The Smart Making in the PCB Factory

Posted by Heiwhite on July 7th, 2019

Today, heavy copper PCB (copper thickness: 4oz) has become popular in the rigid-flex pcb industry because it is suitable for high voltage and high power applications, since most PCBs are made only for low voltage or low power applications with traces, generally contain 0.5 Ounces of copper weight 3 ounces.

1. For weights greater than 4 ounces, it is usually recommended to double a layer rather than thick copper.
2. Due to the trapezoidal cross section emerged from the etching process, a SMT pad may be thinner than designed and this may lead to weak solder joints or difficult component placement. Also, the solder mask will require multiple layers to protect heavy copper traces.
3. Plating the circuit board with heavy copper circuitry allows the circuit board fabricator to increase the amount of copper thickness across the sidewalls.
4. Traditionally used in military applications, when PCBs the designer creates the high circuits by adding double layers of 3 or 4 ounces of copper in parallel and crossing their fingers, the layers share the current between them evenly.

By combining the supportive function supported by rigid circuit boards with the high density and flexibility features afforded by flex boards, rigidrflex boards benefit from the irreplaceable benefits of lightness, thinness, and small dimensions of electronic products. To capitalize on these benefits, the designers mainly use the Blind/ Buried Via and High Density Interconnecting (HDI) techniques. This blog will include some blind / buried techniques in HDI rigid flex circuit boards. At the  rigid-flex pcbs factory you can find the best option now.

HDI rigid-flex PCBs

Above all, we have to take a closer look at the material for the HDI rigid-flex circuit boards. We usually use the FR4 copper foil for the rigid parts and the specific PI for the flexible part. Due to the ease of delamination of rigid-flexible plates, acrylic acid adhesive should be included as a precursor to the rigid-flexible associative part to meet the viscosity requirements. Silicone rubber as a lamination material and PET release film as a mold cleaner are used in the lamination processes. All these materials should be given special attention before production.

• Then for the via technique we should focus on three main processes

Single-stage lamination means laminating all the inner layers, with the advantage of saving time and money. However, it is difficult to position the coverplayer. Once the laminate failure has occurred, the problem can only be found in etching. In contrast, the stepwise lamination means laminates or flexible layer and rigid layer. In this way, the cover layer and the graph in the inner layer can be easily positioned. Once there is a problem, it can be found right away. However, this method has the disadvantage that time and costs increase with the corresponding material.

The second process is the drilling technique

There are two types of holes that we normally use for blind and buried passageways. One is NC drilling and the other is laser drilling. Nowadays, we can also do the UV drilling for the blind vias. However, UV drilling is a new hi-tech technology that is quite complicated and requires extraction costs for its manufacture. Choosing the best  PCB Factory can make a difference here. Visit to https://www.szrcypcb.com/equipment/rigid-flex-pcb-production/ for more.