Solutions & Cases

Yield issues with online automatic locking screws

Customers generally have high expectations for projects, usually requiring at least 99%. Some requirements are higher, such as 99.7%, but the actual operation varies greatly, and each case is different. Some can achieve it, and some may be as low as 95%. Difficulties in communication may arise due to customer incomprehension.

Generally speaking, the system uses visual alignment, visual detection of center and vertical, cover plate fixtures, optimized bit and nozzle designs, and supporting control fine-tuning improvements. The machine itself can achieve this success rate, but there are many reasons that affect the success rate, and the ratio occupied by equipment reasons is actually not high. The main reasons are as follows:

1) Tolerance design of screws. For example, whether there is a chamfer at the bottom of the screw, whether it is a self-tapping screw, and the size of the thread pitch will all affect it. In order to improve the success rate, it is necessary to increase the screw tolerance to correct some deviations in the screw suction, position, posture, etc. For example, in the power module automatic assembly project in cooperation with Huawei, Huawei engineers will study the reasons for screw failure and modify the screw matching process. This is the most important factor in ensuring a high success rate.

2) Customer product assembly errors. For example, if the locked workpiece will move, deform, dislocate, etc., the probability of poor locking will increase.

3) Many sheet metal bases have deviations in tapping positions. The unreasonable position design of some lock screws also greatly increases the defective rate.

4) Screw quality issues. Screws are mixed with impurities, but due to cost control issues, manufacturers cannot guarantee 100% screw quality.

5) If necessary, side vision can be added to detect the screw posture. Materials will be discarded if the error is exceeded, but this will affect production capacity. Customers sometimes complain that the material discarding rate is too high.

6) The limitations of the product itself result in limited protective measures for covers, suction heads, and bits.

In short, improving the success rate is very important for automation equipment. However, many of these factors need to be solved together and are beyond the control of the equipment manufacturer. It is a complex system project that requires a lot of communication with customers and joint negotiation to solve it.

Of course, if the success rate can be guaranteed to be high enough and if the customer accepts a small amount of manual work to fix some faults, this is currently the easiest method. Of course, everyone needs to negotiate.

Waltrontech Electronics has accumulated rich experience in online automatic locking screws. Please contact us to communicate and improve together.