Abstract:
A composite layer composed of an Ni layer and a Pd layer is formed on a solder pad, and a solder on the composite layer is composed of a solder containing no lead. Because a Pd layer (palladium layer) reduces phenomenons such as repellency of the solder, adhesiveness with the solder can be enhanced. Because a Pd layer has a higher degree of rigidity than a gold layer, thermal stress is absorbed into the Pd layer and buffered so as to reduce the degree of transmission of stress to the solder bump, or to the solder layer, by thermal stress.
Abstract:
A composite layer composed of an Ni layer and a Pd layer is formed on a solder pad, and a solder on the composite layer is composed of a solder containing no lead. Because a Pd layer (palladium layer) reduces phenomenons such as repellency of the solder, adhesiveness with the solder can be enhanced. Because a Pd layer has a higher degree of rigidity than a gold layer, thermal stress is absorbed into the Pd layer and buffered so as to reduce the degree of transmission of stress to the solder bump, or to the solder layer, by thermal stress.
Abstract:
A solder resist comprising a thermosetting resin is printed on a surface of an insulating board (7) having a conductor circuit (6). The solder resist is then heat-cured to form an insulating film (1) having a low thermal expansion coefficient. A laser beam (2) is then applied to the portion of the insulating film in which an opening is to be formed, to burn off the same portion for forming an opening (10), whereby the conductor circuit (6) is exposed. This opening may be formed as a hole for conduction by forming a metal plating film on an inner surface thereof. It is preferable that an external connecting pad be formed so as to cover the opening. The film of coating of a metal is formed by using an electric plating lead, which is preferably cut off by a laser beam after the electric plating has finished.
Abstract:
An electronic circuit substrate excellent in reliability, which comprises a porous ceramic sintered body with film devices such as a conductive circuit, a resistor and a capacitor directly formed on a surface thereof. A resin is filled in the pores of the porous ceramic sintered body, and the bottom surface of the film devices are fit into the pores and recesses on the surface of the porous ceramic sintered body in close contact therewith in a wedged state. A method of producing the aforesaid electronic circuit substrate comprises the steps of forming film devices directly on a surface of a porous ceramic sintered body. Then, filling the pores of the porous ceramic sintered body with a resin so as to fit the under surface of the film devices into the pores and recesses on the surface of the porous ceramic sintered body in close contact therewith in a wedge state.
Abstract:
A sliding material made of a sintered silicon carbide having open pores of a three dimensional network structure, the open pores present at a rate of 5 to 40 percent by volume, with the open pores being impregnated with a lubricant, where the lubricant is selected from a group of lubricants consisting of fluorine-type oils and silicone-type oils.
Abstract:
A circuit board comprises a first conductive post for electrically connecting to the first electrode of the semiconductor device, a first metal plate connecting to the first conductive post, a second conductive post for electrically connecting to the second electrode of the semiconductor device, a second metal plate connecting to the second conductive post, a third conductive post for electrically connecting to the third electrode of the semiconductor device, and a third metal plate connecting to the third conductive post.
Abstract:
An opening is formed in resin 20 by a laser beam so that a via hole is formed. At this time, copper foil 22, the thickness of which is reduced (to 3 μm) by performing etching to lower the thermal conductivity is used as a conformal mask. Therefore, an opening 20a can be formed in the resin 20 if the number of irradiation of pulse-shape laser beam is reduced. Therefore, occurrence of undercut of the resin 20 which forms an interlayer insulating resin layer can be prevented. Thus, the reliability of the connection of the via holes can be improved.
Abstract:
A flexible printed wiring board includes a first conductor layer in the element mounting part adjacent to the top surface of the wiring board; a second conductor layer in the element mounting part adjacent to the bottom surface of the wiring board; and a third conductor layer between the first conductor layer and the second conductor layer, wherein the first and third conductor layers extend through and beyond the bending part, and the second conductor layer is absent in the bending part.
Abstract:
A solder resist comprising a thermosetting resin is printed on a surface of an insulating board (7) having a conductor circuit (6). The solder resist is then heat-cured to form an insulating film (1) having a low thermal expansion coefficient. A laser beam (2) is then applied to the portion of the insulating film in which an opening is to be formed, to burn off the same portion for forming an opening (10), whereby the conductor circuit (6) is exposed. This opening may be formed as a hole for conduction by forming a metal plating film on an inner surface thereof. It is preferable that an external connecting pad be formed so as to cover the opening. The film of coating of a metal is formed by using an electric plating lead, which is preferably cut off by a laser beam after the electric plating has finished.
Abstract:
In a printed wiring board, an odd number (n) of conductive layers (11-13) and insulating layers (21-23) are alternately laminated upon another. The first conductive layer (11) is constituted as a parts connecting layer and the n-th conductive layer (13) is constituted as an external connecting layer which is connected to external connecting terminals (7). The second to (n−1)-th conductive layers (12) are constituted as current transmitting layers for transmitting internal currents. The surface of the n-th conductive layer (13) is coated with the outermost n-th insulating layer (23) in a state where the external connecting terminals (7) are exposed on the surface. It is preferable to constitute the initial insulating layers of a glass-cloth reinforced prepreg and the external insulating layers of a resin.