Elimination of Hole Mouth Burr in Multilayer PCB Micro-Hole by Using Micro-EDM
| Autor: | Feng Xinke, Feng Luo, Xiaoyu Wu, Jian-guo Lei, Bin Xu, Fu Lianyu |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
0209 industrial biotechnology
Materials science Mechanical Engineering Drilling micro-EDM 02 engineering and technology hole mouth burr 021001 nanoscience & nanotechnology Article micro-hole Printed circuit board 020901 industrial engineering & automation Machining Control and Systems Engineering Electric spark TJ1-1570 multilayer PCB Mechanical engineering and machinery Electrical and Electronic Engineering Composite material 0210 nano-technology Short circuit Layer (electronics) Pulse-width modulation Voltage |
| Zdroj: | Micromachines Volume 12 Issue 6 Micromachines, Vol 12, Iss 688, p 688 (2021) |
| ISSN: | 2072-666X |
| DOI: | 10.3390/mi12060688 |
| Popis: | The micro-hole is a key structure in multilayer printed circuit board (PCB), as it enables the effective transmission of electrical signals. At present, the most common way to machine PCB micro-holes is mechanical drilling using micro-bit. However, in the mechanical drilling of micro-holes, these holes are prone to burring at the hole mouth due to the micro-bit failing to cleanly cut through the first layer of copper foil on the PCB. Hole mouth burr can seriously affect the performance of the PCB, resulting in potential short circuiting or even ruining the PCB. To solve the above problems, this paper proposed to machine the first layer of copper foil on the PCB via micro electro-discharge machining (micro-EDM) to eliminate hole mouth burr. Compared with the mechanical drilling, micro-EDM is a form of non-contact machining, and the high temperature generated from the electric spark discharge can erode the first layer of copper foil, thus fully eliminating hole mouth burr. This paper performed a detailed study of the influence of spindle speed, machining voltage, pulse width, and pulse interval on hole mouth quality. After that, the technological parameters for eliminating hole mouth burr were obtained. Finally, under the effects of 20,000 rpm spindle speed, 26 V machining voltage, 4 μs pulse width, and 8 μs pulse interval, a micro-bit with a diameter of 200 μm was used to perform micro-EDM of the first layer of copper foil. From the machining results, it can be known that the PCB micro-hole was possessed of overall good quality, with good hole wall surface quality and almost no visible hole mouth burr. |
| Databáze: | OpenAIRE |
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