Printed Electronics for Medical, Wearable & Industrial Applications
Printed electronics provide a thin, lightweight and cost-effective way to integrate electrical functionality directly into flexible substrates. Flexible Circuit Technologies manufactures custom printed electronics and silver conductive circuits for medical devices, wearable electronics, consumer products, industrial controls and other demanding applications.
Using proven conductive inks, functional printing and screen printing processes, FCT helps OEMs develop reliable printed circuits, sensors, human-machine interfaces (HMI) and other flexible electronic solutions. From prototypes to high-volume production, our engineering team works with customers to develop printed electronics designed for consistent electrical performance, durability and manufacturability.
When pressure is applied to the top layer of the printed electronic circuit, it flexes through the punched openings of the spacer to establish electrical contact between conductive pads of the upper and lower sheets, momentarily closing the printed electronic circuit. When pressure is released from the top layer, the printed electronic circuit springs back to its normal open position.
We will take on any printed electronic design challenge involving graphic overlays and flex circuits because we are leaders in technology & process development of printed electronics and flex circuits. We will find a solution within our broad range of capabilities, including circuit design, engineering, manufacturing, die-cutting and surface mount technology. We take pride in tackling the toughest design challenges related to PTF flex circuits.
Benefits
In addition to the general benefits described in flexible printed circuits, there are some unique benefits to polymer thick film circuits. They are as follows:
- Environmentally Friendly – Utilizing additive printing of silver & carbon, the process of making polymer thick film circuits does not generate hazardous gases.
- Cost Effective – Polyester is the most common substrate utilized in the PTF production process. As such, PTF circuits are generally cheaper to manufacture than other flex circuits.
- Ease of Manufacture – Due to the simple screen printing process, printed electronics are very easily manufactured.
- Cosmetic Appeal – Due to their streamlined design and the numerous graphic overlay options, polymer thick film circuits are cosmetically appealing.
- Design Flexibility – As with all flexible circuits, design options are limitless.
Applications
Printed electronic circuit production utilizes high speed screen printing techniques which result in high speed production and high yield throughout. Finally, the circuit is sent thru a process where the conductor needed is left unharmed. Two different types of printed electronics can be utilized with PTF circuits: graphic overlay and key pads. Some applications of PTF circuits are as follows:
Key Pad Switches:
- Phones
- Calculators
- Keyboards
- Remote controls
- Thermostats
Graphic Overlays:
- Dashboards
- Instrumentation
- Appliances
- Electronic games
Materials
Base Material – The standard material used for printed electronics is Polyester. Other base material options include:
- PET (Polyethylene terephthalate)
- PEN (Polyethylene naphthalate)
Conductors – Conductive inks are the most widely used conductors and can be applied in various thicknesses and line widths to meet each customer’s requirements. Additional conductor options include:
- Standard Silver Ink
- Highly Conductive Silver Ink
- Silver/Silver Chloride Ink
- Carbon Ink
- Copper
- Carbon/Silver blend
Insulators – Screen printed dielectrics are used to mask conductors from external elements and to provide insulating layers between multiple conductor layers.
Adhesives – Adhesives are used only when combining printed electronics with touch-pads, keypads or some form of graphic overlay. Common adhesives include:
- Epoxy
- Acrylic
- Pressure sensitive adhesives
Supplemental Information
The following chart provides a sample of the our manufacturing capabilities.
| Product | Standard Flex Capabilities | Advanced Flex Capabilities | Rigid Flex Capabilities | Printed Electronics | |
|---|---|---|---|---|---|
| Standard Panel Size | 9.85" (250mm) x 15.75" (400mm) | 3.94" (100mm) x 3.94" (100mm) | 9.85" (250mm) x 15.75" (400mm) | 9.85" (250mm) x 15.75" (400mm) |
|
| Line Width and Spacing | 1/4 oz. Cu 1/3 oz. Cu 1/2 oz. Cu 1 oz. Cu 2 oz. Cu | .002" (50µm) .002" (50µm) .003" (76µm) .004" (102µm) .005" (127µm) | .001" (25µm) .0014" (35µm) .002" (50µm) .003" (76µm) .004" (102µm) | .002" (50µm) .002" (50µm) .003" (76µm) .004" (102µm) .005" (127µm) | .010" (254µm) |
| Copper Thickness | 1/4 oz. Cu (9µm) 2oz. Cu (71µm) | 1/4 oz. (9µm) to 1/2 oz. (18µm) | 1/4 oz. (9 µm) and higher | .0005" (12.7µm) to .0010" (25µm) |
|
| Layer Count | 10 | 2 typical, Max of 4 | 12 (To Date) | Up to 4 | |
| VIA / DRILL SIZE | |||||
| Minimum Drill (Mechanical) Hole Diameter | .006" (152µm) | .004" (102µm) | .006" (152µm) | .010" (254µm) | |
| Minimum Micro Via (Laser) size | .004" (102µm) | .002" (50µm) | .004" (102µm) | N/A | |
| SOLDER MASK | |||||
| Solder Mask Dam (Web) | .003" (76µm) | .002" (50µm) | .003" (76µm) | .010" (254µm) | |
| Solder Mask Registration Tolerance | .003" (76µm) | .001" (25µm) | .003" (76µm) | .005" (127µm) | |
| SHIELDING MATERIALS | Copper / Silver Ink / Shielding film / Carbon | Copper / Silver Ink / Shielding film Carbon | Silver Foil | ||
| STIFFENER | |||||
| Stiffener Material | Polyimide / FR4 / Metal | FR-4 / Polyimide | PET/Metal/FR-4 | ||
