1、手工焊接培訓教材(7)EET 3124 Soldering 焊接Elements of Project Design, Analysis and Fabrication by Machine Methods手工焊接培訓教材(7)PCB Soldering 電子線路板焊接wRead Chapter 17wSoldering alloying between solder and the metal parts between which an electrical connection is formed.手工焊接培訓教材(7)Soldering Methods焊接方法wSeveral Meth

2、ods of SolderingHand 手工焊接Dip浸焊Wave 波峰焊接Infrared Re-flow 紅外線回流焊接Vapor Phase 熱風回流焊接手工焊接培訓教材(7)Solder Composition 焊料wSolder used in electronics is an alloy of tin and lead. 電子產品焊料是錫鉛合金。wThe amount of tin ranges from 50 to 70%.錫所占比例為50% 到70%。wThe ratio determines the strength, hardness and melting point

3、 of the solder.錫所占比例決定焊點的強度、硬度和熔點。手工焊接培訓教材(7)Solder Melting Point Graph熔點固體狀態液體狀態熔融狀態手工焊接培訓教材(7)Solder Composition Cont.焊料wThe most common tin/lead ratio is 60/40.最常見錫鉛比例為60/40。wEutectic solder has a tin/lead ratio of 63/37 and has almost no plastic transition state.共晶焊錫之錫鉛比例為63/37，幾乎沒有熔融狀態。wDiffere

4、nt ratios can be selected based on specific needs.根據需要可選擇不同比例。手工焊接培訓教材(7)Solder Alloying 焊接合金wWhen solder melts onto a PCB connection, a thin film of metal is dissolved from the copper surface. 當焊錫在PCB焊盤上融化時，銅金屬表面會有一層薄膜融解；wThis copper/solder mixture forms an alloy and establishes an electrically con

5、tinuous joint.這個銅/焊錫形成合金并成為穩定的電氣連接。手工焊接培訓教材(7)Solder Forms 焊錫形狀wSolder is available in the following forms:Wire spools 錫絲（軸裝）Bars錫條Sheets錫片Pellets錫球Washer and other specialized shapes錫制墊片及其它特殊形狀手工焊接培訓教材(7)Solder Forms Cont.焊錫形狀wFor hand soldering, wire solder comes in ranges of 0.030” to 0.090” in d

6、iameter. 對于手工焊接，焊錫絲直徑介于0.030” to 0.090” （ 0.762 mm to 2.286 mm ）wMost solder wire is available with a core containing flux. 多數焊錫絲均有內孔手工焊接培訓教材(7)Flux 助焊劑wFlux is used to remove oxidation from the surface to be soldered.助焊劑用于除去焊接表面的氧化物。wThe flux removes the oxides from the metal surface and suspends t

7、hem in solution where they float to the surface during the soldering process.助焊劑除去金屬表面的氧化物，并在焊接過程中將之移至焊點表面。手工焊接培訓教材(7)Flux Cont. 助焊劑wFlux is corrosive and if left on the surface of the PCB, will deteriorate the conductor surfaces and reduce the resistance of the insulation between soldered connectio

8、ns.助焊劑具有腐蝕性，殘留在PCB表面會使導體變質，并降低焊點間的絕緣性能。wThis corrosive action can also damage components.助焊劑腐蝕性對元器件也有危害。手工焊接培訓教材(7)Flux Cont.助焊劑wThere are three major classifications of flux:Chloride (inorganic salts)氯化物 （無機鹽）Organic (acids and bases)有機物Rosin松香/樹脂wChloride and Organic fluxes are highly reactive at

9、room temperature and are therefore not recommended for use in electronic construction.氯化物、有機物助焊劑在室溫下活性很強，一般不用于電子產品制造。手工焊接培訓教材(7)Flux Cont.助焊劑wRosin core fluxes are used almost exclusively for electronic construction.松香基助焊劑大多專用于電子產品制造。wRosin core fluxes are non-corrosive at room temperature.松香基助焊劑在室溫

10、下沒有腐蝕性。wRosin core fluxes are corrosive at soldering temperatures.松香基助焊劑在焊接溫度下具有腐蝕性。手工焊接培訓教材(7)Flux Application 助焊劑使用wLiquid flux can be applied by:Wiping 擦拭Dipping 浸漬Spraying 噴霧Sponging 用海綿揩拭Foaming 發泡手工焊接培訓教材(7)Flux Application Cont.助焊劑使用wPaste flux can be applied by:Wiping 擦拭Brushing 刷wRosin core

