摘要:
A multilayer printed wiring board includes a mounting portion supporting a semiconductor device and a layered capacitor portion including first and second layered electrodes and a ceramic high-dielectric layer therebetween. The first layered electrode is connected to a ground line and the second layered electrode is connected to a power supply line. The ratio of number of via holes, each constituting a conducting path part electrically connecting a ground pad to the ground line of a wiring pattern and passing through the second layered electrode in non-contact, to number of ground pads is 0.05 to 0.7. The ratio of number of second rod-shaped conductors, each constituting a conducting path part electrically connecting a power supply pad to the power supply line of the wiring pattern and passing through the first layered electrode in non-contact, to number of power supply pad is 0.05 to 0.7.
摘要:
A filet F is added to a portion constituting a corner portion C equal to or smaller than 90° in a crossing portion X of wiring patterns 58b, 58c and 58d, and a wiring pattern 58 is formed. Since the filet F is added, the wiring patterns are not made thin and are not disconnected in the crossing portion X. Further, since there is no stress concentrated to the crossing portion X, disconnection is not caused in the wiring patterns and no air bubbles are left between the crossing portion X of the wiring patterns and an interlayer resin insulating layer so that reliability of a printed wiring board is improved.
摘要:
A multi-layer printed wiring board includes a board covered with a conductor layer, an interlayer insulating resin layer, an etched metal film on the interlayer insulating resin layer, and a via hole. The interlayer insulating resin layer has a fibrous substrate. The via hole has an electrolytic plated film and an electrolessly plated film and connects the conductor layer of the board and the etched metal film.
摘要:
A filet F is added to a portion constituting a corner portion C equal to or smaller than 90° in a crossing portion X of wiring patterns 58b, 58c and 58d, and a wiring pattern 58 is formed. Since the filet F is added, the wiring patterns are not made thin and are not disconnected in the crossing portion X. Further, since there is no stress concentrated to the crossing portion X, disconnection is not caused in the wiring patterns and no air bubbles are left between the crossing portion X of the wiring patterns and an interlayer resin insulating layer so that reliability of a printed wiring board is improved.
摘要:
A board 20 is provided with a Cu film 30 as a conformal mask, in which are formed a register mark 30b and an opening 3a through which a via hole is formed. A camera senses this register mark 30b so that the position of the board 30 is determined. A laser beam is directed to the approximate position of the opening 30a, so that the opening 26a through which the via hole is drilled is formed. The accuracy of the position of the opening of the via hole depends on the accuracy of the position of the opening 30a in the Cu film 30 as the conformal mask. Therefore, the via hole can be formed at an adequate position despite the low accuracy of the position for laser irradiation.
摘要:
A multi-layer printed wiring board includes a board covered with a conductor layer, an interlayer insulating resin layer, an etched metal film on the interlayer insulating resin layer, and a via hole. The interlayer insulating resin layer has a fibrous substrate. The via hole has an electrolytic plated film and an electrolessly plated film and connects the conductor layer of the board and the etched metal film.
摘要:
A filet F is added to a portion constituting a corner portion C equal to or smaller than 90° in a crossing portion X of wiring patterns 58b, 58c and 58d, and a wiring pattern 58 is formed. Since the filet F is added, the wiring patterns are not made thin and are not disconnected in the crossing portion X. Further, since there is no stress concentrated to the crossing portion X, disconnection is not caused in the wiring patterns and no air bubbles are left between the crossing portion X of the wiring patterns and an interlayer resin insulating layer so that reliability of a printed wiring board is improved.
摘要:
A copper-clad laminate is provided which includes an insulative substrate having laminated on one or either side thereof a copper foil whose one side is roughened, the copper foil having formed on the roughened surface side thereof a metal layer whose melting point is lower than that of zinc. There is also provided a circuit board for a printed wiring board, including an insulative substrate having a conductive circuit formed on one side thereof and viaholes formed in through-holes extending from the other side of the insulative substrate to the conductive circuit, there being formed between the one side of the insulative substrate and the conductive circuit a metal layer whose melting point is lower than that of zinc. No desmearing is required in making the circuit board, and so a circuit board for a multilayer printed wiring board can be produced which is superior in stability of the inter-layer electrical connection.
摘要:
A filet F is added to a portion constituting a corner portion C equal to or smaller than 90° in a crossing portion X of wiring patterns 58b, 58c and 58d, and a wiring pattern 58 is formed. Since the filet F is added, the wiring patterns are not made thin and are not disconnected in the crossing portion X. Further, since there is no stress concentrated to the crossing portion X, disconnection is not caused in the wiring patterns and no air bubbles are left between the crossing portion X of the wiring patterns and an interlayer resin insulating layer so that reliability of a printed wiring board is improved.
摘要:
Method and apparatus for controlling the cooling of a hermetic type control box accommodating therein electronic apparatus by means of a cooling system. A cooling member of the cooling system is disposed at an upper portion of a hermetically closed chamber in which the electronic apparatus is housed. On the basis of measurements of intra-box temperature and extra-box temperature, control is so performed that the intra-box temperature is maintained higher than the extra-box temperature by a predetermined value when the cooling is being effected within the control box by means of the cooling system.