Importance

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Abstract

A structure for mounting a wiring board in which the wiring board including a ceramics insulating board, metallized wiring layers arranged on said insulating board, and a plurality of connection terminals mounted on said insulating board and electrically connected to said metallized wiring layer, is placed on a mother board having wiring conductors formed on the surface of an insulator which contains an organic resin, and the connection terminals of said wiring board are connected by brazing to the wiring conductors of said mother board, wherein a value F1 defined by the following formula (1): F1=L.times..DELTA..alpha./H.sup.2 (1) wherein L is a distance (mm) between the two connection terminals which are most separated away from each other among a plurality of connection terminals mounted on said insulating board, .DELTA..alpha. is a difference in the coefficient of thermal expansion (ppm/.degree. C.) between the insulating board of said wiring board and said mother board at 40 to 400.degree. C., and H is a height (mm) of brazing between said wiring board and said mother board. is not larger than 2000. This structure effectively loosens a difference in the thermal expansion between the wiring board and the mother board, and maintains favorable electric connection between the two for extended periods of time.

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First Claim