1、摘要：產品復雜性的增加，組件尺寸的減小以及雙面板的使用已經使基于電子制造組件的表面貼裝技術更難以組裝。這導致了經濟問題，其中電子制造的缺陷是所有制造商面對的主要問題之一。雖然編者已經明顯改進了EM技術的過程，但是現實表明實現自動化線的變化還不能產生足夠高的比例的成品。當前的發展目標是通過創建一個基于互聯網的智能系統的電路板缺陷檢測的進程來對這些新興市場做出貢獻，所以可以在確認成產運行之前EM流程缺陷需要返工操作。隨著這個系統的發展，對于任何成產線和裝配線流程參數返工有缺陷組件需要最小化，生產線引起一些可靠性問題（如錫球，在關節錫不足，焚燒聯合連接，橋接導線，孔洞，關節傾斜，以及未成形的關節）就

2、會直接導致問題，并且返工將從EM裝配線上大大減少。關鍵詞：電子制造 互聯網 印刷電路板 表面貼裝技術 用戶界面1 介紹表面組裝技術向高密度封裝的趨勢已經突出了在有這些非常好搭的設備的組裝線的固有困難。盡管所有都進步了，在印刷電路板裝配技術（PCBA）中各種的缺陷仍然是常見的，并且PCBA的返工是不可避免的而且既然每個組件的成本和PCB本身的話費是幾百美元那么必須在PCBA制造地板時必須手動執行。在過去的幾年里，包括自動在內的在市場上可以供應的返工站的數量大幅度增長。在電子產品制造中，返工被定義為用那些符合執行標準的組件更換有故障的部件的活動。產品復雜性的增加，組件尺寸的減小以及雙面板的使用已經

3、使基于電子制造組件的表面貼裝技術更難以組裝。PCBA制造技術已經隨著完全的自動化，準確組裝機器和機器人的使用得到相對的提高。盡管顯著改善自動返工也已經由編者之一完成，但事實表明自動返工線還不能產生一個足夠可靠地搞得收益比例。這個調查的目的是通過建立一個基于知識的智能系統的電路板缺陷，對表面貼裝返工技術做出貢獻，這樣需要返工操的缺陷可以通過電子制造裝配線被檢測到。隨著這個系統的發展，有缺陷的板的數量將會從PCBA線上最小化，并且那些造成關節水平可靠性問題的PCBA工藝參數將被識別。這些問題的原因將借助于發達的網絡系統被發現。2 通用概述應用于計算機，軍事和電信應用程序的高價值的印刷電路板是21世

4、紀的先進技術的發展的一個關鍵組成因素。在電子元器件中的小腳印和小特征的SMT技術的增長是這樣PCBA的成功產品的巨大的技術障礙。返工是指在一個印刷電路板過程中消除和替換有缺陷的電路組件。在過去的20世紀的幾十年，各種不同的返工方法已經成功開發和測試，但是它也被證明他們沒有一個產生最后的可靠地生產聯合吞吐量線【1】。現在的新目標是開發替代方法，而不是利用手動，半自動或自動重做系統。那些已經在調查中在關注如何消除這些制造業的原因問題的技術因為舊的技術聯系，在返工是昂貴的，復雜的，需要熟練操作的【1，2】。這個返工操作設計幾個步驟：把有缺陷組件清楚，清空組件站點，調劑新錫膏，放置新組件然后回流關節【

5、3】。從圖一可以看出，返工流程的功能是從一個完全填充的印刷板而不是破壞性的印刷板本身，周圍的組件或是焊點周圍的組件刪除和替換單個組件。到目前為止，在這個PCBA方向的主要作者已經取得了重大的進展【1】【4,5】。圖片2顯示了完全自動化的再制造細胞系統通過Fidan創建【2】。在1990年代中期，一些電子產品制造基本知識已經開發為各種PCBA線條和應用【6-11】。這些研究都沒有報道一個集成PCBA工藝規劃環境。已經驗證的系統也弱化了世紀工業裝置。這個調查的目的是通過建立一個基于知識的智能系統的電路板缺陷，對表面貼裝返工技術做出貢獻，這樣需要返工操的缺陷可以通過電子制造裝配線被檢測到。3 工藝參

