When designing a custom overmolded cable, there are several critical design details that engineers must consider such as the overmold material, physical shape, and the type of bulk cable to be used. Design changes during development can create significant delays and cause a direct impact on program schedules, especially if hard tooling or custom bulk wire is involved. Understanding how the cables are produced and the available options to implement design updates can be the difference between completing your project on schedule or a cancelled program. Join us for this webinar as we review overmold cable assembly material options, manufacturing processes, customization options, and more. For more information on our custom cable assembly solutions visit http://www.epectec.com/cable-assemblies/.

1. Manufacturing That Eliminates Risk & Improves Reliability
Managing the Development of Your
Overmolded Cable
11.21.2019

2. Manufacturing That Eliminates Risk & Improves Reliability
2
Agenda
 An Overview of Overmolding
 How To Design An Overmold On Your Cable
 Materials and Design Options
 How To Get Started With Your Custom Overmold
 Summary

3. Manufacturing That Eliminates Risk & Improves Reliability
3
An Overview of Overmolding

4. Manufacturing That Eliminates Risk & Improves Reliability
4
When To Use An Overmold on Your Cable
 Provide strain relief and ruggedize the
connector
 Replacement for an OFF THE SHELF
backshell
 Encapsulate delicate components,
soldered connections
 To provide a grip, handle or other means
to mate/unmate your connection
 Replace RTV, potting, or other backfilled
compound
 Waterproofness or environmental
considerations
 Cosmetic or branding for your custom
cable
 No EOL or Obsolesce
Not all cable designs and applications warrant an overmolded cable

5. Manufacturing That Eliminates Risk & Improves Reliability
5
What is an Overmold?
 Typically an injection molded process using
thermoplastics
 Chemical bond or “interlocked” mechanical
bond between the parent material and
overmold
 One shot or two-shot process requiring
dedicated hard tools
 Innermolds are typically higher durometer for
strength and to protect delicate components
 Overmolds are softer and a cosmetic surface
while offering strain relief
High Durometer Innermold
Micro-USB Connector with Innermold &
Overmolded Connector
Soft Overmold

6. Manufacturing That Eliminates Risk & Improves Reliability
6
How is Overmolding Performed?
 Pelletized thermoplastic is poured into a
hopper
 Pellets are heated and fed into a network
of channels, runners, and sprues
 Molten thermoplastic is injected into a
2-piece tool that acts as a mold
 The overmolded cable is removed from
the tool
 Excess material is cleaned from the
overmolded cable during a visual
inspection
Overmolding Operation
Pelletized Thermoplastic

7. Manufacturing That Eliminates Risk & Improves Reliability
7
How To Design An Overmold On Your Cable

8. Manufacturing That Eliminates Risk & Improves Reliability
8
Understanding the Tooling
 Factory will design a 2-piece mold
– Includes all runners, injector pins, sprue
channels, etc
– Materials have inherent shrink rates
– Draft angles must be considered
 Tolerances
– Generally +/- 0.011”
– Critical dimensions must be noted
– Tighter tolerances are possible- but must
be proved out through tooling
development Bulk Cable
Overmolded Backshell Off The Shelf Connector

9. Manufacturing That Eliminates Risk & Improves Reliability
9
Understanding the Tooling (cont.)
 Making Changes
– Changes to the connector and cable OD
(outer diameter) will impact the tool
– Tooling overmold design changes irreversible
– Material can be removed- not added
 Different Overmold Materials
– Material shrink rates must be reviewed
– Tool maker may require additional changes
Material shrink rates are accounted for in the tooling design
Tool is designed for shutoff on cable OD
(outer diameter)

10. Manufacturing That Eliminates Risk & Improves Reliability
10
3D Modeling of Overmold
 Customers typically supply this to Epec
 Epec uses SOLIDWORKS and can design
– Typically an Engineering NRE fee associated
– Customer must provide design requirements
 Exterior shell is critical- internals aren't
– The 3D model should show the outer most surface
– Internal details will be optimized by Epec
– Critical features must be clearly noted
.STP format is preferred for all overmold concepts
Conductors
Overmolded Region
Overmold without
Bulk Cable

11. Manufacturing That Eliminates Risk & Improves Reliability
11
Critical vs Non-Critical Features
 Critical Features
– Must be noted!
– Critical dimensions
• Max Outer Diameter (OD) or length
• Bulkhead or panelized applications
– Understand the mating connector
 Non-Critical Features
– Strain relief tapered
– Custom materials
– Flexibility to make tooling modifications
– Ruggedized strain reliefs
Allow for design flexibility with non-critical features
Strain Relief Channels Are Generally
Non-critical
Max Outer Diameter (OD) is
a Critical Dimension

12. Manufacturing That Eliminates Risk & Improves Reliability
12
2D Drawing to Define the Assembly
 3D Model must be paired with a 2D drawing to define the overall assembly
 Tabulated BOM
– Manufacturer’s P/Ns
– Usage
– Source of supply
– Item numbers
– Customer must provide design requirements
 Lengths and Tolerances
 Critical Design Details
Drawing must include dimensions, manufacturers P/Ns, and critical design info
2D Cable Drawing with Tabulated BOM, Lengths and
Tolerances

13. Manufacturing That Eliminates Risk & Improves Reliability
13
Materials and Design Options

14. Manufacturing That Eliminates Risk & Improves Reliability
14
Material Options
 Locally Sourced Compounds
– Specialty materials are available, but…
• Risk of sourcing challenges
• MOQs
• Limited manufacturing familiarity
 Broad Range of Compounds Available
– PVC – Polyvinyl Chloride
– SR-PVC – Semi Rigid Polyvinyl Chloride
– PP – Polypropylene
– TPU – Polyurethane
– TPE/TPR – Thermoplastic Elastomers
– Polyurethane/Nylon
UL approved materials are available

