Do you know how to measure the temperature curve?
Source: Dongguan SMT chip processing factory Yitai Electronics, release date: 2019-09-27, browse:
When measuring the reflow soldering temperature curve, a temperature curve tester (hereinafter referred to as a thermometer) is required. Its main body is a flat metal box with a socket at one end and several miniature thermocouple probes with thin wires. When measuring, you can use solder, adhesive, and high temperature tape to fix it on the test point. Turn on the switch on the thermometer. The thermometer enters the oven cavity along with the printed board to be tested, and the sample is recorded automatically according to the internally programmed time program. After the test is recorded, connect the tester to the printer to print out multiple temperature curves of various colors. As the eyes and tools of SMT craftsmen, thermometers have been widely used in the foreign SMT industry.
<b>SMT patch processing 012</b>
When using the thermometer, pay attention to the following points:
① For measurement, a fully assembled board must be used. First, analyze the thermal characteristics of the printed board components. Due to the different heating performance of the printed board, the size of the components and the difference in materials, the actual heating and temperature rise of each point is different. Find the hottest and coldest points, and set the thermoelectricity. Even the highest temperature and lowest temperature can be measured.
② Set as many thermocouple test points as possible to fully reflect the true heating status of each part of the printed board. For example, the center and edge of the printed board have different heating levels, the heat capacity of large-volume components and small components are different, and the location of heat-sensitive components must be set up with test points.
③ The thermocouple probe has a small shape and must be fixed at the test position with designated high-temperature solder or adhesive, otherwise it will be loosened by heat and deviate from the predetermined test point, causing test errors.
④ The batteries used are generally lithium batteries and rechargeable cadmium batteries. In combination with specific conditions, test and charge timely to ensure the accuracy of test data.