Analysis of common problems and solutions for automatic installation of special-shaped DIP parts In the field of PCBA manufacturing, the automatic insertion of special-shaped DIP parts (hereinafter referred to as "shaped parts") is still in its infancy, especially for DDR4 DIMM DIP parts and SMT parts, combined with The problems encountered in the automatic installation process of other special-shaped parts are analyzed, and the effective solutions given by the analysis results are briefly summarized as follows.
Throwing of special-shaped parts: Throwing of special-shaped parts can generally be divided into two kinds of conditions: throwing of bad incoming materials, and throwing of equipment misjudged.
Poor incoming material throwing: In order to ensure the quality of the solder joints after DIP welding in the THT process, the relevant IPC standards stipulate that the ratio of the diameter of the PIN pin of the DIP piece to the diameter of the through hole (we denote it by B) cannot exceed 1:1.6, and in practical applications , most customers will control the ratio around 1:1.4. Therefore, the poor incoming material should be divided into the bad incoming material of special-shaped parts and the bad incoming material of PCB. The judgment of bad incoming material mainly refers to the sum of the deviation of the PIN pin or PCB through hole of the special-shaped part exceeding the industry tolerance range and the accuracy of the equipment.
Poor incoming of special-shaped parts: The poor incoming of special-shaped parts is mainly manifested in the diameter of the PIN needles of the special-shaped parts or the spacing between the PIN needles exceeding the tolerance value range. The diameter of the PIN needle of the special-shaped part is expressed by Φz, and the tolerance value of the diameter of the PIN needle is expressed by Gz; the distance of the root of the PIN needle of the special-shaped part is expressed by Hg, and the distance at the end of the special-shaped part is expressed by Hd; most of the PIN needles of the special-shaped parts are more than four PINs , and most of them are arranged in the form of multi-row and multi-column distribution. Therefore, we use Hz to represent the row spacing between PIN pins, and we use Ghz to represent the tolerance value; the column spacing between PIN pins is represented by Lz, Its tolerance value is represented by Glz.
