Deformation and warping of circuit boards are inevitable problems, especially in mass production. This not only causes considerable losses to circuit board manufacturers, but is also a difficult problem for customers.
The following 9 methods can effectively avoid deformation and board warping:
- Choose high Tg board
Explanation: High Tg (glass transition temperature) board has high heat resistance, which can increase the rigidity of PCB board and reduce the risk of deformation during reflow soldering.
Implementation suggestion: If there is no requirement for thinness, it is recommended to use 1.6mm thick PCB board to reduce the risk of warping and deformation. - Increase PCB thickness
Explanation: PCB board with insufficient thickness is easy to deform during reflow soldering, and increasing thickness can improve its stability.
Implementation suggestion: If there is no requirement for thinness, the board should preferably be 1.6mm thick. - Reduce the size of circuit boards and the number of panels
Explanation: Large-sized circuit boards are prone to dent and deform in the reflow furnace due to their own weight. Reducing the size and number of panels can reduce this deformation.
Implementation suggestion: Try to put the long side of the circuit board as the edge of the board on the chain of the reflow furnace to reduce the number of panels. - Use the furnace tray fixture
Explanation: The furnace tray can fix the circuit board, maintain its original size, and reduce the risk of board bending and warping.
Implementation suggestion: Use a pallet fixture, especially when other methods are difficult to implement. - Use Router instead of V-Cut
Explanation: V-Cut will destroy the structural strength of the board between the circuit boards. Using Router can reduce this effect.
Implementation suggestion: Try not to use V-Cut to separate the boards, or reduce the depth of V-Cut. - Reduce the effect of temperature on PCB board stress
Explanation: Temperature is the main factor causing PCB board stress. Reducing the temperature of the reflow oven or adjusting the heating and cooling speed can reduce warping.
Implementation suggestion: Appropriately reduce the temperature of the reflow oven or slow down the heating and cooling speed of the board in the reflow oven. - Engineering design optimization
Explanation: Optimizing the structure of the PCB during the design phase, such as the consistent arrangement of the interlayer prepregs, can reduce the thermal expansion differences between different materials.
Implementation suggestions: Ensure the consistent arrangement of the interlayer prepregs, and use multi-layer core boards and prepregs. - Structural reinforcement
Explanation: Installing reinforcement materials on the PCB can increase its stability and prevent warping.
Implementation suggestions: Select appropriate reinforcement materials and methods according to actual conditions. - Temperature management
Explanation: Controlling the operating temperature of the PCB can reduce the risk of warping.
Implementation suggestions: During the design and manufacturing process of the PCB, pay attention to temperature management and avoid excessively high operating temperatures. The above methods can help manufacturers and engineers effectively prevent board warping and deformation during the design and manufacturing process of the PCB, and ensure the quality and reliability of the product.