Process for bonding a semiconductor to a circuit substrate including a solder bump transferring step

• US 5,739,053 A
• Filed: 05/15/1995
• Issued: 04/14/1998
• Est. Priority Date: 10/27/1992
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Kawakita, Tetuo, Hatada, Kenzo
• Primary Examiner(s): GRAYBILL, DAVID E
• Application Number:
  US08/440,991
• Time in Patent Office: 1,065 Days
• Field of Search: 437/183, 437/211, 257/737, 257/738, 228/180.22
• US Class Current: 438/108
• CPC Class Codes: H01L 21/563 Encapsulation of active face of flip-chip device, e.g. underfilling or underencapsulation of flip-chip, encapsulation preform on chip or mounting substrate
• CPC Class Codes: H01L 21/6835 using temporarily an auxiliary support
• CPC Class Codes: H01L 2224/11003 for holding or transferring the bump preform
• CPC Class Codes: H01L 2224/13144 Gold [Au] as principal constituent
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/73203 Bump and layer connectors
• CPC Class Codes: H01L 2224/73204 the bump connector being embedded into the layer connector
• CPC Class Codes: H01L 2224/75 Apparatus for connecting with bump connectors or layer connectors
• CPC Class Codes: H01L 2224/75301 Bonding head
• CPC Class Codes: H01L 2224/75745 in the upper part of the bonding apparatus, e.g. in the bonding head
• CPC Class Codes: H01L 2224/81801 Soldering or alloying
• CPC Class Codes: H01L 2224/83192 wherein the layer connectors are disposed only on another item or body to be connected to the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/92125 the second connecting process involving a layer connector
• CPC Class Codes: H01L 24/29 of an individual layer connector
• CPC Class Codes: H01L 24/81 using a bump connector
• CPC Class Codes: H01L 24/83 using a layer connector
• 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 2924/01005 Boron [B]
• CPC Class Codes: H01L 2924/01006 : Carbon [C]
• CPC Class Codes: H01L 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01014 : Silicon [Si]
• CPC Class Codes: H01L 2924/01024 : Chromium [Cr]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/0103 : Zinc [Zn]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01046 : Palladium [Pd]
• CPC Class Codes: H01L 2924/01047 : Silver [Ag]
• CPC Class Codes: H01L 2924/01056 : Barium [Ba]
• CPC Class Codes: H01L 2924/01075 : Rhenium [Re]
• 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 2924/01083 : Bismuth [Bi]
• CPC Class Codes: H01L 2924/01087 : Francium [Fr]
• CPC Class Codes: H01L 2924/0132 : Binary Alloys
• CPC Class Codes: H01L 2924/0133 : Ternary Alloys
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/351 : Thermal stress

Abstract

A process wherein substrate preliminary formed with bumps by electrolytic plating or other technique is prepared. The semiconductor device is opposed to the substrate with the bumps so that the Al electrodes of the semiconductor device are aligned with respect to the bumps and brought into contact with each other. Then, the Al electrodes of the semiconductor device and the bumps are bonded together by the application of pressure and heat with an Au--Al alloy layer formed therebetween. Subsequently, the bumps are peeled off the substrate so as to be transferred to the respective Al electrodes. Thereafter, the semiconductor device is opposed to a circuit board so that the bumps are aligned with respect to the electrodes of wiring and brought into contact with them. Then, the bumps and the electrodes of wiring are bonded together more securely by the application of a larger pressure at a higher temperature or by the application of pressure and heat for a longer period of time than in the preceding process with another Au--Al alloy layer newly formed therebetween to cover a wider range. Thereafter, the bumps and electrodes of wiring are fixed and connected by means of a photo-curing insulating resin. Thus, the bonds between the Al electrodes and the bumps are strengthened while preventing the considerable deformation of the bumps before they are connected to the electrodes of wiring. According to the connecting method, connecting reliability is greatly improved when the transfer method whereby the bumps are easily formed on the electrodes of the semiconductor device at low cost is applied to the flip flop method or to the MBB method.

Claims

1. A method of packaging a semiconductor apparatus having a circuit board made of glass or plastic on which electrodes of wiring are formed and having a semiconductor device on which electrodes are formed to be connected to said electrodes of wiring via bumps composed of a metallic material having a melting point exceeding the highest temperature at which said circuit board can be used when the semiconductor device is mounted on said circuit board, said method comprising:

a preparation step of preliminarily forming a substrate with bumps on which the bumps are positioned corresponding to the electrodes of said semiconductor device;

a transferring/bonding process that includes the steps of,

positioning said semiconductor device opposite to the substrate with bumps so that the electrodes of said semiconductor device are aligned with the bumps,

applying a pressure to either said semiconductor device or said substrate with bumps so that one is pressed against the other,

heating the electrodes of the semiconductor device and said bumps to form an alloy layer between said electrodes of the semiconductor device and said bumps, and

then transferring said bumps from the substrate to the electrodes of the semiconductor device;

a re-alloying process that includes the steps of,

positioning said semiconductor device opposite to said circuit board having said electrodes of wiring so that the bumps, which were transferred and bonded to the electrodes of the semiconductor device in said transferring/bonding process, are aligned with said electrodes of wiring,

applying a pressure to either said semiconductor device or the circuit board so that one is pressed against the other,

heating the electrodes of the semiconductor device and said bumps to form an alloy layer therebetween, which covers a wider range, and which strengthens the bonds between the electrodes of said semiconductor device and said bumps that were obtained in said transferring/bonding process; and

a connecting step for strengthening an electrical connection between said bumps and said electrodes of wiring that includes the step of applying pressure without heating to either said semiconductor device or said circuit board so that one is pressed against the other after said re-alloying process.

2. A method of fabricating a semiconductor apparatus according to claim 1,

wherein the pressure applied in said re-alloying process is larger than the pressure applied in said transferring/bonding process.

3. A method of fabricating a semiconductor apparatus according to claim 1,

wherein heating in said re-alloying process is performed at a higher temperature than the temperature in said transferring/bonding process.

4. A method of fabricating a semiconductor apparatus according to claim 1, 2 or 3,

wherein the application of heat and pressure in said re-alloying process is performed for a longer period of time than in said transferring/bonding process.

5. A method of packaging a semiconductor apparatus according to claim 2,

wherein said re-alloying process and said connecting step for providing connections between the bumps and the electrodes of wiring are performed using the same tool.

6. A method of packaging a semiconductor apparatus according to claim 1,

wherein said connecting step for strengthening connections between the bumps and electrodes of wiring is performed at least by fixing said bumps and electrodes of wiring by means of insulating resin.

7. A method of packaging a semiconductor apparatus according to claim 1, wherein said circuit board is made of a material selected from boron-silicate glass, barium boron-silicate glass, soda glass and soda barium silicate glass.

8. A method of packaging a semiconductor apparatus according to claim 1, wherein said circuit board is made of a material selected from glass-epoxy resin, polyimide resin, heat-resistant epoxy resin and paper phenol resin.

9. The method of packaging a semiconductor apparatus according to claim 1,

wherein said bumps are made of gold.

10. The method of packaging a semiconductor apparatus according to claim 1,

wherein the electrodes of said semiconductor device are made of Al.