Abstract:
A method is provided for wave-soldering printed circuit boards. In order to obtain wave-soldered printed circuit boards with smallest possible number of solder globules, after the passage on the wave of solder, the printed circuit boards are further artificially cooled at an approximately constant time-temperature gradient of 20 K/sec.
Abstract:
There are herein disclosed a method for preparing a modified resin which comprises thermal/reaction by the use of a norbornenyl group-containing compound typified by norbornenecarboguanamine or its derivative, a method for preparing an epoxy-modified resin which comprises the step of reacting the above-mentioned modified resin and an epoxide, a flame-retarding method, a thermal stabilization method, a compatibilizing method and a surface modification method which comprise utilizing the modified resin, as well as a coating resin composition and an adhesive resin composition containing the modified resin. According to the preparation methods of the present invention, the deterioration of a material scarcely occurs, and a functional group which is excellent in flame retardancy, thermal stability, compatibility and the like can be introduced to the resins. By the utilization of these techniques, there can be obtained a flame-retardant material having a good char formability, a thermally stable material whose molded articles can inhibit heat deterioration, a material excellent in miscibility between different kinds of resins, a surface-modified material which is excellent in adhesion and coating properties and the like.
Abstract:
In accordance with the present invention, there is provided a soldering process comprising the steps of: providing in a furnace first and second heaters each adapted to emit infrared energy; setting a printed circuit boad, which has a solder paste and an electronic component thereon, in the furnace; heating the printed circuit boad with the first heater; and heating the electronic component with the second heater; wherein the first and second heaters have different radiation spectra such that infrared energy irradiated by the first heater is more absorbed by the printed circuit board and less absorbed by the electronic component than that irradiated by the second heater. The present invention also provides a soldering apparatus for use in such soldering process.
Abstract:
A method of forming a solder film on a metallic surface such as a pad of a metallic circuit of a printed circuit board and a lead frame of electronic parts, which is capable of forming a precise and fine pattern and which comprises selectively imparting tackiness to only a predetermined part of the metallic surface by means of a tacky layer-forming solution, adhering a powdered solder to the resulting tacky part, and then melting the solder by heating to thereby form a solder film.
Abstract:
A shield (50) for use in wave soldering processes to selectively affix solder to an area of circuit board (20), having one or more electronic components (21) on the solder side of the board, is disclosed. Shield (50) includes a generally planar base member (51) of low thermal conductivity which forms the foundation of shield (50). Marginally disposed registration ridges (54) are formed on the upper surface (52). Registration ridges (54) serve to hold circuit board (20) against shield (50) in a fixed position. Ridges (54) are positioned to closely receive the peripheral edges of circuit board (20). One or more solder flow openings (56) are formed through base member (51) extending from upper side (52) to lower side (53). Solder flow openings (56) are positioned to align with the selected areas of circuit board (20) to which solder is to be affixed. One or more recesses (55) are provided in the upper surface (52) of base member (51) to receive and shield electronic components (21).
Abstract:
The invention provides a device for moving an object by means of thermal change in shape or volume, such that the object is moved when a predetermined process temperature has been reached. Preferably the device can be used in a soldering system on a printed circuit board. The advantage of the invention lies in a temperature-controlled movement of the object with a high-level precision that, for example, ensures a very sparing unsoldering.
Abstract:
The present invention discloses a wire bonder that does not require bonding tool replacement to be performed by an experienced worker, is not bothersome and can be completed in an extremely short time, while also enabling time management of the degree of wear of the bonding tool and so forth to be performed reliably, so as to realize improved work efficiency and yield, as well as being able to demonstrate various other effects. In addition, the present invention also discloses a bonding arm and bonding tool that contribute to the achieving of these effects. The above effects are obtained by adding a tool replacement device that removes a used bonding tool (capillary) installed in a bonding arm and installs a new bonding tool. In addition, the above effects are obtained with respect to the bonding arm and bonding tool by forming a tapered surface that guides their mutual insertion.
Abstract:
The invention relates to a soldering apparatus, comprising a solder vessel; at least one soldering tower located in said solder vessel; transport means for transporting objects to be soldered over said soldering tower; solder wave generating means for generating a solder wave emerging from the apex of the soldering tower and contacting the objects to be soldered, the soldering tower comprising a weir such that at least a part of the solder wave flows parallel to the direction of movement of the objects to be soldered over said weir; and guide means for guiding said part of the solder wave such that the solder wave leaves the soldered object substantially abruptly. As a consequence of said feature the stream of solder is abruptly guided away from the printed circuit board, so that the possibilities for developing short circuits on the printed circuit board are substantially reduced.
Abstract:
The invention relates to a device for measuring the height of a solder wave in a soldering apparatus which comprises a solder bath and which is provided with at least one solder tower for generating a solder wave and a pump connected to the solder tower, wherein the measuring device comprises: means for measuring the liquid pressure in the connection between the pump and the solder tower. As a result of these steps it is possible to measure accurately the pressure of the solder moving out of the pump to the solder tower. This pressure is in any case a good measure for the height of the solder wave. According to a first preferred embodiment the means for measuring the liquid pressure comprise a measuring vessel joined to the connection between pump and tower and communicating at its top with the atmosphere, the upper edge of which vessel is located higher than the outflow opening of the solder tower.
Abstract:
A mask for printing solder paste includes a mask plate, and first mask holes which are formed in the mask plate and have a first size, and second mask holes which are formed in the mask plate and have a second size smaller than the first size. The mask plate has a first region having the first mask holes, and a second region having the second mask holes. The mask plate has a first thickness in the first region, and a second thickness in the second region. The second thickness is smaller than the first thickness.