Overmolding of Wound-Copper Coils for the Electronics Industry

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At Endicott Coil Company, Inc., we manufacture a range of epoxy molded, wound copper coils for use in the transportation, power, aircraft, and electronics industries. To protect these magnetic components from harsh environmental conditions, we mold the coils using a carefully selected thermoplastic or thermoset epoxy compound, such as Hysol®, Rynite®, Ryton®, or Cyglas®, depending on the application requirements. Produced in sizes from less than 1 in³ up to 6 in³, we design and develop all tooling in-house for both prototype and production molds, which also helps us to reduce customer expense.

Primary manufacturing of these epoxy molded coils is done on either a 25 ton injection press, 12 or 28 ton transfer press, or a 75 ton shuttle transfer press, depending on the coil’s size and shape. Visual inspections, SPC techniques, as well as in-process gauging are conducted to ensure that all critical coil dimensions are within tolerances of ±0.005″.

To learn more about this process, or how our epoxy molded wound copper coils can help your next application, contact us today.

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Highlights of Epoxy Molding Project

Product Description

These Coils are Molded to Guard the Coil from Environmental Conditions

Epoxy Molding Capabilities Applied/Processes


  • Design/Product Development
  • Molding – Transfer and Injection
  • In-House Tooling for Prototype and Production Molds


  • Preheating
  • De-Flashing
  • Curing
Equipment Used to Manufacture Part
  • 25 Ton Injection Press
  • 12 and 28 Ton Transfer Presses
  • 75 Ton Shuttle Transfer Press
Overall Part Dimensions

Ranges from Less than 1 in³ – 6 in³ Approx.

Tightest Tolerances

± 0.005″

Material Used

Thermoplastic and Thermosetting Materials, Including:

  • Hysol MH6-0508 Electronic Grade Epoxy Molding Compound
  • Dupont Rynite PET
  • Dupont Zytel Nylon
  • Phillips Ryton R4 PPS
  • Cyanamid Cyglas 501E
In process testing/inspection performed
  • 100 % Visual Inspections for Molding Imperfections and Damaged Pins. SPC (Statistical Process Control)
  • ISO Based Quality System
  • In-Process Inspection/Gages
  • Final Inspection from AQL (Acceptance Quality Limit) to 100%
Industry for Use
  • Transportation
  • Power Conversion & Transmission
  • Aircraft
  • Electronics
Standards Met
  • Customer Specifications
  • 2D CAD Drawing
  • VDE
Product Name

Molded Coils