Sensor Module Case Unit With Reflective Layer for Laser Welding
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Solution Overview
Problem
Existing sensor module designs using laser welding result in resin burrs protruding outside the case, affecting appearance and requiring additional processing to remove, thus reducing productivity.
Innovation Solution
Incorporating a reflective intermediate layer along the outer peripheral edge of the joining surfaces in the sensor module, which reflects laser light to prevent melting and protrusion of resin, using materials with absorptive or transmissive properties for the cases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If laser welding is used to join the front case and rear case, then the sealing performance of the case is improved, but resin burrs protrude toward the outside causing poor appearance
Solution Approach 1:
A light-reflective intermediate layer is introduced between the laser light source and the resin material at the opening end. This intermediate layer reflects the laser light, preventing direct irradiation of the resin and thereby preventing resin burr formation, while allowing the welding process to proceed effectively
2Reliability
If laser welding is used to join the front case and rear case, then the sealing performance of the case is improved, but additional work is required to remove the protruding portions
Solution Approach 1:
The light-reflective intermediate layer acts as a mediator that prevents resin burr formation during laser welding. By blocking the laser light from directly melting the resin at the opening end, it eliminates the need for subsequent burr removal operations, thereby improving productivity while maintaining welding quality
3Shape
If the intermediate layer is formed along the outer peripheral edge of the opening end, then resin burr formation is prevented, but the width of the intermediate layer must be controlled to be less than or equal to half the width of the region
Solution Approach 1:
The width of the intermediate layer is precisely controlled to be less than or equal to half the width of the opening end region. This parameter optimization allows the intermediate layer to effectively reflect laser light and prevent resin burr formation, while avoiding excessive reflection that would interfere with the welding process. The thickness is also controlled to be 50 μm or less to achieve the desired effect
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
Prevents resin burrs from forming, improving appearance and eliminating the need for additional processing, enhancing productivity and design flexibility.
Implementation Method 1
The intermediate layer is reflective of light, and is formed along an outer peripheral edge of a region, in the opening end, in which the opening end faces the joining surface. Laser light, from among irradiated light, that is incident on the intermediate layer formed along the outer peripheral edge of the region in which the opening end faces the joining surface, is reflected off the intermediate layer.
Implementation Method 2
the first case may be made of a synthetic resin material that has absorptive properties with respect to the laser light
Data Source
AI summary
A sensor module according to an embodiment of the present technology includes a sensor element, a first case, a second case, and an intermediate layer. The first case includes an opening end and accommodates therein the sensor element. The second case includes a joining surface welded to the opening end. The intermediate layer is reflective of light, and is formed along an outer peripheral edge of a region, in the opening end, in which the opening end faces the joining surface.