substitute for the first connection electrode.

17. The manufacturing method for a semiconductor device according to claim 13, further comprising:

preparing a first connection clip that is formed with a connection hole at one end and a second connection hole at the other end, the first connection clip and the connection hole respectively functioning as a substitute for the first connection pad and the first connection hole;

overlapping the second connection hole with the first external lead; and

irradiating a laser beam onto an area including the second connection hole, and welding the first connection clip to the first lead in a portion around the second connection hole.

18. The manufacturing method for a semiconductor device according to claim 13, wherein the semiconductor chip includes a vertical MOSFET containing the first connection electrode serving as a source electrode, a second connection electrode serving as a gate electrode formed on the top surface, and a drain electrode formed on a rear surface opposite to the top surface, further comprising:

preparing a third external lead, and a second external lead including a second connection pad formed with a third connection hole,;

connecting the third external lead electrically to the drain electrode;

overlapping the third connection hole with the second connection electrode; and

irradiating a laser beam onto an area including the third connection hole, and welding the second connection pad to the second connection electrode in a portion around the third connection hole.

19. The manufacturing method for the semiconductor device according to claim 18, further comprises forming another bump electrode on the second connection electrode, wherein the third connection hole is overlapped with the another bump electrode as a substitute for the second connection electrode, and the second connection pad is welded to the another bump electrode as a substitute for the second connection electrode.