摘要:
A method of manufacturing a printed wiring board includes preparing a wiring substrate having a conductive circuit, coating a solder-resist layer over the conductive circuit, leveling a surface of the solder-resist layer so as to obtain a maximum surface roughness in a predetermined range, removing the resin film from the surface of the solder-resist layer, and forming multiple openings in the surface of the solder-resist layer to expose multiple portions of the conductive circuit so as to form multiple conductive pads for mounting an electronic components.
摘要:
A method of manufacturing a printed wiring board with solder bumps includes forming a solder-resist layer having small and large apertures exposing a respective conductive pad of the printed wiring board, loading a solder ball in each of the small and large apertures using a mask with aperture areas corresponding to the apertures of the solder-resist layer, forming a first bump having a first height, from the solder ball in the small aperture, and a second bump having a second height, from the solder ball in the large aperture, the first height being greater than the second height, and pressing a top of the first bump such that the first height becomes substantially the same as the second height. A multilayer printed wiring board includes a solder-resist layer with apertures of differing sizes and solder bumps having substantially equal volumes but a difference in height no greater than 10 μm.
摘要:
A solder ball loading apparatus for loading solder balls onto pads of a printed wiring board includes a holding device for holding a printed wiring board having pads and holding a ball array mask having of openings that correspond to pads of the printed wiring board, one or more cylinder members positioned over the holding device such that an opening portion of the cylinder member faces the holding device, the cylinder member gathering solder balls on the surface of the ball array mask under the cylinder member by suctioning air through the opening portion of the cylinder member, and a conveyor mechanism for moving the ball array mask and the printed wiring board relative to the cylinder member such that solder balls gathered under the opening portion of the cylinder member can be loaded onto the pads of the printed wiring board through the openings of the ball array mask held by the holding device.