Abstract: For reflow soldering, radiant heating is applied to one surface of a printed circuit board on which electronic components are placed and onto which cream solder is supplied and at the same time hot air is blown locally and roughly perpendicular to to-be-connected points on said one surface of the printed circuit board. This reflow method permits secure soldering even if the hot air is set at a temperature not exceeding the heat resistance of the electronic components, which is possilbe because of its combination with the radiant heat. Moreover, this reflow method can permit soldering in such a manner that only the to-be-connected points are heated selectively, because the hot air is blown locally and roughly perpendicular to the points to be connected. Thus, this reflow method prevents heat damage to other sections than the to-be-connected points and ensures that the solder at the to-be-connected points is melted.

Abstract: Where the output delay of a combinational circuit in a logic circuit is defined by a clock cycle count, data transfer means for outputting data delayed in the same number of clock cycles is inserted in a block of a cycle-based simulator. The data transfer means comprises registers or a combination of registers and selectors. The cycle-based simulator may be further arranged to automatically recognize the output delay of a combinational circuit in a target logic circuit. Data transfer means for effecting an output delay in the recognized number of clock cycles is then automatically inserted in a block of the cycle-based simulator.

Abstract: An apparatus for printing a solder paste to a printed circuit board with use of a screen mask plate and a squeegee. The apparatus includes a device for moving one of the printed circuit board and the screen mask plate at a first moving speed in a direction to be separated from the other of them after printing of the solder paste and until the moving one of the printed circuit board and the screen mask plate reaches a plate-separation position which is a position immediately before the screen mask plate and the printed circuit board are completely separated from each other, and a controller for changing the first moving speed to a second moving speed higher than the first moving speed when the moving one of the printed circuit board and the screen mask plate reaches the plate-separation position.

Abstract: The present invention provides a reflow apparatus and method effective to make constant the internal gas flow direction in a heating section within a reflow furnace. A circulating gas path is formed in a heating unit which collects and causes the gas to flow from a sirocco fan, up the rear side of the heating unit and then down towards a circuit board moving along a transfer path at the front side of the heating unit. Moreover, a plurality of straightening plates are arranged above the transfer path of the heating unit so as to guide the hot gas, which is flowing forwardly downwardly toward the circuit board moving along the transfer path. A blow-down nozzle is provided and includes a plurality of plates aligned in rows in the transferring direction of the circuit boards. The plates have an inverse U-shaped cross section. The blow-down nozzle is arranged below the straightening plates to cause the vertical hot gas flows to flow uniformly over the whole surface of the circuit board.

Abstract: A method for printing a solder paste to a printed circuit board with use of a screen mask plate and a squeegee, the method includes steps of moving one of the printed circuit board and the screen mask plate at a first moving speed in a direction to be separated from the other of them after printing of the solder paste and until the moving one of the printed circuit board and the screen mask plate reaches a plate-separation position which is a position immediately before the screen mask plate and the printed circuit board are completely separated from each other, and changing the first moving speed to a second moving speed higher than the first moving speed when the moving one of the printed circuit board and the screen mask plate reaches the plate-separation position.

Abstract: A reflow apparatus includes a reflow furnace. A transfer device holds and transfers printed circuit boards with to-be-reflowed electronic components thereon from an inlet to an outlet of the furnace within the furnace. A plurality of adjusting/circulating sections separate an ambient gas for heating the printed circuit boards into predetermined temperature regions in the furnace in which the ambient gas is circulated in a heated state. A feed port is formed in the furnace to feed the ambient gas into the furnace under pressure. Residence parts each provided between adjacent adjusting/circulating sections regulate the amount of the ambient gas when the ambient gas, after having been sent to and heated in the adjusting/circulating section adjacent to the feed port, is circulated and sequentially moved to the adjusting/circulating sections at the inlet or the outlet and finally flows out through the inlet or outlet into atmosphere.

Abstract: The present invention provides a reflow apparatus and method effective to make constant the internal gas flow direction in a heating section within a reflow furnace. A circulating gas path is formed in a heating unit which collects and causes the gas to flow from a sirocco fan, up the rear side of the heating unit and then down towards a circuit board moving along a transfer path at the front side of the heating unit. Moreover, a plurality of straightening plates are arranged above the transfer path of the heating unit so as to guide the hot gas, which is flowing forwardly downwardly toward the circuit board moving along the transfer path. A blow-down nozzle is provided and includes a plurality of plates aligned in rows in the transferring direction of the circuit boards. The plates have an inverse U-shaped cross section. The blow-down nozzle is arranged below the straightening plates to cause the vertical hot gas flows to flow uniformly over the whole surface of the circuit board.

Abstract: The present invention provides a reflow apparatus and method effective to make constant the internal gas flow direction in a heating section within a reflow furnace. A circulating gas path is formed in a heating unit which collects and causes the gas to flow from a sirocco fan, up the rear side of the heating unit and then down towards a circuit board moving along a transfer path at the front side of the heating unit. Moreover, a plurality of straightening plates are arranged above the transfer path of the heating unit so as to guide the hot gas, which is flowing forwardly downwardly toward the circuit board moving along the transfer path. A blow-down nozzle is provided and includes a plurality of plates aligned in rows in the transferring direction of the circuit boards. The plates have an inverse U-shaped cross section. The blow-down nozzle is arranged below the straightening plates to cause the vertical hot gas flows to flow uniformly over the whole surface of the circuit board.

Abstract: Disclosed is a process for the preparation of a modified methacrylic resin molding material, wherein a volatile component is removed from a methacrylic polymer composition containing a volatile component including an unreacted monomer, a solvent or a by-product, and a modifying polymer is added to the methacrylic polymer composition to prepare a modified molding material.