Abstract: Problem Precoating methods for previously adhering solder to areas to be soldered of a workpiece for an electronic part such as a printed circuit board, a chip part, or a wafer include the plating method, the hot leveling method, the solder paste method, the solder ball method, and the like. In these conventional precoating methods, solder did not uniformly adhere to areas to be soldered, solder did not completely adhere, and much equipment and time were required. The present invention provides a method which can perform precoating with uniform application and without the occurrence of defects using simple equipment and a workpiece to which solder is uniformly adhered. Means for Solving the Problem In the present invention, an excess amount of solder powder is dispersed atop an adhesive applied to a substrate, and then excess solder powder which is not adhered to the adhesive is removed.

Abstract: A method of forming solder bumps on electrodes of a circuit board without producing bridging using a solder transfer sheet which does not require alignment includes superposing a circuit board and a solder transfer sheet having a solder layer adhered to at least one side of a supporting substrate, performing heating under pressure to a temperature lower than the solidus temperature of the solder to selectively perform solid phase diffusion bonding of the solder layer to electrodes, and peeling the transfer sheet from the circuit board. The solder layer is in the form of a continuous solder coating or in the form of a monoparticle layer of solder particles which are adhered to the supporting substrate by an adhesive layer.

Abstract: A method of forming solder bumps on electrodes of a circuit board without producing bridging using a solder transfer sheet which does not require alignment includes superposing a circuit board and a solder transfer sheet having a solder layer adhered to at least one side of a supporting substrate, performing heating under pressure to a temperature lower than the solidus temperature of the solder to selectively perform solid phase diffusion bonding of the solder layer to electrodes, and peeling the transfer sheet from the circuit board. The solder layer is in the form of a continuous solder coating or in the form of a monoparticle layer of solder particles which are adhered to the supporting substrate by an adhesive layer.

Abstract: Problem Precoating methods for previously adhering solder to areas to be soldered of a workpiece for an electronic part such as a printed circuit board, a chip part, or a wafer include the plating method, the hot leveling method, the solder paste method, the solder ball method, and the like. In these conventional precoating methods, solder did not uniformly adhere to areas to be soldered, solder did not completely adhere, and much equipment and time were required. The present invention provides a method which can perform precoating with uniform application and without the occurrence of defects using simple equipment and a workpiece to which solder is uniformly adhered. Means for Solving the Problem In the present invention, an excess amount of solder powder is dispersed atop an adhesive applied to a substrate, and then excess solder powder which is not adhered to the adhesive is removed.

Abstract: A solder ball assembly for use in the formation of solder bumps on electrodes of a substrate for electronic components includes a heat-resisting sheet having a plurality of holes formed therein. Each hole has a solder ball disposed therein. The sheet includes an adherent layer exposed to the interior of each hole on the wall and/or bottom of the hole such that the adherent layer contacts and holds the solder balls in the holes. Solder bumps are formed by positioning the assembly on a substrate such that the solder balls held in the holes come into contact with the electrodes of the substrate. The assembly and the substrate are heated together to melt the solder balls in the holes. After solidification of the solder, the heat-resisting sheet of the assembly is removed from the substrate, leaving a solder bump on each electrode.

Abstract: A solder ball assembly includes a mask having first and second sides and a plurality of holes formed therein. Each hole has a first end opening onto the first side of the mask and a second end. A plurality of solder balls are disposed in the holes, and a fixing agent secures the solder balls in the holes. A protective sheet may be attached to one or both sides of the mask to cover the ends of the holes.

Abstract: A solder ball assembly for use in the formation of solder bumps on electrodes of a substrate for electronic components includes a heat-resisting sheet having a plurality of holes formed therein. Each hole has a solder ball disposed therein. The sheet includes an adherent layer exposed to the interior of each hole on the wall and/or bottom of the hole such that the adherent layer contacts and holds the solder balls in the holes. Solder bumps are formed by positioning the assembly on a substrate such that the solder balls held in the holes come into contact with the electrodes of the substrate. The assembly and the substrate are heated together to melt the solder balls in the holes. After solidification of the solder, the heat-resisting sheet of the assembly is removed from the substrate, leaving a solder bump on each electrode.

Abstract: A solder ball assembly includes a mask having first and second sides and a plurality of holes formed therein. Each hole has a first end opening onto the first side of the mask and a second end. A plurality of solder balls are disposed in the holes, and a fixing agent secures the solder balls in the holes. A protective sheet may be attached to one or both sides of the mask to cover the ends of the holes.

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 containing at least one compound selected from benzotriazole derivatives, naphthotriazole derivatives, imidazole derivatives, benzoimidazole derivatives, mercaptobenzothiazole derivatives, benzothiazole thiofatty acid derivatives, and triazine derivatives, adhering a powdered solder to the resulting tacky part, and then melting the solder by heating to thereby form a solder film.

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 containing at least one compound selected from benzotriazole derivatives, naphthotriazole derivatives, imidazole derivatives, benzoimidazole derivatives, mercaptobenzothiazole derivatives, benzothiazole thiofatty acid derivatives, and triazine derivatives, adhering a powdered solder to the resulting tacky part, and then melting the solder by heating to thereby form a solder film.

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 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 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 method is available for 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. The method comprises selectively imparting tackiness to only a predetermined part of the metallic surface by use 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: The present invention is directed to a method for treating resin printing plates to prevent or reduce smudging and/or linting using fluorocarbon surface active agent having a perfluoroalkyl group with 4 to 14 carbon atoms. The surface active agent may be anionic, cationic or ampholytic and may be used in an aqueous, alcohol or aqueous-alcohol solution.

Abstract: A center-opening clamp type ammeter provided with a pair of magnetic cores each having actuating means provided on the basal portion thereof and constructed so that the opening operation of one of the magnetic cores causes the other magnetic core to be opened and that when the opening operation is freed the magnetic cores are brought into a closed state.