1355219 九、發明說明： 【發明所屬之技術領域】 本發明係關於一種電路板製程，特別是有關於一種可避免產生 伽凡尼腐蝕現象的微蝕方法。 【先前技術】 印刷電路板(Printed circuit board, PCB)是電子元件的支撐體，是 • 電子兀器件線路連接的提供者。現今印刷電路板係利用其上的銅 導線圖案來電連結各個電子元件，目前銅導線瞧的製作步驟一 般需經過在電路板上鍍麵、形賴案化光阻、對細進行触刻 .處理以及去除光阻。在完成銅導線圖案之後，依序需再經過壓合、 鑽孔、錢通孔、形成綠漆以及金屬表面處理，其中—般常見的金 2表面處理的方式有喷錫(H〇tAirLevding，舰）、電雜金、化 子錄金直接金、化學錫、化學銀以及形成有機保焊劑(〇_c1355219 IX. Description of the Invention: TECHNICAL FIELD OF THE INVENTION The present invention relates to a circuit board process, and more particularly to a micro-etching method that avoids the occurrence of Galvanic corrosion. [Prior Art] A printed circuit board (PCB) is a support for electronic components and is a provider of electronic circuit device wiring connections. Nowadays, printed circuit boards use the copper wire pattern on them to electrically connect various electronic components. At present, the manufacturing steps of copper wire defects generally need to be plated on the circuit board, the photoresist is formed, and the thinning is processed. Remove the photoresist. After completing the copper wire pattern, it is then subjected to pressing, drilling, money through hole, green paint and metal surface treatment. Among them, the common gold surface treatment method is tin spray (H〇tAirLevding, ship ), electric gold, chemical gold direct gold, chemical tin, chemical silver and the formation of organic soldering agent (〇_c
Solder Preservative，〇SP)。 在办成^ 直接金三種金屬表面處理备 在兀成金屬表面處理之後’從 之-部分的鋼導線上霜右料的表面上觀察仔知，該制 層，而剩細秦上則覆有金 到空氣，即會在其表_^^細銅導線因為接 因此，在進行有:=之_焊劑覆蓋的區域。 ㈣蛛之别，需先對電路板進行微敍翻 5 1355219 • 其目的在於去除銅導線表面_汙和氧化銅，並且將銅導線表面 粗化以利後續有機保焊劑成臈，習知技術中所使用的紐液皆為 酸性系統包含：過親_卩嶋顧水純、硫歡雙氧水水溶 液以及稀硫酸水溶液。進行微#製程時，係將電路板利用上述的 微絲淋沖，而在淋沖的過程，首先氧化銅會先被絲，露出銅 導絲面，之後’電路板的鑛金層和裸露的銅導線會同時接觸微 餘液’如此-來’即會產生伽凡尼雜(galvanicc〇rr〇si〇n)現象， 籲伽凡尼腐钱現象係指具有不同氧化電位的金屬在電解液中，會有 電位差而產生電化學反應，其中由氧化電位高的（如鋅、鐵等） 形成陽極，氧化電位低的作為陰極，而陽極在電化學反應時，會 形成離子而溶於電解液中，因此陽極金屬會逐漸被雜。在微: 製程時，所產修凡尼腐純象，係由減的銅導線作為陽極， 鍍金層作為陰極，陽極的導線會和微餘液中的活化物生成有機銅 錯化物，溶於難射，並拋出兩個電子，而電子將經過線路， φ 使微钮液中的銅離子還原而沉積在陰極的鍍金層JL，造成鍍金層 顏色變深，並且裸露的銅導線逐漸變細，更甚者，職生斷線現 由此可知’目前業界急需一種改㈣微财法，在去除氧化銅 的同時’可以避免電路板上的解線發生伽凡尼雜現象。 【發明内容】 有鏗於此，本發明提出一種新颖的電路板微财法，特別是使 6 1355219 用在形成有機保焊劑前的預處理步驟’其可以有效預防銅導線因 伽凡尼效應而腐餘。 根據本發明之一實施例’本發明提供避免伽凡尼腐蝕效應的電 路板微姓方法’包含：首先，提供一電路板，其上定義有一銅導 線圖案，其中該銅導線圖案之一第一區域覆有一金屬層，該銅導 線圖案之一第二區域覆有一銅氧化物；以及使用一酸性電解水微 φ 蝕該電路板，以去除該銅氧化物，同時避免該第二區域的該銅導 線圖案產生伽凡尼腐蝕現象。根據本發明之一實施例上述之酸 性電解水的PH值係介於2.0至3.5之間。 舉一實施方式， 為讓本發明之上述目的、特徵、和優點能更明顯易懂，下文特 並配合所附圖式，作詳細說明如下。然而如下之 實施方式與圖式僅供參考與說明用，並非用來對本發明加以限 【實施方式】 第2圖繪示的是本 第1圖所繪TF的是本發明之電路板側視圖 發明有機保制的爾歸驟之流程圖。Solder Preservative, 〇SP). After processing the metal surface of the direct gold, the surface treatment of the metal surface of the metal is used to observe the surface of the frosted right material from the steel wire of the part, and the layer is formed, while the remaining fine Qin is covered with gold. To the air, it will be in the table _ ^ ^ thin copper wire because of the connection, therefore, there is: = _ flux coverage area. (4) The difference between the spiders, the circuit board must be micro-swept 5 1355219 • The purpose is to remove the surface of the copper wire _ pollution and copper oxide, and roughen the surface of the copper wire to facilitate the subsequent organic soldering agent into the 臈, in the prior art The new liquid used is an acidic system containing: a pro- _ 卩嶋 水 纯 pure, sulfur