Circuit Board Land White Layer Laser Welding Scattering
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Solution Overview
Problem
The existing manufacturing methods for circuit boards often result in scorching of the insulating parts due to the overlap of direct and reflected laser beams during the welding process, leading to damage of the insulating materials around the land on the circuit board.
Innovation Solution
A method where a white layer is applied to the land on the circuit board, and the irradiation angle of the laser beam is adjusted so that the reflected light strikes the white layer, scattering the light and reducing the heat absorption by the land, thereby minimizing temperature increases and preventing damage to the insulating parts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the laser beam is emitted perpendicularly on the circuit board for welding, then the welding efficiency is improved, but the insulating part is scorched due to overlap of direct light and reflected light
Solution Approach 1:
A white layer is introduced as an intermediary substance between the laser beam and the insulating part. This white layer has high reflectivity and scatters the reflected light from the terminal pin, preventing it from concentrating on the insulating part. The white layer acts as a mediator that redirects the harmful reflected light away from the insulating part while allowing the welding process to continue efficiently.
Solution Approach 2:
The land is changed to a white color by applying a white layer, which has high reflectivity for laser light. This color change causes the reflected light to scatter in multiple directions rather than concentrating in a specific direction, thereby reducing the intensity of reflected light that reaches the insulating part and preventing scorching.
2Duration of action of moving object
If the reflected light of the laser beam is emitted to the land, then the welding process continues, but the land is heated and the insulating part in contact with the land is damaged
Solution Approach 1:
The white color of the land is utilized to scatter the reflected light, reducing the concentration of light energy on any single point of the land. This scattering effect decreases the rate of heat absorption by the land, thereby restraining temperature increase and preventing damage to the insulating part while maintaining welding process continuity.
3Object-affected harmful factors
If the area of the land is increased to accommodate the reflected light, then the reflected light can be distributed, but the area of the entire land increases
Solution Approach 1:
Instead of increasing the land area to distribute reflected light, the white layer is applied to the existing land surface. This color change enables the land to scatter reflected light effectively without requiring an increase in land area, thus maintaining compact circuit board design while preventing insulating part scorching.
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 approach effectively reduces the temperature increase of the land and minimizes damage to the insulating parts, preventing scorching and ensuring the integrity of the circuit board components during the welding process.
Implementation Method 1
the reflected light strikes the white layer on the land. As a white region is provided on the land, and the reflected light of the laser beam is allowed to strike the white region, the reflected light scatters on the white region. Thus, a rate of absorption of the laser beam by the land decreases
Implementation Method 2
A laser beam is used for welding. A laser beam is emitted on a solder material, and a part of the laser beam is also emitted on the terminal pin
Implementation Method 3
When direct light of the laser beam and light reflected by the terminal pin (reflected light) are overlapped and emitted to an insulating part
Data Source
AI summary
A manufacturing method for a circuit board in which a pin inserted in a through-hole of a land is welded to the land is disclosed. The land is covered with a white layer, and an irradiation angle of a laser beam with respect to the circuit board is adjusted so that reflected light of the laser beam emitted to the pin reaches the white layer on the land. As the reflected light of the laser beam is allowed to reach a white region provided on the land, the reflected light is scattered on the white region. A rate of absorption of the laser beam by the land is decreased, and a temperature increase of the land is restrained. As a result, a damage of an insulating part around the land is restrained.