Forecasting method of wettability of low-melting-point element regulation and control silver solder

Abstract

The invention discloses a forecasting method of wettability of a low-melting-point element regulation and control silver solder. The forecasting method comprises the following steps: 1, measuring thecontent WM% (mass percent) of each low-melting-point element in the silver solder; 2, determining a melting temperature range delta TM of the silver solder; 3, expanding the contents WM% of differentlow-melting-point elements in the step 1 for 100 times, and respectively substituting the expanded contents and the melting temperature range data delta TM in the step 2 into a built forecasting mathematical model SM; 4, judging the wettability of the silver solder according to an SM value in the step 3, wherein a larger value indicates higher wettability of the silver solder, and then otherwise,a smaller value indicates lower wettability. By combination of the melting temperature region of the low-melting-point-element-containing solder, the contents of the low-melting-point elements and theforecasting mathematical model, the forecasting method can quickly, efficiently and accurately forecast the wettability of the low-melting-point element regulation and control silver solder.

Description

Technical field: [0001] The invention belongs to the field of brazing filler metal performance evaluation, and in particular relates to a prediction method for adjusting and controlling the wettability of silver brazing filler metal by low-melting point elements. Background technique: [0002] As an important index to evaluate the performance of solder, wettability directly affects the filling ability of solder and the quality and performance of brazed joints, which in turn affects the service life and reliability of the parts to be brazed. Therefore, solder wettability is one of the key scientific issues in the study of brazing materials. [0003] Low-melting-point elements (melting point lower than 350°C) have the beneficial effect of reducing the melting temperature of the solder and improving the wettability of the solder. For silver solder with moderate melting temperature and excellent gap-filling ability, a certain amount of low-melting point is added Elements can ef...

AI Technical Summary

Problems solved by technology

Chinese patent 201310040275.3 discloses a method for improving the wettability of solder by combining ultrasonic field and electrostatic field. This patent adopts the process of wetting test, sample photographing, and drawing software calibration to analyze the wetting angle and wetting area, and judge the brazing area. material wettability; although the ultrasonic + electrostatic composite field can effectively improve the solder wettability, but after a large number of wetting tests, sample photographs, and software calibration procedures to determine whether the wettability is good or bad, the process is complicated, the test cost is high, and the efficiency is high. low

The published Chinese patent 201510865787.2 uses an L-shaped or V-shaped base metal plate to test the wettability of the solder by the crawling area or distance (height) of the solder on both sides of the L-shaped or V-shaped base metal, but it needs to be fabricated L-shaped or V-shaped base metal, adding flux, wet heat preservation-cooling, area or distance measurement and other steps, the process procedure is quite complicated, the cost is high, and the test efficiency is very low

Patent CN201410707428.X discloses a method for calculating the wetting speed of Sn-based solder and Cu substrate. The formula of wetting speed is established by means of the relationship between the area of ​​the wetting spot, the effective radius of the wetting spot, and time, but the image acquisition , Establish time-wetting spot area relationship curve, time-wetting spot effective radius relationship curve, the test workload is huge, the accuracy rate is poor, and the calculation efficiency is low

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