Producing HDI (high-density interconnect) circuit boards is a complex and technology intensive process that involves multiple challenges that need to be overcome. The following are some of the main issues that need to be addressed during the production of HDI circuit boards:
1. Stress problems caused by differences in thermal expansion coefficients of materials
Problem description: HDI circuit boards are composed of multiple layers of materials, which may have different coefficients of thermal expansion. When the temperature changes, the degree of shrinkage and expansion of different materials varies, which may cause stress inside the circuit board, leading to interlayer separation, cracking, or deformation.
Solution: Choose the appropriate material combination and control the thickness and size of the circuit board. In addition, adopting appropriate temperature cycling and aging testing are also important mitigation measures.
2. Stability issue of pins
Problem description: The pin size on HDI circuit boards is small and easily affected by mechanical shock or vibration, leading to pin breakage or detachment.
Solution: Improve the strength and stability of the pins, use high-quality solder and welding processes, and strengthen the fixation and protection of the pins.
3. The problem of circuit failure
Problem description: The circuits on HDI circuit boards are connected through fine wires or holes, which are susceptible to contamination, oxidation, or damage, leading to circuit blockages or short circuits.
Solution: Improve the cleanliness and flatness of wires or holes, use high-quality copper-clad and gold-plated processes, and adopt effective detection and repair methods.
4. Difficulty and accuracy issues in production
Problem description: The difficulty of producing HDI boards mainly lies in the following aspects:
Difficulty of interlayer connection: The circuit has multiple layers and concentrated connection points. If all connections are perforated, it will inevitably lead to a high perforation frequency, affecting the stability of the circuit and the performance of the board.
Difficulty in blind hole production: The production technology requirements for blind holes are higher because they cannot be repaired after perforation. Once the quality is not up to standard, a new board needs to be made.
Circuit precision: The line width and spacing of HDI board circuits are also manufacturing difficulties. There are many layers of HDI boards, and the lines are becoming thinner. There are also strict requirements for the position, thickness, and bending angle of the lines.
Solution: Select high-performance materials, optimize the process flow, use advanced production equipment and technology to ensure the accuracy and reliability of each step.
5. Efficiency and cost issues of the production line
Problem description: In the context of the continuous increase in the cost of customized HDI circuit board production lines, how to improve the current production line’s yield and material prices, especially in the context of high copper prices, is also worth considering in terms of product stability, product quality, and affordability.
Solution: Optimizing equipment and current density can increase output, with no severe contamination of copper surface layer, low coating smoothness, and minimal severe contamination of plating solution. The optimized plating solution can control the substrate copper within the range of 1-5 μ M.
6. Innovation and competitiveness issues
Problem description: HDI circuit board factories must continuously innovate in technology and management in order to surpass competitors and seize market opportunities.
Solution: Producing HDI circuit boards is a multi-step process that involves multiple aspects such as material selection, manufacturing process control, and precise equipment operation. Solving these problems not only requires advanced technology and equipment, but also strict quality management processes and sound innovation mechanisms.
7. Compression problem
Problem description: The pressing of HDI boards is an important process in the production process, and the pressing production process directly affects the reliability of HDI board products. During the compression process, there may be issues such as interlayer displacement and warping.
Solution: Adopt advanced pressing technology and equipment, such as willow nail positioning and solder joint positioning, to ensure that the holes and circuits in different layers have a good alignment relationship; Perform pre compensation before compression to reduce deviation after compression.
8. Pollution issues
Problem description: The pollutants on the PCB directly affect its appearance and performance. Under high temperature and humid conditions, residues may absorb moisture and turn white, leading to corrosion, short circuits, and other malfunctions.
Solution: Strictly control the cleanliness of the production environment, adopt efficient cleaning processes, and ensure that the surface of the circuit board is clean and pollution-free.
9. Manufacturing difficulty of multi-stage HDI board
Problem description: The manufacturing process of multi-stage HDI boards is more complex, requiring multiple pressing and laser drilling. This not only increases the complexity of the process, but also increases the difficulty of alignment, drilling, and copper plating processes.
Solution: Select high-performance materials, optimize the process flow, use advanced production equipment and technology to ensure the accuracy and reliability of each step.
By solving the above problems, the production quality and reliability of HDI circuit boards can be improved, meeting the needs of various high-end applications.