Connector production requires four stages

Connector production requires four stages

There are various types of electronic connectors, but the manufacturing process is basically the same. The manufacturing of connectors can generally be divided into four stages: stamping, electroplating, injection molding, and assembly.

1. Stamping

The manufacturing process of electronic connectors usually starts with stamped pins. By using a large high-speed press, electronic connectors (pins) are stamped from thin metal strips. One end of the large metal belt is fed into the front end of the punching machine, and the other end is wound on the belt reel through the hydraulic workbench of the punching machine. The metal strip is pulled out of the reel and pushed out to produce the finished product.

2. Electroplating

After stamping the connector pins, they should be sent to the electroplating section. At this stage, various metal coatings will be plated on the electronic contact surface of the connector. A problem similar to the stamping stage, such as twisting, fracture, or deformation of the pin, also occurs during the process of delivering the stamping pin to the electroplating equipment.

This quality defect is easily detected through the techniques introduced in this article. However, for most machine vision system suppliers, many quality defects during the electroplating process are also prohibited areas for inspection systems.

Electronic connector manufacturers hope that the detection system can detect various inconsistencies in the electroplating surface of connector pins, such as small scratches and pinholes. Although these defects are easily recognized by other products, such as aluminum tank bottoms or other relatively flat surfaces, it is difficult to obtain a visual inspection system due to the irregular and angular design of most electronic connectors. This is sufficient to identify the images required for these subtle defects.

Due to the need to apply multiple layers of metal for certain types of sales, manufacturers also hope that the detection system can distinguish various metal coatings to verify whether they are in the correct position and proportion. This is a very difficult task for a visual system using black and white cameras, as images of different metal coatings are actually similar.

Although cameras with color vision systems can successfully distinguish these different metal coatings, it is still difficult to illuminate due to the irregular angles and reflections on the coating surface.

3. Injection molding

The plastic shell of the electronic connector is made during the injection molding stage. The usual method is to inject molten plastic into a metal film and cool it quickly. When the molten plastic is not fully filled with the film, the so-called plastic will leak. This is a typical defect that needs to be detected during the injection molding stage.

Other drawbacks include jack filling or partial blockage (the jack must be kept clean to correctly insert the pin during the final assembly process). The machine vision system for quality inspection after injection molding is relatively simple and feasible, as the backlight can easily identify lost and blocked jacks.

4. Assembly

The final stage of electronic connector manufacturing is the assembly of the finished product. There are two ways to insert electroplating pins into the injection box bracket: individually or in combination. A separate plugin means inserting each plug; Every time the plug-in is inserted, the plug will also be inserted into the box. Regardless of the type of plugin, manufacturers require testing for missing pins and correct positioning during the assembly phase; Another routine inspection task involves measuring the distance between the connector and the surface.

Like the stamping stage, the assembly of connectors also challenges the detection speed of automatic inspection systems. Although most assembly lines take one to two beats per second, the visual system typically needs to provide multiple different inspection items for each connector passing through the camera. Therefore, detection speed has once again become an important system performance indicator. After assembly, the external dimensions of the connector are several orders of magnitude larger than the allowable size tolerance for a single pin.

This also poses another issue for the visual inspection system. For example, some connector shells have dimensions exceeding one foot and have hundreds of pins, each pin must have a detection accuracy of one thousandth of an inch. Obviously, one foot long connector testing cannot be performed on images, and visual inspection systems can only detect a limited number of pin quality in a small field of view.