The key parameters and influencing factors of the accuracy of automatic solder paste printer are important knowledge points of operation. Improper operation, machine cleaning and image positioning can directly affect the working quality of solder paste printer. Let's take you to understand and have a look

Precision parameters of automatic solder paste printer

1. Printing accuracy:

That is, the accuracy of the coincidence between the actual printing position and the target position, that is, the image recognition accuracy of the visual system, is a comprehensive index to measure the performance of the printing press.

2. Repeat positioning accuracy:

That is, the coincidence accuracy of multiple working positions of the printing press is generally expressed by the average value of the position deviation of 100 consecutive reciprocating movements of each moving shaft. It is not only a comprehensive reflection of the reproducibility of each combined shaft of the printing press, but also a key index to measure the advantages and disadvantages of the design of the printing press.

3. Printing cycle time:

It usually refers to a printing cycle from the entrance of PCB to the exit of PCB, excluding the scraper travel time and screen cleaning time.

4. Mark point:

That is, mark the point. It is specially made on PCB board and steel mesh board as a specific geometric figure for optical positioning and alignment of PCB and steel mesh board of vision system.

Factors determining the printing accuracy of solder paste printing machine

1、 The cleaning of steel mesh of solder paste printing machine affects the accuracy of solder paste printing

All automatic solder paste printers adopt three methods: dry cleaning, wet cleaning and vacuum cleaning. The automatic solder paste printer should automatically clean the steel mesh and ensure the printing quality. With the development of SMT, the gap is small and the speed is fast. Many pull points and even tin on PCB are closely related to cleaning! The quality of automatic cleaning is directly related to the quality of products. The improvement of cleaning function can realize the speed, that is, the high efficiency of production. The independent cleaning mechanism and brand-new cleaning concept of Desen solder paste printing machine, including the vacuum adsorption system of powerful exhaust fan, more uniform alcohol injection system and more efficient cleaning method, can realize the benign and sustainable printing of finepitch.

2、 The image positioning part of automatic solder paste printing machine affects the accuracy of solder paste printing

The image positioning of automatic solder paste printer depends on the positioning algorithm, which is also one of the core algorithms of automatic solder paste printer. With the increasing production efficiency of PCB board, the electronic components on the board are becoming smaller and smaller, which also puts forward higher requirements for positioning accuracy and speed. At present, the positioning algorithms of most automatic solder paste printers in the market are based on image gray and realized by autocorrelation matching. For the copper clad plate with good surface uniformity, the gray algorithm can well complete the function of automatic positioning. However, the emergence of more and more tinplate, gold-plated plate and flexible PCB brings great challenges to gray-scale positioning. Due to tin plating and gold plating, the surface uniformity of the plate is not very good and the reflection rate is high, which makes the difference of the imaging brightness of the mark point on the PCB board very large, and increases the false detection rate and missed detection rate of gray positioning. Due to the poor flatness of the surface of the flexible board, the imaging of mark points on the PCB will also have the problem of large brightness difference, and the size and shape of mark points will change. These problems are difficult to overcome based on the gray-scale positioning algorithm. The location algorithm based on geometry can well adapt to these problems.

Because the commercial geometric positioning tools in the market are relatively expensive, they are usually about 10000 yuan. Considering the cost factor, most automatic solder paste printers use relatively cheap traditional gray-scale positioning tools. Based on the geometry of the paste printing machine. Through this technical transformation, the positioning ability of tinplate, gold-plated plate and flexible PCB has been greatly improved. According to the market, it can realize the perfect identification of various types of mark points.

3、 The release mode of solder paste steel mesh of solder paste printing machine affects the accuracy of solder paste printing

The printing demoulding of solder paste printing machine directly affects the printing effect. Generally, automatic solder paste printing machine has two demoulding methods

(1) "Lift the scraper first and then demould", which is widely used, mainly simple PCB boards;

(2) "Demoulding first and then scraper", using thinner PCB board, etc;

The key parameters and influencing factors of the accuracy of the automatic solder paste printer have been told. Friends who need to know about the automatic solder paste printer can come to hongyitek for consultation. We have professional customer service personnel to answer with you.