摘要:
The invention relates to a method of self-assembly including self-alignment of components (1) on a substrate (2) on the basis of surface tension of liquid solder, involving a solder stack composed of an outermost layer of solder (3) on top and at least another layer of solder (4), the layers of solder having successively increasing melting points from top to bottom. In a first step the solder stack is heated to melt the outermost layer of solder (3), this solder layer is used to form a receptor, which adheres to the components (1), which are self-assembled, self-aligned, and attached in the following. In the next step the solder stack is heated to a temperature further elevated above the melting point of the at least another layer of solder (4). Thereby a reflow soldering-process is initialised and the two layers of solder (3, 4) form a mixed solder layer as an alloy (5). As a consequence, an interconnect between the components (1) and the substrate (2) with a melting point higher than that of the outermost layer of solder (3) is formed. The invention further relates to an apparatus for self-assembly of components (1) onto receptor sites (11) of the surface of a substrate (2) where each receptor site (11) is formed of a selective adhesive element which adheres to at least part of the components (1) resulting in the capture, self-assembly, self-alignment and/or attachment of the components at the receptor sites (11). Such an apparatus comprises a basin (14) containing a fluid (13), first transporting means for transporting the substrate (2) with the receptor sites (11) being in an essentially upright position at a predetermined speed and/or angle of inclination into and out of a delivery zone (16) in the fluid (13), a dispensing unit (17) located above the delivery zone (16) for dispensing components (1), rotating means for rotating the substrate (2) into a position where the receptor sites (11) take an essentially upside-down position, collecting means for collecting excess components (18) not attached to receptor sites (11) at the bottom of the basin (13), and second transporting means for returning excess components (18) to the dispensing unit (17).
摘要:
The invention relates to a method for shortening the process time during the soldering of electric or electronic components by means of electromagnetic induction heating, in particular the soldering of electric contact elements to solder connection surfaces that are applied to a non-metallic substrate, in particular a pane of glass. According to the invention, an electric contact element is first produced, designed as a solder foot, made of a material with an iron-nickel or iron-chromium alloy base. Subsequently, a lead-free connecting material is applied to the solder foot. After the solder foot has been positioned on the respective solder connection surface, the solder foot is inductively heated by means of high frequency energy with increased heating of the solder foot material and reduced heating of the silver-containing material of the respective solder connection surface. The soldering stage is completed after a time of
摘要:
Provided is a flux which can remove metal oxides to improve solder wettability and can fix the object to be soldered with flux residue. The flux contains thermosetting resin, and long-chain dibasic acid mixture including one or more species of first long-chain dibasic acid having an alkyl group in a side chain, the first long-chain dibasic acid being added as a hardening agent for hardening the thermosetting resin and an activator, and second long-chain dibasic acid having an alkyl group and an alkoxycarbonyl group in a side chain and having carbon number of 8 or more in a main chain between the carboxyl groups at opposite terminals. It is preferable that content of the thermosetting resin is 30 % through 70 % and content of the long-chain dibasic acid mixture is 20 % through 60 %.
摘要:
A solder wire composition may include 85 to 95 weight percent bismuth, and at least 5 weight percent copper. The solder wire composition may have a diameter of less than about 1 millimeter, and an elongation at break of at least 20%.
摘要:
Problem: Even if the strength of a solder composition close to a SnBi eutectic composition was improved, it was brittle, so when it was used for small electronic devices such as mobile phones or notebook computers, the resistance to drop impacts when the small electronic equipment was dropped was low. Therefore, interface peeling often took place between the soldered surface and a printed circuit board, resulting in the devices being destroyed. Means for Solving the Problem: When soldering using a solder paste containing a SnBi-based low-temperature solder, at least one type of solder composition selected from a Sn-Ag, a Sn-Cu, and a Sn-Ag-Cu solder composition is diffused into the solder paste by simultaneously supplying at least one type of preform selected from a Sn-Ag, a Sn-Cu, and a Sn-Ag-Cu solder composition, whereby resistance to drop impacts is improved.