Laser Micromachining and Laser Drilling

Laser Micromachining & Laser Drilling

Exceeding Laser Specifications for Tighter Tolerance &
Smaller, More Accurate Microvias

MicroConnex employs three high-end lasers, each serving well-defined purposes for our Laser Micromachining and Laser Drilling. Our ESI 5200, 5330 and 5330HE lasers are similar in that they all operate at a wavelength of 355nm (frequency tripled Nd-YAG), with a spot size of 25μm.

Over the years we’ve pushed the limits of our systems to come up with solutions for our customers. We use engineering rigor to push the envelope in our processes, and we’ll work closely with you to optimize our processes for your specific applications.

As a result, we’ve been able to routinely exceed the advertised specifications for the lasers. For example, we can achieve a sub +/-5μm tolerance with some select materials. We’ll work with you to understand your requirements and will suggest alternatives that avoid tight tolerance issues while maximizing the value you receive.

MicroConnex will continue to deliver precision and accuracy with our laser micromachining, laser drilling, and laser ablation with an end goal of achieving or exceeding your desired results.

Our Laser Micromachining and Laser Drilling Capabilities

Laser drilling through inhomogeneous, multi-layer structures requires careful control of laser parameters to achieve the desired hold while maintaining substrate integrity. Because different materials will ablate at different rates, we’ll tailor the laser drilling algorithm to the specific material to achieve highly consistent geometries. This is especially important with densely packed circuits or features.

Specific laser micromachining and laser drilling capabilities include:

• Blind Vias, Buried Vias and Microvias. We’re able to drill very small (25μm) and/or high aspect ratio microvias, blind vias and buried vias with an extremely high degree of accuracy. Our expertise with our laser systems enables us to regularly exceed the OEM spec of +/- 10 μm positional accuracy over an optimized 12”x12” stage, with a 22×26″ total work surface. Standard spot size is 25μm, with a 10μm spot available for specialized applications through the use of advanced beam shaping optics.
• Dielectric Laser Ablation and Skiving. “Flying Leads” are often used for fine scale interconnect to high density piezoelectric transducer arrays, where mass loading must be minimized. After circuit fabrication, the kapton may be removed by low power laser ablation, exposing the circuit traces for subsequent processing.
• Dicing, Micromachining and Marking. Precise laser control allows patterning and cutout of complex features in a wide range or materials and thicknesses.
• Drill through metallization with no additional masking required.

Feature depths up to ~500μm (0.5 mm) can be efficiently machined in metals and from one side. We’ve learned, for example, that although thermally sensitive materials require longer processing times to allow heat dissipation, surprisingly good results can be obtained in extremely thermally sensitive materials, e.g. single crystal ferro-electrics, with a laser algorithm tailored to the material and the particular cutting pattern.

Into the Future: Beyond Laser Micromachining and Laser Drilling

“I am excited to push the limits of these systems while looking toward the future. It helps us streamline our processes and deliver better results for our customers today.”

~ Ethan Fontaine, Laser Value Stream Manager

Like many of our engineers, Ethan Fontaine and another laser specialist, Ben Ross, like a good challenge. They’re also visionaries, looking beyond the typical applications for lasers to using them as effective prototyping tools.

We can ultimately help our customers to create MEMS prototypes faster and at a lower cost than conventional methods with fine line laser ablation processes.

Lasers used for Laser Micromachining, Laser Drilling and Laser Ablation

All systems are frequency-tripled Nd:YAG diode-pumped Q-switched (pulsed) and operate at a 355nm wavelength.  The spot profile is gaussian, which means that the baseline effective laser spot size (kerf width) can vary between 15 and 25μm, depending on the energy levels and material ablation thresholds.

Larger controlled spot sizes can also be achieved in some cases.

The primary difference between the laser systems are the average work surface power levels, pulse repetition frequencies, and pulse widths, which affect the peak power of the laser.

Below is a simplified comparison of our three lasers:

ESI 5200 – The 5200 has the lowest pulse repetition frequency, low average power, mid pulse energies, and mid peak power. This laser is best suited for lower throughput applications that need reduced thermal effects.

ESI 5330 – The 5330 has a high pulse repetition frequency,  low to medium average power, lower pulse energies, and lower peak power. This is the workhorse for the our flex circuit business because it is particularly well-suited for high throughput polymer/metal ablation and drill applications and sub 25μm spot low-energy polymer applications.  The 5330 has some shaped-beam optics capability, but this is currently in the process development stage only.

ESI 5330HE – The 5330HE has low to high pulse repetition frequency, low to high average power, higher pulse energies and higher peak power.  It’s our newest acquisition and it is well-suited to the widest range of applications.