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| 共 147 篇文章 |
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不润湿和反润湿现象是焊接过程中常见的缺陷，它们分别表现为焊料与基体金属之间的不完全接触和部分润湿后的退缩。在不润湿的情况下，焊料并未与基体金属充分接触，因此可以清楚地观察到未被覆盖的基体金属表面。反润湿表现为焊料首先润湿了基体金属表面，但由于润湿不良，焊料发生收缩，形成薄膜，并且在基体金属表面上形成分离的焊料球。改善... 阅1 转0 评0 公众公开 24-05-20 10:12 |
Non-wetting and De-wetting during Soldering.In the case of non-wetting, the solder is not in fullcontact with the base metal, so that the uncovered base metal surface can beclearly observed.Backwettingoccurs when the solder first wets the surface of the base metal, but due topoor wetting, the solder shrinks, forming a... 阅1 转0 评0 公众公开 24-05-20 10:11 |
焊点内空洞率与焊锡膏的活性息息相关，图1焊点内气泡与助焊剂活性关系显示，助焊剂活性与焊点内气泡成反比——活性剂含量越高、焊点内空洞率越小。锡膏助焊剂粘度与焊点空洞率同样成反比关系，图2：随着助焊剂粘度增高，焊点内气泡合量降低。锡膏助焊剂沸点与焊点内气泡含量同样成反比关系如图3：助焊剂沸点越高，焊点内空洞越小。选择具有较高... 阅1 转0 评0 公众公开 24-05-17 09:23 |
Void Caused by the Inherent Characteristics of Solder Paste Flux.Voidrate in the solder joint is closely related to the activity of the solderpaste, Figure 1 solder joint bubbles and flux activity relationship shows thatthe flux activity is inversely proportional to the bubbles in the solder joint- the higher the cont... 阅1 转0 评0 公众公开 24-05-17 09:22 |
Gold Embrittlement in BGA Solder Joints.The BGA solder joint gold embrittlement can be subdividedinto two categories, one is the gold embrittlement caused by insufficient heat,and the other is the gold embrittlement caused by excessive gold content.Another type of gold embrittlement problemis caused by the BGA solder ... 阅1 转0 评0 公众公开 24-05-15 09:36 |
BGA焊点金脆化究竟是什么原因？PCBA焊接过程中热量不足，PCB沉金层的金属会进入液态焊锡内，形成AuSn4堆积在焊点的金属间化合物（IMC）附近，导致焊点产生金脆化现象。为降低焊点内金含量，可以控制金层的厚度或增加焊锡量，使得焊点内的金含量维持在合适的范围内。对于焊点内金含量过高的情况，可以通过控制金层厚度和增加焊锡量等方式，维持... 阅1 转0 评0 公众公开 24-05-15 09:35 |
详解金属偏析对焊点可靠性的影响。金属偏析导致焊点中化学成分的不均匀性，从而导致局部力学性能的差异。金属偏析导致焊点中某些区域含有更多的腐蚀敏感元素，使这些区域成为焊接结构中的腐蚀易发区。因此，金属偏析降低了焊点的疲劳寿命，限制了焊接结构的使用寿命。金属偏析会导致焊点中电导率和热导率的不均匀分布，从而影响焊接结构的电性... 阅1 转0 评0 公众公开 24-05-13 09:55 |
The effect of metal segregation on the reliability of welded joints.Therefore, metalsegregation reduces the fatigue life of welded joints and limits the servicelife of welded structures.Metal segregation leads to an unevendistribution of electrical and thermal conductivity in the welded joint, whichaffects the electri... 阅1 转0 评0 公众公开 24-05-13 09:54 |
详解水溶性助焊剂的分类及特点。水溶性助焊剂是一种在电子焊接过程中广泛应用的助焊剂，它可以提高焊料的润湿性能，防止氧化，并在焊接后用水清洗残留物。水溶性助焊剂的最大特点是助焊剂组分在水中溶解度大、活性强、助焊性能好，焊后残留物易溶于水，因此可以直接采用水作为清洗溶剂。无机系水溶性助焊剂：这类助焊剂以松香系助焊剂为主流。... 阅2 转0 评0 公众公开 24-05-11 09:35 |
Characteristics and Types of Water-Soluble Flux.The biggestfeature of water-soluble flux is that the flux component is highly soluble andactive in water with good fluxing performance, and the residue after solderingis easily soluble in water, so water can be directly used as the cleaningsolvent.InorganicSystem Water-S... 阅1 转0 评0 公众公开 24-05-11 09:33 |