11、 solder uses flux that melts upon heat application during the soldering process.手工焊接培訓教材(7)Flux Removal 清除助焊劑wAfter the soldering process is complete, the flux must be removedImproves appearance 改善外觀Eliminates possible corrosion problems避免可能的腐蝕問題Less chance of electrical leakage減少漏電機會手工焊接培訓教材(7)Flux

12、 Removal Cont.清除助焊劑wSome techniques for flux removal are:Use of flux remover sprays 助焊劑清洗劑Brushing with denatured alcohol用非飲用酒精刷洗Dipping PCB assembly into a solvent solution將PCBA浸入清洗液Ultrasonic equipment 超聲波清洗設備手工焊接培訓教材(7)The Soldering Iron 烙鐵wThe soldering iron consists of 4 basic parts:Tip 烙鐵頭Heat

13、ing Element 加熱單元Handle 手柄Power Cord 電源線手工焊接培訓教材(7)The Soldering Iron Cont.烙鐵wSoldering irons are selected based on:Size and style of tip尺寸和烙鐵頭形狀Tip material烙鐵頭材料Required tip temperature 要求的烙鐵頭溫度Tip temperature recovery time.烙鐵頭溫度恢復時間手工焊接培訓教材(7)Tip Selection烙鐵頭選擇wSoldering iron tips come in many styl

14、es.wTips are selected on the basis of personal preference and the goal of providing the largest contact area to the area to be soldered while minimizing the possibility of heat damage to surrounding leads and components.烙鐵頭選擇依據焊盤大小、零件大小、焊接溫度、元器件對溫度的敏感性、個人喜好等。手工焊接培訓教材(7)Tip Types烙鐵頭形狀wChisel & Pyrami

15、d Used for hand wiring and general repair work. Allows large areas to be heated rapidly.鑿子、棱椎形用于線材焊接和一般的修理工作。可以使較大區域迅速加熱。wBevel Used for soldering terminal pad connections on single sided boards.斜角形用語焊接單面板上的接線端焊盤。手工焊接培訓教材(7)Tip Types Cont.烙鐵頭形狀wConical Used for high density wiring and heat sensitive

16、 parts.圓錐形用語焊接微小間距和溫度敏感元器件。wRadius Groove - Used on round components.半凹槽形用語圓形器件。手工焊接培訓教材(7)Tip Types Cont. 烙鐵頭形狀手工焊接培訓教材(7)Soldering Iron Temperature烙鐵溫度wA tip temperature of 600 to 900 degrees F is sufficient for general purpose soldering.烙鐵頭溫度600到900華氏度（316到482攝氏度）可以足夠滿足一般的焊接需要。wSoldering irons ar

17、e rated in watts. They are typically available from 15 to 60 Watts.烙鐵功率一般為15到60瓦。手工焊接培訓教材(7)Soldering Iron Temperature Versus Wattage烙鐵溫度/功率手工焊接培訓教材(7)Soldering Iron Tip Color Versus Temperature烙鐵頭顏色/溫度手工焊接培訓教材(7)Hand Soldering 手工焊接wBoards must be clean to begin with, especially if theyre not previo

18、usly tinned with solder. Clean the copper tracks using e.g. an abrasive rubber block and clean with denatured alcohol.首先必須保證PCB潔凈，特別是沒有預鍍錫的板。可以使用橡膠擦子或者非飲用酒精清潔PCB。手工焊接培訓教材(7)Hand Soldering手工焊接手工焊接培訓教材(7)Hand Soldering手工焊接wClean the iron bit (tip) using a damp sponge. Iron featured is an Ungar Concept

19、 2100 Soldering Station. 使用潮濕海綿清潔烙鐵頭。手工焊接培訓教材(7)Hand Soldering手工焊接wInsert components and bend the leads so that the part is held in place. 插入元件，將管腳折彎以固定元件。手工焊接培訓教材(7)Hand Soldering 手工焊接wIts usually best to snip the wires to length prior to soldering. This helps prevent transmitting mechanical shocks

20、 to the copper foil. 通常最好的做法是提前將零件腳剪至需要的長度。這可以預防對銅箔的機械沖擊。手工焊接培訓教材(7)Hand Soldering 手工焊接wApply a clean iron tip to the copper and the lead, in order to heat both items at the same time. 務必保持烙鐵頭潔凈，并同時接觸加熱元件腳和焊盤。手工焊接培訓教材(7)Hand Soldering 手工焊接wContinue heating and apply a small amount of solder. Remove