Huan hydrogen peroxide aqueous solution and dilute sulfuric acid aqueous solution. When the micro-process is performed, the circuit board is blasted by the above-mentioned microfilament, and in the process of rinsing, first, the copper oxide is firstly filved to expose the copper guide surface, and then the 'metal layer of the circuit board and the bare one. The copper wire will contact the micro-remaining liquid at the same time 'so-like' will produce the phenomenon of galvanicc〇rr〇si〇n, and the phenomenon of gamma-van rot is a metal with different oxidation potential in the electrolyte. There is a potential difference to produce an electrochemical reaction, in which an anode is formed by a high oxidation potential (such as zinc, iron, etc.), a cathode having a low oxidation potential is used, and an anode is formed in an electrochemical reaction, and ions are dissolved in the electrolyte. Therefore, the anode metal will gradually become miscellaneous. In the micro: process, the pure image of the varnish is made of reduced copper wire as the anode, the gold plating layer as the cathode, the anode wire and the activator in the micro-remaining liquid to form the organic copper complex, which is difficult to dissolve. Shooting, and throwing two electrons, and the electrons will pass through the line, φ reduces the copper ions in the micro button liquid and deposits on the gold plating layer JL of the cathode, causing the gold plating layer to become darker and the bare copper wire to be tapered. What's more, the employee's disconnection is now known as 'the current industry is in urgent need of a change (4) micro-finance method, while removing copper oxide, 'can avoid the gamma-neparation phenomenon on the circuit board. SUMMARY OF THE INVENTION In view of the above, the present invention proposes a novel circuit board micro-finance method, in particular, the use of 6 1355219 in a pre-treatment step before forming an organic soldering agent, which can effectively prevent copper wires from being affected by the gamma-neon effect. Corrupted. According to an embodiment of the present invention, the present invention provides a circuit board micro-surname method for avoiding the Galvanic corrosion effect. Included: First, a circuit board is provided having a copper wire pattern defined thereon, wherein the copper wire pattern is first The region is covered with a metal layer, a second region of the copper wire pattern is covered with a copper oxide; and the circuit board is etched using an acidic electrolyzed water to remove the copper oxide while avoiding the copper in the second region The wire pattern produces a Galvano corrosion phenomenon. According to an embodiment of the present invention, the pH of the above acidic electrolyzed water is between 2.0 and 3.5. The above described objects, features, and advantages of the present invention will become more apparent from the aspects of the invention. However, the following embodiments and drawings are for reference and description only, and are not intended to limit the invention. [FIG. 2] FIG. 2 is a side view of the circuit board of the present invention. The flow chart of the organic guarantee system.
