上世紀90年代初開始,在美國、歐洲和日本等先(xiān)後立法對鉛在工業(yè)上的(de)應用加以限製,並進行無鉛焊料的研究與開發工作,我國對此也(yě)十(shí)分(fèn)重視,許多高等院校、科研院所(suǒ)及(jí)有條件的企業,都在廣泛開展研究(jiū)與開發工作,取得了較好的成果,基本(běn)上與國際同步。
含鉛焊料與鉛合金塗覆工藝長期以(yǐ)來在電子產品(pǐn)製造技術中被廣泛應用,尤其是Sn-Pb共晶焊料以其使用的方便性、穩定的焊接性、價格的合理性作為實用的低溫合金,從古羅馬時代開始直到當今高密度的電子組裝,一直擔任著最適宜的角色。但是(shì)由於(yú)大量(liàng)電子產品廢棄物及舊家用電(diàn)器逐漸造成的鉛汙染,對人類生存(cún)的地球環境也造成很大的危害,從日前舉辦的第13屆(jiè)NEPCON展上(shàng)展示的電子設備、電子材(cái)料來看,電子組裝業已開始邁向(xiàng)一個適合綠色環保要求(qiú)的新時期。無鉛化電子(zǐ)組裝工藝已成為新世紀(jì)電子製造業的開發和應用重點。
1990年美國(guó)提出了“在所有電子機器的廣泛(fàn)範圍內禁止(zhǐ)使用鉛的法案”,由此世界範圍內開始了電子組裝業替代焊料(無鉛焊料)的研發活動(dòng),並對替代焊料的各種應用穩定性、可靠(kào)性等進行了(le)係(xì)列(liè)研究。
在目前的應用情況下,無鉛化組裝還留有一些技術課題,在使用特性、可焊性方麵有以下幾項:潤濕性不如原來(lái)的Sn-Pb焊料;焊接作(zuò)業性比原來的差;對波峰焊接(jiē)會發(fā)生的Lift-off還沒(méi)有完好的對(duì)策(cè);焊(hàn)點的(de)耐腐(fǔ)蝕性問(wèn)題;量產化的品質管理、工藝問題;接合後的長期可靠性等。
建立針對無鉛化組裝的簡便式檢測方法(fǎ)是(shì)亟待完善的(de)任務。譬如無(wú)鉛化組裝焊點的外(wài)觀檢查,必須要建立外觀檢查的有關標準,對於整個行業來說(shuō),應該早日(rì)完成行業或國(guó)家標準。
無鉛化組裝的可靠(kào)性,一般來說(shuō)無鉛焊料難以發生蠕變(biàn),焊料本身同樣具有(yǒu)良好的可靠(kào)性,組裝時的不利因素主要來自組裝元件(jiàn)和基(jī)板焊區的組裝應力,這個方麵(miàn)的可(kě)行性認定,可以由企業自行展開,也可以通過專業學會,或企業間(jiān)共同努力來推進。
在推行無(wú)鉛化組裝的過程中,要看到向無鉛化轉移時的時間偏差,如(rú)生產(chǎn)周期短的產品,完成無鉛化可能會簡(jiǎn)單(dān)一些,周期長或多品種少批量的企業向無鉛化轉(zhuǎn)移的時間就會(huì)長一些。還有一個現象是,對於無鉛化應用中的判斷、評價(jià),因為目前的應用標準還(hái)沒有,要(yào)是不能及時完善,對產品向無鉛化轉移會變得不吻合。
無鉛(qiān)化的推廣應用會帶來應用成本的(de)提升,但(dàn)是作(zuò)為一項全球化的應用趨勢,作為整機(jī)廠商,對於無(wú)鉛化的成本上升問題,應從綜合的觀點來考慮,最好是在保持產品性(xìng)價比的基礎上,消化吸引因(yīn)無鉛化技術引起的成本上升,這才是適應市場競爭(zhēng)的理性觀點,也是整(zhěng)機廠、元件廠有待深入探(tàn)討的問題。
為了人類居住的地球環境,電子產(chǎn)品推行(háng)無鉛化已是一個不可扭轉的趨勢,日、歐、美等國的產業研究所、專業學會曾專門就此事向廣大市民、中小企業、跨國製造(zào)商作了無鉛化調查,所得到(dào)的調查結(jié)果(guǒ)可歸納為下麵幾項。
大企業應該向中小企業提供或公示無鉛化技術信息。跨國公(gōng)司類的著(zhe)名企業,因經濟實力雄厚,可能會先(xiān)行一步進入無鉛(qiān)化領域,但對於眾多的中小(xiǎo)企(qǐ)業,僅依靠自己的技術或力量,要一下進入實用無鉛化領域,還會存在一些困難(nán),希(xī)望已經進入無鉛化技術的大企業能提供無鉛應用技術信息,為全行業的無(wú)鉛化作(zuò)相應貢獻。
對無鉛焊料統一命名、製(zhì)訂相應標準。當(dāng)前不管是已完成無(wú)鉛化的元件廠(chǎng)商,還是(shì)焊料生產廠商,所設定的應用工藝、應用(yòng)焊料名稱是(shì)不統一的,這對於推廣(guǎng)中會出現因(yīn)供應廠商的不同,所提供的使用說明(míng)、技術確(què)認方式也不(bú)同的局麵,由此隻會給無鉛化(huà)的推進(jìn)造成障礙。要徹底解決這個問(wèn)題,在不同廠商之間期待於焊(hàn)料組成、組裝(zhuāng)工藝(yì)條件、無鉛焊接使用時間的規定等方麵的統一是必要的。
國際標準化。關於無鉛化國際標準的(de)建立,眾多廠商提出(chū)“建立向世界各國發布無鉛化技術信息製度”、“在(zài)國際標(biāo)準方案的製訂上要采(cǎi)取主動權”、“向其(qí)他國家發(fā)布信息或技術轉移的前提是應該(gāi)設立無鉛化公用方(fāng)案”、“盡快設定世界性的推廣應用方針,訂出無鉛化SCHEDULE”。這些意見對我們來說應該積極參考。
知識產權與國際協調。電子組裝(zhuāng)無鉛化的專利,調查中跨國類公司發表了(le)很多(duō)意見,代表性的有兩點,一(yī)是要盡快建立無鉛焊料(liào)的專利信息數據庫,二是應設法使已有的美國(guó)專利(lì)經專業網站給予公布,以減少重複申(shēn)請。
現在生產組織性跨國的大(dà)公司,基本是“世界性工廠”,這類公司生產新(xīn)技術(shù)的應(yīng)用,生產規模(mó)製(zhì)訂等,必須在不同國家子公司的(de)協調下才能完成。同樣推廣無鉛化計(jì)劃必須要進行國際間的協調,同步展開才(cái)能取得相應效果。
關於無鉛(qiān)化的技(jì)術標(biāo)準,從目前還在使用的鉛錫焊料來說,在(zài)共晶焊料以外已有多種(zhǒng)焊料(liào)標準,對應的作用也很廣。鉛錫焊料的特征反映在不同產品(pǐn)上(shàng)的使用方便性(xìng),所以(yǐ)不一定要(yào)強製設立標準。對於無鉛化推廣(guǎng)來說,應用標準不一定是(shì)單一品種組成的統(tǒng)一,主(zhǔ)要是指所限定(dìng)焊料合(hé)金係的應用範疇(chóu)與分類。例如日(rì)本NEDO的執行方案中已對無鉛焊料 的標準分類有了提案。
與無(wú)鉛化標準發生牽連的(de)另一方麵是元器件連接(jiē)電極鍍(dù)層(金屬)是否同無鉛焊料取得統一(yī)。對這個問題首先要搞清楚(chǔ)在組裝基板焊區、元件(jiàn)電極與使用的無鉛(qiān)焊料間有沒有等同性的必(bì)要。同類焊料和不同類元素混放時給(gěi)產品會帶來什麽樣的影響(xiǎng),同時(shí)也有待於權威性標準化組織在綜合各(gè)方麵的意見後提出(chū)相應的(de)建議(yì)。
無鉛(qiān)化國際標準的建(jiàn)立對推動這項事業是(shì)有利的。目前公開(kāi)的(de)技術信息,專利文獻還不是很多,但隨著今後國際法(fǎ)規時間表推出,一定會形成一個適用(yòng)性(xìng)很強的標準框架。
無鉛焊接應用案例
SONY(索尼)公司(sī)從1996年開始a研究無鉛化(huà)組裝工藝,並在無鉛(qiān)化的可靠性、量產性(xìng)、成本性方麵對Sn-Ag係、Sn-Zn係焊料進行了驗證。在1999年的(de)第三季度與500多(duō)家元(yuán)器件(jiàn)製造銷售商進行無鉛化協商,簽訂(dìng)了無鉛實用化協議。
在無鉛(qiān)產品商品(pǐn)化推(tuī)廣中,2000年3月向(xiàng)市場推出DCR-TRV20數碼攝錄一(yī)體機。
NEC 從NEC公司的對外公告上(shàng)獲(huò)知,其2002年Sn-Pb焊料的使用量同1997 年相比削減50%。20 00年以來,NEC已在多種產品上執行了無(wú)鉛化,於1999 年率先在筆記本電腦上進入量(liàng)產化生(shēng)產(chǎn)。
