Rigid & Flex Circuit Materials
MLT specializes in a number of laser cut rigid and flex materials used in the PCB manufacturing process including laser microvia drilling, laser cavity formation, and precision routing and excising.
We have extensive experience with most of the rigid and flex materials used in today’s electronics production environment. Our laser processes are for both copper clad and unclad laminate manufacturers with a varying assortment of dielectrics, reinforcements, and chemistries.

Prepregs and Laminate Cores
A prepreg is a system of fiberglass impregnated with resin. The resin and compatible glass styles are determined by what properties are required for a specific circuit board design. Prepregs and laminated cores are also available in High-Tg and halogen-free types.
Copper Clad Laminates:
• Rolled Annealed (RA) copper = Smooth surface ideal for FPC.
• Electro-Deposited (ED) copper = Standard shiny copper, copper tooth (rough)
• HTE = High temp elongation shiny copper, copper tooth
• RTF = Reverse treat, low profile copper tooth
• DT = Double treat copper, no black oxide needed
• Cu weights – 1/8 oz. (5μm), 1/4 oz. (9μm), 1/3 oz. (12μm), 1/2 oz. (18μm), 1 oz. (35μm), 2 oz. (71μm), 3 oz. (107μm)
Surface Finishes:
- Lead Free HASL
- Leaded HASL
- Immersion Tin
- Immersion Silver
- Immersion Gold
- ENIPIG
- Electroless Nickel
- Electrolytic Nickel
- Electrolytic Gold
Coverlays and Bonding Adhesives:
Kapton® -DuPont’s trademark for polyimide film
Pyralux® -DuPont’s trademark for flexible circuit materials (Cu clad laminates, coverlays and bonding adhesives)
Coverlay –Kapton coated with adhesive on one side (insulating material that is applied over a conductive pattern)
Bondply –Kapton coated with adhesive on both sides
Flex Materials:
Copper clad laminates:
Adhesiveless – AP (excellent thermal, chemical, electrical, & mechanical properties)
Acrylic Adhesive – LF (High Reliability) Aerospace, – FR (Fire Retardant) Commercial Grade, UL 94 V0
Stiffeners: – Epoxy-glass (FR-4), polyimide-glass, polyimide, copper, and other mechanical support material.
PSA (Pressure-sensitive adhesive): 1 mil (25μm), 2 mil (50μm), 5 mil (125μm)
Rigid-Flex: – FR4, Polyimide, RF Materials – PTFE
Dielectrics
Reinforcements
Woven Glass (106,1080,2216,2213,2313) | Aramid (Thermount) | Ceramic |
Non-woven glass | PTFE |
Chemistries
BCB (benzocyclobutene) | Epoxy | Cyanate ester |
PEEK (polyetheretherketone) | Epoxy blends | Polyimide |
FEP (fluorinated ethylene propylene) | Polyester | Acrylics |
LCP (Liquid Crystal Polymer) | PPE (polyphenylene ether) | BT resins |
Please contact our sales staff if you have a specific material you want to laser or any questions about capability. Below are quick links to product selector and material guides for common PCB materials.