| Abstract: | IC載板(IC Substrate)是IC產業供應鏈的一環，也是IC構裝重要零組件，占封裝製程30~50%成本。IC載板是提供晶片與電路板的重要連結元件，內部有線路可以連接晶片與電路板，其功用在於保護電路完整減少漏失、固定線路位置、產生散熱途徑以保護IC，並建立零組件模組化標準。其產品特性承接上一段的半導體IC製程，連接下一段的封裝製程，由於IC的功能愈趨精密與複雜，因此IC載板的重要性相對提高，藉由良好效能的IC載板產品，以及精密的封裝製程，IC功能才得以充份發揮。 隨著科技的日新月異，可攜式電子產品的普及化，我們的生活與電子產品有著密不可分的關係，電子產品製作完成後，必須確定是否能在使用期間發揮其功能，所以必須測試電子產品的可靠性，以知道電子產品的使用壽命。一項電子產品在使用上通常需要長時間，可能一年或者是三年，才能得知電子產品的可靠性，但是在商業考量似乎不能等上這麼長的時間，才把產品送到客戶手上，所以必須模擬使用情況，加速測試，讓產品失效，建立失效機構，即可以預防失效原因，進一步提高電子產品可靠度。所有的測試皆以電性失效來判斷電子產品失效，但是造成電性失效原因可能是機械、化學性、輻射、熱和電性所造成的，針對這些原因，可以觀察構裝材料的破壞模式，評估可靠性。 部分因子實驗設計主要用於篩選實驗，通常是在實驗初期，先利用部分因子實驗法找出重要因子，然後再針對這些重要因子進行仔細的分析。 而經由客訴反應大部分的電子元件失效的因素，主要均因為IC載板、印刷電路板之間不當應力引起的元件失效造，本文特別針對IC載板所引起的元件失效。故電子構裝中可靠度改善便是討論如何提昇IC載板元件的結構強度使得信號做有效的連結，以改善應力所造成的元件失效增加其壽命的可能性。 而影響錫球焊墊與錫球經由迴銲後的結合強度除了錫球的選擇、迴銲參數外錫球銲墊的鍍層(鎳)品質更是影響銲錫強度的重要因子，因此本研究為探討鍍層(鎳)品質經由迴銲後錫球銲墊與錫球的結合強度並透過實驗計劃法找出最佳的鍍鎳配方組合來提昇電子構裝中IC載板錫球銲墊與錫球的結合強度。IC substrate is part of the IC industry supply chain, and also one of the important components which stands 30 to 50% of the total cost. The importance of IC substrate if to do connection between chip and PCB with the traces inside. Their main functions are trace protecting, trace location fixing, heat spreading, IC protection, and module standardization. The main characteristic is to do connection between the IC process and the assembly process. Because of the increasing function and the complexity of IC design, the importance of the IC substrate also increased. The IC’s function can be fully unleashed only under a good substrate and a precise assembly process. As the technology improved day by day, and the popularizing of portable electronic devices, our daily life becomes closely related to those electronic products. Because we need to know if one electronic device can be well function in certain period of time, the reliability tests need to be applied. Usually a device needs one or three years for the reliability tests, but considering in business aspect, this is unacceptable. We need to do stimulating tests to speed up the test, so that the failure mode can be setup, and further more, to increase the reliability. All tests are judged under a simple rule: electrical failure, but the root cause of the failure might be various. Mechanical, chemical, radiation, and heat are the causes that we can evaluate the reliability. Fractional factorial experiment mainly use in screening tests, where in the initial stage of the experiment, we use fractional factorial experiment to find the key factor, and then we focus on the key factor to do analysis. As for the failure mode feedback through customer complaint, most of them are from the improper stress between IC substrate and PCB. This paper is focusing on the failure caused by IC substrate. Therefore the improvement is focusing on the reliability performance of electrical packaging, and the life increasing by stress improvement. Except the solder ball type, reflow profile, the surface finish plating quality also plays an important role in the strength between solder ball and the pad. This research is to analyze the relationship between plating quality and the strength of solder ball and pad. Through proper DOE, we are able to find the best Ni plating parameter, so that the strength between solder ball and the pad can be improved. |
