浅谈PCBA线路板清洗:有哪些因素影响着水基清洗工艺窗口?

关键词导读:电路板清洗、电子组件清洗、水基清洗技术、水基清洗剂、印制电路板 在生产中,有关印制电路板(PCB)、印制线路板(PWB)和印制线路组件(PWA)的清洗在IPC文件和手册里均有相关指导文件,如:CH-65 印制板及组件清洗指南、SM-839 施加阻焊剂前、后的清洗指南、SC-60 焊接后溶剂清洗手册、SA-61 焊接后半水基清洗手册、AC-62 焊接后水基清洗手册。 随着技术的进步,使用更小的元器件、高密度布局、材料的变化,和环境条件重新提高了电路板清洁度的重要性,印制电路组件的清洗性已成为一个非常具有挑战的任务。 印制电路板按照既定的行业标准进行设计,组装和品质控制。为了减轻由于污染造成产品失效的风险,清洗工艺必须提供一个已定义的工艺窗口,该窗口是可重复的并且是横跨组装工艺中所遇到的变量的广阔区间。为实现一个高良率的清洗工艺,许多因素影响着清洗工艺窗口:基板,污染物,可用的清洗技术,清洗设备,和环境因素。 (一)基板:设计清洗工艺的第一步是印制线路板布局的彻底审查以确定镀覆孔,孔的厚径比,任何适用堵塞或掩蔽的导通孔,和阻焊膜材料的选择。部件组成、尺寸和几何形状可以创造低间隙和小出口的夹层元器件而导致残留很难去除。 小型和轻量的部件当它们通过清洗工艺时增加了夹持组件的需求。清洗工艺设计首先考虑电路板表面、金属化和兼容性的限制。部件独特的限制可能会使一些元器件在进行清洗工艺时受到限制。 (二)组件污染物:对独特部...

Aluminum Wire Rods Market Report Forecast by Market Outlook, Capital Investment, Opportunities & Trends 2024

Aluminum Wire Rods Market 2019 report contains a focused socio-economic, political, and environmental analysis of the factors affecting the Aluminum Wire Rods industry. The report contains an analysis of the technologies involved in production, application and much more. The report also carries in-depth case studies on the various countries which are actively involved in the Aluminum Wire Rods production. An analysis of the technical barriers, other issues, cost effectiveness affecting the Aluminum Wire Rods Market. Determining the opportunities, future of the Aluminum Wire Rods and its restraints becomes a lot easier with this report. Look insights of Global Aluminum Wire Rods industry market research report at https://www.pioneerreports.com/report/451485    With the slowdown in world economic growth, the Keyword industry has also suffered a certain impact, but still maintained a relatively optimistic growth, the past four years, Keyword market size to maintain the average annual growth rate of XXX from XXX million $ in 2015 to XXX million $ in 2018, Industry Report analysts believe that in the next few years, Keyword market size will be further expanded, we expect that by 2024...

The Vemag bun and roll divider from Reiser provides the highest levels of product quality and

The Vemag bun and roll divider from Reiser provides the highest levels of product quality and scaling accuracy across multiple lanes. The Vemag features a double-screw portioning system that ensures accurate scaling with minimal work on the product. Recent advances in the infeed system and the double-screws allow it to produce exact-weight portions with less work on the product. For high-speed production, a Vemag waterwheel flow divider with a matching multi-lane rounding conveyor can be added to the line. Hydraulic Power Unit, Hydraulic Power Pack, Mini Power Pack – Guorui,https://www.minipowerunit.com/

For full functionality of this site it is necessary to enable JavaScript. Here are the instructions

For full functionality of this site it is necessary to enable JavaScript. Here are the instructions how to enable JavaScript in your web browser. Save to read list Published by Nicholas Woodroof, Assistant Editor Oilfield Technology, Monday, 12 August 2019 15:00 Hydraulic and instrumentation (H&I) systems are vital and often very large installations on both land-based plants and marine offshore applications. Normally, they consist of many kilometres of high-quality stainless steel, nickel base or copper alloy tubing with strict dimensional tolerances. The tubes are connected with fittings, each fitting being precision made and expensive. It is therefore not surprising that engineering companies and plant owners will try to find the most cost-effective material solution, while at the same time avoiding a compromise on quality and lifetime of the installation. When choosing material for H&I installations in inland regions, the most commonly used alloy is stainless steel of type 316L (UNS S31603) with matching fittings. Unless there is some specific plant-related condition requiring special consideration, this will provide the system with sufficient corrosion resistance for...

PACK EXPO International 2018 Innovations Report: Machinery

Each year the editors at PMMI Media Group roam the aisles of PACK EXPO looking for the next big thing in the packaging sector. Of course, with a show this size it’s never one big thing we find but rather a multitude of things big, medium, and small, all of them innovative and meaningful in one way or another to packaging professionals of today. This report sums up what we found in six main categories. We present them here for your review knowing full well that, inevitably, we missed a few. Probably more than a few. That’s where you come in. Let us know what we missed and we’ll look into it. Or at the very least, we’ll know to be on the lookout for it at the next PACK EXPO. CODING & MARKINGID Technology, a ProMach company, announced at PACK EXPO the launch of a digital thermal ink-jet technology called Clearmark (1). HP Indigo cartridges are used to print high-resolution text, graphics, or codes on nonporous as well as porous substrates. Suitable for primary, secondary, or tertiary packaging applications and purpose-built from the ground up, it uses a 10-inch HMI with large buttons and typeface fonts. Additional information is displayed clearly along the bottom of th...

Stoneridge to produce MirrorEye system for second CV OEM

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them. Informa PLC’s registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726. Stoneridge recently partnered with a second commercial vehicle OEM to deliver its MirrorEye Camera Monitor System (CMS) to the market. The electronic components manufacturer said the latest award represents an estimated $10 million in peak annual revenue, based on its forecasted production levels, and an assumed penetration rate of 10% to 15% for the system. “As the industry continues to focus on technologies that improve vehicle safety and efficiency, we are excited to support another OEM partner in bringing industry leading technology to its customers,” said Jon DeGaynor, president and chief executive officer at Stoneridge. “Our MirrorEye platform helps drivers operate more safely, reduces vehicle maintenance and safety-related costs for our end users, and improves fuel efficiency of the vehicle.” MirrorEye CMS replaces traditional rear and side view mirrors with digital cameras, and, according to the company, provides significant improve...

DIYers Take Note – the 2019 Ford Ranger’s Oil Change Procedure Contains a Big Extra Step [UPDATED]

Ever swapped out the battery in a cloud-car Chrysler, or maybe an old Sebring or PT Cruiser? You’ll be reminded of that when the time comes to change your new-generation Ford Ranger’s oil, assuming you’re a proud member of the DIY crowd. Job One for those looking to freshen the Ranger’s internal lubricant, besides heading to the store for a couple of jugs of synthetic and a filter, is to break out the jack. You’ll need to remove a wheel. (Editor’s Note: Ford has reached out to us to inform us that the service procedure we referenced below is incorrect, and that the wheel does not need to be removed. We regret the error, and we have further addressed it here.) Because the 2.3-liter Ecoboost four-cylinder found in the 2019 Ranger isn’t exactly the same beast as that found in other Ford vehicles, the oil filter migrates to a slightly new location. A larger oil cooler means the filter no longer hangs towards the oil pan near the rear of the engine. Instead, the filter sticks out the left side, at right angles to the engine’s cylinders, making it less accessible for fumbling hands. Sliding under there and going to town just isn’t in the cards, at least for the oil filter phase of the...

At the beginning of the 19th century, Thomas Bruce, Lord Elgin, was the British Ambassador to

At the beginning of the 19th century, Thomas Bruce, Lord Elgin, was the British Ambassador to the Ottoman Empire, which occupied Greece. He entered the Parthenon in Athens and documented the sculptures, making moulds and casts. He bribed Turkish officials to allow him to engage in daily excavations before removing a large part of the marbles to Britain. Bribing occupying powers to purloin national treasures is not the sort of behaviour usually deemed worthy of a British Ambassador.  The looting that happened during the Second World War has, on the whole, been made good. No one accepts the right of those who occupied half of Europe to walk off with the revered relics of those subjugated nations in the 20th century. So why was it acceptable to do so in the 19th century? Britain missed a trick by failing to hand the marbles back during the 2012 Olympic Games, which would have been a spectacular gesture. That it did not is a sad reflection on the enfeebled spirit of philhellenism in Britain. Lord Byron, who died in Greece after travelling to fight in its war of independence, condemned the cultural vandalism of his fellow peer, Elgin. But today there are no Lord Byrons in Britain wil...

