Technical Library | 2023-01-17 17:19:44.0
A test program was developed to evaluate the effectiveness of vacuum reflow processing on solder joint voiding and subsequent thermal cycling performance. Area array package test vehicles were assembled using conventional reflow processing and a solder paste that generated substantial void content in the solder joints. Half of the population of test vehicles then were re-processed (reflowed) using vacuum reflow. Transmission x-ray inspection showed a significant reduction in solder voiding after vacuum processing. The solder attachment reliability of the conventional and vacuum reflowed test vehicles was characterized and compared using two different accelerated thermal cycling profiles. The thermal cycling results are discussed in terms of the general impact of voiding on solder thermal fatigue reliability, results from the open literature, and the evolving industry standards for solder voiding. Recommendations are made for further work based on other void reduction methods and additional reliability studies.
Technical Library | 2023-01-17 17:12:33.0
Reflowed indium metal has for decades been the standard for solder thermal interface materials (solder TIMs or sTIMs) in most high-performance computing (HPC) TIM1 applications. The IEEE Heterogeneous Integration Thermal roadmap states that new thermal interface materials solutions must provide a path to the successful application of increased total-package die areas up to 100cm2. While GPU architectures are relatively isothermal during usage, CPU hotspots in complex heterogeneously-integrated modules will need to be able to handle heat flux hotspots up to 1000W/cm2 within the next two years. Indium and its alloys are used as reflowed solder thermal interface materials in both CPU and GPU "die to lid/heat spreader" (TIM1) applications. Their high bulk thermal conductivity and proven long-term reliability suit them well for extreme thermomechanical stresses. Voiding is the most important failure mode and has been studied by x-ray. The effects of surface pretreatment, pressure during reflow, solder flux type/fluxless processing, and preform design parameters, such as alloy type, are also examined. The paper includes data on both vacuum and pressure (autoclave) reflow of sTIMs, which is becoming necessary to meet upcoming requirements for ultralow voiding in some instances.
Technical Library | 2021-09-02 08:17:07.0
We are a professional manufacturer of PCB depaneling machines, which is workable for all boards, including flex and regid boards, v-scored boards and routed boards. Laser pcb depaneling is non-contact way without mechanical stress,this solution is good for modern precision PCB depaneling. It has below advantages: 1. No dust The production environment of the circuit board industry is carried out in the dust-free workshop. The traditional pcb depaneling equipment, such as blade moving type machine, will inevitably produce residues and micro powder, which will pollute the 10000 and 1000 class dust-free workshops and affect the conductivity of products. The UV laser PCB cutting machine is a vaporization processing process, which will not produce dust and is conducive to the conductivity of the product. 2. High cutting precision The processing gap of high-precision traditional processing equipment can not reach the gap width of less than 100 microns, which will cause certain damage to the lines on the edge or PCBA circuit board containing components. The focus spot of the laser cutting machine is small, and the ultraviolet cold processing mode has little thermal impact on the edge of the circuit board. The cutting position accuracy is less than 50 microns, and the cutting size accuracy is less than 30 microns, which will not affect the edge of the circuit board, and the precision is high. 3. No stress Traditional processing methods generally have V-grooves, which will cause certain damage to the board in the manufacturing process. The UV laser PCB cutting machine can directly cut the bare board without making V-grooves. In addition, the traditional processing methods directly use tools to act on the circuit board, especially the stamping method has a great impact on the circuit board, which is easy to cause board deformation. The laser cutting machine is a non-contact processing mode, which acts on the surface of the material through the high-energy beam, which will not cause the influence of stress and the deformation and damage of the circuit board. 4. For special-shaped cutting, it is easy to automate The UV laser PCB cutting machine can cut for any shape without replacing any props and fixtures, and without steel mesh. The same equipment can meet special-shaped and straight-line cutting, which is easy to realize assembly line automatic production and high flexibility. It is easy to improve production efficiency and save production process and production cycle. In particular, it can quickly and efficiently meet the needs of rapid proofing, directly import the drawing, and then locate the cutting. 5. High compatibility The UV laser PCB cutting machine can process the materials around the circuit board, such as PCB, FPC, covering film, pet, reinforcing board, IC, ultra-thin metal cutting, etc. it has strong practicability, is compatible with the processing of a variety of materials, is easy to operate, can be imported into the drawing, does not need to adjust any mechanical parts, and is easy to operate and maintain. 6. Good cutting edge effect The cutting edge is smooth and neat without burr. It can be processed and formed directly according to the size of the drawing, which is conducive to improving the yield of the product. It can be directly installed into the subsequent process without further processing. For more details about UV laser depaneling, please feel free to contact us. www.pcbdepanelingrouter.com