FUJITSU研究所
FUJITSU研究所於1999年10月發表了(le)無鉛化在“全球通信程序服務器(qì)GS8900”的應用(yòng)。GS8900全(quán)球通信程序服務器中的(de)MCM無鉛化組裝(zhuāng)(分級焊接),這種分級焊接無鉛化方式今後還將在更多的高端產品中得到應(yīng)用。
Panasonic
鬆下(xià)公司從1998年開始在便攜式數碼音頻產(chǎn)品“MD”上進行(háng)了(le)無鉛化量(liàng)產生產(chǎn)。近年來已形成P-MD 產(chǎn)品(pǐn)的無鉛化係列。
Since the beginning of the 1990s, in the United States, Europe and Japan have legislation to limit the application of lead in the industry to be limited, and lead-free solder research and development work, our country also attaches great importance to many institutions of higher learning, scientific research Institutions and qualified enterprises, are in a wide range of research and development work, and achieved good results, basically with the international synchronization. The same time as
Lead-containing solder and lead alloy coating process has long been widely used in electronic product manufacturing technology, especially Sn-Pb eutectic solder with its convenience, stable welding, the price of rationality as a practical low-temperature alloys , From the ancient Roman era until today's high-density electronic assembly, has served as the most appropriate role. However, due to a large number of electronic products and old household appliances and lead gradually lead pollution, the human environment of the human environment also caused great harm, from the recently held at the 13th NEPCON show on the display of electronic equipment, electronic materials, Electronic assembly has begun to move towards a new era of green environmental requirements. Lead-free electronic assembly technology has become the new century, the development and application of electronic manufacturing focus. The same time as
In 1990, the United States proposed the Act on the Prohibition of the Use of Lead in the Extensive Range of All Electronic Machines, which began the development of alternative solder (lead-free solder) in the electronic assembly industry and the various applications of alternative solders Stability, reliability and so on a series of studies. The same time as
In the current application, the lead-free assembly also left some technical issues, the use of characteristics, solderability aspects of the following: wetting less than the original Sn-Pb solder; welding work than the original poor; The Lift-off of the wave soldering will not have a good countermeasure; the corrosion resistance of the solder joint; the quality management of the mass production, the process problem; the long-term reliability after the joining. The same time as
The establishment of a simple detection method for lead-free assembly is an urgent task. For example, the appearance of lead-free assembly of solder joints inspection, must establish the relevant standards of inspection, for the entire industry, should be completed early industry or national standards. The same time as
Lead-free assembly of the reliability, in general, lead-free solder is difficult to creep, the solder itself has the same good reliability, the assembly of the unfavorable factors mainly from the assembly components and substrate welding area of the assembly stress, this aspect of the feasibility Identified, can be launched by the enterprise itself, you can also learn through professional, or to work together to promote the enterprise. The same time as