6、數對PCBA質量的影響與不斷小型化電子組件和整體系統互連的PCB和組件，焊點也變得小了。接頭地方尺寸的減小更要求機械屬性的焊料來確保共同的魯棒性。在除了足跡大小的減少，是一個重點總空間減少，常常導致尺寸的包裝硅模具。作為向更小的包裝尺寸遷移的SMT技術，每個包裝的加工條件的變得更加關鍵【12】。 在一個包裝的顯著的差異（從層到層之間或承運人和模具）會引起廣泛的內部應力。一旦安裝到電路板，焊接頭通常必須通過包裝的擴裝和PCB在熱源組來吸收所有的應力。對于SMT設備，如扁平包，引線和焊點提供合規需要彌補不匹配在熱膨脹系數的包和PCB。為了讓關節變得更小，他們的質量變得更為重要。物理缺陷（如，可憐的

7、可焊性，孔焊，焊料球和橋焊）可以對聯合魯棒性和焊料的收益性有負面影響。 影響PCBA收益的因素可以分為幾個主要類別，包括組裝材料，多氯聯苯和組件以及過程方法和人類的表現【2】。 組裝材料的類別可以進一步細分到錫焊膏和通量的相關材料，如應用體積，回流參數，造渣，焊膏沉積方法，以及處理和儲存條件。在這個類別最關鍵的我問題是在回流操作中適當的稀釋的附件表面和創造冶金凝固。包含了許多因素的PCB范疇影響整個焊點可靠性，包括電路板厚度，墊大小，基材，通過形成技術，印刷電路板層數，焊接掩膜技術。組件子群參數影響裝配可靠性可能包括距大小，銷數，包裝大小和基材。 PCBA的各個步驟的需求嚴重影響過程方法的類別

8、。回流方法等因素（對流與紅外輻射）和環境條件會影響焊料潤濕，共同形成或形狀和空隙的存在。接頭質量是收到幾乎所有裝配變量，但是是強烈影響錫膏調劑，元件分布，回流條件。焊錫膏調劑在SMT沉積技術中最常見的方法是絲網印刷技術。在這個過程中，焊膏會通過在金屬箔上相應的洞沉積到附件墊的印刷板。對于小模數SMT，印刷過程變得至關重要，因為沒有足夠的空間來拉長的焊料模板孔徑。對于0.5毫米的螺距組件來說，實現打印率不到60%并不少見【12】。孔徑大小和鋼網厚度需要適當調整確保了高轉移率（黏貼沉積和孔徑卷）【13】。一般來說，光圈相對于附件墊應該是超大號的來增加焊料沉積體積和轉移率。然而這可能導致增加焊料球的

9、形成。氮可能在黏貼套印是幫助抵消形成錫球的形成趨勢【14】。圖片3顯示栽培要影響焊點質量的輸出的所有可能的數量。4 新的組件放置用于在印刷板上放置組建的策略可以分為進入管道，質量，順序，同時放置【16】。在高容量生產中，專用的順序或質量可能會執行位置。在大多數情況下，柔性對于適應新產品和組件式非常重要的。通常SMT組裝使用順序元件布局。兩個類型的放置設備用于順序挑揀和放置操作；第一個是一個X-Y龍門式第二個是定頭移動表放置機器【12】。頭頂的設備提供高靈活性，中放置的速度，精度高，最小加速度或運動的PCB。相比之下，表運動及其（通常旋轉炮塔頭）提供高位置速度和中等精度額靈活性，但征收高加速度的

10、PCB【17】。另一個重要特性放置系統映像的是視覺系統的需要【17,18】。一個主要問題是設備的能力來識別功能在黑板上和組件和正確地放置在設備的校準設備導致附件墊在PCB。照明的包從低角度，即側照明，可以需要防止錯誤的位置和SMT【19】。4 聯合水平附件傳熱機制用于大規模回流焊接過程包括對流，輻射（使用輻射來源）和冷凝（氣相）【20】。回流焊的最流行方法是基于強制對流或紅外輻射。一些其他的方法的焊料是氣相，激光和熱棒。處理大規模的回流焊接，PCBA主要往往受到一個波峰焊接操作。在波焊的應用程序中，經過的PCBA一波喊的焊料是吸引所有科室的表面，包括組建領導。波溫必須仔細控制預防從燃燒的焊點。

