| 摘要 |
<p>A printed circuit board unit includes a first substrate (24), a second substrate (27), and a spacer (10). The second substrate is coupled to the first substrate via a solder material (26). The second substrate has different coefficient of thermal expansion from the first substrate. The spacer is disposed between the first substrate and the second substrate. The spacer is formed of a thermally-expandable material and a thermosetting material. The thermosetting material has a curing temperature higher than a melting point of the solder material.</p> |
