Low Flow Polyimide Prepreg

General Information

Arlon’s 37N is a 200⁰C glass transition temperature polyimide low-flow resin system designed for bonding multilayer rigid flex, heat sink attachment to MLB’s or other applications where minimal and uniform resin flow is required. 37N can be cured as low as 350⁰F and has excellent thermal stability. Applications include military, aerospace, space, commercial and industrial PWB electronics. Meets requirements of IPC-4101/42

Detailed Specs

Because of varying storage conditions, it is recommended that 37N prepreg be dried at 29” (736mm) Hg for 12 to 24 hours.

37N Low-Flow prepreg is very process tolerant. It laminates well with either a cold platen press start or with a hot start. Vacuum or vacuum assist lamination is recommended for the removal of moisture and air. Low-Flow products do not displace air voids as well as standard prepregs, and vacuum will help assure a void-free final product.

Lamination Cycle:

  1. Vacuum draw down the package for 30 minutes at <29” (736 mm Hg) prior to applying pressure in the press. Maintain the vacuum beyond the set point of the resin, i.e., above 320°F (160°C)
  2. Use a platen temperature in the range of 370°F - 380°F (188°C - 193°C).
  3. Control the heat rise to about 8°F - 12°F per minute (4.5°C - 6.5°C) between 210°F and 300°F (100°C and 150°C)
  4. Use a pressure of 180 to 350 psi (12.6 to 24 kg/sq.cm), depending on panel size and complexity. Following are recommended pressures relative to panel size to use as starting points:
  • Cure time is 90 minutes at temperature.
  • The subsequent processing should be the same as those normally used for rigid-flex PCBs

Low Flow Selector Guide

SDS -37N Prepreg-US

Low Flow Prepreg – Defining the Beast

Low Flow Prepreg – Taming the Beast


Arlon EMD is the first U.S. laminator recognized under IPC’s Quality Product Listing. We are the only laminator to have achieved certification for all three slash sheets on polyimide materials, IPC-4101/40, IPC-4101/41 and IPC-4101/42.

IPC-4101 Tested Products Validation

IPC-4101 Qualifed Products Listing

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