Tear Resistance In Flex PCB Design

- Aug 14, 2019-

All flex PCB styles need to be made as tear-resistant as possible. While the product might not be fundamentally tear-resistant, tear resistance can be boosted by using specific functions in the flex PCB design. There are a number of possible techniques that are described below and showed. 1. Big span in edge 2. Installed glass fabric 3. Recessed port 4. Hole in slit 5. Pierced opening at corner 6. Installed aramid fiber 7. Extra copper in edge The adhering to strategies have actually been utilized successfully to aid protect against tearing. Several of the strategies can be made use of.

RADIUS ALL INTERNAL CORNERS

The very first line of protection against tearing is making specific that interior edges are given with the most generous span possible. This design method is one of the most important and also most basic of all techniques made use of to avoid tearing of the flex PCB manufacturing material.

LEAVE METAL IN CORNERS

The circuit design should, when possible, have small locations of copper provided for at internal corners to serve as tear stops at the inside of corner span. This prevents, or at the very least alleviates, proliferation of a tear through the polymer needs to a tear in the material initiate.

LAMINATE GLASS FABRIC IN CORNERS

Glass cloths can be laminated flooring into corners throughout the fabrication process. Though not flexible, this approach offers a robust corner construction and has actually been favored in the past by army item designers. It is a pricey remedy, nevertheless, as a result of the sort of prep work called for as well as ought to just be made use of after cautious consideration of the alternatives.

USAGE FLUOROPOLYMER COVERLAYER

Using fluoroplastics, such as Teflon ®, as coverlayers boosts tear resistance by virtue of the high tear resistance of the polymer itself. Fluoropolymers have the tendency to extend, as opposed to tear, which adds durability to the substrate. In high frequency PCB design, an additional benefit of using fluoropolymer coverlayers is that the dielectric constant of the coverlayer is a lot lower.

USE OF RADIUSED SLOTS

Using slots with ends that have a radius to access relieved flex circuit attributes could also supply tear resistance. Typically, such functions can conveniently be offered throughout the boxing procedure or various other flex PCB manufacturing process.

DRILLED HOLES AT CORNERS OR ENDS OF SLITS

Drilled or punched holes in corners or at the end of accessibility slits have been made use of efficiently when flexible appendages should be positioned close together. This technique optimizes using flex PCB manufacturing product, however the hole dimension picked will impact tear resistance. If the holes are absolute tiny the overall toughness will certainly be decreased.

ARAMID FIBERS INSIDE CUT LINE

As an option to glass fabric, aramid fibers routed through corners or along the entire synopsis of the flex PCB give a distinct method to quit flexible circuits tearing. The thin polymer fibers are high-strength and flexible, minimally impacting adaptability. Making use of aramid fibers is labor extensive as well as ought to only be made use of with factor to consider of the expense impact. The selection of method to restrain or prevent tearing of the flex PCB is not a key issue. What is extremely important is that the developer makes use of some appropriate approach to safeguard versus tearing. To summarize, all interior edges should be offered with radii. It is very important to repeat as well as highlight that square or sharp interior edges are an invitation to difficulty and also should be studiously stayed clear of. If the area of the corner is to be completely adhered to a rigid base, it is less important, however still recommended, that a distance be utilized.