| PI Stiffener | |||||
| Stiffener Registration | .008" (203µm) | .004" (102µm) | .008" (203µm) | .010" (254µm) | |
| FR4 Stiffener | |||||
| Stiffener Registration | .006" (152µm) | .004" (102µm) | .006" (152µm) | .010" (254µm) | |
| LEGEND | |||||
| Minimum Height | .032" (813µm) | .020" (508µm) | .032" (813µm) | Graphic Overlay | |
| Minimum Width | .006" (152µm) | .0032" (81µm) | .006" (152µm) | ||
| Registration | +/-.005" (127µm) | +/-.005" (127µm) | +/-.005" (127µm) | ||
| IMPEDENCE | +/- 10% | +/- 10% | +/- 10% | N/A | |
| TOOLING | |||||
| Hard Tooling Tolerance | .002" (50µm) | .002" (50µm) | .002" (50µm) | .005" (127µm) | |
| Zif Tolerance (Hard Tool, CMD, or Laser) | .002" (50µm) | .002" (50µm) | .002" (50µm) | .005" (127µm) | |
| CMD Tolerance (Chem Mill Die) | .004" (102µm) | .004" (102µm) | .004" (102µm) | .005" (127µm) | |
NOTE: FCT's capabilities Chart provides general capabilities for review; capabilities related to any specific circuit are dependent on various factors including circuit size, layer count, materials, design, and other considerations. We encourage customers to get our Application Engineers involved early in the design process.
As the membrane switch market continues to expand, there have been many advances in technology including:
Touch Pads (or Key Pads) – The tactile response to the end user is the “feeling” felt upon touching the interactive component of the membrane switch. The tactile response can be designed in varying degrees: very little (or none) to extremely heavy and easily felt. Silicon Rubber Keypad Single Sided Screened Silver.
- Silicone Rubber Keypads
- Tactile & Non-Tactile Keys
- Compression Molded or Cast
- Multi-Color Mold & Screen Printed Legends
- Abrasion Resistant Coatings
Component Assembly – At Flexible Circuit, we offer through hole and surface mount capabilities, as well as in circuit testing, conformal coating and electrostatic protective packaging.
Graphic Overlays – Graphic Overlays can be placed over flex circuits, rigid boards or membrane switches. The overlays provide the user interface with the underlying circuit and typically are used in conjunction with LEDs, LCD displays or dome switches mounted on their circuits. The overlays are made from polycarbonate, polyester or acrylic.
Z-Axis Adhesives – Adhesive substrates enable easy hot bar soldering procedures.
What are printed electronics?
Printed electronics are electronic circuits and components created by printing conductive or functional inks onto flexible substrates. They provide thin, lightweight and customizable solutions for applications such as sensors, medical devices, wearables and electronic controls.
What are printed electronics used for?
Printed electronics are used in medical devices, wearable electronics, sensors, consumer products, industrial controls, membrane switches and other applications where thin, flexible and lightweight electronics are beneficial.
What types of conductive inks are used in printed electronics?
Silver-based conductive inks are commonly used in printed electronics because of their excellent electrical conductivity. Silver/silver chloride (Ag/AgCl) inks are also used for applications such as medical sensors and electrodes.
What are silver printed circuits?
Silver printed circuits are electronic circuits created by printing conductive silver ink onto a substrate. They provide reliable electrical pathways in thin, flexible formats and are commonly used in medical, wearable and electronic applications.
Can printed electronics be used in medical devices?
Yes. Printed electronics can be used in medical devices for sensors, electrodes, diagnostic circuits, disposable medical electronics, wearable devices and other healthcare applications. Their thin profile and flexible construction make them well suited for many medical applications.
Can FCT manufacture disposable medical electronics?
Yes. FCT provides custom printed electronics manufacturing for disposable medical applications, including printed sensors, electrodes, medical patches and diagnostic circuits. Our engineering team works with customers to develop solutions based on their specific application and manufacturing requirements.
Can printed electronics be used for sensors?
Yes. Printed electronics are widely used to manufacture flexible sensors and sensing electrodes. Conductive inks such as silver and silver/silver chloride can be printed to create electrical pathways and sensing elements for medical, wearable and other applications.
Does FCT provide custom printed electronics manufacturing?
Yes. FCT provides custom printed electronics manufacturing from design and prototyping through production. Our capabilities include conductive ink printing, functional printing and screen printing for custom circuits, sensors and electronic assemblies.
Can FCT manufacture flexible printed electronics?
Yes. FCT manufactures flexible printed electronics designed for applications where space, weight and flexibility are important. Our solutions can be customized for medical devices, wearables, sensors, consumer electronics and industrial applications.
What is the difference between printed electronics and membrane switches?
Printed electronics is a broad technology used to create conductive circuits, sensors and other electronic functions using printed inks. A membrane switch is a specific type of user interface that uses printed conductive circuits and layers to provide switching and control functions. Membrane switches can therefore be one application of printed electronics.