俱備防水功能之電子產品在出廠前需確認產品到達標示之防水等級規範，目前在檢測出不合格的產品後卻難以進一步檢測其漏水位置，因此無法通過快速更換零件使產品防水能力達到標準。而下水實測雖然最為精確但其為破壞性檢測，檢測過後的產品無法提供給客戶。本論文研究目的是開發一種適用於小型電子產品之非破壞性漏水位置檢測方法，其使用空氣替代水進行檢測以避免破壞電子產品。本研究檢測方法一開始先透過內外壓差變化速度了解電子產品氣密性，以此判斷其是否完全密封。之後對無法達到標準的產品使用兩種新的方法檢測其漏水位置。第一種水霧流動檢測法透過覆蓋在產品表面的水霧當作洩漏氣流的追蹤粒子，由於壓力空氣輸入產品內部後會由產品漏水位置外洩，因此在線雷射照射下漏水位置會產生可視的外洩氣流。第二種方法為紅外線溫度檢測，其透過輸入低溫空氣使漏水位置的溫度因外洩氣流降低，在紅外線熱影像中形成局部低溫位置。通過實測結果比較兩種方法之精度與適用情形，在兩者中水霧流動檢測法有較佳洩漏量為0.38 ml/sec以上即可得到較好的結果，需避免洩漏氣流互相干擾，適合漏水位置較少之情形。而對紅外線溫度檢測法而言，檢測時間長短與漏水位置多寡無關，但其在洩漏量大於1.381 ml/sec有較佳之效果，電子產品不同的外殼厚度與材料組成會造成較差的紅外線檢測結果。

Waterproof electronic products must pass waterproof tests before launching to the market. To fix the products that cannot pass the tests, we need information about leaking positions. However, it is difficult to detect leaking position by non-destructive testing. The objective of this paper is to develop two non-destructive methods for electronic products to detect leaking positions. Those methods replaced water with air to avoid the damage caused by water. Before using the methods, we measured the pressure change rate of a product’s inner space to check whether the product was completely sealed or not. If not, then we used the two novel methods to detect leaking positions. One is the mist flow test, and the other is infrared thermography. The mist flow test uses mist to provide trace particles that cover the upper surface of the product. The particles move by following the leaking airflow, and they can be viewed by using line laser. Infrared thermography is to fill the low-temperature air into the electronic product to create the local low-temperature spots that can be seen in infrared thermography. The mist flow test can detect small leakage that is greater than 0.38 ml/sec, but is easy to be interfered by nearby leaks. Infrared thermography can have better results when the leakage is greater than 1.381 ml/sec, and the test time is irrelevant to the number of leaks. However, a product with different thickness and various materials may cause misjudgment on the leaking positions.

1. 維基百科，取自：https://zh.wikipedia.org/wiki/國際防護等級認證
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