PCB Laser Aperture Switching for Clean Through-Hole Formation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing laser processing methods for printed circuit boards often result in suboptimal hole formation, leading to issues like beer barrel shapes, voids, and irregular plating due to excessive energy use, which affects the quality and accuracy of hole formation and increases processing time.
Innovation Solution
A method involving a laser processing machine with a galvano device and fθ lens, using apertures of different diameters to shape the laser beam for precise processing of copper and insulating layers, ensuring the laser beam diameter for the insulating layer is equal to or less than the hole diameter, thereby reducing energy usage and improving hole quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a single aperture is used for laser beam shaping during processing of both copper layer and insulating layer, then the device structure is simple, but the hole quality deteriorates due to excessive energy causing beer barrel shapes and voids
Solution Approach 1:
The single aperture is divided into multiple apertures with different diameters (first aperture for copper layer processing, second aperture for insulating layer processing). Each aperture is positioned at different locations on the same plate, allowing selective use based on the processing stage to achieve optimal hole quality without excessive energy concentration
Solution Approach 2:
The system dynamically switches between different apertures based on the processing requirements. The plate is movable to select different apertures, enabling adaptation of laser beam diameter to match the specific needs of processing different materials (copper vs. insulating layer) at different stages
2Manufacturing precision
If the laser beam diameter for insulating layer processing is larger than hole diameter, then processing speed is faster, but hole quality worsens with beer barrel shapes and increased voids
Solution Approach 1:
Different aperture diameters are used for different processing stages: the first aperture (larger diameter) is used for copper layer removal where faster processing is acceptable, while the second aperture (smaller diameter, equal to or less than hole diameter) is used for insulating layer processing where precise hole shape control is critical. This local optimization of beam parameters achieves both quality and efficiency
3Productivity
If excessive laser energy is used for insulating layer processing, then processing time is reduced, but harmful effects increase including beer barrel shapes, voids, and peeling
Solution Approach 1:
The laser beam parameters are changed by switching between different apertures. The second aperture reduces the laser beam diameter to equal to or less than the hole diameter during insulating layer processing, which controls the energy distribution and prevents excessive energy concentration that causes beer barrel shapes, voids, and peeling, while maintaining acceptable processing speed
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 enhances hole quality by preventing beer barrel shapes, reducing voids and peeling, and shortening processing time, while maintaining high accuracy and consistency in hole formation, thus improving the plating process and increasing the mounting density of printed circuit boards.
Implementation Method 1
When a hole is processed by a carbon dioxide laser beam
Implementation Method 2
forming a through-hole (a window) in the copper layer by the laser beam
Implementation Method 3
an fθ lens (a focusing lens or a condensing lens) 6 is held by a processing head
Implementation Method 4
A galvano device 5 includes a pair of galvanometer mirrors 5a and 5b, can be rotated around a rotation shaft
Data Source
AI summary
A manufacturing method for a printed circuit board includes: passing a first laser beam output from a laser output device through a first aperture so as to define an outer diameter of the first laser beam, positioning the first laser beam by an optical axis positioning device including a galvano device and an fθ lens, and irradiating the printed circuit board with the first laser beam such that a through-hole is formed in a copper layer; and passing a second laser beam output from the laser output device through a second aperture so as to define an outer diameter of the second laser beam whereby a diameter of the second aperture is smaller than a diameter of the first aperture, positioning the second laser beam by the optical axis positioning device, and irradiating the printed circuit board with the second laser beam such that an insulating layer is processed.