11、在任何回流系統，均勻的溫度在PCB和在一個組件是一個主要目標【2,21】。對于一個SMT系統，一個溫度梯度是10攝氏度或更少應該保持的防止變形包和確保所有關節正常回流。5 組建的開發工具發達的系統由兩個主要組件組成。這個組件式面向對象的性質，分別代表一個特定的功能組件的整體。這種形式的編程時聲明性的，代表事實和主張而不是程序。·主要的組件包括測試軟件，這將決定是否將輸入的值不產生一個可靠地焊接接頭。這是通過使用可擴展標記語言（XML）來完成的。晚間定義了參數進行測試，起約束和依賴以及一個程序模塊解釋測試。這是一個簡單地，非常靈活的文本格式最初是為了滿足大規模電子出版的挑戰。XML在W

12、eb和別處各種的數據交流也發揮著越來越重要的作用【22】。6 未來研究方向這種直觀的系統將積極消除的主要問題導致表面組裝PCB操作。談話種類與快樂度關系和數目的減少缺陷也將被制作成表格的工具的理由。統計分析焊點的質量輸出在這項研究中沒有被提出。在不久的將來，完成測試的結果和統計研究不同的組件和流程變量。參考文獻Internet-based electronics manufacturing troubleshooting toolfor surface mount PCB assemblyReceived: 2 March 2004 / Accepted: 6 May 2004 / Publi

13、shed online: 9 February 2005. Springer-Verlag London Limited 2005Abstract Increasing product complexity, decreasing component size, and using double-sided boards have made surface mount technology (SMT) based electronics manufacturing (EM) component more difficult to assemble. This has resulted in t

14、he economic troubleshooting of EM defects being one of the main problems facing all manufacturers. Although the authors have made significant improvements in the EM process, it has been shown that the implemented changes in the automated lines have not yet produced a high enough percentage of reliab

15、le finished products. The objective of this current development is to make a contribution towards these EM processes by creating an Internet-based intelligent system of circuit board defect detection so that EM process flaws that necessitate rework operations can be identified prior to manufacturing

16、 runs. With the development of this system, the need to rework the defective components will be minimized for any assembly line and assembly line process parameters, which cause some reliability problems (such ass older balls, insufficient solder at joints, burnt joint connections, bridged leads, vo

17、ids, skewed leads, and unformed joints) will be troubleshot directly, and the rework will be greatly reduced from the EM assembly line. This paper reports the current development and its structure.Keywords Electronics manufacturing Internet Printed circuit board Surface mount technology User interfa

18、ce1 IntroductionThe trend to high-density packaging in surface mount technology assembly has highlighted inherent difficulties in the assembly line of these very fine-pitched devices. A variety of defects is still common in printed circuit board assembly (PCBA) technology despite all of the improvem

19、ents made, and rework of PCBA is inevitable and must be performed manually in PCBA manufacturing floors since the cost of each component and the PCB itself may be hundreds of dollars. In the last few years, the number of rework stations available on the market has grown considerably including automa

20、ted ones, but there has still been no significant reduction in the number of defects. In electronics manufacturing, rework is defined as the activity that replaces defective components with those that are acceptable such that the populated board performs to specifications. Increasing product complex

21、ity, decreasing component size, and using double-sided boards have made rework more difficult and the economic reworking of PCBA is one of the main problems facing PCB manufacturers .PCBA manufacturing has been relatively improved with fully automated, accurate assembly machines and the use of robot

22、s.Although significant improvement in automated rework has also been made by one of the authors, it has been shown that the outcome of the automated rework line has not produced a high enough reliable yield percentage. The objective of this research project is to make a contribution towards this sur

23、face mount rework y creating a knowledge-based intelligent system of circuit rd defects so that the defects that necessitate a rework operation can be detected through the electronics manufacturing line. With the development of this system, the number of defective boards will be minimized from the P

