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Thick Film Resistor PCB

What is Thick Film Resistor PCB

Introduction:

1. Thick Film Resistors PCB or calls Printed Resistors PCB or Printed Carbon Resistor or Embedded Resistors technology is to incorporate reliable carbon resistors printing inside the printed wiring boards using standard PCB processing. The printed resistor materials are based on a novel hydrophobic polyimide resin developed specifically to serve as a polymeric thick film resistors or thin film resistor material .

2. Resistance range of thick film resistors can be from 40 ohms/square to 10K ohms/square,The thick film resistor or carbon resistor are printed on an etched copper outter layer and cured in a standard convection oven, infra-red furnace, or a thermal belt furnace. Laser trimming can be processed at this time to achieve tight tolerances.

This Printed Resistors PCB solution makes resistors embedded into printed circuit boards more complex, But more versatile than the selection of surface mounted passive components. This frees up the surface space for the placement of more active components that increase functionality.

3. Thick Film Resistor technology is a new material that will improve the process of embedded resistors by eliminating the need for special termination treatment, such as immersion silver,or silver palladium, gold palladium, Also speed up the laser trim process with tighter TCR’s; and increase the reliability performance with a stable binder system.

Thus far, The environmental and mechanical testing of Printed Resistors PCB processing has also been successful. Continuing to test and formulate higher resistivity values will prove these thick film resistor technology has a future in the embedded passives market.

On the other hand, Thick Film Resistor values currently available for testing show good adhesion to a clean copper surface. This eliminates the need for silver immersion, or silver palladium, gold palladium which presents a cost savings as well as reduces concerns of silver migration. Up to two times the standard polymer laser trimming speeds have proven successful.

 

Target Resistance:

The target resistance values of polymer resistor materials is related to the optimized circuit design and fabrication process. The materials and process parameters of polymer resistors must be taken into account in order to successfully achieve the performance requirements of PCB designs.

To get target resistance values,we have to control following factors. For example, electrical considerations, available paste resistivity values, trimming requirements, and the distribution of resistances of all the resistors present on the same layer of the printed resistor board. The resistance of a linear resistor is written as:
R= ρ×L/A = (ρ/t) × (L/w) = Rs (L/W).
Using these standard resistor thick film equations, along with actual resistor linearity and blend curves, the designer will be able to calculate and design a variety of options for a given target resistance value.

 

Main advantages: Typical applications:

Excellent high frequency performance
Calibrated voltage dividers available
Special ohmic values available
Functional (in-circuit) trimming
Low profile
Long life
Low cost
No insertion costs
No insertion errors
No soldering problems
Unlimited fixed and variable resistor combinations
Laser trimming capabilities

HOME APPLIANCES:
Satellite Signal transmission equipment
Light dimmers
High frequency wireless communication
Heavy duty equlpment
Speed control for hand power tools
Commercial Phased Array Networks
Power conversion devices
Electric regulator
Voltage stabilize
Diskette Drive

AUTOMOTIVE:
Pedal sensors
Swilrl actuator position sensor
Climate control
Fuel tank level sensor
Distribution
Headlight positioning control
Dashboard dimmer control
Mirror position sensor
Headlight position sensor
Column integrated module