1. OVERMOLDING PROCESS & MATERIAL ELECTRONIC MODULE ASSEMBLIES
PolyTecttm
OVERMOLDING PROCESS & MATERIAL
for
ELECTRONIC MODULE ASSEMBLIES

2. ELECTRONIC MODULE Overview
Electronic modules are encapsulated for various reasons, e.g., protection of delicate components due to environmental conditions including dust, dirt, and moisture, protection in thermally unstable environments, and to protect technologies and designs.
Applications: Hand held equipment, industrial controls, retail security, automotive components, electronic sensors (motion, photonic, etc..)

3. ELECTRONIC MODULE COMPOSITION
Electronic Modules may consist of:
Populated Printed Circuit Boards
Custom Components
Input/Output Connectors
RF Transmission Capability
Mounting Hardware

4. CONVENTIONAL ENCAPSULATION
Option 1:
Injection mold housing and insert PCB into housing. Then fill housing cavity with a potting compound and bake unit. Total assembly time up to 3 hours.

5. CONVENTIONAL ENCAPSULATION
Option 2:
Cast or formed housing and insert PCB into housing.
Place seal or gasket around parameter. Affix cover
plate with fasteners. Total assembly time 2-3 minutes.

6. INJECTION MOLDING ENCAPSULATION
Process:
Typical injection molding cavity pressures
range between 1200psi and 2400 psi
Problem:
Shear stress of common solder (63%sn, 37%pb)
for mounting components to PCB’s 500 psi
Result:
Component solder failure would occur during
injection molding due to shearing of solder joints

7. INJECTION MOLDING ENCAPSULATION
Process:
Typical injection molding material temperatures
range between 218 C (425 F) and 382 C (720 F)
Problem:
Melting point of common solder is 183 C (361 F)
Result:
Component solder failure would occur during
injection molding due to melting of solder joints

8. PCB ENCAPSULATION PARAMETERS
PolyTect molding pressures less than 500 psi
PolyTect molding temperatures less than 180 C

9. ADVANTAGES OF THE PolyTect PROCESS
Low molding pressures of 100 psi
Low material temperatures of 100F
Low mold temperatures of 140F
Use of solid or foam materials

10. PolyTect OVERMOLDING PROCESS
1. The populated PCB’s and any associated
hardware components are placed into the mold
base
Conventional multi-cavity mold

11. PolyTect OVERMOLDING PROCESS
2. The molding cycle takes between 30 and 120
seconds and monitors material temperature,
pressure, velocity and shot size
Molding press closed during polymer injection

12. PolyTect OVERMOLDING PROCESS
The PolyTect process can be a single or multi-mold
depending on the part size
Molds can be single or multi-cavity
Multi-cavity molds can be located in a single press,
carousel-rotating press or a self-contained press

13. PolyTect OVERMOLDING PROCESS
3. Completed parts are removed and inspected

14. PolyTect OVERMOLDING PROCESS
The PolyTect process allows parts to be molded
clear then opaque sequentially providing
for preprogrammed QC inspection.
Parts can be molded with or without color providing
part security and/or identification.

15. PolyTect MATERIAL PROPERTIES
Mechanical and thermal properties are custom tailored for each application.
Materials used are proprietary multi-component polyurethane systems.
Tensile strengths range between 2500 psi and 9000 psi
Elongation values range between 20% and 300%
Operating temperatures range between –40C and +85C
Very low absorption rates

16. PolyTect MATERIALS Have the ability to be custom blended to provide:
Foam (Low density and rigid)
Solid (high density and rigid or very flexible)
Soft or Hard (shore A 55 to shore D 95)
Fast or slow reactivity (1 second gel to 45+ seconds)

17. PROCESS & MATERIAL SUMMARY
PolyTect OVERMOLDING
PROCESS & MATERIAL SUMMARY
Developed to address the market need for an efficient way to encapsulate electronic modules. Modules consist of fully populated printed circuit boards
Eliminates the need to mold polymer housings used in conjunction with standard sealing methods with a one step molding process.

18. PROCESS & MATERIAL SUMMARY
PolyTect OVERMOLDING
PROCESS & MATERIAL SUMMARY
Made of specialty-formulated materials to mold at temperatures and pressures below the shear stress of solder joints. Allows for over molding of delicate components without degradation of performance
Cost Reduction of traditional manufacturing and assembly methods