Inspection specifications and methods for electroplating quality of stamping parts

After a stamping part is stamped by a die on a punching machine, there may be many processes next, of course, some can be directly taken to the assembly line for assembly, but this situation is relatively rare, and at least a process of washing and rinsing is required. For such products, it is relatively easy to manage, and it will not be too troublesome in handling and storage. There are also hardware products like door frames. They do not need to be processed twice at all. They can be directly put on the line after falling from the punch. However, the whole In the stamping industry, I think more than 90% of them need to be processed twice or more. For example, if we talk about electroplating today, there are also many types. There are also electroplating on the mold, such as the deep-drawn lower template, but the types of electroplating are different. Let's take terminal products as an example to talk about the inspection specifications and methods of electroplating quality. The inspection of electroplated terminals is an indispensable work after electroplating is completed, and only products that pass the inspection can be used in the next process. The usual inspection items are: film thickness (thickness), adhesion (adhesion), solderability (solderability), appearance (appearance), packaging (package). Salt spray test (salt spray test), there are special requirements for drawings There are porosity test (30U') gold using nitric acid vapor method, palladium nickel plating product (using gel electrolysis method) or other environmental testing. A film thickness 1. The film thickness is the basic item of electroplating testing, and the basic tools are The principle of the fluorescent film thickness meter (X-RAY) is to irradiate the coating with X-rays, collect the energy spectrum returned by the coating, and identify the thickness and composition of the coating. 2. Notes for using X-RAY: 1) Do a spectrum every time you turn it on Calibration 2) 　　 Do cross-hair calibration every month 3) Gold-nickel calibration should be done at least once a week 4) Test files should be selected according to the steel used in the measurement 5) Test files should be established for new products if there is no test file 3 ．The significance of the test file: Example: Au-Ni-Cu(100-221 sn 4%Au-Ni-Cu———-Test the thickness of nickel plating and gold plating on the copper substrate. (100-221 sn 4 %——-AMP copper material number 4% tin copper material) 2. Adhesion: Adhesion test is the basic test item of electroplating, and poor adhesion is one of the most common adverse phenomena in electroplating. There are two detection methods: 1. Bending method: First, use a copper sheet with the same thickness as the required test terminal to pad the place to be bent, use flat-nose pliers to bend the sample to 180 degrees, and observe whether there is peeling or peeling of the coating on the curved surface with a microscope. Tape method: Use 3M tape to stick firmly on the surface of the sample to be tested, perpendicular to 90 degrees, and quickly tear off the tape to observe the load and peeling metal film on the tape. If you cannot observe it clearly, you can use a 10x microscope to observe. The result is judged: a) There should be no falling metal powder and sticking of the patch tape. b) There should be no peeling off the metal coating. yc) The substrate is not broken, and there should be no serious cracks and peeling after bending. The phenomenon. d) There must be no blistering. e) The underlying metal must not be exposed when the substrate is not broken. 4. For poor adhesion, you should learn to distinguish the position of the peeling layer. You can use a microscope and X-RAY test the thickness of the peeled coating to judge, and use some work stations to find the problem. 3. Solderability 1. Solderability is the basic function and purpose of tin-lead and tin-plating, if there is a post-soldering process If required, poor soldering is absolutely unacceptable. 2. The basic method of soldering test: 1) Direct immersion tin method: According to the drawing regulations, directly immerse the solder part with the required flux and immerse it in a 235 degree tin furnace After 5 seconds, it should be taken out slowly at a speed of about 25MM/S. After taking it out, it is observed with a 10x microscope when it is cooled to room temperature and judged: the area of u200bu200bthe tin should be greater than 95%, and the part of the tin should be smooth and clean, without solder rejection. Desoldering, pinholes and other phenomena are deemed qualified. E2) Older After welding, for products with special requirements on some of the strength surfaces, the samples should be aged for 8 or 16 hours with a steam aging tester before the welding test to judge the welding performance of the product in the harsh environment. four. Appearance: 1. Appearance inspection is the basic function of electroplating inspection. From the appearance, it can be seen that the suitability of the electroplating process conditions and the possible changes in the electroplating solution. Different customers have different requirements on the appearance, and the electroplated terminals should be observed with a microscope at least 10 times. For the defects that have occurred, the larger the magnification, the more helpful it is to analyze the cause of the problem. 2. Inspection steps: 1. Take the sample and place it under a 10x microscope, illuminate it vertically with a standard white light source: 2. Observe the surface condition of the product through the eyepiece. 3. Judgment method: 1. The color is uniform, no dark or light color, different color (such as blackening, redness, yellowing), and no serious color difference in gold plating. 2. Do not stick to any foreign matter (dust, dust, oil, crystals) 3. It must be dry and free from moisture. 4. Good smoothness, no cavities, particles 5. There shall be no crushing, scratching, scratching and other deformation phenomena and the phenomenon of damage to the plated parts. 6. There must be no exposure of the lower layer. Regarding the appearance of tin-lead, a small amount (not more than 5%) of pitting and pitting is allowed without affecting the solderability. 7. The coating shall not have poor adhesion such as blistering, peeling, etc. 8. The electroplating position shall be carried out in accordance with the drawing regulations, and the QE engineer can decide to relax the standard appropriately under the premise of not affecting the use function. For suspected appearance defects, the QE engineer should determine the limit samples and appearance auxiliary standards. Related news: The characteristics of the main materials of the stamping parts The common problems of the stamping parts The characteristics of the scaffolding stamping parts and the importance of inspection The advantages of metal stamping parts Introduce the advantages, procedures and characteristics of stamping parts