Abstract:
A method of soldering electronic component (6) having solder bumps (7) formed thereon to substrate (12), wherein bumps (7) are pressed against a flux transferring stage on which a thin film is formed of flux (10) containing metal powder (16) of good wettability to solder so as to cause metal powder (16) to penetrate oxide films (7a) and embed in the surfaces on the bottom parts of bumps (7), and bumps (7) in this state are positioned and mounted to electrodes (12a) on substrate (12). Substrate (12) is then heated to melt bumps (7) and allow the melted solder to flow and spread along the surfaces of metal powder (16) toward electrodes (12a). The method can thus provide solder bonding portions of high quality without any soldering defect and deterioration of the insulating property.
Abstract:
An LTCC module includes a base on one or more surfaces for receiving one or more external components to be attached to the module. A base is formed of a plurality of layers of metallization in a predetermined pattern. The layers include an adhesion layer on the LTCC module surface, with one or more intermediate layers, followed by a top layer. The module is fired with each application of the layers at a reduced temperature lower than the normal cofiring temperature of the LTCC module, but of sufficient value to partially sinter the layers. After the last applied top layer, the module is fired once at an elevated temperature to fully sinter the layers.
Abstract:
A multiple printing is carried out by screen printing, whereby the doctor blade (1) and the screen (5) are employed at a higher separation than for a previous printing. Particularly fine and very high structures can thus be formed.
Abstract:
The invention relates to a method of improving the manufacturing safety of weld joints (7) between a ceramic support (1) and a printed-circuit board (10). Said method consists of the deposition of a first metallization layer (5) resistant to alloy breakdown on the ceramic support (1), followed by the imprinting of a second metallization layer (6), which enhances wetting behaviour, on the first metallization layer (5). In this way the thickness of the overall metallization layer (5, 6) can be increased in the area of the edges (8) of a weld joint (7). The resulting raised solder ring in turn permits the fully automatic optical control of the weld joint (7).
Abstract:
Holes (40a) are formed with a laser beam through an insulating substrate (40) on which a metallic layer (42) is formed. After the holes (40a) are formed, via holes (36a) are formed by filling up the holes (40a) with a metal (46) and a conductor circuit (32a) is formed by etching the metallic layer (42). Then, a single-sided circuit board (30A) is formed by forming projecting conductors (38a) on the surfaces of the via holes (36a). The projecting conductors (38a) of the circuit board (30A) are put on the conductor circuit (32b) of another single-sided circuit board (30B) with adhesive layers (50) composed of an uncured resin in between and heated and pressed against the circuit (32b). The projecting conductors (38a) get in the uncured resin by pushing aside the resin and are electrically connected to the circuit (32b). Since single-sided circuit boards (30A, 30B, 30C, and 30D) can be inspected for defective parts before the boards (30A, 30B, 30C, and 30D) are laminated upon another, only defectless single-sided circuit boards can be used in the step of lamination.
Abstract:
A method for making electrical connections between a lead and a conductor on a substrate, the method including the steps of disposing a copper conductor on a ceramic substrate; positioning a lead in contact with the conductor; applying a copper film to the lead and the conductor to attach the lead to the conductor; and heating the substrate, lead and conductor assembly to secure bond the lead and conductor together. In a preferred embodiment, the conductor, lead and film are made of copper. The method can further include disposing a resistive film on the substrate using thin or thick film processes.
Abstract:
A method for forming a conductive vias in a non-conductive substrate having a through-hole formed therein intermediate two side thereof. The method utilizes the steps of: applying gold paste to the through-hole so as to provide electrical conduction therethrough; and under firing the gold paste when a thin conductive film is present upon the substrate and fully firing the gold paste when no thin conductive film is present on the substrate. Under firing the gold paste when a thin-film is present upon the substrate prevents degradation of the thin conductive film. Subsequent processing of the gold paste assures the integrity and reliability thereof. Thus, the gold paste provides enhanced conductivity and improved reliability, as compared to contemporary thin-film vias.
Abstract:
A method for forming a conductive vias in a non-conductive substrate having a through-hole formed therein intermediate two side thereof. The method utilizes the steps of: applying gold paste to the through-hole so as to provide electrical conduction therethrough; and under firing the gold paste when a thin conductive film is present upon the substrate and fully firing the gold paste when no thin conductive film is present on the substrate. Under firing the gold paste when a thin-film is present upon the substrate prevents degradation of the thin conductive film. Subsequent processing of the gold paste assures the integrity and reliability thereof. Thus, the gold paste provides enhanced conductivity and improved reliability, as compared to contemporary thin-film vias.
Abstract:
A connecting terminal (2) of copper foil is formed on a substrate (3) of a glass epoxy base material, and a layer (1) of super-fine particles of Ag is deposited on the surface of this connecting terminal (2). The layer (1) is connected electrically with a connecting terminal (4) of copper foil formed on another substrate (5) comprising a polyamide base film via a bonding agent (6). The layer (1) compensates for a defect of conduction of the connecting terminals and increases the contact areas of the conductive connecting portions to attain the reduction of the resistance thereof. The fine particle layer lessens the stress imparted to the connecting terminals during a connecting operation, and, even when a crack occurs in a connecting terminal, this layer makes up therefor. This stabilizes the conductive connecting portions and improves the yield of structures thereof.
Abstract:
A conductive circuit pattern portion is formed on an insulating substrate film, the pattern portion being constituted by a laminate of a thin metal film pattern layer with excellent electrical properties and an easily formable printed pattern layer, and a hot-melt adhesive layer with anisotropic electrical conductivity is further formed on the circuit pattern portion, whereby it is possible to easily a flexible conductive film connector which is accurately formed with a minute conductive circuit pattern having excellent electrical characteristics. The conductive film connector has excellent electrical characteristics and makes it possible to obtain complete adhesion. Further, there is no danger that the conductive film connector will fail as a result of long use; hence, it provides a highly reliable connection.