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The function of patch red glue, to put it simply, is to make the parts firmly stick to the surface of the PCB to prevent them from falling. However, when there is a wire drawing phenomenon during use, the glue will randomly fall on other parts of the PCB and on the components. It is obvious It affects the appearance of the PCB and seriously affects the use of electronic products. The wire drawing is caused by many factors, including process, material, glue, environment, etc. Now I will share with you some of the patch red glue Factors and solutions for wire drawing.
1. Fast dispensing speed
A suitable SMT patch adhesive has its fixed performance indicators, such as viscosity, thixotropy index, etc., to meet the needs of a fixed production process, but some users do not understand the performance of the glue,
in order to improve production efficiency, The speed of glue is increased, but it ignores that the performance of the product itself cannot meet the needs of the new process. When the dispensing speed suddenly increases and the thixotropy cannot keep up, it is easy to bring up the glue and the phenomenon of wire drawing. The solution is to speed up the production efficiency and change the process. Before consulting the manufacturer, to determine whether the current product performance can meet the new technology, if not, you can ask the manufacturer to provide solutions to prevent abnormalities.
What is the reason for the drawing process of SMT patch red glue? How to solve?
2. Not evenly stirred before use
We all know that SMT patch red glue is a material with high thixotropy. The purpose is to solve the phenomenon of wire drawing in production. However, the index of reaction thixotropy is the thixotropy index. The size of the thixotropy index is related to the viscosity. During the printing process Or when dispensing, random or probabilistic wire drawing occurs, it can be considered that the local viscosity of the glue is uneven, which leads to local differences in thixotropy. At this time, the red glue can be punched out, stirred evenly and continue to use.
Third, the printing network problem
The use process of SMT patch red glue is generally printing and dispensing. Now we are going to talk about the problem of printing nets. First of all, we must understand the materials of the printing nets, such as metal, plastics, etc. The metal printing nets are generally steel nets or copper nets. If the printing hole is not smooth and not polished, it will produce wire drawing during the printing process. When choosing to use the plastic printing screen, it is necessary to choose the appropriate patch red glue, because some formula red glue is not suitable for use on plastic materials. One of the reasons is to mention the cleanliness of the printing screen. Therefore, understanding the requirements of the printing screen can also avoid the phenomenon of wire drawing in production.
Fourth, the glue itself
The problem of the glue itself mentioned here is mainly due to the changes in the performance and quality of the patch red glue due to some reasons during the storage process. For example, the storage environment does not match. The general storage requirement is low temperature storage. At high temperatures, the glue will thicken for a long time, making it easy to use. Wire drawing occurs; storage environment humidity is too high, poor airtightness leads to moisture absorption or the glue itself absorbs moisture too fast, which causes the red glue to collapse and also leads to wire drawing during use. Therefore, the storage environment of red glue should be kept at a low temperature and dry to prevent glue. The quality of the glue changes due to external influences.
