Surface reformation method of high polymer material

• US 6,423,405 B1
• Filed: 08/27/1999
• Issued: 07/23/2002
• Est. Priority Date: 03/23/1995
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Shirai, Mitugu, Sasaki, Hideaki, Shibuya, Tsutomu, Kazui, Shinichi, Katayama, Kaoru, Iwata, Yasuhiro
• Primary Examiner(s): LAM, CATHY FONG FONG
• Application Number:
  US09/384,105
• Publication Number:
  US 20020048664A1
• Time in Patent Office: 1,061 Days
• Field of Search: 428/209, 428/345, 228/180.21, 228/223, 174/259, 204/157.15
• US Class Current: 428/345
• 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 2224/16 of an individual bump connector
• CPC Class Codes: H01L 2224/73203 Bump and layer connectors
• CPC Class Codes: H01L 2224/81191 wherein the bump connectors are disposed only on the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/81801 Soldering or alloying
• CPC Class Codes: H01L 24/81 using a bump 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 2924/01004 Beryllium [Be]
• CPC Class Codes: H01L 2924/01005 Boron [B]
• CPC Class Codes: H01L 2924/01006 Carbon [C]
• CPC Class Codes: H01L 2924/01029 Copper [Cu]
• CPC Class Codes: H01L 2924/01033 Arsenic [As]
• CPC Class Codes: H01L 2924/014 Solder alloys
• CPC Class Codes: H01L 2924/09701 Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/12042 LASER
• CPC Class Codes: H01L 2924/14 Integrated circuits
• CPC Class Codes: H01L 2924/15787 Ceramics, e.g. crystalline carbides, nitrides or oxides
• CPC Class Codes: H05K 2201/0154 Polyimide
• CPC Class Codes: H05K 2201/10674 Flip chip
• CPC Class Codes: H05K 2201/10734 : Ball grid array [BGA]; Bump grid array
• CPC Class Codes: H05K 2203/0783 : Using solvent, e.g. for cleaning; Regulating solvent content of pastes or coatings for adjusting the viscosity
• CPC Class Codes: H05K 2203/107 : Using laser light shaping a substrate by laser ablation H05K3/0026
• CPC Class Codes: H05K 3/22 : Secondary treatment of printed circuits H05K3/1283 takes precedence; embedding circuits in grooves by pressure H05K3/107
• CPC Class Codes: H05K 3/303 : Surface mounted components, e.g. affixing before soldering, aligning means, spacing means H05K3/32 takes precedence
• CPC Class Codes: H05K 3/305 : Affixing by adhesive
• CPC Class Codes: H05K 3/3436 : having an array of bottom contacts, e.g. pad grid array or ball grid array components
• CPC Class Codes: H05K 3/3452 : Solder masks
• CPC Class Codes: Y02P 70/50 : Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10T 29/49144 : by metal fusion
• CPC Class Codes: Y10T 428/24917 : including metal layer
• CPC Class Codes: Y10T 428/2809 : including irradiated or wave energy treated component

Abstract

There is disclosed a surface reformation method of a high polymer material such that by irradiating and excimer-laser beam to only a predetermined area in which electronic parts and the like are temporarily immobilized by a liquid on a substrate which has a high polymer layer on the surface, wettability of the liquid for temporary immobilization only with respect to the predetermined area is improved. After the electronic parts are temporarily immobilized on the substrate by using the method, the electronic parts can be soldered with preferable durability by a fluxess reflow soldering.

Claims

1. A circuit board, comprising:

a substrate; and

a high polymer material layer formed on a surface of said substrate, including a first area of said high polymer material layer on which to implement an electronic part, and a second area different from said first area of said high polymer material layer on which no electronic part is to be implemented;

wherein said first area is an area processed by irradiating a light energy, the wavelength of said light energy being in a range from 100 to 600 nm, and the energy density of said light energy being more than 0.03 J/cm² and less than or equal to 0.5 J/cm²; and

the wettability on said first area is greater than the wettability on said second area, in accordance with a liquid material contact angle on said first area being smaller than that on said second area.

2. A circuit board according to claim 1, wherein the wavelength of said light energy is longer than 180 nm.

3. A circuit board according to claim 1, wherein the light energy is irradiated onto said first area in at least one pulse of duration 20 to 100 ns.

4. A circuit board according to claim 1, wherein the energy density of said light energy is between 0.05 J/cm² and 0.15 J/cm² inclusive.

5. A circuit board according to claim 1 further comprising a metal pattern on said substrate below said first area of the high polymer material layer.

6. A circuit board according to claim 5, wherein said high polymer material layer is a polyimide system resin layer.

7. A circuit board according to claim 1, wherein said liquid material contact angle on said first area is less than 20 degrees.

8. A circuit board according to claim 1, wherein a liquid material having said liquid material contact angle on said first and second areas is an alcohol system solvent.