Technical Library | 2014-06-19 18:13:23.0
For high-density electronic packaging,the application of flip-chip solder joints has been well received in the microelectronics industry. High-lead(Pb) solders such as Sn5Pb95 are presently granted immunity from the RoHS requirements for their use in high-end flip-chip devices, especially in military applications. In flip-chip technology for consumer electronic products, organic substrates have replaced ceramic substrates due to the demand for less weight and low cost. However, the liquidus temperatures of high-Pb solders are over 300°C which would damage organic substrates during reflow because of the low glass transition temperature. To overcome this difficulty, the composite solder approach was developed...
Parts & Supplies | Soldering Equipment/Fluxes
3D Solder Paste Inspection Machine Features : Easy to use by fully motorize X-Y scan mechanism. Easy to program by Gerber image navigator Easy to repeat the same job by loading the saved program User-friendly color image live view operation Ea
Parts & Supplies | Visual Inspection
MiView USB Digital Microscope (MV200UM-PL) With Polarizer is a handheld color digital microscope with a high quality 2.0 Megapixel image sensor, adjustable high magnification from 5x to 200x, and an adjustable polarizer. This allows you to remove gl
Technical Library | 2020-09-23 21:37:25.0
The need to minimise thermal damage to components and laminates, to reduce warpage-induced defects to BGA packages, and to save energy, is driving the electronics industry towards lower process temperatures. For soldering processes the only way that temperatures can be substantially reduced is by using solders with lower melting points. Because of constraints of toxicity, cost and performance, the number of alloys that can be used for electronics assembly is limited and the best prospects appear to be those based around the eutectic in the Bi-Sn system, which has a melting point of about 139°C. Experience so far indicates that such Bi-Sn alloys do not have the mechanical properties and microstructural stability necessary to deliver the reliability required for the mounting of BGA packages. Options for improving mechanical properties with alloying additions that do not also push the process temperature back over 200°C are limited. An alternative approach that maintains a low process temperature is to form a hybrid joint with a conventional solder ball reflowed with a Bi-Sn alloy paste. During reflow there is mixing of the ball and paste alloys but it has been found that to achieve the best reliability a proportion of the ball alloy has to be retained in the joint, particular in the part of the joint that is subjected to maximum shear stress in service, which is usually the area near the component side. The challenge is then to find a reproducible method for controlling the fraction of the joint thickness that remains as the original solder ball alloy. Empirical evidence indicates that for a particular combination of ball and paste alloys and reflow temperature the extent to which the ball alloy is consumed by mixing with the paste alloy is dependent on the volume of paste deposited on the pad. If this promising method of achieving lower process temperatures is to be implemented in mass production without compromising reliability it would be necessary to have a method of ensuring the optimum proportion of ball alloy left in the joint after reflow can be consistently maintained. In this paper the author explains how the volume of low melting point alloy paste that delivers the optimum proportion of retained ball alloy for a particular reflow temperature can be determined by reference to the phase diagrams of the ball and paste alloys. The example presented is based on the equilibrium phase diagram of the binary Bi-Sn system but the method could be applied to any combination of ball and paste alloys for which at least a partial phase diagram is available or could be easily determined.
Solder Joint Inspection and Measurement System, for both pre and post reflow applications
World's First Solder Joint Encapsulant Perfect solution for customers looking to eliminate underfilling processes. The SMT 256 Individual Solder Joint Encapsulation Adhesive is the world’s first combined flux gel/individual solder joint encapsulati
SMT 256B series dip adhesives have been designed to enhance solder joint reliability and eliminate solder joint cracking for CSP, BGA, Flip chip and PoP (package on package), particularly for lead free application. SMT 256B is a kind of polymer adhes
SMT266 offers all the features and advantages of our SMT256 series, in a convenient jetting adhesive form (and can also be brushed on during rework). SMT 266 series spray adhesives have been designed to enhance solder joint reliability and eliminat
SMT256EP solderable adhesive is self-leveling and self-soldering adhesives, which has been designed for high temperature Pb-free application. By comparison with conductive adhesives (Ag), SMT256EP solderable adhesive has higher stable electrical and
BP 256 ball attach adhesives have been designed to enhance solder joint reliability and eliminate cleaning process for ball bumping process of CSP, BGA, Flip chip and PoP (package on package) and so on, particularly for lead free application. During
