晶圓針測用鈀合金探針之影像－電能模型

An Image-Electric Energy Model of a Palladium Alloy Needle Used in Wafer Probing

10.29987/CCUHKJE.201206.0029

張達元(Dar-Yuan Chang)；張智傑(Zhi-Jie Chang)

鈀合金探針 ； 影像處理 ； 電熱效應 ； 電能 ； palladium alloy needle ； image processing ； electrothermal effect ； electric energy

華岡工程學報

29期（2012 / 06 / 01）

183 - 188

繁體中文

鈀合金探針為晶圓測試常使用的測試媒介，藉由探針與受測焊墊的直接接觸，將電氣訊號傳遞至測試機上，以判斷晶片電路的良窳。測試過程中，每組探針需施予150mA～2A的電流量，並在2～5g的探針接觸壓力、1～2歐姆的接觸阻抗下，完成焊墊的刮擦行為。但是，不當的電氣條件會使探針因電熱效應，而發生軟化或燒針的現象。本研究規劃進行探針導電實驗，利用數位攝影機記錄探針的電熱過程；然後，依設定的時間間隔擷取探針的彩色影像，分析影像的RGB模型，應用影像處理方法建立鈀合金Cobra探針的影像－電能模型。實驗結果發現：4mil直徑的鈀合金探針在施以2.0A電流時，電能達到3.84焦耳時，開始有了顏色上的變化；當輸入電能超過13.44焦耳時，探針會因高熱而轉成橙紅色。瞭解了探針的電熱反應，才能設定適當的電氣測試參數，發揮最佳的功能。

In wafer testing, a palladium alloy needle usually adopts as a testing medium, which delivers the electric signals of the detected welding pad to the testing machine by directly contacting, to check the status of the electric circuit on the wafer chip. Each needle applies a current of 150mA~2A, and under a contact pressure of 2~5gram and a resistance of 1~2 ohm to finish the scrub motion on the welding pad. However, improper probing conditions cause a needle softening or burning from electrothermal effect. This study implements a series of conductive experiments simulating the contact situation to observe the electrothermal reactions in probing. A digital video camera was first used to record the conduct process, and then a great deal of colored image was captured in a specified time interval. By analyzing the RGB components of the images, an image-electric energy model was developed for the palladium alloy cobra needle. Experimental results show that the needle begins turning into yellow when the electric energy up to 3.84 Joules. As the input energy increases, the needle turns to orange-red when the energy reaches 13.44 Joules. Understanding the electrothermoal reaction of the needle is helpful for setting the proper probing parameters to obtain the optimal performance.