14之第一區域A之表面覆有一金屬層2〇， 20 ’例如以 7 比5219 電顯麵化學齡為本實關之說明，其巾金制20分為-第 金屬層2%和一第一金屬層20a，第二金屬層20b為-鍵錄層， 而第金屬層2〇a為一鍍金I，然在其他未繪示的實施例中，該 金j層20亦可以為單一金屬層結構例如金、銀、始等。而銅導 '、之第一區域B則為裸露的銅導線，但由於曝露在空氣 中’因此’在第二區域B的銅導線圖案14很快就會形成—氧化銅 卜在第區域A的銅導線圖案14和部分第二區域B的 • ^軸案14係轉電通孔16電連結。換句話說，電路板1〇已 、左1鑽孔、鍍通孔、形成圖躲銅導線以及選擇性鎳金表面處 理的製程’ f路板1G準備要進行有機保焊劑製程之前的預處 • 驟。 如第2圖所示’形成有機保焊膜之前’電路板10首先需經過 酸f生脫月曰30以去除表面上的油脂，接著進行水洗32以洗淨酸性 鲁脫知劑，然後再進行微钱處理34，以去除前述的氧化銅，接著 再進入水洗36以去除微蝕液，之後進行預浸38和水洗40，即可 進入有機保焊劑製程42。有別於傳統製程，本發明的特徵在於微 餘處理34中係使用酸性電解水作為微钱液來淋沖電路板10。 第3圖所繪示的是微餘槽之示意圖。請同時參閱第1圖和第3圖， 一徵飯槽50承裝酸性電解水52作為微蝕液，電路板1〇經由一輸 送▼ 53送入微餘槽50中，在徵钮槽50中的酸性電解水52可經 由栗供應給徵飯槽50的喷灑裝置54，利用喷灑裝置54將酸性電 解水52淋沖在電路板1〇上，而酸性電解水的溫度則保持在 8 1355219 45士5 C，如此一來，即可去除電路板10上的氧化銅22，此外，也 可以利用浸泡的方式來去除氧化銅22。根據本發明之一實施例， 其中该酸性電解水52的氧化還原電位介於1〇〇〇mV〜13〇〇mV之 間，而pH值介於2〜3.5之間。 由於刖述適當操作條件的酸性電解水主要會對氧化銅產生反 應’而幾乎不會溶飯銅表面。因此，在去除氧化銅後而裸露的銅 鲁導線圖案不會被進-步被溶触’如此一來，伽凡尼腐触效應即被 抑止’而銅斷線現象以及在鑛金層產生銅還原的現象則可以被有 效避免。值得生意的是：雖然上述實施例是以經過鎳金表面處理 的電路板為例，但本發明之雜電解水，不鑛_金表面處理 後的電路板，有防止伽凡尼腐蝕效應的效果，對於經過其它金屬 表面處理的電路板’使得電路板表面±树金、舰、賴或是 其它氧化電錄銅為_金屬的航，皆可贿財發明之酸性 電解水來進彳了錄，制去輯化銅和避免伽凡尼飾效應的目 •的。 上述的酸性電解水52,係利用陽極與陰極之間具有離子穿透性 隔膜的電解槽，進行純水電解所獲得，由於純水的導電性差，因 此在純水中會加入少量的氯化鈉。根據本發明之一實施例，要生 成酸性電解水的起始預電解時間介於5〜1〇分鐘之間，電解電壓介 於200〜240伏特(V)之間。 9 1355219 第4a圖至第6b縣分別使用傳紐做和本發明之酸性電解 水微蝕電路板之電子顯微鏡檢測圖。 第如圖中的電路板係經由本發明之酸性電解水重覆微敍三 次’第4b圖為第4a圖中的電路板之部分放大圖，如第处圖戶^示， 電路板上的銅導線圖案皆完整。第5a圖中的電路板係經由傳統微 蝕液重覆微飯三次，第5b圖為第5a圖中的電路板之部分放大圖。 •如第5b圖所示，相較於4b圖，“b圖中的銅導線圖案有數個明 顯的斷線部位。 第6a圖中的電路板係經由本發明之酸性電解水重覆微蝕三 次’如第6a圖所示’電路板上的銅導線圖案皆完整。第饨圖中 的電路板係經由傳統難液重覆微n如第6b _示相較 於6a圖’第6b圖中的銅導線圖案有數侧方框標示處，顯示被 伽凡尼腐蝕效應侵蝕的部位。由上述檢測圖可知，即使用酸性電 癱解水微赖二次後’銅導線圖案依然可以維持完整，所以本發明之 酸性電解水的確可以成功的避免伽凡尼腐蝕效應。 有別於習知技術，本發明採用酸性電解水取代過硫酸鈉稀硫酸 水/谷液、硫酸/雙氧水水溶液以及稀硫酸水溶液作為微敍液，根據 申請人的長期研究發現，使用酸性電解水來微蝕經過鎳金表面處 理製程的電路板，不但可以有效的將氧化銅去除，更可以避免在 清洗過程中，伽凡尼腐蝕現象的發生。因為具有適當操作條件的 子，電，:主要會對氧化銅產生反應，使得氧化銅溶出變成銅離 而幾乎不會雜鋼表面。因此，在絲氧偏後而裸露的銅 線圖案不會被雜，如此—來，伽凡尼腐佩餅被抑止，而 •3斷線現象以及在鍍麵產生鋼還原⑽㈣可以被有效避免。 以上所述僅為本發明之一實施例，凡依本發明申請專利範圍 斤做之均㈣化與料，皆應屬本發明之涵蓋範圍。 【圖式簡單說明】 第1圖所繪示的是本發明之電路板側視圖。 第2圖繪示的是本發明有機保焊劑的預處理步驟之流程圖。 第3圖所繪示的是本發明之微触槽示意圖。 苐4a圖至第6b圖為分別使用傳統微蝕液和本發明之酸性電解水 微飾電路板之電子顯微鏡檢測圖。 【主要元件符號說明】 10 電路板 12 基材 14 銅導線圖案 16 導電通孔 20b 第二金屬層 20a 第一金屬層 22 氧化銅 30 酸性脫脂 32 水洗 34 微蝕處理 36 水洗 38 預浸 40 水洗 42 有機保焊劑製程 1355219 50 徵蝕槽 52 53 輸送帶 54 20 金屬層 酸性電解水 喷灑裝置The surface of the first region A of 14 is covered with a metal layer 2〇, 20', for example, 7 to 5219, the chemical age of the electrical surface is the actual description, and the towel gold 20 is divided into - the second metal layer 2% and one A metal layer 20a, the second metal layer 20b is a-bond layer, and the metal layer 2a is a gold-plated I. However, in other embodiments not shown, the gold layer 20 may also be a single metal layer. Structures such as gold, silver, and so on. The copper region ', the first region B is a bare copper wire, but due to exposure in the air 'so' the copper wire pattern 14 in the second region B will soon form - copper oxide in the region A The copper wire pattern 14 and the portion of the second region B are electrically connected to the electrical via 16 . In other words, the board 1〇, the left 1 hole, the plated through hole, the pattern-forming copper wire, and the selective nickel-gold surface treatment process 'f-plate 1G are ready for the pre-preparation of the organic flux-preserving process. Step. As shown in Fig. 2, 'Before forming the organic solder mask', the circuit board 10 first needs to pass the acid f to remove