Abstract:
A circuit board includes an insulating substrate, a first conductive layer on the insulating substrate, a second conductive layer on the first conductive layer, and a third conductive layer covering the first conductive layer and the second conductive layer. The first conductive layer has a surface provided on the surface of the insulating substrate, and a surface having a width smaller than a width of the above surface. In this circuit board, the conductive layers have small impedances even if a high-frequency signal flows in the conductive layers.
Abstract:
The printed wiring board comprises, on at least one surface of an insulating film, a base metal layer and a conductive metal layer formed on the base metal layer, and is characterized in that in a section of the wiring board the bottom width of the conductive metal layer is smaller than the top width of the base metal layer. The circuit device comprises the printed wiring board and an electronic part mounted thereon. The process for producing a printed wiring board comprises bringing a base metal layer and a conductive metal layer into contact with an etching solution capable of dissolving the conductive metal to form a wiring pattern and then sequentially bringing the resultant into contact with a first treating solution capable of dissolving the metal for forming the base metal layer, a microetching solution capable of selectively dissolving the conductive metal and a second treating solution having a different chemical composition from the first treating solution in this order.
Abstract:
The wiring substrate comprises: a recess section and a projecting section formed on at least one surface of the wiring substrate; and wires formed on both the recess section and the projecting section.
Abstract:
A high-frequency wiring structure includes a microstrip line having a ground conductor, a dielectric disposed on the ground conductor, and a transmission conductor that is at least partially disposed in the dielectric. The transmission conductor is defined by a flat bottom parallel to the ground conductor, a pair of flat sides that are perpendicular to the ground conductor and are positioned on both sides of the flat bottom in the wiring width direction, and curved parts that continuously join the flat bottom and the pair of flat sides. The curved parts have a radius of curvature within the range of 5% to 50% of the thickness of the transmission conductor.
Abstract:
There is provided a structure for mounting a semiconductor part having improved productivity, in which a bump is detached from a land portion and a method of manufacturing a mounting substrate used therein. The structure for mounting the semiconductor part includes a mounting substrate 1 having an insulating substrate 2 on which a wiring pattern 3 and a land portion 4 are provided, a semiconductor part 5 mounted on the mounting substrate 1 using a bump 7 and the land portion 4, and an underfill 8 inserted between the semiconductor part 5 and the insulating substrate 2. An undercut portion 4c having an inverse tapered shape from the insulating substrate 2 to an upper surface of the land portion 4 is provided in an edge 4a of the land portion 4 in which the bump 7 is located, and the bump is inserted into the undercut portion. Accordingly, since the couple between the bump 7 and the land portion 4 becomes stronger, the bump is not detached from the land portion 4 when the underfill 8 expands or contracts.
Abstract:
There is provided a metal/ceramic circuit board capable of eliminating discrepancy during mounting of parts to improve the reliability of mounting of the parts. The metal/ceramic circuit board has a ceramic substrate 10, and a metal circuit plate (a copper plate 14) bonded to the ceramic substrate 10, the metal circuit plate having a thickness which is more than 0.25 mm and which is less than 0.3 mm, and the metal circuit plate having a skirt spreading length (a dimensional difference between the bottom and top portion of the peripheral edge portion of the metal circuit plate) of less than 50 μm.
Abstract:
A high-frequency wiring structure includes a microstrip line having a ground conductor, a dielectric disposed on the ground conductor, and a transmission conductor that is at least partially disposed in the dielectric. The transmission conductor is defined by a flat bottom parallel to the ground conductor, a pair of flat sides that are perpendicular to the ground conductor and are positioned on both sides of the flat bottom in the wiring width direction, and curved parts that continuously join the flat bottom and the pair of flat sides. The curved parts have a radius of curvature within the range of 5% to 50% of the thickness of the transmission conductor.
Abstract:
A substrate for packaging a semiconductor chip is disclosed. The substrate includes a dielectric layer, a plurality of conductive circuits and bonding pads formed on the dielectric layer, a metal thin deposition layer formed on the conductive circuits and the bonding pads, and a solder mask formed on the dielectric layer and the conductive circuits. The first ends of the bonding pads extend from the conductive circuits. The metal thin deposition layer has at least a portion to protrude out of the conductive circuits and the bonding pads such that the protruding portion of the metal thin deposition layer is not supported by the conductive circuits or the bonding pads. The bonding pads are exposed from the solder mask except that the second end of each bonding pad is covered by the solder mask in the manner that the protruding portion of the metal thin deposition layer is embedded in the solder mask. The present invention further provides a method for manufacturing a substrate.
Abstract:
Trace configurations for carrying high-speed digital differential signals provide for reduced conduction loss and improved signal integrity. In one embodiment, a circuit board has a first set of conductive traces disposed on non-conductive material, and a second set of conductive traces parallel to the first set and disposed within the conductive material. The second set is separated from the first set by non-conductive material. Corresponding traces of the first and second sets may be in a stacked configuration. In other embodiments, conductive material may be provided between corresponding traces of the first and second sets resulting in an “I-shaped” or “U-shaped” cross-section. In yet other embodiments, the trace configurations have “T-shaped” and “L-shaped” cross-sections.
Abstract:
A metal layer 12 of aluminum or an aluminum alloy is formed on at least one side of a ceramic substrate 10, and a resist 14 having a predetermined shape is formed on the metal layer 12. Then, an etchant of a mixed solution prepared by mixing ferric chloride with water without adding any acids is used for etching and removing an undesired portion of the metal layer 12 to form a metal circuit 12 on the at least one side of the ceramic substrate 10.