摘要:
The problem to be solved by the invention is to provide an epoxy resin composition for a prepreg, which is used in the manufacture of a printed circuit board containing a multilayer printed circuit board, wherein the epoxy resin composition for a prepreg is characterized by containing as essential components, a phosphorus compound that has 1.8 or more and less than 3 on average of a phenolic hydroxyl group that is reactive to an epoxy resin in the molecule, and that has 0.8 or more on average of a phosphorus element; a bifunctional epoxy resin that has 1.8 or more and less than 2.6 on average of epoxy groups in the molecule; a multi-functional epoxy resin that contains 2.8 or more on average of epoxy groups in one molecule; a hardening agent; an inorganic filler; and a molybdenum compound, wherein the epoxy resin composition for a prepreg is obtained by blending a pre-reacted epoxy resin, which is obtained by reacting at least the phosphorus compound with the bifunctional epoxy resin and the multi-functional epoxy resin, or the bifunctional epoxy resin only in advance, the bifunctional epoxy resin or the multi-functional epoxy resin, the hardening agent, the inorganic filler, and the molybdenum compound, which is excellent in flame retardance, heat resistance, thermal stiffness, and excellent in hole position accuracy without the production of a harmful substance at the time of combustion, a prepreg using the epoxy resin composition for a prepreg, and a multilayer printed circuit board using the prepreg.
摘要:
A multilayer interconnection substrate is disclosed that includes a multilayer interconnection layer having at least a first interconnection layer and a second interconnection layer stacked with an insulating layer provided therebetween, and a connection via configured to electrically connect the first interconnection layer and the second interconnection layer. The connection via includes an internal conductor and a metal film covering the internal conductor. The internal conductor is an aggregate of metal particles.
摘要:
A circuit board has a low thermal expansion coefficient that suits the thermal expansion coefficient of an element to be mounted thereupon and can prevent the occurrence of delamination and cracking of a core layer when the circuit board is used in a low temperature environment. The circuit board is constructed by laminating a core layer and at least one wiring layer, where the at least one wiring layer has slightly smaller external dimensions in a planar direction than the core layer.
摘要:
A semiconductor device includes a mount substrate and a semiconductor chip mounted upon the mount substrate via a metal bump, wherein metal bump includes an inner part joined to the semiconductor chip and an outer part covering the inner part, the outer part having an increased hardness as compared with the inner part.
摘要:
A transport channel selecting apparatus is provided, in which the transport channel selecting apparatus includes: a storage for storing information on combinations of transport blocks of transport channels to be transmitted to a radio base station; a transmission buffer for storing transport blocks of the transport channels; an address generation part for generating an address by using numbers of the transport blocks stored in the transmission buffer for each transport channel; an extraction part for extracting, from the storage, information on a combination of transport blocks of transport channels corresponding to the address; and a selection part for selecting transport blocks from the transmission buffer according to the combination indicated by the extracted information.
摘要:
A semiconductor device includes a support body, a first substrate provided on a surface at one side of the support body, a second substrate provided on a surface at the other side of the support body, and a semiconductor chip provided on the first substrate exposed to an opening part piercing the support body and the second substrate. The first substrate includes a first dielectric layer and a wiring layer, a plurality of first electrodes connected to the semiconductor chip which first electrodes are provided on a first surface of the first substrate exposed to an inside of the opening part, and the second substrate includes a second dielectric layer made of a material substantially the same as the first dielectric layer.
摘要:
In a file management method, a management entry is recorded in a predetermined position, and creation or deletion of a file is carried out. During file creation or deletion, data relating to the management entry and a file deletion destination entry of a file to be deleted or a file creation destination entry of a file to be created are updated, whereby the latest link is created among the management entry, the deletion entry, and the unused entry. So, even when a deletion entry or an unused entry is located in a backward position in the directory, these entries can be speedily detected during file formation regardless of the number of files.
摘要:
A transport channel selecting apparatus is provided, in which the transport channel selecting apparatus includes: a storage for storing information on combinations of transport blocks of transport channels to be transmitted to a radio base station; a transmission buffer for storing transport blocks of the transport channels; an address generation part for generating an address by using numbers of the transport blocks stored in the transmission buffer for each transport channel; an extraction part for extracting, from the storage, information on a combination of transport blocks of transport channels corresponding to the address; and a selection part for selecting transport blocks from the transmission buffer according to the combination indicated by the extracted information.
摘要:
The present invention discloses a system and a method for transmitting data in a shield machine and for calculating the filling amount of a void by detecting the distance to the natural ground. The system and the method are capable of transmitting analogue signals or signals of relatively high frequencies with reliability, enabling an unskilled operator to accurately detect buried articles and accurately carry out the back-filling work. Therefore, an optical rotary joint (100) is disposed between a rotary cutter head (10) and a non-rotary shield body (2) to count time taken to detect the peak value of a reflected signal larger than a standard value or time taken to detect the zero cross position present prior to the peak value. In accordance with the counted time, the distance between the antenna and the natural ground is calculated and displayed. Then, the void volume is calculated in accordance with the distance so that a target value of the back-filling amount is set.
摘要:
Disclosed herein is a low hydrogen type coated electrode comprising a steel core wire entirely coated with a coating agent, wherein the coating agent contains, by weight, 35-55% CaCO.sub.3, 1-4% SrCO.sub.3, 1.5-4% CaF.sub.2, 1-5% TiO.sub.2, 5-12% SiO.sub.2, 3-9% Si, 1-6% Mn and 15-40% Fe and fulfills the following relationships:CaCO.sub.3 /CaF.sub.2=from 9 to 25, andFe/CaF.sub.2=from 5 to 22.The low hydrogen type coated electrode produces excellent effects particularly when applied to downward welding for circumferential butt joints of pipes.