US 12,032,039 B2
Solder joint life predictor and solder joint life prediction method
Takuya Saeki, Tokyo (JP)
Assigned to MITSUBISHI ELECTRIC CORPORATION, Tokyo (JP)
Appl. No. 17/422,329
Filed by Mitsubishi Electric Corporation, Tokyo (JP)
PCT Filed Jan. 18, 2019, PCT No. PCT/JP2019/001505
§ 371(c)(1), (2) Date Jul. 12, 2021,
PCT Pub. No. WO2020/148896, PCT Pub. Date Jul. 23, 2020.
Prior Publication US 2022/0105583 A1, Apr. 7, 2022
Int. Cl. G01R 31/71 (2020.01); B23K 3/08 (2006.01); B23K 101/40 (2006.01); G01N 3/60 (2006.01); G06F 119/04 (2020.01); H05K 1/02 (2006.01)
CPC G01R 31/71 (2020.01) [B23K 3/08 (2013.01); G01N 3/60 (2013.01); H05K 1/0268 (2013.01); B23K 2101/40 (2018.08); G01N 2203/0224 (2013.01); G06F 2119/04 (2020.01)] 13 Claims
OG exemplary drawing
 
1. A solder joint life predictor comprising:
a temperature sensor to measure temperature of a solder joint on an electronic circuit board that drives a load;
a storage to store a reference acceleration factor, the reference acceleration factor being an acceleration factor based on a test condition of a thermal shock test of an electrical appliance including the electronic circuit board and a reference condition in an environment in which the electrical appliance is used;
a calculator to calculate an actual acceleration factor on the basis of a temperature variation range and a maximum reached temperature of the solder joint during one cycle from start to end of driving of the load, and to integrate acceleration factor ratios each obtained by dividing the actual acceleration factor by the reference acceleration factor for each one cycle from start to end of driving of the load to obtain an integrated value of the acceleration factor ratios; and
a determiner to predict life of the solder joint by comparing the integrated value of the acceleration factor ratios with a threshold.