In the process of lead-free assembly, to see the time shift to lead-free transfer, such as the short production cycle of the product, the completion of lead-free may be simple, long or many varieties of small batch of enterprises to no Lead transfer time will be longer. There is also a phenomenon, for the application of lead-free evalsuation, evalsuation, because the current application standards have not, if not timely improvement of the product to lead-free transfer will become inconsistent. The same time as
Lead-free application will bring the application of the cost of upgrading, but as a global application trends, as a whole machine manufacturers, the cost of lead-free rise, should be considered from a comprehensive point of view, it is best to maintain Product cost-effective on the basis of digestion and attracting lead-free technology caused by rising costs, this is to adapt to market competition rational point of view, but also machine factory, component plant to be further explored. The same time as
In order to human living in the global environment, the implementation of lead-free electronic products is an irreversible trend, Japan, Europe, the United States and other countries of the Institute of Industry, professional society has specialized on the matter to the general public, small and medium enterprises, multinational manufacturers The results of the survey can be summarized as follows. The same time as
Large enterprises should provide or publicize lead-free technical information to small and medium-sized enterprises. Multinational companies like the famous enterprises, due to economic strength, may be the first step into the field of lead-free, but for many small and medium enterprises, relying solely on their own technology or strength, to enter the field of practical lead-free, there will be some Difficult, hope that has entered the lead-free technology, large enterprises can provide lead-free application of technical information for the industry-wide lead-free contribution to the corresponding. The same time as
Lead free solder named after the formation of the corresponding standards. Whether the current has been completed lead-free component manufacturers, or solder manufacturers, set the application process, the application of solder name is not uniform, which will appear in the promotion due to the different manufacturers, provided instructions, Technical confirmation is also a different situation, which will only lead to lead to promote the obstacles. It is necessary to completely solve this problem, and it is necessary to unify the consistency between the different manufacturers and the requirements of the composition of the solder, the assembling process conditions and the lead-free soldering time. The same time as
International Standardization. On the establishment of international standards for lead-free, many manufacturers put forward the "establishment of the world to publish lead-free technology information system", "in the development of international standard programs to take the initiative", "to other countries to publish information or technology transfer The premise is that should be set up lead-free public program "," as soon as possible to set the world to promote the application of guidelines, made of lead-free SCHEDULE ". These comments should be a positive reference for us. The same time as
