Abstract:
A method of manufacturing a joint between metal and a ceramic substrate for a high temperature sensor. First, a predetermined hole is formed in the ceramic substrate to serve as a joint portion. A bonding layer is preferably disposed on the ceramic substrate to form on the inner surface and the surrounding portion of the hole. Next, the hole is filled with a supporting metal. Then, a conductive layer is formed on the supporting metal and the bonding layer. A metal signal conductive frame is then formed on the conductive layer. Next, a welding spot is formed through the metal signal conductive frame, the conductive layer and the supporting metal at the joint portion by a welding process.
Abstract:
A method for fabricating a printed circuit board includes the steps of: fabricating a printed circuit board having at least one collapsed portion; depositing a first solder resist in the collapsed portion; exposing the first solder resist-coated printed circuit board at a pressure lower than atmospheric pressure for a predetermined time; coating a second solder resist on the entire surface of the printed circuit board; and drying and hardening the first and the second solder resists. With this method, when a solder resist is coated, since an air space does not remain in a blind via hole, the reliability of the attachment between a printed circuit board and the solder resist layer is increased.
Abstract:
A first signal routing layer may be formed on a first surface of a printed circuit board (PCB). An array of interconnections may formed on the first surface of the PCB, the array of interconnections comprising at least one padless via formed within the PCB, the at least one padless via extending from the first signal routing layer to at least one conductive plane and/or a second signal routing layer. The at least one padless via may be in electrical contact with the at least one conductive plane and/or a conductive trace on the second signal routing layer. A component may be attached to the PCB, with a solder interconnection between the at least one padless via and a contact pad on a bottom surface of the component. The component may be, for example, an electronic component such as a ball grid array (BGA) component or a leadless surface mount component.
Abstract:
A semiconductor device includes: a multi-layered wiring substrate in which a multiple wiring pattern layers are laminated through insulating layers. The multi-layered wiring substrate has a first, semiconductor element mounting face and a second face opposite to the first face. A semiconductor element is mounted on and connected to connecting pads on the first face. A chip-capacitor is arranged on and connected to the connecting pads on the second face. An electric power supply circuit includes the chip-capacitor for supplying electric power to the semiconductor element. Conductor paths for electrically connecting the first connecting pads with the second connecting pads are substantially extended vertically and penetrate through the multi-layered wiring substrate through so as to reduce the length of the conductor paths to a minimum, so that the chip-capacitor is located at the opposite side of the semiconductor element.
Abstract:
Mesh holes 35a and 59a of upper solid layers 35 and upper solid layers 59 are formed to overlie on one another, so that the insulating properties of interlayer resin insulating layers 50 are not lowered. Here, the diameter of each mesh hole is preferably 75 to 300 &mgr;m. The reason is as follows. If the diameter of the mesh hole is less than 75 &mgr;m, it is difficult to overlay the upper and lower mesh holes on one another. If the diameter exceeds 300 &mgr;m, the insulating properties of the interlayer resin insulating layers deteriorate. In addition, the distance between the mesh holes is preferably 100 to 2000 &mgr;m. The reason is as follows. If the distance is less than 100 &mgr;m, the solid layer cannot function. If the distance exceeds 2000 &mgr;m, the deterioration of the insulating properties of the interlayer resin insulating film occurs.
Abstract:
Methods are provided for the manufacture of a conductive layer on an insulating layer and for the manufacture of a built-up circuit board, each include an innovative step of irradiating the surface of an insulating (resin) layer with ultraviolet light, so that a conventional swelling process can be eliminated or simplified.
Abstract:
An insulator substrate or printed circuit board (PCB) having a filled and plated via. A sidewall of the via and preferably opposite sides of the insulator substrate are first plated with a conductive material. The plated via is then filled with an electrically conductive fill composition. A conductive cap layer is preferably formed over both ends of the conductive fill composition and the opposite surfaces of the insulator substrate, and can be bonded to a surface mount contact as a land or a pad.
Abstract:
The present invention provides a solution to the problem of controlling the inter-layer impedance of a deposited thin film layer stack accommodating high-density interconnects. The invention enables high-density signal lines to be routed over a reference plane to achieve a desired characteristic impedance. In one embodiment, a first thin-film metal layer is formed on a planarized layer fabricated from multiple thin film dielectric layers. The reduced pad footprint in the first thin-film metal layer allows a major portion of the first thin-film metal layer to serve as a reference, or ground, plane to signal lines formed in a second thin-film metal layer that is separated from the first thin-film metal layer by a thin dielectric layer.
Abstract:
A solder mask manufacturing method adapted to apply a solder mask on a surface of a substrate of a circuit board, said surface is provided with a conductor pattern having an unsheltered portion and a sheltered portion which is covered by said solder mask. The method comprises the steps of: a) disposing a layer of semi-solid solder mask material having an expansion coefficient substantially the same as that of the substrate on the surface of said substrate to cover said copper conductor pattern, and a metal foil covering the material layer; b) applying pressure to the metal foil and applying baking treatment to cure the solder mask material in to solid; c) utilizing chemical solution and plasma etching to remove the metal foil and the solid solder mask material above the unsheltered portion of said copper conductor pattern respectively such that the unsheltered portion can be exposed; and d) using chemical solution to remove the residual metal foil.
Abstract:
A method of wave soldering a circuit board while avoiding reflow of a solder joint on the topside of the board from heat conducted from the solder wave through at least one via in the board in heat conducting relation with the topside solder joint, comprises subjecting the circuit board to a solder wave and absorbing heat being conducted from the solder wave through the at least one via with an endothermic material in the via hole which undergoes a heat absorbing reaction. The heat absorbing reaction of the endothermic material is preferably a phase change, such as melting. The melted endothermic material is retained in the via hole during wave soldering by capillary forces and a cap on the lower end of the via hole. A disclosed method of making the circuit board includes locating the endothermic material in the via hole by inserting a preform of the endothermic material into the via hole or hot dispensing the endothermic material into the via hole. An electronic board product for practicing the method/made by the method is also disclosed.