Chip Resistor Laser Bonding via High-Absorptance Coating Film
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The conventional method of bonding strips for chip resistors using electron beam welding is inefficient due to the need for a vacuum atmosphere, which is troublesome to evacuate and return to atmospheric pressure.
Innovation Solution
A chip resistor design featuring a coating film with higher laser beam absorptance than the electrodes, allowing for bonding using a laser beam, eliminating the need for a vacuum environment and improving manufacturing efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If electron beam welding is used to bond strips, then bonding strength is achieved, but manufacturing efficiency deteriorates due to vacuum chamber requirements
Solution Approach 1:
The patent replaces electron beam welding with laser beam welding. Electron beam welding requires a vacuum environment and complex equipment, while laser beam welding can be performed in atmospheric conditions with simpler equipment. This substitution maintains bonding capability while eliminating vacuum chamber requirements, thereby improving manufacturing efficiency and productivity.
2Reliability
If vacuum chamber is used for electron beam welding, then bonding can be performed, but process complexity increases due to evacuation and pressure return steps
Solution Approach 1:
The patent substitutes electron beam welding with laser beam welding, replacing a process that requires vacuum chambers with one that operates in atmospheric conditions. This eliminates the need for evacuation and pressure return steps, significantly reducing process complexity while maintaining reliable bonding through the laser-induced melting and fusion of materials.
3Ease of manufacture
If laser beam welding is used without coating film, then process simplicity is maintained, but bonding effectiveness deteriorates due to low absorptance of electrode material
Solution Approach 1:
The patent applies a coating film selectively on the surface of the electrode material that will be exposed to the laser beam. This coating has high absorptance for laser wavelengths, enabling effective heating and bonding. The rest of the electrode structure maintains its original properties. This localized modification solves the low absorptance problem without changing the bulk material properties or overall process complexity.
Solution Approach 2:
The patent creates a composite structure by depositing a coating layer on the electrode material. The coating material is selected to have high laser beam absorptance, while the base electrode material provides structural integrity and electrical conductivity. This composite approach enables effective laser heating at the surface while maintaining the functional properties of the underlying material.
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 method enhances manufacturing efficiency by allowing bonding in atmospheric pressure, reducing the complexity and time required for the bonding process, and enabling the production of chip resistors with improved bonding strength and accuracy.
Implementation Method 1
The coating film is made of a material having a higher absorptance of a laser beam of a predetermined wavelength than that of a material forming the first electrode
Implementation Method 2
bonding the electrically conductive member and the resistive member to each other by application of a laser beam
Data Source
AI summary
A chip resistor includes a first electrode 1, a second electrode 2, a resistor portion 3, a first intermediate layer 4 connected to the first electrode 1 and the resistor portion 3, a second intermediate layer 5 connected to the second electrode 2 and the resistor portion 3, a coating film 61 covering the first electrode 1, and oxides existing in the first intermediate layer 4. The coating film 61 is made of a material having a higher absorptance of a laser beam of a predetermined wavelength than that of the material forming the first electrode 1. The oxides are oxides of the material forming the coating film 61.