Electronic device and manufacturing method

• US 7,993,984 B2
• Filed: 04/21/2008
• Issued: 08/09/2011
• Est. Priority Date: 07/13/2007
• Status: Expired due to Fees

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Yokota, Yasuo, Yoshida, Hisahiko
• Primary Examiner(s): Wagner; Jenny L.
• Application Number:
  US12/106,459
• Publication Number:
  US 20090014873A1
• Time in Patent Office: 1,205 Days
• Field of Search: 257/795, 257/E23.127, 438/127
• US Class Current: 438/127
• CPC Class Codes: B23K 1/018 Unsoldering; Removal of melted solder or other residues
• CPC Class Codes: H01L 21/56 Encapsulations, e.g. encapsulation layers, coatings
• CPC Class Codes: H01L 21/67126 Apparatus for sealing, encapsulating, glassing, decapsulating or the like processes H01L23/02, H01L23/28
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/16227 the bump connector connecting to a bond pad of the item
• 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 2224/81052 Detaching bump connectors, e.g. after testing unsoldering in general B23K1/018
• CPC Class Codes: H01L 2224/81203 Thermocompression bonding, e.g. diffusion bonding, pressure joining, thermocompression welding or solid-state welding
• CPC Class Codes: H01L 2224/81801 Soldering or alloying
• CPC Class Codes: H01L 2224/831 the layer connector being supplied to the parts to be connected in the bonding apparatus
• CPC Class Codes: H01L 23/3185 the coating covering also the sidewalls of the semiconductor body
• CPC Class Codes: H01L 24/81 using a bump connector
• 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 2924/01006 Carbon [C]
• CPC Class Codes: H01L 2924/01013 Aluminum [Al]
• 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 2924/0105 : Tin [Sn]
• 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 2924/19041 : being a capacitor
• CPC Class Codes: H01L 2924/3511 : Warping
• CPC Class Codes: H05K 2201/0212 : Resin particles
• CPC Class Codes: H05K 2201/10689 : Leaded Integrated Circuit [IC] package, e.g. dual-in-line [DIL]
• CPC Class Codes: H05K 2201/10734 : Ball grid array [BGA]; Bump grid array
• CPC Class Codes: H05K 2201/10977 : Encapsulated connections applying non-metallic protective coatings for encapsulating mounted components H05K3/284
• CPC Class Codes: H05K 2203/176 : Removing, replacing or disconnecting component; Easily removable component thermal arrangements, e.g. to prevent overheating H05K1/0201
• CPC Class Codes: H05K 2203/304 : Protecting a component during manufacturing
• CPC Class Codes: H05K 3/284 : for encapsulating mounted components H05K1/185 takes precedence
• CPC Class Codes: H05K 3/305 : Affixing by adhesive
• CPC Class Codes: Y02P 70/50 : Manufacturing or production processes characterised by the final manufactured product

Abstract

An electronic device including a semiconductor device with a plurality of bump electrodes, a mounting board connected to the semiconductor device, thermally expandable particles, and adhesive. The thermally expandable particles are provided on the sides of the semiconductor device and the surface of the mounting board around a projected area of the semiconductor device. The adhesive is provided on the sides of the semiconductor device and the surface of the mounting board such that it covers the area of thermally expandable particles. This improves the impact resistance of the semiconductor device soldered onto the mounting board, and also facilitates removal of the semiconductor device from the mounting board when the semiconductor device needs repair.

Claims

1. A method of manufacturing an electronic device, comprising steps of:

electrically connecting a semiconductor device and a mounting board, the semiconductor device having a bottom face facing the mounting board and including a plurality of connecting terminals and a side face adjacent to the bottom face; and

applying thermally expandable particles to the side face of the semiconductor device and a surface of the mounting board around a projected area of the semiconductor device, and then covering the thermally expandable particles with adhesive,

wherein the thermally expandable particles are located adjacent to the side face of the semiconductor device and the surface of the mounting board around the projected area of the semiconductor device.

2. The method of manufacturing the electronic device of claim 1, wherein:

the electrically connecting step adopts reflow soldering, and

the thermally expandable particles are applied by injecting the thermally expandable particles together with disperse media from an injector in the applying step.

3. The method of manufacturing the electronic device of claim 2, wherein:

the injector in the applying step has a first nozzle and a second nozzle for separately injecting the thermally expandable particles and the adhesive, the first nozzle and the second nozzle being disposed with a predetermined distance in between, and at least one of an injection pressure and injection time of the first nozzle and the second nozzle being independently controllable; and

the thermally expandable particles are injected from the first nozzle to the side of the semiconductor device and the surface of the mounting board around the projected area of the semiconductor device, and then the adhesive is injected from the second nozzle so as to cover the thermally expandable particles.

4. The method of manufacturing the electronic device of claim 2, wherein the thermally expandable particles are dispersed in disperse media in the applying step.

5. The method of manufacturing the electronic device of claim 3, wherein a width of a rectangular tube of the second nozzle seen from a direction of movement is wider than a width of a rectangular tube of the first nozzle seen from a direction of movement, and the disperse media contains an adhesive resin component.

6. The method of manufacturing the electronic device of claim 4, wherein the disperse media contains an adhesive resin component.

7. The method of manufacturing the electronic device of claim 1, wherein:

electrodes included on one main face of the semiconductor device and aligned with board electrodes of the mounting board are electrically connected with the board electrodes via solder bumps in the electrically connecting step; and

the adhesive applied in the applying step is thermosetting adhesive, and is cured for bonding and fixing in a fixing step.

8. The method of manufacturing the electronic device of claim 7, wherein an expansion temperature of the thermally expandable particles is higher than a curing temperature of the adhesive and not higher than 260°

C.

9. The method of manufacturing the electronic device of claim 1, wherein an expansion temperature of the thermally expandable particles is higher than a curing temperature of the adhesive.