Dana Lee Church - Excimer Laser Channel Drilling in LDPE

22
TeoSys Engineering LLC Capabilities & Review A Development Effort For Laser Channel Drilling in LDPE For Laser Channel Drilling in LDPE Using an Excimer Laser and It’s Available Wavelengths TeoSys Engineering, LLC 2138 Priest Bridge Ct. Ste. 10 Crofton, Maryland 21114 Dana Lee Church Page 1 TeoSys Engineering LLC Confidential Dana Lee Church Tel: 410-451-8058 Fax: 410-451-8059 www.teosys.com

Transcript of Dana Lee Church - Excimer Laser Channel Drilling in LDPE

Page 1: Dana Lee Church - Excimer Laser Channel Drilling in LDPE

TeoSys Engineering LLC Capabilities & Review

A Development EffortFor Laser Channel Drilling in LDPEFor Laser Channel Drilling in LDPE

Using an Excimer Laser and It’s Available Wavelengths

TeoSys Engineering, LLC2138 Priest Bridge Ct. Ste. 10

Crofton, Maryland 21114

Dana Lee Church

Page 1TeoSys Engineering LLC Confidential Dana Lee Church

Tel: 410-451-8058Fax: 410-451-8059www.teosys.com

Page 2: Dana Lee Church - Excimer Laser Channel Drilling in LDPE

TeoSys Engineering LLC Capabilities & Review

Overview of Contents of Report

•Part #1 120µm Thick LDPE M3 Requirements & Results

•Part#1 120µm Thick LDPE Results

•Part #1 120µm Thick LDPE Implementation

•Implementation of Line Generator using Excimer Laser

•Part #2 & Part #3 480µm Thick LDPE M7 (50 Pass) & M15 (40 Pass) Requirements & Resultsµ ( ) ( ) q

•Part #2 480µm Thick LDPE Results

•Part #2 480µm Thick LDPE Isotropic Testing

•Part #2 480µm Thick LDPE Implementation•Part #2 480µm Thick LDPE Implementation

•Part #4 200µm Thick LDPE M3 Results

•Recommendations for Future Channel Drilling Applications Using Excimer Lasers

Page 2TeoSys Engineering LLC Confidential Dana Lee Church

Page 3: Dana Lee Church - Excimer Laser Channel Drilling in LDPE

TeoSys Engineering LLC Capabilities & Review

Requirements & Results for Part #1 120µm Thick LDPE M3

Part #1 120µm Thick LDPE Requirements•Drill channels through 120µm thick LDPE.

Part #1 120µm Thick LDPE Results•4CM by 4CM part was drilled using 193nm g µ

• Channel thickness should be as small as possible with goal of less than 20µms.

•Part is 4CM by 4CM requiring 280 channels in the horizontal and 280 channels in the vertical

wavelength in 12 hours

• Horizontal and vertical appeared all right but there were some discontinuities with respect to the quality of the part when viewed from the top

and 280 channels in the vertical.

• TeoSys requirement is that drilling time be less than 10 hours for this part. We achieved a 12 hour runtime for the first part delivered.

•It was determined after much development effort that the material is non-isotropic which leads to nonlinearities when drilling in certain directions

• We did not align for the non-isotropic nature of theWe did not align for the non isotropic nature of the material so the resulting top view shows the non-linearity of the resulting squares.

•The nonlinearity was corrected in subsequent parts.

Part #1 Implementation•4CM by 4CM part was drilled using 193nm wavelength in 12 hours

Page 3TeoSys Engineering LLC Confidential Dana Lee Church

wavelength in 12 hours

Page 4: Dana Lee Church - Excimer Laser Channel Drilling in LDPE

TeoSys Engineering LLC Capabilities & Review

Requirements for Part #1 120µm Thick LDPE Part #1 Results•Channels were drilled for the 120µm thick part using 193nm wavelength.

•The vertical channel width is approximately 16µms but the horizontal channel width is much larger at 29µms. We found this to be true in all of our experimentation.

•This turned out to be a prime example of the non-isotropic nature of the material with respect to channel drilling. We did not know the reason for this ow e e so o sbehavior at the time we drilled this part.

• We did not align for the non-isotropic nature of the

Page 4TeoSys Engineering LLC Confidential Dana Lee Church

pmaterial so the resulting top view shows the non-linearity of the resulting squares.

Page 5: Dana Lee Church - Excimer Laser Channel Drilling in LDPE

TeoSys Engineering LLC Capabilities & Review

Channel Drilling Through 120µm Thick Part #1 M3

Because we had already proven that 193nm wavelength could drill channels through the

D th t d imaterial, the difficulty with this new purchase order was to find a way to economically drill the channels through varying thicknesses of the LDPE material.