Intellectual Property and International Coordination. Electronic assembly of lead-free patent, the survey of multinational companies published a lot of opinions, there are two representative, one is to establish a patented information database as soon as possible lead-free solder, the second is to try to make the existing US patents by professional The website is given a notice to reduce duplicate applications. The same time as
Now the production of organized transnational large companies, the basic "world factory", the production of new technologies such companies, the scale of production, etc., must be coordinated in different countries to complete the subsidiary. The same promotion of lead-free plan must be carried out international coordination, synchronized to achieve the appropriate effect. The same time as
On the lead-free technical standards, from the currently used lead-tin solder, eutectic solder in addition to a variety of solder standards, the corresponding role is also very wide. The characteristics of the lead solder are reflected in the ease of use on different products, so it is not necessary to enforce the standard. For lead-free promotion, the application of standards is not necessarily a single species of unity, mainly refers to the limited scope of the application of solder alloy and classification. For example, Japan NEDO implementation of the program has been on the standard classification of lead-free solder with a proposal. The same time as
Another aspect related to lead-free standards is whether the electrode-attached electrode coating (metal) is united with lead-free solder. The first question on this issue is to find out whether there is any need for uniformity between the component electrodes and the lead-free solders used in assembling the substrate pads. Similar products and different types of elements mixed when the product will bring what kind of impact, but also to be authoritative standardization organizations in the comprehensive views of various aspects of the corresponding recommendations. The same time as
The establishment of international standards for lead-free to promote the cause is beneficial. The current disclosure of technical information, patent literature is not a lot, but with the future international regulatory timetable introduced, will form a very applicable standard framework. The same time as
Lead - free soldering applications
SONY (Sony) from 1996 to study a lead-free assembly process, and in the lead-free reliability, mass production, cost of Sn-Ag, Sn-Zn solder was verified. In the third quarter of 1999 with more than 500 components manufacturing and sales of lead-free consultation, signed a lead-free utility agreement. The same time as
In the lead-free product commercialization promotion, in March 2000 to market the market DCR-TRV20 digital camcorder. The same time as
NEC from NEC's external announcement that its 2002 Sn-Pb solder usage compared with 1997 reduced by 50%. Since 20 years, NEC has been in a variety of products on the implementation of the lead-free, in 1999 took the lead in the notebook computer into mass production. The same time as
FUJITSU Institute
The FUJITSU Institute published the lead-free application in the "Global Communications Program Server GS8900" in October 1999. GS8900 global communication program server MCM lead-free assembly (graded welding), this grading welding lead-free way in the future will be more high-end products in the application. The same time as
Panasonic
Matsushita Corporation since 1998 in the portable digital audio products "MD" on the lead-free production. In recent years has formed P-MD products lead-free series.