A5E002710416工业框架,YOKOGAWA使用范围
如此长的使用寿命的原因之一是灌封材料的气密性,让转换器的电子器件保持在一个清洁且稳定的环境里。上面列出的所有优点仅适用在气密和水密的灌封情况下。 如果灌封胶中包含空气或“气泡”,可能就不会那么有效。气泡会因为内部电弧放电或表面电痕而降低绝缘效果,而这当然也会降低导热性。另外,夹杂物会因为极高或极低的气压或空隙中的空气随温度膨胀或收缩而产生机械应力进而导致灌封胶破裂有几种技术可用来消除灌封胶中的大量空气,最有效的是真空混合和分装。在真空下准备并混和灌封胶会使气泡上升到表面,然后透过加压系统分装到注射器,不让空气回流到材料里面。某些产品如我们的RAC-K系列AC/DC电源使用灌封作为合格的安全隔离屏障的一部分,安全机构要求在生产中必须控制灌封胶的渗透度且无气泡。真空注入的制程以及定期监视“截面”或X射线的结果可以确保这一点。
A5E002710416工业框架,YOKOGAWA使用范围但是,我们大多数的产品都不是真空灌封,因为需要大幅提高产量,当每月生产超过一百万种产品的产量时就显得特别重要。RECOM仍可以通过使用其他技术来避免灌封胶中的气泡,这些技术可以消除几乎所有的气孔。首先是正确的灌封过程。先在外壳中填充一部份的灌封胶,然后插入经过测试的PCBA,再将外壳填充到几乎全满。然后将转换器半成品放在温暖的烘箱中,烤箱温度保持低于灌封胶的固化温度。灌封胶在温暖的温度下变为液态,因此任何气泡都会浮上表面。如果必要,可将转换器放在振动台上让气泡顺利上升。最后,完全填满外壳并将转换器放到温度较高的固化炉中。
双组分环氧灌封胶具吸湿性,会吸收空气中的水分,然后导致表面呈斑点状,称为“油面”。因此储存在低温低湿的环境是非常重要的。另外,PCB本身应保持清洁且无残留。RECOM拥有自己的SMD产线,因此我们可以在生产区内严格管控清洁度、湿度和温度。干净的裸板转换器可让灌封胶很好地粘附在器件和PCB上,以减少空气。我们可以使用X射线来检查转换器是否有气孔。在新设计中,可能会有些气泡意外地残留在器件或PCB下方而且难以清除。此时我们可以使用X射线检查的结果来重新定位器件或在PCB上增加开孔,让残留的空气在封装过程中得以排出。
影响灌封胶选择的因素
所有的灌封胶从液态转变为固态时都会收缩。China's traditional manufacturing industries are experiencing a new round of competition in structural adjustment and industrial upgrading. Through the introduction of advanced quality control equipment, enterprises carry out technological transformation, and gradually replace the traditional manual operation field with automation technology, so as to achieve the effect of leap forward improvement of product quality. With its high-precision and tireless image processing function, machine vision has overcome the weakness of fatigue and large error of traditional human eyes in product quality detection. It is rolling up a revolution in quality detection. The machine vision detection system armed with advanced embedded computers, high-pixel industrial cameras, industrial displays, communication software and hardware is becoming the secret weapon of leading manufacturing enterprises in various industries at home and abroad. To adapt to the rapid development of the visual inspection industry, Shenzhen Lantian Industrial Control Co., Ltd. took the lead in launching the "bsky" embedded visual inspection special board ec3-1698, the first domestic high-end visual computer embedded motherboard. Basic components:? Power supply system, pneumatic device? Computer network? According to the feeding device placed by the customer? Rotary table and various cameras for surface and specification detection. Ec3-1698 plays the role of connecting image equipment to real-time data acquisition, image processing and transmission to the server in the rotary table visual inspection system.