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Pockets of gas, or voids, trapped in the solder interface between discrete power management devices and circuit assemblies are, unfortunately, excellent insulators, or barriers to thermal conductivity. This resistance to heat flow reduces the electrical efficiency of these devices, reducing battery life and expected functional lifetime of electronic assemblies.

Voids in solder joints are largely a function of differential pressure between vapor pressure of the gases inside of the joint and environmental conditions. By entering joints still in their liquid state into decompression chambers, voids can be eliminated.

The problem is not limited only to rosin fluxes and solvent cleaning, but also occurs when water soluble fluxes are used and when either flux type is removed with water. The soldering and cleaning processes involve so many chemicals in the flux, circuit board, components and cleaning agents that a complete understanding of the reactions is very difficult if not impossible. There are white residue problems with water soluble fluxes and many of the causes not related to the flux compositions are the same as for rosin fluxes.

Progressive cavity pumps are ideal solutions for applications requiring a high level of dosing accuracy while minimizing shear on dispensed materials. By nature, progressive cavity pumps operate in accordance with a positive displacement principle. Material flows through the valve as it progresses through fixed cavities created as a helical rotor turns.

As powerful electronics shrink in size and increase in variety, thermal interface materials [TIM] for heat dissipation continue to gain importance in the manufacturing industry. A variety of methods exist for aiding this heat transfer. Gap filling pads, adhesive tapes, and dispensable gels are the most common. The primary considerations when selecting a TIM material is the thermal conductivity and dielectric strength.

This paper will discuss commonly experienced defects associated with NoClean surface mount processes and propose methods to solve these issues. Much of the discussion can be applied to any surface mount process (i.e. water soluble, RMA, or No-Clean), but some are directly associated with No-Clean processes.

Driven by environmental and health concerns, the RoHS legislation has mandated the electronic assembly industry to transition from eutectic tin-lead to lead-free soldering, which carries forward a revolution in the formulation of soldering materials.

Vapor phase soldering is the ideal process for modern soldering technology. Electronic assemblies can be soldered faultlessly in each configuration. Easy and flexible adjustable temperature gradients assure for each product the optimal, absolutely reproducible temperature profile. No complex test series and line set-up times – applicable from prototype up to serial production.

The majority of today’s SMT market today in the United States and Europe is high-mix/low- to medium-volume and parts of it even are considered extreme high-mix and/or extreme low-volume.

With solder reflow, relying on commonly accepted practices can lead engineers to overlook some relatively simple factors that are critical to optimizing the process. An examination of six “conventional wisdom” tenets reveals that challenging them can contribute significantly to improved yields.

Back in 1999 ASSCON’s invention of the worldwide first vapour phase vacuum soldering process has already set a milestone for industrial electronic production. The vacuum soldering process proofed as a successful solution for constantly challenging soldering tasks while process windows were getting continuously smaller. The rising number of vapour phase vacuum soldering systems in the electronic industry proofs the essential impact of this vacuum soldering process.

The essential quality features required for these future applications are provided by the multivacuum soldering process. In the multivacuum soldering process assemblies are subjected to several vacuum applications during the soldering process, with the option of applying vacuum processes both before and during the melting of the solder paste.

In the world of bonding, filling, and encapsulating the term “meter-mix” refers to the process and the hardware required to accurately manage, blend, and dispense multi-part fluids in an automated fashion. Most often in electronics and industrial dispensing, meter-mix dispensing is based upon processing a 2-part adhesive that is supplied as a base component plus a hardener component.

Manufactures who have looked at VOC-Free fluxes have discovered that VOC-free fluxes are not simply "drop in" replacements for the existing flux chemistries. Because VOC-free fluxes contain water as a solvent difficulties are encountered when soldering boards with these fluxes. The difference between VOC-Free and alcohol based fluxes lies in the characteristics of the solvent (thinner).

As lead-free gains momentum, many engineers are striving to set-up a wave solder process that maintains production yields but also offer reliable assemblies. Much has been written on these topics in the past 5 years. Less confusion does exist today about alloy choices available to replace leaded solders, however many are struggling with their successful implementation. Once the lead-free alloy is selected, a solid understanding of its chemical and physical properties is required to enable reliable soldering.

Tin-Silver-Copper alloys are the primary choice for lead-free SMT assembly. Although there are other options available such as alloys containing bismuth or indium and other elements, tin-silver-copper solders, also known as SAC alloys are by far the most popular. They are used by approximately 65% of users, as last surveyed by Soldertec in 2003.

The oven recipe, which consists of the reflow oven zone temperature settings and the speed of the conveyor, will determine a specific time‐temperature profile for a given PCB assembly. In order to achieve a good quality PCB assembly, the time‐temperature profile should be within the product and process specifications.

Electrochemical migration (ECM) is an electrochemical process where metal ions move between adjacent metal conductors through an electrolyte solution subjected to an applied electric field. ECM is also characterized by the dendrites growth on printed circuit boards (PCBs).

Vapor Phase Soldering is also known as Condensation Soldering. In the first process step the cold PCB is delivered to a chamber in which there is vapor evaporated from a special liquid (medium) for this process perfluoropolyether (PFPE). The liquid is chemically inert and with density almost twice higher than the water.

This paper will discuss the results of a thorough comparison of the various methods of attaching thermocouples to a printed circuit board for thermal profiling. The focus will be on non-destructive attachment methods and how well they compare to the standard method of attachment using high temperature solder.

The modern production of electronic assemblies in SMD-technology is unthinkable without the efficient printing process, placement process and particularly the soldering technology. In particular, for a high and constant product quality the soldering technology is of utmost importance. From the start of the SMD-technology there have been two processes competing constantly with each other.

Due to the switch to lead-free manufacturers are faced with multiple new challenges. Simple processing, successful soldering for various products, high quality and user-friendliness are the basic requirements that current soldering systems have to provide. Vapor phase soldering meets these demands. However, individual systems vary greatly when looking at important details

Vapor phase reflow soldering systems set standards in the soldering technology. Vapor as energy transfer medium is one of the most efficient procedures for the heating of assemblies. The efficiency is much higher than with the heating of convection. Through the use of a special liquid GALDEN, an oxygen-free atmosphere is created, where the whole pre-heating and soldering process is running oxidation-free.