Solder paste inspection equipment is a measurement equipment in SMT chip processing that has been introduced in the past two years. Similar to AOI. Solder Paste Inspection (SPI) is to check the height, volume, area, short circuit and offset of solder paste after solder paste printing.

At present, the main inspection methods in the field of SPI are laser inspection and fringe light inspection. Wherein the laser method is realized with a point laser. Since the point laser and CCD image acquisition must have an X, Y point-by-point mechanism, the measurement speed has not been significantly increased. In order to increase the measurement speed, the point laser is changed to a scanning line laser light.

Solder paste inspection equipment is mainly divided into two categories: on-line and off-line on-line

Most of them use 3D image processing technology. The 3D solder paste inspection equipment can obtain the 3D data of each point through the movement of the automatic X-Y platform and laser scanning of the SMT patch solder paste solder joints, and can also be used to measure the entire pad patch processing process. The average thickness of the solder paste is applied, so that the solder paste printing process of SMT chip processing is well controlled. 3DSPH adopts a programmed design method. The same product can be programmed successfully at one time, and unlimited scanning can be performed at a faster speed. 2D solder paste inspection equipment only measures the height of a certain line on the solder paste to represent the solder paste thickness of the entire pad. The working principle is: the laser beam emitted by the laser transmitter is irradiated on three different planes of PCB, copper and solder paste, and the relative height of the solder paste is converted based on the laser brightness values ​​reflected from different planes. Since 2DSPI is a point scanning method, solder paste tipping or solder paste slope will lead to inaccurate measurement results of solder paste thickness. 2DSPI mostly uses manual knobs to adjust the PCB platform to align the solder paste points that need to be measured, and the speed is relatively slow.

Usually, in addition to its main task of measuring the thickness value of the solder paste, the solder paste inspection equipment of the SMT patch processing factory can also obtain the area, volume, offset, deformation, bridge, lack of tin, and sharpening through it. Wait for the specific data, debug the machine according to the customer's needs, and export the detailed solder joint data to the customer for inspection. The size range of the inspected substrate is generally 50mx50mm~250mm×330mm, and the thickness range of the substrate is 0.4~5.0mm. The indicators to distinguish the advantages and disadvantages of solder paste inspection equipment focus on the fraction rate, measurement repeatability, inspection time, operability and GR&R (repeatability and reproducibility).