Resistor Electrode Overlap Structure for Thermal Stress Adhesion
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Solution Overview
Problem
Resistors with metal plate resistive elements face separation issues between electrodes and protective films due to thermal stress, leading to fluctuations in resistance values and reduced heat dissipation performance.
Innovation Solution
A resistor design featuring a resistive element with insulation and protective films, along with intermediate conductive layers containing synthetic resin and metal particles, where the electrodes are spaced apart and have overlapping bottom portions with the protective film, reducing thermal stress and improving adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the surface area of electrodes is increased to improve heat dissipation performance, then heat dissipation performance is improved, but the size of the resistor increases
Solution Approach 1:
The electrode structure transitions from a planar configuration to a three-dimensional overlapping configuration. The second electrode overlaps with the first electrode in the thickness direction, allowing increased effective surface area for heat dissipation without increasing the planar footprint of the resistor. This dimensional transition enables heat dissipation enhancement while maintaining compact size.
2Area of stationary object
If the electrodes are disposed to overlap with the protective film to suppress size increase, then the size of the resistor is suppressed, but thermal stress causes separation between the electrode and protective film
Solution Approach 1:
An intermediate layer is introduced between the electrode and the protective film as a mediating element. This intermediate layer has adhesive properties that bond to both the electrode and the protective film, distributing thermal stress and preventing separation. The intermediate layer acts as a buffer that maintains the integrity of the electrode-protective film interface under thermal expansion and contraction.
3Loss of energy
If the pair of electrodes are disposed to partially overlap with the protective film, then heat dissipation performance is improved, but separation occurs due to thermal stress at the interface
Solution Approach 1:
The intermediate layer serves as a stabilizing intermediary between the electrode and protective film at their overlapping interface. It maintains the structural integrity and adhesive bonding under thermal stress conditions, preventing separation while allowing the overlapping configuration to function for heat dissipation.
Solution Approach 2:
The intermediate layer changes the physical and chemical parameters at the electrode-protective film interface. By introducing materials with appropriate adhesive properties and thermal expansion characteristics, the interface stability is enhanced, allowing the overlapping structure to maintain bonding under thermal stress.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The design prevents electrode separation, stabilizes resistance values, and enhances heat dissipation by mitigating thermal stress and improving adhesion between electrodes and protective films.
Implementation Method 1
a pair of intermediate layers formed of a material electrically conductive and containing a synthetic resin, where the intermediate layers are spaced apart from each other in the first direction. The pair of intermediate layers each include a cover portion covering a part of the protective film, and the cover portion of each of the pair of intermediate layers is disposed between the protective film and the bottom portion of one of the pair of electrodes
Implementation Method 2
When the resistor is made to detect a larger current, the amount of heat generated by the resistive element will increase. When the temperature of the resistive element rises higher owing to the heat, fluctuation in resistance value of the resistor may be incurred
Data Source
AI summary
A resistor includes a resistive element, an insulation plate, a protective film, and a pair of electrodes. The resistive element includes a first face and a second face arranged to face in opposite directions in a thickness direction. The insulation plate is on the first face, and the protective film on the second face. The electrodes are spaced apart in a first direction perpendicular to the thickness direction, and held in contact with the resistive element. Each electrode includes a bottom portion opposite to the insulation plate with respect to the resistive element in the thickness direction. Each bottom portion overlaps with a part of the protective film as viewed in the thickness direction. The resistor further includes a pair of intermediate layers spaced apart in the first direction. The intermediate layers are formed of a material electrically conductive and containing a synthetic resin. Each intermediate layer includes a cover portion covering a part of the protective film. The cover portion of each intermediate layer is disposed between the protective film and the bottom portion of one of the electrodes.