Abstract: A transfer molding process and an apparatus for carrying out the same for sealing electronic devices, such as semiconductor devices, in a resin by driving a plunger downward in a pot to inject the resin into a mold. In injecting a resin into a mold by driving the plunger downward, the rotary motion of the output shaft of an electric motor is converted into a linear motion to drive the plunger downward, the downward displacement of the plunger from the initial position is detected, and pressure applied to the plunger is varied according to the displacement of the plunger. Thus, the transfer molding process and the apparatus for carrying out the same reduces defects, such as voids and incompletely filled parts, in the resin-sealed device, and prevents burrs and the deformation of the insert during the transfer molding operation.

Abstract: Apparatus for producing semiconductor devices is provided with mold and lead frame suitable for improving the production efficiency and product quality. Also disclosed is a method of producing semiconductor devices by means of the apparatus. The mold is characterized by the shape of a die and has a plurality of pots for pressure-feeding resin, a flow passage communicating the pots with each other so as to uniformalize the molding pressure applied to the pots even if there are variations in the weights of the resin charged in the pots, and a plurality of cavities disposed in series.

Abstract: A resin-molded semiconductor is produced by using an apparatus which comprises a mold having a plurailty of pots from which a molding resin is fed under pressure, mutually independent runners extending from each pot, and a plurality of cavities serially disposed at the end of each runner, said cavities being filled with a molding resin fed under pressure from said pots, with a part to be molded placed in each cavity. The process and apparatus of this invention prevent the molding defects resulting from the excessive flow resistance of resin and greatly improves the use efficiency of resin.

Abstract: A photoelastic effect measuring device comprising a single white light source, a prism dispersing light emitted by said white light source and a variable slit device, which selects an arbitrary spectrum of light thus dispersed is disclosed, in which for a photoelastic effect measurement using white light, the slit width is opened totally so that all the light spectrum pass therethrough so as to pass through a sample to be measured and for a photoelastic effect measurement using a specified monochromatic light beam, the slit width is controlled so as to have a predetermined opening so that only a specified light spectrum can pass therethrough so as to pass through a sample to be measured.

Abstract: A compressor has stationary and orbiting scroll members formed thereon with spiral wraps engaged with each other to define compression chambers which, when the orbiting scroll member is moved relative to the stationary scroll member, are radially inwardly moved while decreasing their volumes. Each scroll member is composed of a metallic base scroll member having a spiral wrap formed on one side and a coating layer of a resin compound formed on the said side of the scroll member, including the surfaces of the wrap. The coating layer is molded by placing the base scroll member in a mold cavity with a space left between the said side of the base scroll member and a mold part and by injecting the resin compound into the space.

Abstract: An apparatus for measuring photoelasticity permitting to control mechanical stress applied to an elastic body, by visualizing phase differences of polarized light transmitted by the elastic body is disclosed. In such a prior art apparatus a quarter wavelength plate was used in order to obtain circularly polarized light. However, the precision of the circularly polarized light is worsened, when it works in a wide wavelength region. To the contrary, in an apparatus according to this invention, circularly polarized light is obtained by means of Fresnel's rhombic body. As the result good circularly polarized light can be obtained for a wide wavelength region from the visible region to the near infrared region and control of products including thin films and semiconductor substrates can be effected by visualizing mechanical stress therein.

Abstract: A connector means includes a connector housing provided with a plurality of bores which is defined by a pair of plastic bases each having a plurality of hemicycle grooves each of which has an inner diameter 1 to several .mu.m larger than an outer diameter of each of the optical cables to be connected. After the optical fibres are inserted into the respective bores and secured therein, one end surface of the connector housing is polished. A pair of connected housings are retained so that the polished end surfaces abut on each other thereby to attain a connection between a plurality of optical cables.

Abstract: A plastic information-recording medium comprises a pair of juxtaposed transparent plastic substrates molded from a composition, which is comprised of a copolymer consisting of 5 to 25% by weight of acrylonitrile or methacrylonitrile and 95 to 75% by weight of at least one of other monomers copolymerizable with acrylonitrile or methacrylonitrile than styrene or a styrene derivative, or a composition comprising at least 70% by weight of the copolymer and at most 30% by weight of butadiene rubber, and has a clearance between the substrates, the clearance being gas-tightly blocked from an outside atmosphere by joining the substrates together at peripheral edges thereof, and a recording film being provided on each of clearance-facing sides of the substrates.

Abstract: An optical fiber connector comprising a pair of plugs, a sleeve and a pair of cap nuts which is assembled at the site where optical fibers are installed, so as to connect the optical fibers with a high degree of positional accuracy. The plugs and the sleeve are molded of a composition including a synthetic resin added with a suitable content of a filler, such as glass beads.

Abstract: A transfer molding machine for filling at least one cavity of a mold with a resin by means of a plunger including a resin pressure sensor for sensing the resin pressure in the mold, and a control device for controlling the pressure applied to the plunger to drive same in such a manner that an arbitrarily selected primary pressure higher than a holding pressure is applied to the plunger to drive same until the pressure of the resin charged into the mold which pressure is detected by the resin pressure sensor in the mold reaches a predetermined pressure level and a secondary pressure corresponding to the holding pressure is applied to the plunger to drive same after the predetermined pressure level has been exceeded by the pressure of the resin being charged into the mold sensed by the resin pressure sensor in the mold, and a warning device that issues a warning when the pressure applied to the plunger to drive has exceeded a predetermined pressure.

Abstract: A method of and an apparatus for molding a plastic wherein the injection pressure (transfer pressure) is switched to a holding pressure when the internal pressure of the mold cavity sensed by a pressure sensor reaches a predetermined injection pressure (transfer pressure), to initiate holding of the pressure applied to the cavity. The holding pressure is removed when the internal pressure thereof becomes zero or in accordance with the detection of a predetermined inflection point in the internal pressure which is indicative of a gate sealing point in the mold cavity or is brought to a predetermined value close to zero. The molded articles are of high precision finishes, and conservation of energy and natural resources can be achieved.

Abstract: An apparatus for pre-heating resin tablets comprising a resin tablet heater, a switch for setting a reference softening degree and a softening degree detector for the resin tablet. The detector includes a pressure source and a pressure transmitting member coupled to the pressure source and adapted for contact with the resin tablet. The pressure transmitting member is movable a distance representative of the softening degree of the resin tablet being heated due to deformation of the resin tablet.

Abstract: A spider of loudspeaker having a base material in the form of a plain-woven fabric of warps and wefts each of which constituted by fibers of an inorganic material. The warps and wefts are coated with a thermosetting resin which in turn is coated with a thermoplastic resin. The spider thus formed is less liable to absorb the ambient moisture and, therefore, is free from distortion.

Abstract: A mold die including two or more cavities shaped to profile the configuration of mold products, a pot serving as a lead-in portion for resin of a tablet-form, or a sprue serving as a lead-in portion for molten resin, a runner leading to the pot or sprue, and gates branching from the runner and leading to respective cavities, the aforesaid gates having given convergent slopes at their exits to the cavities. The cross-sectional area of the runner is progressively decreased in the direction away from the pot or sprue, and the convergent slopes of the gates are progressively increased in the direction away from the pot or sprue, in a manner that the sum of a pressure drop in a runner portion and a pressure drop in a gate portion may be made equal for each of the cavities, thereby minimizing a difference in timing of resin to arrive respective cavities, and rendering the velocity of resin flowing into respective cavities equal to one another.