In PCB design, circuit layout is fundamental for engineers. However, even experienced engineers may overlook critical details in basic PCB design, which can lead to errors. Sometimes, these errors may cause problems or even a complete failure of the circuit when converted into a PCB. To help engineers avoid redesigns and improve work efficiency, here are some essential aspects to consider during PCB design.

Heat Dissipation System Design

The heat dissipation system includes selecting cooling methods, choosing components for heat dissipation, and accounting for thermal expansion. Common heat dissipation methods include:

• Heat dissipation through the PCB itself, adding a heat sink, or attaching a thermal conductive plate.
• Material selection: Copper-clad epoxy or phenolic materials offer good electrical properties but poor thermal conductivity. With the use of components like QFP and BGA, heat needs to be effectively transferred through the PCB.

When only a few components on the board generate high heat, adding a heat sink or heat pipe to these components is effective; if additional cooling is needed, a fan-assisted heat sink can be used. For high-performance boards, such as video-processing computers, water cooling may even be required.

Component Selection and Layout

Choosing the right components is crucial. Parameters may vary even among components from different manufacturers, affecting board performance. Key considerations include:

• Memory Selection: Keeping up with DRAM and Flash updates is critical; engineers need to monitor the market and maintain close contact with suppliers.
• Component Placement: High-power components need special consideration for heat dissipation, as poor layout can lead to coating deformation or even ignition.

The PCB size is also essential: an oversized board increases conductor length and impedance; a too-small board causes poor heat dissipation. After determining the board size, place the components according to their functional blocks.

Testability Design

Testability design includes strategies to facilitate testing. In PCB design, this involves implementing mechanisms that simplify diagnostics. Ensuring access for probes, DFT, and accounting for component density is critical as miniaturization increases. With fewer test points, diagnosis becomes more challenging, so the appropriate testing equipment is essential.

MSL: Moisture Sensitivity Level

MSL (Moisture Sensitivity Level) indicates special storage requirements for moisture-sensitive components like BGA, QFP, and MEM. Components marked with MSL require a controlled temperature and humidity environment, minimizing the risk of damage. Baking requirements vary based on temperature tolerance and time. After baking, components should not remain at room temperature for more than 12 hours.

These PCB design precautions aim to help engineers avoid mistakes and achieve stability in PCB design.

KKPCB conducts research on special processing technologies such as ordinary double-sided boards, thick copper circuit boards, high-frequency circuit boards, HDI circuit boards, rigid-flexible circuit boards, FPC flexible boards, buried blind hole circuit boards, and IC carrier boards. Provides PCB design, PCB layout, PCB prototyping and PCB assembly services.