24、CBA line and PCBA process parameters that cause joint level reliability problems will be identified. The causes of these problems will be troubleshot with the help of the developed online system. 2 Generic overviewHigh value printed circuit boards used for computer, military ,and telecommunications

25、applications are a critical mission sensitive eel e m en t for the 21st centurys advanced technologicaldevelopments. The growth of small-footprint and small-feature SMT in electronic components presents enormous technical obstacles to the successful production of such PCBAs.Rework refers to the gene

26、ral technical problem of removing and replacing defective circuit components on a printed circuit board. A variety of different rework methods have been successfully developed and tested during the last decades of the 20th century, but it has also been proven that none of them has perfectly produced

27、 final reliable joint throughputs out of the manufacturing line 1. Now the new objective is to develop alternative methods instead of utilizing manual, semi-automated, or automated rework systems. The technology, which has been under investigation now focuses on eliminating the causes of these manuf

28、acturing problems since the old technologies practiced in rework are costly, complicated, and require skilled operators 1, 2. The rework operation involves several steps: removing defective components, cleaning the vacant component sites, dispensing new solder paste, placing new components, and then

29、reflowing the joints 3.To date, major advances have been made in this direction for PCBAs by the authors 1 4, 5. Figure 2 shows the fully automated remanufacturing cell system created by Fidan 2. In the mid 1990s, some electronics manufacturing knowledge bases have been developed for various PCBA li

30、nes and applications 611. None of these studies reported an integrated PCBA process planning environment. The validations of the systems were also weakly presented in real industrial settings. The purpose of this research project is to make a contribution towards this surface mount rework and PCBA b

31、y creating an interactive knowledge base system of circuit board defects so that defects requiring rework operation can be detected through the PCBA line.3 The effect of the process parameters on PCBA qualityWith the continual miniaturization of electronic components and overall systems, the interco

32、nnection of the PCB and the component namely, the solder joint becomes smaller as well. This reduction in the size of the joint places more demands on the mechanical properties of the solder to ensure joint robustness. In addition to footprint size reduction, there is an emphasis on total space redu

33、ction, often leading to reduced size in the packaging of the silicon die. As SMT migrates toward smaller package dimensions, the processing conditions of each packaging become more critical 12. Significant differences between properties within a package (from layer to layer or between the carrier an

34、d the die) can cause extensive internal stresses. Once mounted to a PCB, the solder joint typically must absorb all strains induced by the expansion of the package and the PCB in thermal excursions. For SMT devices, such as quad flat packages, the leads and solder joints provide the compliance neede

35、d to compensate for the mismatch in the coefficient of thermal expansion of the package and the PCB. As joints become smaller, their quality becomes more critical .Physical defects (e.g., poor solderability, voids, solder balls, and bridging) can have a negative impact on joint robustness and solder

36、 yields. Factors that affect PCBA yields can be classified into several main categories, including assembly materials, PCBs, and components, as well as process methods and human performance 2. The assembly materials category can be subdivided further into solder-paste- and flux-related materials, su

37、ch as applied volume, reflow parameters, fluxing, and solder paste deposition methods, as well as handling and storage conditions. The most critical issue within this category is the proper fluxing of the attachment surfaces and the creation of metallurgical bonds during the reflow operation. The PC

38、B category contains many factors influencing the overall solder joint reliability, including board thickness, pad size, base material, via formation technology, PCB layer count, and solder mask technology. The component subgroup parameters that influence the assembly reliability may include pitch si

39、ze, pin count, package size, and base material. The process methods category is influenced heavily by the individual steps in the PCBA. Factors such as reflow methodology (convection versus infrared (IR) radiation) and ambient conditions will affect solder-wetting, joint formation or shape, and the

40、presence of voids. Joint quality is affected by almost all assembly variables, but is influenced strongly by the solder paste dispensing, component placement, and reflow conditions. 3.1 Solder paste dispensingThe most common method for solder paste deposition in SMT is stencil printing. In this proc

41、ess, solder paste is deposited onto the attachment pads of the board through corresponding holes made in a metal foil. For fine-pitch SMT, the printing process becomes critical because there is insufficient room to elongate the solder stencil aperture. For 0.5-mm-pitch components, it is not uncommon