the grease on the surface, followed by water washing 32 to wash the acid Lubiao agent, and then proceed The micro-money treatment 34 removes the aforementioned copper oxide, and then enters the water wash 36 to remove the micro-etching liquid, and then performs the pre-dip 38 and the water wash 40 to enter the organic solder resist process 42. Different from the conventional process, the present invention is characterized in that the residual electrolytic treatment 34 uses acidic electrolyzed water as the micro-money liquid to rinsing the circuit board 10. Figure 3 is a schematic view of a micro-remaining groove. Please refer to FIG. 1 and FIG. 3 at the same time. A rice cooking tank 50 carries the acidic electrolyzed water 52 as a micro-etching liquid, and the circuit board 1〇 is sent into the micro-reservoir 50 via a conveyance ▼ 53 in the button groove 50. The acidic electrolyzed water 52 can be supplied to the spraying device 54 of the rice recovery tank 50 via the pump, and the acidic electrolyzed water 52 is sprayed on the circuit board 1 by the spraying device 54, while the temperature of the acidic electrolyzed water is maintained at 8 1355219 45 As a result, the copper oxide 22 on the circuit board 10 can be removed, and in addition, the copper oxide 22 can be removed by immersion. According to an embodiment of the present invention, the acidic electrolyzed water 52 has an oxidation-reduction potential of between 1 〇〇〇 mV and 13 〇〇 mV and a pH of between 2 and 3.5. Since the acidic electrolyzed water which cites the proper operating conditions mainly reacts to the copper oxide, it hardly dissolves the copper surface. Therefore, after removing copper oxide, the bare copper wire pattern will not be touched by the step-by-step, the gamma-negative effect is suppressed, and the copper wire-breaking phenomenon and copper reduction in the gold layer The phenomenon can be effectively avoided. It is worthwhile to deal with the business: although the above embodiment is exemplified by a nickel-gold surface treated circuit board, the mixed electrolyzed water of the present invention, the non-mineral-gold surface treated circuit board has the effect of preventing the galvanic corrosion effect. For the circuit board that has been treated with other metal surfaces, the surface of the circuit board can be recorded by the acid electrolyzed water of the invention, such as the gold, the ship, the la, or the other oxidized copper. The purpose of compiling copper and avoiding the effects of the Gavignan effect. The above-mentioned acidic electrolyzed water 52 is obtained by performing pure water electrolysis using an electrolytic cell having an ion-permeable separator between the anode and the cathode. Since pure water has poor conductivity, a small amount of sodium chloride is added to the pure water. . According to an embodiment of the present invention, the initial pre-electrolysis time for generating the acidic electrolyzed water is between 5 and 1 minute, and the electrolysis voltage is between 200 and 240 volts (V). 