Before releasing a multilayer PCB for fabrication, agree the process route, material specification and handling conditions with the fabricator. This article covers those manufacturing preparations. For estimating the required layer count and routing space, use the PCB layer planning guide. The three checks below help turn the selected design into an unambiguous fabrication order.
1. Consider the Choice of Process Flow
The production of multi-layer circuit boards is prone to be affected by many factors, and the number of layers, punching process, surface coating treatment and other technological processes will affect the quality of the finished PCB circuit board. Confirm the released copper layers, stack-up, finished board thickness, plated and non-plated drill requirements, surface finish and any impedance requirements before production. Blind or buried vias and sequential lamination need a process route agreed with the fabricator; a layer count alone does not define that route.
2. The Choice of Substrate
The base material of the circuit board can be divided into two types: organic material and inorganic material. Each material has its unique advantages. Therefore, the determination of the type of substrate considers various properties such as dielectric properties, copper foil type, laminate and dielectric thickness, and processability characteristics. Among them, the thickness of the surface copper foil is a key factor affecting the performance of this printed circuit board. Thinner copper can support finer etched features, while current, thermal and reliability requirements may call for thicker finished copper. Specify the required construction and confirm achievable feature sizes with the fabricator.
3. Consider the Setting of the Production Environment
The environment of the multi-layer circuit board manufacturing workshop is also a very important aspect, and the regulation of ambient temperature and ambient humidity are both crucial factors. Storage and process conditions affect moisture uptake, dimensional stability and material handling. Follow the laminate supplier’s storage and conditioning instructions; via cracking requires investigation of the material, plated-hole construction and thermal history rather than attribution to workshop temperature alone. Therefore, it is very necessary for circuit board manufacturers to maintain proper environmental conditions during production.
For a multilayer PCB fabrication review, provide the released manufacturing files and the requirements above. Resolve material substitutions, stack-up changes and manufacturing questions before releasing the order.