21、the iron and allow the solder joint to cool naturally.繼續加熱，并放入少量錫絲。移開烙鐵以使焊點自然冷卻。手工焊接培訓教材(7)Hand Soldering 手工焊接wIt only takes a second or two, to make the perfect joint, which should be nice and shiny.只須12秒鐘焊點就可以形成。良好的焊點應該整潔明亮。 手工焊接培訓教材(7)Solder Defects 焊接缺陷wSolder Peaking - Sharp point of solder pro

22、truding from a connection.Rapid removal of heat prior to solder becoming completely melted to liquid stage.w錫尖在焊錫未完全熔化成為液體狀態之前快速移開烙鐵所致。手工焊接培訓教材(7)Solder Defects Cont.焊接缺陷wIncomplete wetting Alloying process not completed.w未潤焊合金過程未完成Usually the result of insufficient heat and/or solder. 通常由加熱不足或者焊錫不足

23、導致。May also occur if contamination is on the terminal pad or soldering iron tip.也可能由于焊盤或者烙鐵頭污染所致。手工焊接培訓教材(7)Solder Defects Cont.焊接缺陷wExcessive solder lead contour not completely visible. 多錫（包焊）- 元件腳周線不可見。Reduce the amount of solder applied減少用錫量wCold solder joint dull-gray, grainy appearance.冷焊錫點呈暗灰色

24、，表面粗糙。Result of insufficient heat.加熱溫度不足導致。手工焊接培訓教材(7)Solder Defects焊接缺陷wAn example of a dry joint - the solder failed to flow, and instead beaded to form globules around the wire. 手工焊接培訓教材(7)Solder Defects Cont.焊接缺陷wTenfold excess of solder, and (extreme left) incomplete joint with poor coverage. T

25、here is no need to add more solder for luck. 手工焊接培訓教材(7)Solder Defects Cont.焊接缺陷wOne example of several dry joints found within a commercial PSU adaptor for a computer peripheral. 手工焊接培訓教材(7)Solder Defects Cont.焊接缺陷wA close-up reveals the terrible standard of soldering (and quality control), with a

26、fracture visible on this ground/ earth joint. 手工焊接培訓教材(7)De-soldering PCBs 去錫（解除焊接）wSeveral aids to use for de-solderingSolder wick 吸錫芯繩Solder sucker吸錫器De-soldering bulb 去錫燈泡De-soldering tips 去錫尖頭Extraction Tools 抽吸工具Vacuum de-soldering station 真空去錫工作臺手工焊接培訓教材(7)De-soldering去錫wThe two solder joints

27、to be de-soldered, to enable a faulty component to be removed. 手工焊接培訓教材(7)De-soldering Cont.去錫wIf using a de-soldering pump, apply the iron first to melt the solder (1-2 seconds). 若使用吸錫器，先用烙鐵使錫熔化。（12秒）手工焊接培訓教材(7)De-soldering Cont.去錫wThe nozzle of the de-soldering pump is applied to the molten solder

28、 and the spring-loaded plunger is then released, drawing the solder up into the pump. Repeat if needed. 吸錫器吸嘴對準熔化的焊錫，釋放彈簧活塞，吸走焊錫。可重復進行。手工焊接培訓教材(7)De-soldering Cont.去錫手工焊接培訓教材(7)De-soldering Cont.去錫wThe first joint, now de-soldered. The second joint will be de-soldered using braid.手工焊接培訓教材(7)De-solde

29、ring Cont.去錫wSelect a suitable width of braid編織, and press it down onto the COLD joint using the hot tip of the iron. 手工焊接培訓教材(7)De-soldering Cont.去錫wMolten solder is drawn up by capillary action into the braid. Care not to overheat, or drag whiskers of solder over the board, nor let the braid solid

30、ify on the joint! 毛細管吸附作用手工焊接培訓教材(7)De-soldering Cont.去錫手工焊接培訓教材(7)De-soldering Cont.去錫wThe component dropped out of the board after de-soldering. Sometimes, it may need persuading with pliers 鉗子. 手工焊接培訓教材(7)De-soldering Cont.去錫wClose-up shot of both joints, now de-soldered and ready for the replacement part to be fitted. 手工焊接培訓教材(7)Dip Soldering 浸焊wPCB is physically dipped into a molten pot of solder.wBoard is cleaned and then fluxed prior to dipping.PCB預先上助焊劑。wUsually dipped by hand.手工焊接培訓教材(7)Solder Pot Examples 錫爐手工焊接培訓教材(7)Wave Soldering 波峰焊接wA conveyor system consis