| 摘要 |
PURPOSE:To prevent flux from blowing out through a through-hole beneath a surface mounting component and gas from making a noise when it passes through a viahole at vacuum suction when an electric test is executed by a method wherein the opening of a through-hole is blocked by a copper foil where no component is mounted. CONSTITUTION:For instance, three one-sided copper plated plates 1 are bonded by pressure through the intermediary of prepregs 2 to form a multilayer printed board, an interlayer connection through-hole 5 is blocked by a copper foil 3. By this constitution, a test device can secure a sucking force large enough to pull a printed board by a vacuum pump at an electric test after the component is mounted. And soldering flux is prevented from blowing out through a through-hole beneath a component and standing. |