We did successfully reconfigure our general excimer l i hi h i f

•Depth study using 193nm through 120µms of LDPE

system several times to achieve the requirements of the purchase order, however we learned a lot about the material and its interaction with not only 193nm but also 248nm.

W d t i d th t t i l ith thi kWe determined that materials with thicknesses below 200µms could be drilled using 193nm wavelength but anything thicker than that would require a reconfiguration of the excimer laser to operate at 248nm. 193nm just did not have the

•Actual 120µm part being drilled using 193nm

p jenergy in order to drill the channels through the thicker materials in a reasonable amount of time.

We also determined that the material itself is non-isotropic requiring channel drilling to occur along

Page 5TeoSys Engineering LLC Confidential Dana Lee Church

certain directions in order for the vertical and horizontal channels to be equal in width and depth.

Page 6: Dana Lee Church - Excimer Laser Channel Drilling in LDPE

TeoSys Engineering LLC Capabilities & Review

Channel Drilling – Home Made Line Generator Aperture Configuration

To solve the problem of drilling the channels economically, we decided to create a line generator as opposed to drilling with a round spot.

The line generator uses an external aperture at the output of the laser to block any beam that is not part of the vertical line being generated.

The final width of the line aperture was 750µms wide by 2MM tall.

Page 6TeoSys Engineering LLC Confidential Dana Lee Church

Page 7: Dana Lee Church - Excimer Laser Channel Drilling in LDPE

TeoSys Engineering LLC Capabilities & Review

Channel Drilling – Line Generator

The line generator that we used created a line image at the work surface that was approximately 10 microns

Our final calibration at 193nm had a depth of focus of 300 microns which makes this an extremely favorable methodology for production processing.

D lt Z t th h i f fi i l h twide by 350 microns long.

The line allows us to remove more material than a single round spot with the equivalent diameter of 10 microns.

Delta Z represents the change in focus as we fire a single shot on the work surface. For all of our calibration and setup, we used a glass slide.

Page 7TeoSys Engineering LLC Confidential Dana Lee Church

Page 8: Dana Lee Church - Excimer Laser Channel Drilling in LDPE

TeoSys Engineering LLC Capabilities & Review

Channel Drilling Through 120µm Thick Part #1 M3 - Implementation

We had to determine our actual drilling recipe speeds, frequencies and number of passes using the material in

d t hi th t t d th f 120 i t tlorder to achieve the target depth of 120µms consistently.

Page 8TeoSys Engineering LLC Confidential Dana Lee Church

Page 9: Dana Lee Church - Excimer Laser Channel Drilling in LDPE

TeoSys Engineering LLC Capabilities & Review

Channel Drilling Through 120µm Thick Part #1 M3 - ResultsThe final run time for the 4CM x 4CM piece of M3 material which is 120µms thick LDPE was 12 hours.

After the development that occurred following the production of this sample, the run time can be reduced significantly b i 248 l thby using a 248nm wavelength.

However, 248nm is a more thermal process and care must be taken to ensure that the material does not melt instead of ablate.

The final recipe was the following:

•Single pass solution

•550uJ +/- 30uJ as measured post line generator aperture.

•0.5 MM/sec moving speed

•300 Hertz laser repetition rate

•Fluence of approx. 17 J/cm^2

•12 Hour run time

Page 9TeoSys Engineering LLC Confidential Dana Lee Church

Page 10: Dana Lee Church - Excimer Laser Channel Drilling in LDPE

TeoSys Engineering LLC Capabilities & Review

Requirements & Results for Part #2 480µm Thick LDPE M7

Part #2 480µm Thick LDPE Requirements

Part #2 & #3 (480µm Thick LDPE Results)•3CM by 3CM part was drilled using 248nm wavelength in 7.5

•Drill channels through 480µm thick LDPE as measured by our microscopes and as indicated by Joe. The PO was for a 480µm part and the material that was sent

y p g ghours significantly reducing the run time for all of the channel drilling

• It became extremely apparent, as will be shown, that the wavelength of 193nm would not achieve our run time requirements

to us was 480µms although in subsequent e-mails with the customer, the thickest material is indicated at 400µms.

• Channel thickness should be as small as ibl i h l f l h

g qof less than 12 hours. After optimization of the recipe for 193nm, our run time calculation was 45 hours of continuous drilling.

•We converted our excimer to 248nm wavelength and re-optimized to get a final run time of 7.5 hours for the 50 pass Part #2 and even

possible with goal of less than 20µms.

•Part is 3CM by 3CM, 210 lines each direction. The requirement was 210 lines in each direction but because our line

less for the 40 pass Part #3.

generator loses energy at the ends, we actually ran for 230 lines in each direction in order to provide the actual 3CM x 3CM.

Page 10TeoSys Engineering LLC Confidential Dana Lee Church

• TeoSys requirement is that drilling time be less than 12 hours for this part.

