Shunt Resistor Metal Block Layout for Heat Dissipation
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Solution Overview
Problem
The existing semiconductor devices with shunt resistors experience inadequate heat dissipation, leading to a deterioration in the reliability of the entire semiconductor device due to insufficient cooling of the heat generated by the shunt resistor.
Innovation Solution
A semiconductor device design where the resistance element includes a metal block with a resin layer and a resistance film, bonded to a circuit pattern on an insulated circuit board, with the metal block being thicker than the circuit pattern to enhance heat dissipation, and concave portions in the circuit pattern to accommodate thermal expansion and reduce stress on the insulating plate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a shunt resistor with a metal block is used to measure potential, then measurement function is achieved, but heat dissipation is insufficient leading to reliability deterioration
Solution Approach 1:
The patent extends the heat dissipation path from two-dimensional conduction through the circuit pattern to three-dimensional conduction by positioning the metal block below the circuit pattern at a specific distance. This vertical spatial arrangement creates a dedicated heat dissipation pathway that does not occupy lateral space, effectively adding a dimensional aspect to heat management while maintaining measurement functionality.
Solution Approach 2:
The patent separates the measurement function (resistance element) from the heat dissipation function (metal block). By positioning these components at different locations and allowing independent optimization, the design resolves the conflict between maintaining measurement precision and ensuring adequate heat dissipation for reliability.
2Loss of energy
If the circuit pattern area is increased to improve heat dissipation, then heat dissipation improves, but the area occupied on the insulating plate increases
Solution Approach 1:
The patent moves the primary heat dissipation function from the lateral plane to the vertical dimension by positioning the metal block below the circuit pattern. This allows heat dissipation to occur through vertical thermal conduction rather than requiring expanded lateral area, effectively utilizing the z-axis dimension to resolve the area-constraint conflict.
Solution Approach 2:
The patent introduces the metal block as an intermediary heat dissipation component positioned between the circuit pattern and the insulating plate. This intermediary element provides an additional thermal conduction pathway that enhances heat dissipation without requiring the circuit pattern itself to occupy more area, thus resolving the contradiction between heat dissipation needs and area constraints.
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
This design effectively improves heat dissipation and reduces the risk of cracks in the insulating plate, thereby enhancing the reliability and durability of the semiconductor device.
Implementation Method 1
the shunt resistor which generates heat is not sufficiently cooled. If heat generated by the shunt resistor is transferred to surroundings, then the heat dissipation property of the whole semiconductor device deteriorates
Implementation Method 2
a resistance element including a metal block 7a, a resin layer 7b disposed on the metal block 7a, and a resistance film 7c disposed on the resin layer 7b
Data Source
AI summary
A semiconductor device has a resistance element including a metal block, a resin layer disposed on the metal block, and a resistance film disposed on the resin layer and an insulated circuit board including an insulating plate and a circuit pattern disposed on the insulating plate and having a bonding area on a front surface thereof to which a back surface of the metal block of the resistance element is bonded. The area of the circuit pattern is larger in plan view than that of a front surface of the resistance element. The metal block has a thickness greater than that of the circuit pattern in a direction orthogonal to the back surface of the metal block. As a result, the metal block properly conducts heat generated by the resistance film of the resistance element to the circuit pattern.