The multilayer hybrid dielectric PCB is used in aerospace applications, including different laminates and structures. The multilayer structure (shown above) consists of multiple laminates and different dielectric constants. It is a mixed dielectric printed circuit board manufactured by standard printed circuit company of aerospace industry. Starting from inventory, pull out all the correct materials and check them according to customer requirements and specifications.
Initially, all inner layers were drilled, imaged and etched. The inner layer is then laminated in which a low DK adhesive film is used to press it into a plate. After lamination and cooling, the panel is moved to the borehole where all major holes are drilled. In order to prepare the hole wall for direct metallization, the panel was treated by plasma and sodium etching.
After DMS, the outer layer of the panel is imaged, copper plated, tin plated and etched. Trace width must be controlled to + / -. 0005 inches to provide proper electrical characteristics for the final product. Liquid photoimageable (LPI) solder resist was applied and ENIG (electroless nickel immersion gold) coating was performed. We use a variety of product evaluation techniques, including flying pin testing, to ensure that the PCB meets all customer product requirements. At the end of the project, our company produced 75 layers of Multilayer Hybrid dielectric printed circuit boards for the aerospace customer, vacuum packaged and shipped all the finished products to their factories in the northeast of the United States.
Hybrid High-Frequency Multilayer PCBs
A hybrid multilayer PCB uses materials with significantly different critical properties than those related to a standard multilayer PCB. A hybrid could use a mixture of FR-4 materials with high-frequency materials, or a mixture of various high-frequency materials with different dielectric constants.
Hybrid construction is becoming more popular as technology evolves,but they carry with them some benefits and challenges which require to be better understood.The reasons for employing a hybrid multilayer PCB typically fall under one among three categories: cost, improved reliability, or enhanced electrical performance.
High frequency circuit materials are typically costlier than FR-4 types. Sometimes, hybrids employing a combination of those two different materials are constructed to ease cost issues. repeatedly , a multilayer PCB will feature some circuit layers that are electrically critical and lots of layers that aren’t critical. during this case, the less costly FR-4 material is employed within the non-electrically-critical layers and therefore the costlier high-frequency material is employed within the more critical layers.