15. Manufacturing That Eliminates Risk & Improves Reliability
15
Material Options (cont.)
 Material Compatibility
– Pair PVC overmold with PVC jacket
– Teflon
 Some Materials Won’t Bond
– Mold release
– Teflon
– Chemical vs Mechanical Bond
 Colorization
– Some materials cannot be colorized
– PMS Pantone color
– Color match sample
Match the overmold material to the jacket
Bulk Cable Jacket
Conductor Jacket
Overmold

16. Manufacturing That Eliminates Risk & Improves Reliability
16
Durometer
 Lots Of Hardness Tests
– Durometer Shore A is most common
 Tolerances
– +/- 5 Durometer Shore A Scale
 Material Property-Inherent
 If a durometer change is required, it may impact the tooling!
– Must review the shrink rate of the materials
Most overmolded strain relief designs are 80 – 90 Shore A
Typical Durometer: 50-60 Shore A
Typical Durometer: 80-90 Shore A

17. Manufacturing That Eliminates Risk & Improves Reliability
17
Plasticized PVC
 PVC is a rigid and flame-retardant compound
 Add plasticizers is a common way to increase
flexibility
 Aging and flammability are concerns
 PVC hardness is expressed in P%
 Example Calculation:
– PVC material of 50kg
– Plasticizer material of 40kg
– 40kg Plasticizer / 50kg PVC =80%
– Hardness is 80P
Common hardness for plasticized PVC is “45P” which is about 90 Shore A

18. Manufacturing That Eliminates Risk & Improves Reliability
18
 Parting lines are inherent in the process
– Tool design can help minimize
– Post processing is another option
 Tooling marks
– Ejector pins
– Gate locations
 Surface finish
Managing the Cosmetics
Optimizing gate location can help mitigate cosmetics
Parting Lines
Tooling Marks

19. Manufacturing That Eliminates Risk & Improves Reliability
19
Artwork in an Overmold
 Company Logos
 Device Information
 Polarity Markings
 .AI Artwork Files
 Definition
– Include the location
– Preferred pocket depth/emboss
– Layer in 3D Model
Provide Logos and Artwork in .AI vectorized format
ProductionInitial Design
Power Ratings

20. Manufacturing That Eliminates Risk & Improves Reliability
20
Customization of Features
 Implement design features to pass qualification testing
– Waterproofness
– Radiated / conducted emissions and susceptibility
– Salt fog
 Employ specialty materials, processes
– Fungal resistance jacket
– Encapsulate PCBA, switches, sensors
– LEDs to indicate status
Consider adding passive components and PCBAs to your build plan

21. Manufacturing That Eliminates Risk & Improves Reliability
21
Custom Connectors
 Use 3D modeling to create desired design
– Solidworks, .STP, .IGS, etc
 Complete control of the design
– Pin engagement
– Customizable overmold
 Add all those design pesky details
– Beryllium copper coating to pins
– Polarity markings
 No EOL or Obsolesce
– Custom tooling is catalogued and
maintained
By owning the tooling, obsolesce can be mitigated.

22. Manufacturing That Eliminates Risk & Improves Reliability
22
How To Get Started With Your Custom Build

23. Manufacturing That Eliminates Risk & Improves Reliability
23
Development Timeline
Production tooling typically requires 2 - 6 weeks
Proof of Concept
3D Model
Samples
Fit Check
Production
Typical Tooling Lead-Times
House Tooling 0-2 weeks
Simple Tooling 2-4 weeks
Complex Tooling 4-8 weeks

24. Manufacturing That Eliminates Risk & Improves Reliability
24
How to Get Started with your Overmold Proof of Concept
1. 3D model of the overmold
2. 2D assembly drawing
3. Overmold material requirements
4. Critical dimensions
 Varies with complexity tooling up an
overmold can take 2 - 6 weeks
 House tooling exists for many standard
connector schemes and sizes
Using house overmold tooling on Industry Connectors can save time and money

25. Manufacturing That Eliminates Risk & Improves Reliability
25
Epec Inquiry Form
 When starting a project with Epec,
we ask if you could please fill out
our Inquiry Form.
 This allows us to capture all the
information of your design upfront,
eliminating guess work.
 Also allows us to provide you with
an accurate quote.

26. Manufacturing That Eliminates Risk & Improves Reliability
26
Summary

27. Manufacturing That Eliminates Risk & Improves Reliability
27
Summary
 Low cost and high reliability cable solutions
 Overmolding is not for every project
 Customer to provide the geometry, factory will develop the process
 Dimensional changes to the overmold will require tooling rework
 Specialty materials are available, but there is a potential for cost and lead-time
impact

28. Manufacturing That Eliminates Risk & Improves Reliability
28
Our Products
Battery Packs Flex & Rigid-Flex PCBs Cable Assemblies Printed Circuit Boards
RF Products User Interfaces Flexible Heaters EC Fans & Motors

29. Manufacturing That Eliminates Risk & Improves Reliability
29
Q&A
 Questions?
– Enter any questions you may have
in the Control Panel
– If we don’t have time to get to it, we
will reply via email

30. Manufacturing That Eliminates Risk & Improves Reliability
30
Thank You
Check out our website at www.epectec.com.
For more information email sales@epectec.com.
Stay Connected with Epec Engineered Technologies
Follow us on our social media sites for continuous technical updates and information: