[派瑞林日记]Parylene and A-174 Silane

mproving Parylene Adhesion

Parylene provides an entirely conformal, durable, pinhole-free substrate coating of extreme utility for an exceptional range of materials, products and purposes. Despite its many advantages, parylene\’s chemical structure can actually interfere with the reliable interface adhesion required for optimal performance. The chemical vapor deposition (CVD) process that generates so many of parylene\’s benefits also nullifies chemically-based substrate adhesion; only mechanical adhesion is possible.

Implementing optimal adhesion can require surface modification via application of adhesion promoting agents or methods. The materials and processes used for these purposes are largely dependent on the substrate surface and component\’s specific operational environments and functions. Although most adhesion promotion methods are used prior to CVD, several can be integrated into the coating-process itself, Among the methods of adhesion promotion used with parylene are:

·        Thorough surface-cleaning, which stimulates enhanced adhesion by eliminating accumulated substrate contaminants whose presence can diminish overall coating quality.

·        Heat-treating. for three hours at temperatures of 140°C, beneficially activates longer-term adhesion and insulation.

·        Active, wired devices profit from bilayer component-encapsulation processes.

While these techniques have their uses for parylene adhesion promotion, the chemical monolayer Silane A-174 (3-Methacryloxypropyltrimethoxysilane – C10H20O5Si) is used most frequently to modify substrate surfaces and improve parylene adhesion.

The Uses of Silane A-174

Silane A-174\’s value as an adhesion promoting agent stems largely from its versatility. It can be successfully applied to substrate materials like elastomer, glass, metal, paper, plastic or quartz, among a wide range of surface substances. The A-174 silane molecule develops a robust chemical bond with the substrate, facilitating the improved surface adhesion capacity of parylene’s mechanical property. Optimal parylene adhesion is commonly achieved by a treatment with A-174 silane prior to initiating the CVD process. However, regarding appropriate procedural scheduling:

·        it is recommended that A-174\’s application be completed after any necessary masking operations have been finished;

·        depending on substrate materials, manual spray, soaking, or vapor phase silane processing techniques may be used to apply A-174.

Process Balance

While the silane promotes adhesion, the parylene assures protection. Thus, appropriately proportional intermixtures of silane A-174 and parylene need to be used, in all cases. Corrosion-resistance can be diminished where the relationship between parylene and silane is inexact, causing part and function deterioration from both beneath- and external to the conformal covering. This is especially the case with medical implants, where reliable component function is mandatory, despite being subjected to persistent exposure to often harsh bodily fluids.

Of the two basic methods for applying silane A-174 to substrates, the first, in-chamber vapor delivery, is somewhat easier to enact but offers significantly diminished coating outcomes. Silane vapor promotion is impossible to efficiently supervise during real time, causing a proportional loss of effective process monitoring. As a consequence:

·        the potential of operator error increases,

·        leading to a far greater incidence of insufficient or excessive silane promotion;

·        imperfect silane surface-conformity frequently develops under these conditions,

·        stimulating degraded parylene coverage during the subsequent deposition cycle.

Thus, the problems inherent in achieving inappropriate production-intermixture alluded to above are more likely to occur, adding to production downtime and expense, as well as customer dissatisfaction.

The wet application method of silane application further allows inspection and monitoring of the immersion-solution throughout the process. Following silane A-174 immersion, CVD processes for parylene application should be implemented within 30 hours.

Mixing only the quantity of silane required for the procedure at hand is recommended, to assure appropriate preparation/application and safe work conditions, Silane\’s 24-hour shelf-life precludes storage of any excess, which should be discarded immediately in a solvent sink, subsequently drained, then rinsed with IPA. At all times, avoid breathing the solution\’s vapors or causing contact with skin or eyes:

Conclusion

Improving substrate adhesion is necessary because parylene will peel-off some substrates, if not appropriately treated with silane A-174. Immersion methods of application provide the most reliable solution.

简易译文翻译

改进Parylene黏附力

Parylene给予彻底保形，经久耐用，无针眼的板材镀层，具备很高的应用性，适用各种各样原材料，商品和主要用途。虽然聚对二甲苯具备很多优势，但它的化学结构事实上很有可能会影响最好特性需要的靠谱页面粘合力。化学气相沉积（CVD）加工工艺造成这么多的聚对二甲苯的好处也使根据有机化学的板材黏附失效; 只有开展机械设备黏合。

执行最好黏合很有可能要根据增加黏合硫化促进剂或方式开展外表改性材料。用以这种目标的材质和加工工艺在较大水平上在于基材表层和构件的特殊实际操作自然环境和作用。虽然在CVD以前应用了大部分黏合推动方式，可是几类可以融合到镀层加工工艺自身中。与聚对二甲苯一起应用的黏合推动方式包含：

·完全的外表清理，根据清除积累的板材污染物质来刺激性提高的粘合力，其存有会减少总体镀层品质。

·热处理工艺。在140°C的溫度下隔热保温3钟头，有益于激话长期性黏合和绝缘层。

·主题活动的有线电视机器设备从两层部件封装形式全过程中获利。

尽管这种技术性在推动聚对二甲苯黏合，但有机化学单面氯硅烷A-174（3-羟基pe酰氧基丙基三叔丁基氯硅烷-C10H20O5Si）最常见于改性材料板材表层并改进聚对二甲苯黏合性。

氯硅烷A-174的主要用途

氯硅烷A-174做为粘结硫化促进剂的使用价值非常大水平上来源于其生态性。它可以取得成功地运用于基材原材料，如弹性体材料，夹层玻璃，金属材料，打印纸张，塑胶或石英石，及其各种各样表层成分。A-174氯硅烷分子结构与板材产生结实的离子键，有利于提升聚对二甲苯的物理性能的表层黏附工作能力。最好的聚对二甲苯黏合通常用在逐渐CVD全过程以前用A-174氯硅烷解决来完成。可是，有关适度的流程分配：

·提议在进行必需的掩蔽实际操作后进行A-174的申请办理;

·在于板材原材料，可以应用手动式喷漆，泡浸或气相色谱氯硅烷解决技术性来增加A-174。

步骤均衡

尽管氯硅烷推动黏合，但聚对二甲苯保证了维护。因而，在全部状况下，需要应用适度比率的氯硅烷A-174和聚对二甲苯的混合物质。当聚对二甲苯和氯硅烷关系不精准时，可以降低耐蚀性，进而使共形覆盖层的下边和外界一部分和作用劣变。针对诊疗假体特别是在这般，在其中靠谱的部件作用是强制的，虽然常常曝露于通常严苛的血液中。

在将氯硅烷A-174运用于板材的二种基本上步骤中，第一种房间内蒸气运输在某种意义上更非常容易执行，但镀层实际效果显着减少。氯硅烷蒸汽推动不太可能在即时合理监管，造成合理全过程检测的占比损害。做为結果：

·操作工不正确的概率提升，

·造成氯硅烷推动不够或过多的发病率更高一些;

·在这种前提下常常产生有缺憾的氯硅烷表层融合，

·在接着的堆积循环系统期内刺激性溶解的聚对二甲苯遮盖。

因而，在上面提及的完成不恰当的生产制造 – 混和的原有问题更很有可能产生，提升了生产制造停产和花费，及其消费者不满意。

氯硅烷运用的干法增加方式还容许在整个过程中定期检查检测浸入饱和溶液。在氯硅烷A-174预浸以后，应在30钟头内执行用以聚对二甲苯的CVD加工工艺。

提议仅混和手头上程序流程需要的氯硅烷量，以保证合理的制取/运用和安全性的工作中标准，氯硅烷的24钟头保存期不允许储存一切不必要的，应该马上丢掉在有机溶剂槽中，接着耗光，随后用IPA清洗。在无论怎样，防止吸气饱和溶液的蒸汽或造成肌肤或双眼触碰：

结果

改进板材黏合是必需的，由于要是没有用氯硅烷A-174适度解决，聚对二甲苯将脱离一些板材。浸入式运用方式提高了最安全可靠的解决方法。

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