| 摘要 |
<p>PURPOSE: To provide a sufficient amount of joint volume and a reliable connecting height by, e.g. stencil-printing a solder paste having low viscosity and high metal content through apertures of a ultrathick stencil and forming bumps on a metal pad of a part. CONSTITUTION: Solder paste deposits 21 are stencil-printed on a pad 13 of a part 10. The solder, after being heated to its reflow temperature, is solidified to form bumps on the pad 13. A stencil printing is made through apertures 20 of a ultrathick stencil 19. Each aperture 20 is trapezoidal in vertical cross section, with its upper opening being smaller than its bottom opening and its walls inclined at an angle ranging from 1 to 45 deg. with respect to its vertical surface. A solder paste, having a low viscosity and a high metal content, is used. It is arranged so that the deposits 21 cover either the same area as the pad 13 or an area larger than that of the pad 13 at a ratio ranging from 1.5:1 to 5:1.</p> |
