Technical Library | 2019-08-19 23:55:20.0
Electronic dry cabinet for MSD storage Humidity is one of the key reasons for rejected products, many manufacturers are taking measures to control the humidity to increase production efficiency and save cost. In semiconductor and electronic industry, the key section of rejected products mostly happen during SMT heating process, Climatest Symor® auto dry cabinet is a superior solution to avoid the cracking. Warranty: two years with lifetime technical support
Technical Library | 2019-04-11 05:59:57.0
Are your MSD safely stored? As humidity is found to be one of the key reasons for rejected products, many manufacturers are taking measures to control the humidity to increase their production efficiency and save the cost. In the industries of semi-conductor and electronics, the key section in which the rejected products are most probably to be made is that during the heating process of SMT, the IC(e.g.,PBGA,BGA,or TQFD) is likely to crack and thus cause non-effective welding because of the humidity. Climatest Symor® auto dry cabinet is the best solution to avoid the cracking and non#2;effective welding by dehumidifying the surface of your components. The dry unit can be used for 20 years without replacement,and controller is calibration free within 5 years.We attach dry cabinet application with different humidity range,welcome to download.
Technical Library | 2020-08-27 01:22:45.0
Initially adopted internal specifications for acceptance of printed circuit boards (PCBs) used for wire bonding was that there were no nodules or scratches allowed on the wirebond pads when inspected under 20X magnification. The nodules and scratches were not defined by measurable dimensions and were considered to be unacceptable if there was any sign of a visual blemish on wire-bondable features. Analysis of the yield at a PCB manufacturer monitored monthly for over two years indicated that the target yield could not be achieved, and the main reasons for yield loss were due to nodules and scratches on the wirebonding pads. The PCB manufacturer attempted to eliminate nodules and scratches. First, a light-scrubbing step was added after electroless copper plating to remove any co-deposited fine particles that acted as a seed for nodules at the time of copper plating. Then, the electrolytic copper plating tank was emptied, fully cleaned, and filtered to eliminate the possibility of co-deposited particles in the electroplating process. Both actions greatly reduced the density of the nodules but did not fully eliminate them. Even though there was only one nodule on any wire-bonding pad, the board was still considered a reject. To reduce scratches on wirebonding pads, the PCB manufacturer utilized foam trays after routing the boards so that they did not make direct contact with other boards. This action significantly reduced the scratches on wire-bonding pads, even though some isolated scratches still appeared from time to time, which caused the boards to be rejected. Even with these significant improvements, the target yield remained unachievable. Another approach was then taken to consider if wire bonding could be successfully performed over nodules and scratches and if there was a dimensional threshold where wire bonding could be successful. A gold ball bonding process called either stand-off-stitch bonding (SSB) or ball-stitch-on-ball bonding (BSOB) was used to determine the effects of nodules and scratches on wire bonds. The dimension of nodules, including height, and the size of scratches, including width, were measured before wire bonding. Wire bonding was then performed directly on various sizes of nodules and scratches on the bonding pad, and the evaluation of wire bonds was conducted using wire pull tests before and after reliability testing. Based on the results of the wire-bonding evaluation, the internal specification for nodules and scratches for wirebondable PCBs was modified to allow nodules and scratches with a certain height and a width limitation compared to initially adopted internal specifications of no nodules and no scratches. Such an approach resulted in improved yield at the PCB manufacturer.
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