Can a PCB Stiffener Be Reused in Different Board Revisions?
PCB Stiffener Be Reused in Different Board Revisions
A PCB stiffener is an additional component added to a flex circuit board that reinforces particular areas of the flexible portion and enhances handling. They can be made from several materials and are bonded to the circuit board using either a pressure sensitive adhesive or thermal bonding. Depending on the material, there are advantages and disadvantages to both methods of attaching a stiffener to a flex circuit.
Adding a stiffener can increase abrasion resistance and strengthen solder joints. They can also prevent the flex PCB from twisting in the components area, which could cause damage to the connector pads. Stiffeners can also make it easier to handle the flex circuit by machine pickers during the reflow assembly process.
There are two main types of pcb stiffener: polyimide and FR4. Both have their own benefits, but a designer will need to decide which one is best for the specific application. Polyimide stiffeners are ideal for creating a rigid surface that increases abrasion resistance and offers better bond strength to the conductive layers on the flex circuit. They are also more affordable than other materials, such as aluminum and stainless steel, which have higher costs and require longer turnarounds.
FR-4 stiffeners are a good choice for creating a solid, flat surface for mounting Plated Through Hole (PTH) components. They are typically used on the backside of gold fingers, as they offer more controlled flexibility than flex PCBs do. Unlike a metal core PCB, FR-4 is non-conductive and has low heat dissipation capabilities. They are a more economical choice than other materials, such as aluminum and stainless, and can be bonded to the flex circuit using a pressure-sensitive adhesive or thermal bonding.
Can a PCB Stiffener Be Reused in Different Board Revisions?
In addition to increasing the rigidity of a flex circuit, a stiffener can also provide an area for additional components. For example, a stiffener can be used to mount a PTH socket or ZIF connector, which can help save space on the flex circuit by eliminating the need for an additional layer. Adding a stiffener can also help improve the quality of the resulting product by reducing vibration and noise.
When selecting a stiffener manufacturer, it is important to choose a company that offers high-quality and diverse products. A reputable manufacturer will be able to supply the proper size and type of stiffener for any design, and they will be able to manufacture the parts quickly. The company should also have the resources and pedigree to produce stiffeners in a wide range of different materials, including FR-4, kapton, and aluminum.
When choosing a stiffener, a fab engineer will need to ensure that the hole locations on the stiffener match up with the plated holes on the flex circuit. This is crucial to ensuring that the stiffener will be properly registered and attached, allowing for easy access to the circuit board components through the plated holes. The fab engineer will need to work with the customer to determine how this can be accomplished, such as through the use of registration and pre-tack of prepreg.