42、 to achieve a print efficiency of less than 60 percent 12. Aperture size and stencil thickness need to be adjusted properly to ensure the highest transfer ratio (paste deposited versus aperture volume) 13. In general, the apertures should be oversized slightly compared to the attachment pad geometry

43、 to increase the solder deposit volume and transfer ratio. However this may lead to an increase in solder ball formation. Nitrogen may help counteract the tendency of the paste to form solder balls during paste overprinting 14. Figure 3 shows the number of all possible factors in dispensing affectin

44、g solder joint quality output. 4 New component placementThe strategies used to place components on boards can be divided into in-line, mass, sequential, and simultaneous placement 16. In high volume manufacturing, dedicated sequential or mass placement may be performed. In most cases, flexibility is

45、 important to accommodate new products and components. Typically SMT assembly uses sequential component placement. Two types of placement equipment are used for sequential pick-and place operations; the first is an xy gantry style, and the second is fixed-head moving-table placement machines 12. The

46、 overhead equipment offers high flexibility, medium placement speed, high accuracy, and minimal accelerations or movement of the PCB. In contrast, the table movement machines (usually rotary turret heads) offer high placement speeds and medium accuracy and flexibility, but impose high accelerations

47、on the PCB 17.Another important feature of the placement system that affects the PCBA is the vision system 17, 18. A major issue I the ability of the equipment to recognize features on the board and component and accurately place the device by aligning the device leads to the attachment pads on the

48、PCB. Illumination of the package from a lower angle, namely side-lighting, may be required to prevent erroneous placements with SMT 19. 5 Components of the developed toolThe developed system consists of two major components. The components are object-oriented in nature, each representing a specific

49、functional component of the whole. This form of programmingis declarative, representing facts and assertions, rather than procedural. The primary component consists of the testing software which will determine whether the values entered will or will not produce a reliable solder joint. This is accom

50、plished through the use of an extensible markup language (XML) file that defines the parameters to be tested, their constraints, and dependencies/equations along with a program module that interprets the tests. XML is a non-proprietary language for data storage. It is a simple, very flexible text fo

51、rmat originally designed to meet the challenges of large-scale electronic publishing. XML is also playing an increasingly important role in the exchange of a wide variety of data on the Web and elsewhere 22. It allows for verbose definitions, hierarchical relationships, and cross-platform compatibil

52、ity. It is a tagged language similar to HTML and therefore consists of human readable markers for defining objects, relationships, and their parameters.6 Future research directionsThis intuitive system will positively eliminate the major problems resulting in surface mount PCB operations. Cause-and

53、effect relationships and the reduction in the number of defects will also be tabulated for the tools justification. Statistical analysis of the solder joint quality outputs has not been presented in this study. Complete results of the beta testing and statistical studies for different components and

54、 process variables will be presented in the near future.References1. Fidan I, Kraft RP (2000) Inline troubleshooting for electronics manufacturing systems. In: Proceedings of the 2000 IEEE/CPMT InternationalElectronics Manufacturing Technology (IEMT) Symposium, pp 3383432. Fidan I (1996) The design,

55、 implementation, and performance analysis of a prototype SMD automated rework cell. PhD thesis, Rensselaer Polytechnic Institute3. Fidan I, Derby S (1995) Surface-mount rework operations. Circuits Assem 6(7):36384. Fidan I, Kraft RP, Ruff L, Derby S (1998) Designed experiments toinvestigate the sold

56、er joint quality output of a prototype automated surfacemount replacement system. IEEE Trans Compon Packag ManufTechnol 21(3):1721825. Fidan I, Kraft RP, Ruff L, Derby S (1998) Integration steps ofa fully-automated remanufacturing cell system used for fine-pitch surfacemounted devices. IEEE Trans Co

57、mpon Packag Manuf Technol21(1):71786. Maria A, Srihari K, Emerson CR (1994) Solder advisor a knowledgebasedsolder paste selection system. Int J Comput IntManuf 7(4):2292417. Shih W, Srihari K, Adriance J (1996) Expert system based placementsequence identification for surface mount PCB assembly. Int J AdvManuf Technol 11:4134248. Wu CH, Srihari K (1996) Automated knowledge acquisition for