Technical Library | 2012-12-17 22:05:22.0
Package on Package (PoP) has become a relatively common component being used in mobile electronics as it allows for saving space in the board layout due to the 3D package layout. To insure device reliability through drop tests and thermal cycling as well as for protecting proprietary programming of the device either one or both interconnect layers are typically underfilled. When underfill is applied to a PoP, or any component for that matter, there is a requirement that the board layout is such that there is room for an underfill reservoir so that the underfill material does not come in contact with surrounding components. The preferred method to dispensing the underfill material is through a jetting process that minimizes the wet out area of the fluid reservoir compared to traditional needle dispensing. To further minimize the wet out area multiple passes are used so that the material required to underfill the component is not dispensed at once requiring a greater wet out area. Dispensing the underfill material in multiple passes is an effective way to reduce the wet out area and decrease the distance that surrounding components can be placed, however, this comes with a process compromise of additional processing time in the underfill dispenser. The purpose of this paper is to provide insight to the inverse relationship that exists between the wet out area of the underfill reservoir and the production time for the underfill process.
Technical Library | 2007-10-10 23:23:40.0
Process engineers, who are seeking to achieve the most effective and reproducible thermal transfer process, look to today's forced convection ovens for applications such as flipchip, BGA, and lead-free soldering. A forced convection process to maximize thermal uniformity can be best accomplished by employing static pressure generation in what's known as "closed loop convection".
Technical Library | 2021-01-13 21:34:29.0
Package-on-Package (PoP) is a popular technology for fabricating chipsets of accelerated processing units. However, the coefficient of thermal expansion mismatch between Si chips and polymer substrates induces thermal warpage during the reflow process. As such, the reflow temperature and reliability of solder joints are critical aspects of PoP. Although Sne58Bi is a good candidate for low-temperature processes, its brittleness causes other reliability issues. In this study, an in-situ observation was performed on composite solders (CSs) made of ...
Technical Library | 2012-12-20 14:36:09.0
The increased function of personal electronic devices, such as mobile phones and personal music devices, has driven the need for smaller and smaller active and passive components. This trend toward miniaturization, occurring at the same time as the conversion to RoHS-compliant lead-free assembly, has been a considerable challenge to the electronics assembly industry. The main reason for this is the higher reflow process temperatures required for Pb-free assembly. These higher temperatures can thermally damage the PCB and the components. In addition, the higher reflow temperatures can negatively affect the solder joint quality, especially when coupled with the smaller paste deposits required for these smaller components. If additional thermal processing is required, the risk increases even more. First Published at SMTA's International Conference on Soldering and Reliability in Toronto, May 2011
Technical Library | 1999-05-06 12:11:42.0
The newest workstations and servers, targeting computationally-intensive applications and large-scale database management, use 64-bit microprocessors and provide the next generation of computing power.
Technical Library | 2017-11-08 23:22:04.0
Due to the ongoing trend towards miniaturization of power components, the need for increased thermal conductivity of solder joints in SMT processes gains more and more importance. Therefore, the role of void free solder joints in power electronics becomes more central. Voids developed during soldering reduce the actual thermal transfer and can cause thermal damage of the power components up to their failure. For this reason, the company has developed a new technique to minimize the formation of these voids during the soldering process.
Technical Library | 1999-05-06 11:42:16.0
The most reliable and well-designed electronic device can malfunction or fail if it overheats. Considering thermal issues early in the design process results in a thermally conscious system layout and minimizes costs through the use of passive cooling and off-the-shelf components. When thermal issues are left until completion of the design, the only remaining solution may be a costly custom heat sink that requires all the space available. Incorporating a heat sink or a fan into a product after it is fully developed can be expensive, and still may not provide sufficient cooling of the device.
Reflow ovens for automated SMT PCB assembly, specializing in lead free processing and nitrogen reflow. The best convection reflow ovens on the market.
4 Vreeland Rd.
Florham Park, NJ USA
Phone: 973-377-6800
winsouce.jpg)
