Title :
Line-structured laser scanning measurement system for BGA lead coplanarity
Author :
Sun, Changku ; Shi, Hongyan ; Qiu, Yu ; Ye, Shenghua
Author_Institution :
State Key Lab. of Precision Meas. Technol. & Instrum., Tianjin Univ., China
Abstract :
This paper presents line-structured laser scanning measurement technology in SMT-based BGA chip leads´ coplanarity. An experimental measurement system is put forward. A corresponding mathematical model and contact-datum-plane assessment method on BGA chip lead coplanarity is established. A study of optical image splitting and splicing technology is made illustrating the capability of higher resolution. The experimental studies on a 20×20 BGA chip is carried out; the inaccuracy error of the measurement system is 2σ=0.033 mm
Keywords :
ball grid arrays; inspection; integrated circuit packaging; measurement by laser beam; optical scanners; surface mount technology; BGA lead coplanarity; SMT; contact-datum-plane assessment method; line-structured laser scanning measurement system; mathematical model; optical image splitting; resolution; splicing technology; Charge coupled devices; Laser beams; Lead; Lenses; Mathematical model; Mathematics; Optical sensors; Semiconductor device measurement; Size measurement; Splicing;
Conference_Titel :
Circuits and Systems, 2000. IEEE APCCAS 2000. The 2000 IEEE Asia-Pacific Conference on
Conference_Location :
Tianjin
Print_ISBN :
0-7803-6253-5
DOI :
10.1109/APCCAS.2000.913620
