1. Sample detection and recognition phase:

When the project or business delivers samples, the products must be rigorously tested and checked:

A Product size, especially the important parts and wall thickness required by customers as the focus of control.

B strength test, the general skeleton can reach 3Kgf, the strength is relatively small when the structure is thin or the product is small.

C Withstand voltage test, through high voltage test (such as 3.5KV, 2mA, 60S withstand voltage conditions), in the design stage can avoid the pressure tolerance caused by the material selection, wall thickness is not reasonable.

D Solder test, test the tin on the pins, and the deformation and blistering of the body after an instant (1-3S) high temperature.

E Product flatness, test the bottom bump or plane in contact with the PCB board, whether there is warpage deformation, the industry generally uses 0.1mm max as the standard for control, the larger the skeleton, the relaxation of the flatness size. At present, the stitching of the frame-type skeleton is the most strict, because the stitch flatness is the control point directly related to the PCB flat post.

When the customer has requested CPK control over important parts, the CPK confirmation must be added.

G After the customer acknowledges the product, the product should be retained and the customer's signed approval letter should be retained.

H data files (product specification drawings, operation standards, full inspection instructions, packaging specifications, etc.) need to be issued to relevant departments for the subsequent control of product quality during mass production.

When the skeleton is changed, change the logo on the drawing surface to increase the detailed record of the version change. At the same time, isolate the product before the change to avoid mixing the product before and after the mold modification.

2. Skeleton production stage

1 injection molding

The process is that the molten wood raw material and the plastic material in a high temperature state are sprayed into the skeleton mold cavity by the pressure of the injection molding machine, and after a certain molding and cooling time, the skeleton is separated from the mold through the ejection system. The focus of this process control is the temperature and pressure at the time of injection, and the ratio of recycled materials in the plastic material. The change in injection temperature and pressure must affect the change of the basic size of the product, the change of product strength and characteristics, and the thickness variation of the burrs. The thickness of the burrs will directly affect the operation of the next process. This process can be monitored by the PQC import SPC to detect changes in the series, so that changes can be found as early as possible, and adjustments can be made as early as possible to ensure the quality of the products. For the finished mold, timely cleaning and maintenance are needed to extend the service life of the mold and bring more benefits to the enterprise. Transformer skeleton

2 raw edge processing

This process is mainly for the bakelite skeleton. In order to smoothly discharge the gas generated during the molding process, we need to add a venting groove to the mold. The molten raw material fills the venting groove under the action of high pressure, so we need to pass For the specific process, the raw edge is processed by a flashing machine. In the management of the burrs, we need to measure the size of the product to determine whether the size of the skeleton is affected by the thickness of the burrs. In addition, it is generally determined whether the burrs are transparent or not.

In the process of raw edge processing, we should choose the size of the sand according to the structural characteristics of the product, such as the size of the wire trough and the strength of the product. Otherwise, the sand will be stuck in the wire trough to block the copper wire, or it may be stuck in the pinhole to affect the next pin. Do not perform burr processing after the pin, otherwise it will affect the verticality of the pins.

For plastic products, only by hand. SMD-based bakelite products can be processed through a tunnel-type burr machine and manually removed from the burrs attached to the terminals.