• CN: 11-2187/TH
  • ISSN: 0577-6686

›› 2004, Vol. 40 ›› Issue (10): 170-174.

• Article • Previous Articles     Next Articles

STUDY ON MELTING PROCESS CONTROLLING METHOD OF FINE PITCH SOLDER JOINTS BY LASER HEATING

Li Mingyu;Wang Chunqing;Kong Lingchao;Takahashi Kunio   

  1. Shenzhen Graduate School, Harbin Institute of Technology State Key Laboratory of Advanced Welding Production Technology, Harbin Institute of Technology Graduate School, Tokyo Institute of Technology
  • Published:2004-10-15

Abstract: In order to develop a no solder bridging assembly method for high density electronic devices, temperature distribution of joints of fine pitch QFP device is simulated under heating condition of laser single point and laser scanning. Then experiments of QFP256 device assembly are performed under heating condition of infrared furnace and laser scanning. Simulation results shows that temperature distribution in fine pitch joints is controlled by laser local heating characteristics, and then melting range of solder on the joint is controlled for defense solder bridging on adjacent leads. Experimental results show that suitable laser heating can carry out no bridging assembly for fine pitch devices.

Key words: Bridge, High density assembly, Laser soldering, Simulation, Grain size, Laser ultrasonics, Low carbon steel sheets, Time domain energy attenuation

CLC Number: