Ultrashort Pulsed Laser Drilling of Printed Circuit Board Materials
We report on a comprehensive study of laser percussion microvia drilling of FR-4 printed circuit board material using ultrashort pulse lasers with emission in the green spectral region. Laser pulse durations in the pico- and femtosecond regime, laser pulse repetition rates up to 400 kHz and laser fl...
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MDPI AG
2022-05-01
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| Series: | Materials |
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| Online Access: | https://www.mdpi.com/1996-1944/15/11/3932 |
| _version_ | 1797492782343913472 |
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| author | Daniel Franz Tom Häfner Tim Kunz Gian-Luca Roth Stefan Rung Cemal Esen Ralf Hellmann |
| author_facet | Daniel Franz Tom Häfner Tim Kunz Gian-Luca Roth Stefan Rung Cemal Esen Ralf Hellmann |
| author_sort | Daniel Franz |
| collection | DOAJ |
| description | We report on a comprehensive study of laser percussion microvia drilling of FR-4 printed circuit board material using ultrashort pulse lasers with emission in the green spectral region. Laser pulse durations in the pico- and femtosecond regime, laser pulse repetition rates up to 400 kHz and laser fluences up to 11.5 J/cm<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mn>2</mn></msup></semantics></math></inline-formula> are applied to optimize the quality of microvias, as being evaluated by the generated taper, the extension of glass fiber protrusions and damage of inner lying copper layers using materialography. The results are discussed in terms of the ablation threshold for FR-4 and copper, heat accumulation and pulse shielding effects as a result of pulse to pulse interactions. As a specific result, using a laser pulse duration of 2 ps appears beneficial, resulting in small glass fiber protrusions and high precision in the stopping process at inner copper layer. If laser pulse repetition rates larger than 100 kHz are applied, we find that the processing quality can be increased by heat accumulation effects. |
| first_indexed | 2024-03-10T01:08:40Z |
| format | Article |
| id | doaj.art-bac6c36d4ed14058a401d83d95b43b1e |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-10T01:08:40Z |
| publishDate | 2022-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Materials |
| spelling | doaj.art-bac6c36d4ed14058a401d83d95b43b1e2023-11-23T14:22:37ZengMDPI AGMaterials1996-19442022-05-011511393210.3390/ma15113932Ultrashort Pulsed Laser Drilling of Printed Circuit Board MaterialsDaniel Franz0Tom Häfner1Tim Kunz2Gian-Luca Roth3Stefan Rung4Cemal Esen5Ralf Hellmann6Applied Laser and Photonics Group, University of Applied Sciences Aschaffenburg, Würzburger Straße 45, 63743 Aschaffenburg, GermanySchmoll Maschinen GmbH, Odenwaldstraße 67, 63322 Rödermark, GermanySchmoll Maschinen GmbH, Odenwaldstraße 67, 63322 Rödermark, GermanyApplied Laser and Photonics Group, University of Applied Sciences Aschaffenburg, Würzburger Straße 45, 63743 Aschaffenburg, GermanyApplied Laser and Photonics Group, University of Applied Sciences Aschaffenburg, Würzburger Straße 45, 63743 Aschaffenburg, GermanyApplied Laser Technologies, Ruhr University Bochum, Universitätsstraße 150, 44801 Bochum, GermanyApplied Laser and Photonics Group, University of Applied Sciences Aschaffenburg, Würzburger Straße 45, 63743 Aschaffenburg, GermanyWe report on a comprehensive study of laser percussion microvia drilling of FR-4 printed circuit board material using ultrashort pulse lasers with emission in the green spectral region. Laser pulse durations in the pico- and femtosecond regime, laser pulse repetition rates up to 400 kHz and laser fluences up to 11.5 J/cm<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mn>2</mn></msup></semantics></math></inline-formula> are applied to optimize the quality of microvias, as being evaluated by the generated taper, the extension of glass fiber protrusions and damage of inner lying copper layers using materialography. The results are discussed in terms of the ablation threshold for FR-4 and copper, heat accumulation and pulse shielding effects as a result of pulse to pulse interactions. As a specific result, using a laser pulse duration of 2 ps appears beneficial, resulting in small glass fiber protrusions and high precision in the stopping process at inner copper layer. If laser pulse repetition rates larger than 100 kHz are applied, we find that the processing quality can be increased by heat accumulation effects.https://www.mdpi.com/1996-1944/15/11/3932laser drillingultrashort pulse (USP) laserprinted circuit board (PCB)heat accumulationpulse to pulse interactionsmicrovia |
| spellingShingle | Daniel Franz Tom Häfner Tim Kunz Gian-Luca Roth Stefan Rung Cemal Esen Ralf Hellmann Ultrashort Pulsed Laser Drilling of Printed Circuit Board Materials Materials laser drilling ultrashort pulse (USP) laser printed circuit board (PCB) heat accumulation pulse to pulse interactions microvia |
| title | Ultrashort Pulsed Laser Drilling of Printed Circuit Board Materials |
| title_full | Ultrashort Pulsed Laser Drilling of Printed Circuit Board Materials |
| title_fullStr | Ultrashort Pulsed Laser Drilling of Printed Circuit Board Materials |
| title_full_unstemmed | Ultrashort Pulsed Laser Drilling of Printed Circuit Board Materials |
| title_short | Ultrashort Pulsed Laser Drilling of Printed Circuit Board Materials |
| title_sort | ultrashort pulsed laser drilling of printed circuit board materials |
| topic | laser drilling ultrashort pulse (USP) laser printed circuit board (PCB) heat accumulation pulse to pulse interactions microvia |
| url | https://www.mdpi.com/1996-1944/15/11/3932 |
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