9 1355219 The electron microscopic examination patterns of the acid electrolyzed water micro-etched circuit board of the present invention are used in the 4th to 6th counties, respectively. The circuit board in the figure is repeated three times through the acidic electrolyzed water of the present invention. FIG. 4b is a partial enlarged view of the circuit board in FIG. 4a, as shown in the figure, the copper on the circuit board. The wire pattern is complete. The circuit board in Fig. 5a repeats the micro-rice three times via a conventional micro-etching solution, and Figure 5b is a partial enlarged view of the circuit board in Figure 5a. • As shown in Figure 5b, the copper conductor pattern in Figure b has several distinct wire breaks compared to Figure 4b. The circuit board in Figure 6a is repeatedly micro-etched three times via the acidic electrolyzed water of the present invention. 'As shown in Figure 6a', the copper conductor patterns on the board are complete. The circuit board in Figure 重 is repeated by the traditional hard-to-liquid micro-n as shown in Figure 6b_ compared to Figure 6a in Figure 6b. The copper wire pattern has a number of side frame marks showing the part eroded by the galvanic corrosion effect. It can be seen from the above test chart that the copper wire pattern can still be maintained after using the acid hydrazine to dissolve the water twice. The acidic electrolyzed water of the invention can successfully avoid the Galvanic corrosion effect. Different from the prior art, the present invention uses acidic electrolyzed water to replace sodium persulfate dilute sulfuric acid water/column solution, sulfuric acid/hydrogen peroxide aqueous solution and dilute sulfuric acid aqueous solution as micro According to the applicant's long-term research, the use of acidic electrolyzed water to micro-etch the circuit board subjected to the nickel-gold surface treatment process can not only effectively remove the copper oxide, but also avoid the cleaning process. Nie corrosion occurs. Because of the proper operating conditions, the electricity, mainly reacts to the copper oxide, so that the copper oxide dissolves into copper and hardly causes the surface of the steel. Therefore, the bare copper after the partial shift of the oxygen The line pattern is not miscellaneous, so that the gamma can be suppressed, and the 3 break phenomenon and the steel reduction (10) (4) on the plating surface can be effectively avoided. The above is only one embodiment of the present invention. The scope of the present invention should be within the scope of the present invention. [Fig. 1 is a side view of the circuit board of the present invention. The figure shows a flow chart of the pretreatment step of the organic soldering flux of the present invention. Fig. 3 is a schematic view of the micro-contact groove of the present invention. 苐4a to 6b show the use of conventional micro-etching liquid and the present Electron microscopic inspection chart of the inventive acidic electrolyzed water micro-decorated circuit board. [Main component symbol description] 10 circuit board 12 substrate 14 copper wire pattern 16 conductive via 20b second metal layer 20a first metal layer 22 copper oxide 30 acid Degreasing 32 Washing 34 Micro-etching 36 Washing 38 Pre-dipping 40 Washing 42 Organic soldering flux process 1355219 50 Erosion trough 52 53 Conveyor belt 54 20 Metal layer Acidic electrolyzed water Spraying device
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