What should be paid attention to in stamping parts of electrical products?

The core of stamping processing of electrical product parts is "ensuring accuracy+ensuring electrical performance+meeting safety standards", which needs to be controlled from multiple dimensions such as process, material and quality. The key points for attention are as follows:

1. Material selection to adapt to electrical performance

Materials with good conductivity, heat conductivity, corrosion resistance and formability are preferred, such as copper, brass, phosphor bronze (shrapnel) and tinned/gold plated steel plate (low contact resistance requirement).

Avoid using materials with high impurity content, so as to avoid affecting the conductivity or causing cracking during stamping.

It is necessary to confirm the mechanical properties (such as yield strength and ductility) of the material to match the requirements of stamping process (punching, stretching and bending).

2. Control of stamping accuracy and dimensional stability

The accuracy of the die should reach ±0.01~±0.03mm to meet the miniaturization and high-density assembly requirements of electrical parts (such as terminals and shrapnel).

Control the springback in the stamping process (especially the bending process), and reduce the size deviation by adjusting the die gap and increasing the press device.

Avoid excessive burr of parts (burr height ≤0.02mm), and prevent other parts from being scratched or affecting conductive contact during assembly.

3. Electrical performance guarantee

Contact parts (such as terminals and contacts) need to ensure smooth surface, avoid oxidation and oil residue, and reduce contact resistance.

The cross-sectional dimensions of the conductive parts should be accurate, so as to ensure that the current-carrying capacity reaches the standard and avoid heating due to insufficient cross-sectional area.

The elastic deformation consistency of shrapnel parts should be controlled to ensure the plugging and unplugging life and contact reliability (usually it is required to plug and unplug for ≥ 10,000 times without failure).

4. Surface treatment and cleanliness requirements

Select appropriate surface treatment (gold plating, silver plating, tin plating, passivation) according to requirements to improve electrical conductivity, wear resistance and corrosion resistance.

The surface treatment layer shall be uniform (thickness deviation ≤ 10%) without peeling, pinholes and bubbles, so as to avoid affecting the stability of electrical connection.

After stamping, it should be thoroughly cleaned to remove impurities such as oil stain and iron filings, so as to prevent impurities from causing short circuit or poor contact.

5. Mold and process optimization

For thin-walled and complex-shaped parts (such as deep-drawn conductive sheets), progressive die or compound die is adopted to reduce the positioning error between processes.

Reasonably design the fillet and gap of the mold to avoid the parts from cracking and wrinkling, especially to protect the key conductive areas.

Set up process parameter monitoring (such as stamping speed and pressure) during mass production to avoid batch defects caused by parameter fluctuation.

6. Safety and compliance

The parts shall meet the electrical safety standards (such as UL and IEC), and the insulation area (if any) shall ensure the insulation performance to avoid the risk of electric leakage.

Avoid sharp corners and edges in the stamping process, and avoid scratching the operator or damaging cables and insulation layers during assembly.

Environmental protection requirements: the surface treatment should meet RoHS, REACH and other standards, and it is forbidden to use coatings or materials containing harmful substances such as lead and cadmium.

7. Quality inspection and traceability

The key dimensions are sampled in batches by image measuring instrument and three-coordinate measuring instrument to ensure the consistency of dimensions.

The electrical and mechanical indexes such as contact resistance, insulation performance and elastic fatigue life are tested to meet the requirements of product use.

Establish batch traceability system, record material batch, mold number and process parameters, so as to facilitate the traceability and improvement of defective products.