A5E002710416工業(yè)框架,YOKOGAWA使用范圍
如此長(zhǎng)的使用壽命的原因之一是灌封材料的氣密性,讓轉(zhuǎn)換器的電子器件保持在一個(gè)清潔且穩(wěn)定的環(huán)境里。上面列出的所有優(yōu)點(diǎn)僅適用在氣密和水密的灌封情況下。 如果灌封膠中包含空氣或“氣泡”,可能就不會(huì)那么有效。氣泡會(huì)因?yàn)閮?nèi)部電弧放電或表面電痕而降低絕緣效果,而這當(dāng)然也會(huì)降低導(dǎo)熱性。另外,夾雜物會(huì)因?yàn)闃O高或極低的氣壓或空隙中的空氣隨溫度膨脹或收縮而產(chǎn)生機(jī)械應(yīng)力進(jìn)而導(dǎo)致灌封膠破裂有幾種技術(shù)可用來(lái)消除灌封膠中的大量空氣,最有效的是真空混合和分裝。在真空下準(zhǔn)備并混和灌封膠會(huì)使氣泡上升到表面,然后透過(guò)加壓系統(tǒng)分裝到注射器,不讓空氣回流到材料里面。某些產(chǎn)品如我們的RAC-K系列AC/DC電源使用灌封作為合格的安全隔離屏障的一部分,安全機(jī)構(gòu)要求在生產(chǎn)中必須控制灌封膠的滲透度且無(wú)氣泡。真空注入的制程以及定期監(jiān)視“截面”或X射線(xiàn)的結(jié)果可以確保這一點(diǎn)。
A5E002710416工業(yè)框架,YOKOGAWA使用范圍但是,我們大多數(shù)的產(chǎn)品都不是真空灌封,因?yàn)樾枰蠓岣弋a(chǎn)量,當(dāng)每月生產(chǎn)超過(guò)一百萬(wàn)種產(chǎn)品的產(chǎn)量時(shí)就顯得特別重要。RECOM仍可以通過(guò)使用其他技術(shù)來(lái)避免灌封膠中的氣泡,這些技術(shù)可以消除幾乎所有的氣孔。首先是正確的灌封過(guò)程。先在外殼中填充一部份的灌封膠,然后插入經(jīng)過(guò)測(cè)試的PCBA,再將外殼填充到幾乎全滿(mǎn)。然后將轉(zhuǎn)換器半成品放在溫暖的烘箱中,烤箱溫度保持低于灌封膠的固化溫度。灌封膠在溫暖的溫度下變?yōu)橐簯B(tài),因此任何氣泡都會(huì)浮上表面。如果必要,可將轉(zhuǎn)換器放在振動(dòng)臺(tái)上讓氣泡順利上升。最后,完全填滿(mǎn)外殼并將轉(zhuǎn)換器放到溫度較高的固化爐中。
雙組分環(huán)氧灌封膠具吸濕性,會(huì)吸收空氣中的水分,然后導(dǎo)致表面呈斑點(diǎn)狀,稱(chēng)為“油面”。因此儲(chǔ)存在低溫低濕的環(huán)境是非常重要的。另外,PCB本身應(yīng)保持清潔且無(wú)殘留。RECOM擁有自己的SMD產(chǎn)線(xiàn),因此我們可以在生產(chǎn)區(qū)內(nèi)嚴(yán)格管控清潔度、濕度和溫度。干凈的裸板轉(zhuǎn)換器可讓灌封膠很好地粘附在器件和PCB上,以減少空氣。我們可以使用X射線(xiàn)來(lái)檢查轉(zhuǎn)換器是否有氣孔。在新設(shè)計(jì)中,可能會(huì)有些氣泡意外地殘留在器件或PCB下方而且難以清除。此時(shí)我們可以使用X射線(xiàn)檢查的結(jié)果來(lái)重新定位器件或在PCB上增加開(kāi)孔,讓殘留的空氣在封裝過(guò)程中得以排出。
影響灌封膠選擇的因素
所有的灌封膠從液態(tài)轉(zhuǎn)變?yōu)楣虘B(tài)時(shí)都會(huì)收縮。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.