HDI PCB is a printed circuit board designed to maximize the density of surface components, provide breakthrough solutions and / or transmit high-frequency signals for ICs with a large number of closely spaced pins or pads. The aim is to provide greater functionality in smaller packages. To achieve this goal, you need to select a contract manufacturer (CM) with the equipment and expertise required to achieve the specialization required for HDI PCB electronic manufacturing. To optimize the manufacturing of HDI designs, you should follow clear paths or design techniques that combine your design intent with CM’s functionality.
Design skills of HDI PCB electronic manufacturing
PCB layout design can be very complex, so designers are required to make difficult decisions about the specification that assigns the greatest importance. If the design is for key systems industries, such as aerospace, medical equipment, automotive or automotive manufacturing, the process will be more complex. Military, or to get high-performance Internet of things (IOT) or HDI. Regardless of the type of circuit board design, when designers combine manufacturing design (DFM) with a strategy to target the benefits of PCB development and coordinate with its CM functions.
DFM is not universal. This is a set of rules and guidelines for specific manufacturing stages, such as design for assembly (DFA) and design for testability (DFT). DFM can also focus on specific board design types, such as HDI. Let’s look at some of the key design techniques designed to optimize the manufacturing of HDI PCB electronics.
Tip 1: select via type to minimize process complexity
The selection of through holes is a critical decision, not only determining the equipment and manufacturing steps required, but also affecting processing time and additional costs. The use of blind or buried micro vias helps to reduce the number of layers and the cost of materials; however, whether to use them or not, dog bone shaped or near pad vias will affect the process complexity.
Tip 2: select the minimum number of components to apply HDI
The choice of components is always important. However, component selection optimization is more important for HDI PCB. HDI designed components determine the routing width, location, type and size of the drill and stack. Obviously, performance is the primary consideration, but packaging, traceability and availability should also be considered. Having to replace components or redesign the layout can result in a surge in additional manufacturing time and material costs.
Tip 3: space components minimize stress and EMI
When the components are placed in such a way that the through-hole positions are asymmetrically distributed, uneven stresses may be applied to the plate, which may lead to warpage. This will seriously affect the yield, the number of plates per panel that can be used. If the components are separated from the dense high-power components, the signal may introduce electromagnetic interference (EMI) into the track, thus affecting the signal quality. In addition, parasitic capacitance and / or inductance of nearby pins or pads may affect signal quality. Therefore, it is recommended to include EMI modeling during design to extract parasitic effects.
Tip 4: routing to minimize signal integrity issues
One of the advantages of HDI is its ability to transmit signals with a smaller routing width. Although the trace width is reduced, it should be designed to achieve the best width signal integrity. This includes the use of the shortest routing length, consistent path impedance, adequate ground plane, and isolation of digital, analog and power signals.
Tip 5: choose stacking to minimize material costs
In addition to selecting through holes, the selection of PCB stack also has a significant impact on the manufacturing cost of HDI PCB electronic products. The type of material, the number of layers and the number of layers directly affect the number of lamination and drilling cycles required. In making these decisions, cost should be one of the determinants.
