Title:
ELECTRONIC DEVICE
Document Type and Number:
Japanese Patent JP2019021768
Kind Code:
A
Abstract:
To provide an electronic device in which deterioration of solder life due to stress can be restrained, even when a filler added to resin is settled upon resin curing.SOLUTION: A print circuit board 3 is formed by laminating a core layer 3a on an upper surface and a surface layer 3b on a lower surface. Electronic components 4 are mounted on both surfaces of the print circuit board 3 by a solder 8. The print circuit board 3 is housed in an enclosure, and is filled with liquid sealant added with a filler so as to form resin layers 5, 6. On the lower surface of the print circuit board 3, a low distribution layer 6a is formed in contact with the electronic component 4 by settlement of the filler. The low distribution layer 6a has a large linear coefficient of expansion compared with the resin layer 6 containing the filler, and the stress of thermal strain due to temperature change is applied to the solder 8. Since the degree of elasticity (Young's modulus) is set low, the surface layer 3b can absorb stress, and thereby stress to the solder 8 is reduced and deterioration of solder life can be suppressed.SELECTED DRAWING: Figure 1
Inventors:
MATSUMOTO EIICHI
Application Number:
JP2017139062A
Publication Date:
February 07, 2019
Filing Date:
July 18, 2017
Export Citation:
Assignee:
DENSO CORP
International Classes:
H01L23/12; H01L23/29; H01L23/31; H01L25/065; H01L25/07; H01L25/18; H05K1/03; H05K1/18; H05K5/00
Domestic Patent References:
| JP2007329311A | 2007-12-20 | |||
| JP2007329441A | 2007-12-20 | |||
| JP2004179313A | 2004-06-24 | |||
| JP2005252219A | 2005-09-15 | |||
| JP2004281695A | 2004-10-07 |
Foreign References:
| WO2014007129A1 | 2014-01-09 |
Attorney, Agent or Firm:
Patent Business Corporation Sato International Patent Office