Discovering Alternatives for High Lead Solders in Electronics
This article discusses the high-lead exemption for electronics, potential alternatives and what would happen if manufactures had to replace Pb. ...
Flux-free vacuum soldering with preforms is very unique compared to conventional soldering techniques with paste. A set of completely different parameters must be considered for the development of soldering profiles. As the removal of contaminations is severely limited at flux-free soldering, the material quality of the components is crucial. Mostly, formic acid, hydrogen, forming gas or plasma is used to reduce surface oxides.
We offer advanced vacuum soldering training courses, which will enable engineers to develop more robust soldering processes in a shorter amount of time.
Reflow soldering is a cheap and widespread method of connecting power semiconductors. Soldering represents a material-joining technique. The connection between two joining partners (semiconductor and circuit carrier) is made by an additional material. The parts to be joined are heated and wetted by the liquid solder without melting themselves. The diffusion processes between the joining partners and the solder material create an alloy zone at the interface and thus a materially bonded connection.
The term reflow soldering describes the process in which a locally defined volume of solder is applied to the circuit board before the heating process. Paste systems with a flux are often used for this purpose to reduce surface oxides of the connection partners. Another process is the use of so-called preforms (punched metal plates) with forming gas or formic acid for oxide removal. Since no residues are left in the semiconductor connection during paste-free soldering, a void-free and thus significantly more reliable connection layer can be achieved than with paste soldering. During reflow soldering, heat can be introduced into the components via all types of heat flow, i.e. convection, radiation and heat conduction.
Since the prohibition of lead in European electronic products (RoHS), tin-silver-copper solders (SAC solders) are mainly used in Europe. Their transition to the liquid phase is usually between 217 °C and 220 °C. The load cycle resistance as well as the mechanical and thermomechanical behaviour of this group of solders have already been investigated in detail in many publications. A summary of the studies can be found here.
This article discusses the high-lead exemption for electronics, potential alternatives and what would happen if manufactures had to replace Pb. ...
Study on the high temperature power cycling capability of SiC-Modules with silver sinter, gold germanium, tin-silver-copper and high lead solders....
Aaron Hutzler will be speaking about soldering and sintering in controlled atmospheres at the ISAPP Conference in Osaka, Japan, focussing on the use of hydrogen atmospheres in combination with vacuum. ...
In this training you will learn to deal with all important aspects (thermo-mechanics, thermal management, surfaces) in the design of solder fixtures / jigs. ...
In part four of the article series Process development for fluxless soldering we deal with the process window and process control....
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