PCB科技 - PCB製造商，無鉛焊接表面處理OSP

印刷電路板製造商, 外包服務提供者 for lead-free soldering surface treatment

In addition to the lead-free solder (Solder) must be completely lead-free, 上的焊盤 印刷電路板 surface (including various packages), 通孔焊環和零件脚以及其他表面處理也必須無鉛. 第一, 我會把焊盤寫在黑板上. 預計將有七到八種可焊處理用於批量生產選項. 對於那些可以線上進行大規模生產的人, 似乎只有OSP和I-Sn或只有兩種或3種I-Ag.

對於零件脚或焊盤的可焊表面處理, in addition to the early various IC metal tripods (LeadFrame, also known as lead frames), which are continuously electroplated with reel-to-reel (ReeltoReel), the rest of the bulk components (Discrets are separated) The formula is a poor translation) Regardless of whether it is passive or active, most of them adopt a large number of "barrelplating" (Barrelplating) processing methods. The current and future mainstream bath solutions will include:
1 Electroplating pure tin (with acidic tin sulfate TinSulfate or tin methane sulfonate as the bath, 它可以用作機架電鍍或滾鍍. 這種銅資料的表面鍍錫可分為光亮錫和啞光錫. 前者容易產生錫須, 而後者更貴.)
2 Silverplating (mainly alkaline cyanide bath, 也可用作機架電鍍和滾鍍.)
3. NickelandTinplating (Plating the surface of copper with a layer of nickel and then plating with pure tin will reduce the problem of tin whiskers.)
4. There are also electroplating of nickel and lithium (Ni/Pd), and electroplating of nickel and gold (Ni/Pd/Au), 甚至電鍍各種其他錫合金. 然而, 由於缺乏兩方面的成本過高或科技成熟度不足, 電流不足以形成氣候，囙此不會引入.

1. Organic flux OSP:
Simply put, OSP is to grow a layer of organic film on the clean bare copper surface to protect the copper surface in a normal environment from rusting (oxidation or sulfide, 等.); but in the subsequent welding high temperature, 這種保護膜必須易於去除，並用助焊劑去除, 囙此，暴露的清潔銅表面可以立即與熔融焊料結合，在很短的時間內形成牢固的焊點. This can be protected Copper anti-rust organic film is called "OrganicSolderabilityPreservatives" (OrganicSolderabilityPreservatives).
早期, some types of coating containing rosins or active resins (Preflux) were formulated as the early products of this type of OSP. 然而, 過去在單面面板領域, it was often called "full-surface treatment" (finishing the copper surface), which was a physical organic protective film coated on the copper surface; ) Chemicals, 它直接與銅表面反應，形成“有機銅絡合物”的化學保護膜. 原理並不完全相同, 但銅保護和焊接的效果非常相似, 所以現在也叫. OSP.
恩通 uses Azole chemicals (such as Benzo-Triazole) to protect the copper surface, 哪個是業界知名的產品Entek. 這是IBM當年首次使用的CU-56的臨時水基銅保護劑. 經過多年的經驗和改進, 這種外包服務提供者已經取得了很大的進展. 它可能成為未來無鉛焊接時代加工板面焊盤和廉價平整表面的主要方法.

The following will be introduced according to the five generations of the main chemicals used:
(1) Brenzotriazole (BTA), the first generation
This BTA protects the copper surface from corrosion and oxidation. It can be traced back to the temporary coating CU-56 (1% BTA aqueous solution) used by IBM to protect the copper surface in its 印刷電路板 20世紀60年代的制造技術. 恩通不斷學習和改進, and became the well-known Entek processing method (Enthone Technology). 即使到目前為止, 仍然有許多行業參與者只知道Entek的商業名稱, 但不是BTA創始人的學名.

BTA能够保護銅免受腐蝕的原因是它會立即直接與銅資料表面的氧化亞銅Cu20發生反應, and then generates a polymer-state organic copper complex salt (Complexor Tailu translated as complexing agent, It seems to be more clever than the one that quotes Japanese complexing agent), 以下公式是反應過程的示意結構, 那就是, 銅表面多薄膜形成的假想圖. The film formed by these BTA and cuprous oxide (Cu20) is a bovine transparent and colorless film (turns brown after aging), 在浴缸裏會變厚, 取決於溫度, 時間, 酸鹼度, 等. 1989年, Tornkwist等學者在《電化學學會雜志》上發表了一篇專題文章, 指出當BTA分子第一次與氧化亞銅反應時, BTA will interact with its special orientation (orientation) of the "triple seat" in the molecule., And make it face outwards to form a long chain of [Cu(I)BTA)n. 具有其他吸附機制, 可以形成平面分子膜並將其附著到銅表面.
以下是P. 《電路板信息雜志》1996年6月. 80 for the textual explanation of the copper protection agent BTA:
The so-called BTA is the abbreviation of Benzotriazole, 它的官方學名是1,2,3-苯並3唑, 這意味著在1, 2, 和3個位置並形成5-碳雜環化合物. 它被稱為“含氮异戊烷”或唑苯化合物.
BTA是白色的, 淡黃色的, 無味結晶粉末. 它在酸性和鹼性溶液中非常穩定, 並且不容易發生氧化和還原反應, 所以它很穩定. 它可以與金屬形成穩定的化學物質. 這種BTA不易溶于水, 但它可以溶解在酒精或苯中, 通常用作光保護膜或紫外線吸收劑.
十多年前, Enthone, 美國著名的電路板化學品供應商, 在甲醇和水的溶液中出售，作為銅表面的變色氧化劑, 商品名是ENTEKCU-55和CU-56. 它已被IBM認可. 後者是眾所周知的, 國內大部分 電路板工廠 使用其0.25%稀釋水溶液作為銅保護劑. 銅加厚完成後, 電路板僅浸入30-60號槽中，可在幾秒鐘內處理, 然後用熱空氣乾燥，以獲得良好的保護效果. It can directly complete the image transfer work without brushing (either dry film or printing). 在進入二次銅之前，稀硫酸活化和清洗，可以很容易地將其去除, 這有助於銅和織錦之間的粘合和粘合.
Its high-concentration (l%) bath immersion treatment has stronger protection for bare copper, 它可以替代SMOBC進行長期銅保護, 並且在組裝過程中優於電路板的焊接效能. 熔融過程, 噴塗, 滾錫也不算太多. 本文是一篇IBM研究文章. 今天, 當“减少浪費”的概念越來越多，電路板的成本被迫下降時, 全文翻譯為杏子，作為工藝改進的參攷.