Technical Library | 2017-04-13 10:57:53.0
Parylene has been used for decades as a barrier layer to protect critical devices and components. The parylene deposition process typically requires an adhesion promotion step to make sure the parylene adheres well to the base substrate. Typical adhesion methods don't work well on Kapton and Polyamide, until VSI Parylene came up with a solution.
Technical Library | 2018-10-29 05:03:59.0
We found that NPI process of SMT is mostly similar and sometimes overlapping to tooling process. In addition, in most cases the programmer is part of the team working on the NPI process. So, QPlan was extended with NPI Tools as a part of tooling process. This allows the team to carry out the NPI process at offline. And at the end of it, they can create corrected SMT program at zero time.
Technical Library | 2019-08-07 22:56:45.0
The requirement to reconsider traditional soldering methods is becoming more relevant as the demand for bottom terminated components (QFN/BTC) increases. Thermal pads under said components are designed to enhance the thermal and electrical performance of the component and ultimately allow the component to run more efficiently. Additionally, low voiding is important in decreasing the current path of the circuit to maximize high speed and RF performances. The demand to develop smaller, more reliable, packages has seen voiding requirements decrease below 15 percent and in some instances, below 10 percent.Earlier work has demonstrated the use of micro-fluxed solder preforms as a mechanism to reduce voiding. The current work builds upon these results to focus on developing an engineered approach to void reduction in leadless components (QFN) through increasing understanding of how processing parameters and a use of custom designed micro-fluxed preforms interact. Leveraging the use of a micro-fluxed solder preform in conjunction with low voiding solder paste, stencil design, and application knowhow are critical factors in determining voiding in QFN packages. The study presented seeks to understand the vectors that can contribute to voiding such as PCB pad finish, reflow profile, reflow atmosphere, via configuration, and ultimately solder design.A collaboration between three companies consisting of solder materials supplier, a power semiconductor supplier, and an electronic assembly manufacturer worked together for an in-depth study into the effectiveness of solder preforms at reducing voiding under some of the most prevalent bottom terminated components packages. The effects of factors such as thermal pad size, finish on PCB, preform types, stencil design, reflow profile and atmosphere, have been evaluated using lead-free SAC305 low voiding solder paste and micro-fluxed preforms. Design and manufacturing rules developed from this work will be discussed.
Technical Library | 1999-05-06 13:38:45.0
This paper traces the key steps that led to the invention of the integrated circuit (IC). The first part of this paper reviews the steady improvements in the performance and fabrication of single transistors in the decade after the Bell Labs breakthrough work in 1947. It sketches the various developments needed to produce a practical IC. In addition, the more advanced processes such as diffusion, oxide masking, photolithography, and epitaxy, which culminated in the planar process, are summarized.
Technical Library | 1999-05-07 10:23:43.0
Software decoding of Dolby Digital allows it to become a baseline capability on the PC, with greater flexibility than a hardware approach. Intel's MMX™ technology provides instructions that can significantly speed up the execution of the Dolby Digital decoder, freeing up the processor to perform other tasks such as video decoding and/or audio enhancement. Intel has worked closely with Dolby Laboratories to define an implementation of Dolby Digital based on MMX technology that has achieved Dolby's certification of quality.
Technical Library | 1999-07-20 11:00:12.0
It's quite common for a power supply (PSU) designer to work with a circuit designer to realize a system design compliant with international EMC regulations. PSU designers will be well aware of the requirement of the power supply to provide clean DC voltage and not disturb the AC mains voltage. However, they may not have any idea of the noise that can potentially be introduced to the mains through the PSU by the target circuit. Likewise, the circuit designers (digital or analogue) may not know what attenuation the PSU will provide.
Technical Library | 1999-08-09 11:09:42.0
Organic Solderability Preservatives (OSPs), also known as anti-tarnish, on bare copper printed circuit boards (PCBs) are becoming more prevalent in the electronics industry as the low-cost replacement to Hot Air Solder Leveling (HASL). Introducing the anti-tarnish alternative into the customer sites requires working closely with the coating supplier, assembler, and Original Equipment Manufacturer (OEM) to gain a mutual understanding of respective processing concerns and finished product requirements.
Technical Library | 2007-04-04 11:43:41.0
The present work offers a discussion and a first case study to identify and illustrate voiding mechanisms for a particular TIM between a heat spreader and the back of a flip chip. Pronounced differences were observed between stencil printing and dispensing in terms of initial void formation, apparently related to the specific properties of the material. Measurements of the effects of heat ramp rate and peak temperature showed the subsequent evolution and final void size distribution to be determined by the initial part of the cure profile up to the material gelling temperature.
Technical Library | 2007-07-12 14:29:37.0
Over the last ten years, there have been a large number of publications describing work into lead free electronics soldering. They have come from all regions of the world and from academic organisations, individual companies and consortia. Although a number of these studies have culminated in "production trials", these have invariably been on a limited scale and they were essentially a demonstration, rather than the first step to implementation.
Technical Library | 2007-12-27 11:41:37.0
The latest screen printing platforms unlock more of the potential from dual-lane processing. Simultaneous demands to enhance flexibility while increasing utilisation and overall throughput apply to manufacturers operating at virtually any point in the mix-volume continuum: capacity must work hard to deliver the required return. As these lean manufacturing principles hold sway from the US and Europe to the Far East, no modern assembler has a second to spare.