Hilcorp has approval from the Bureau of Ocean Energy Management to acquire the first geophysical survey

Hilcorp has approval from the Bureau of Ocean Energy Management to acquire the first geophysical survey since 2015 over the Cook Inlet off southern Alaska. The 3D program, across part of the lower Cook Inlet, west of Kachemak Bay, should take 60 days to complete.                                                              ◆◆◆ Abrado Wellbore Services will support Chevron’s campaign to P&A over 30 wells in federal waters around 19.3 km (12 mi) offshore California. The wells are exhibiting signs of sustained casing pressure, with some in need of dual-string remediation for permanent abandonment. Abrado will provide section milling using its Medusa VS variable stabilized dual-string technology, supported by downhole video diagnostics.                                                              ◆◆◆ Suncor Energy has sanctioned a life extension program for the Terra Nova oilfield and FPSO, 350 km (217 mi) southeast of Newfoundland, until 2031. Production started in 1984, and the FPSO/subsea production system was the first in North America protected against sea ice and icebergs. The latest development phase, due to start next year, should recover a further 80 MMbbl.            ...

For all that its gangling, angular appearance made the Fieseler Fi156 one of the most ungainly

For all that its gangling, angular appearance made the Fieseler Fi156 one of the most ungainly aircraft of the Second World War, the Storch – or Stork – was also one the most capable machines of its type. Whether working as an ambulance, artillery spotter or courier, the Fi156’s remarkable short take-off and landing (STOL) characteristics made it the perfect utility vehicle in support of troops – on both sides of the conflict! Virtually every captured example was pressed into service by the Allies; even Monty acquired one, which Churchill borrowed when he wanted to review the progress of the D-Day landings.DEFYING GRAVITY Conceived by Fieseler’s chief designer, Reinhold Mewes, and first flown in 1936, the Storch answered the German Air Ministry’s demand for a STOL aircraft in unequivocal style: given a light headwind, the Fi156’s slow-flying wing allowed the machine to take-off in a little over 60 yards, and land in just over 30! Powered by a 240hp air-cooled Argus As 10C, and using wholly conventional steel tubing and fabric fuselage construction, the Fieseler achieved this gravity-defying act with its remarkable wooden wing, which featured fixed slats running...

Global Chain Couplings Market – Segmented By Type, Application, Technology and Geography – Growth, Trends & Forecast (2018 – 2024)

Chain Couplings Market reports provides  5 year pre-historic and forecast for the sector and include data on socio-economic data of global. Key stakeholders can consider statistics, tables & figures mentioned in this report for strategic planning which lead to success of the organization.Chain Couplings Market reports provides a comprehensive overview of the global market size and share. Global Chain Couplings Market report provides strategists, marketers and senior management with the critical information they need to assess the global Chain Couplings sector.  Look insights of Global Chain Couplings industry market research report at https://www.pioneerreports.com/report/354190    With the slowdown in world economic growth, the Keyword industry has also suffered a certain impact, but still maintained a relatively optimistic growth, the past four years, Keyword market size to maintain the average annual growth rate of XXX from XXX million $ in 2015 to XXX million $ in 2018, Industry Report analysts believe that in the next few years, Keyword market size will be further expanded, we expect that by 2024, The market size of the Keyword will reach XXX million $.  The overviews,...

Observing Liquid Metal Embrittlement Cracks In Couple Systems | Science Trends Observing Liquid Metal Embrittlement Cracks In Couple Systems

Bring a couple system such as brass, a copper-zinc alloy, in contact with a liquid metal — say, mercury. Mechanically stretch brass with a tensile machine past its yield point (the stress at which the alloy irreversibly plastically yield), and a brittle crack will suddenly initiate and propagate at a fast speed of the order of ten centimeters per second. This rupture, triggered by the liquid metal, occurs in an otherwise ductile alloy. Such process, which can lead to catastrophic fracture well below usual engineering safety loads in several couples like brass/mercury, is called liquid metal embrittlement (LME). First reported in 1914, LME is still the subject of active research to understand its small-scale mechanisms. In spite of decades of investigations, the prediction of its occurrence still escapes our reach. The number of LME cases keeps increasing with time, as many couples have still not been properly investigated. The nuclear power community faces the challenge of better understanding this phenomenon as future reactors, so-called fourth-generation reactors for sustainable nuclear energy, plan to use low melting point liquid metals such as sodium or lead-bismuth alloy as...

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