Page 11: Dana Lee Church - Excimer Laser Channel Drilling in LDPE

TeoSys Engineering LLC Capabilities & Review

Requirements & Results for Part #2 480µm Thick LDPE M7

Part #2 & #3 (480µm Thick LDPE Results) –Con’t•Most of the orthogonality testing for the non-isotropic nature of the material was performed at the 248nm wavelength. The result of this effort was that the material had to be rotated 45° in order for the lines in both the horizontal and the vertical to drill at the same dimensions given the same laser recipe.

• All of the subsequent parts were drilled at an angle of 45° in order to achieve the same dimensions in both horizontal & vertical.

•Part #2 M7 was the first part drilled at an angle and was drilled slightly off when rotated to drill the opposite direction group of lines. In order to make up for this slight offset, we drilled another part which was drilled with the lines exactly orthogonal to each other.

•We consider this effort to have extremely successful as given a much larger format excimer, we can reduce the

i ki h l i f

Page 11TeoSys Engineering LLC Confidential Dana Lee Church

run times even more making the laser processing of material areas of 10CM x 10CM realistic.

Page 12: Dana Lee Church - Excimer Laser Channel Drilling in LDPE

TeoSys Engineering LLC Capabilities & Review

Part #2 480µm Thick Material - ImplementationPart #2 Implementation•The depth and speed study for the 480µm thick part indicated quickly that the deepest we could get using 193nm and a single pass solution such as the first part was 330µms.

•This solution would not meet TeoSys requirements of a drill time of less than 12 hours.

•Convert to 248nm.

Page 12TeoSys Engineering LLC Confidential Dana Lee Church

Page 13: Dana Lee Church - Excimer Laser Channel Drilling in LDPE

TeoSys Engineering LLC Capabilities & Review

Part #2 480µm Thick Material - Implementation

Part #2 Implementation•After the 248nm conversion the same alignment and speeds and g pfeeds studies had to be performed in order to get an idea of what was possible using this wavelength.

•248nm is a more thermal process and it became apparent that the issue with directionality was worsened when we changed y gwavelengths. We had to solve the problem before we could optimize our recipe.

•Because of the more thermal process, melting is always an issue. We had to drill fast.

•We determined through testing that the material could only be drilled in one direction. The material is unidirectional at 248nm.

Page 13TeoSys Engineering LLC Confidential Dana Lee Church

Page 14: Dana Lee Church - Excimer Laser Channel Drilling in LDPE

TeoSys Engineering LLC Capabilities & Review

Part #2 480µm Thick Material - Implementation

Part #2 Implementation•A cross test was drilled to see the performance of bothA cross test was drilled to see the performance of both vertical and horizontal lines.

•The exact same program which means the exact same recipe was run in both directions.

Th l diff O di i h d hi•The results were different. One direction had thinner channels and the other direction had thicker channels.

•This material would not be able to be drilled as expected (and as delivered) but would have to be rotated. We then h d t d t i h h t ti d b tlhad to determine how much rotation and subsequently, was the rotation the same for all material thicknesses…?

•The results were that the material must be rotated 45° in order for both sets of lines to exhibit the same behavior. However both sets are degraded in performance comparedHowever, both sets are degraded in performance compared to the best line generation seen on the material.

•This means that there is a best angle and direction in which to drill channels on this material but in order to create a criss crossing pattern that angle and direction must be let go

Page 14TeoSys Engineering LLC Confidential Dana Lee Church

criss-crossing pattern, that angle and direction must be let go in favor of one that allows the best overall performance.

Page 15: Dana Lee Church - Excimer Laser Channel Drilling in LDPE

TeoSys Engineering LLC Capabilities & Review

Part #2 480µm Thick Material – Isotropic Testing• Continuous cross tests were performed on the material to determine at what angle both horizontal and vertical properties began to be the samebegan to be the same.

• A 45° angle from the way the material is fabricated is the best angle

Page 15TeoSys Engineering LLC Confidential Dana Lee Church

Page 16: Dana Lee Church - Excimer Laser Channel Drilling in LDPE

TeoSys Engineering LLC Capabilities & Review

Part #2 480µm Thick Material – Implementation• After the 45° angle was determined, we were back to recipe generation.

Page 16TeoSys Engineering LLC Confidential Dana Lee Church

Page 17: Dana Lee Church - Excimer Laser Channel Drilling in LDPE

TeoSys Engineering LLC Capabilities & Review

Part #2 480µm Thick Material – Implementation•Determine number of passes.

Page 17TeoSys Engineering LLC Confidential Dana Lee Church

Page 18: Dana Lee Church - Excimer Laser Channel Drilling in LDPE

TeoSys Engineering LLC Capabilities & Review

Part #2 480µm Thick Material – Implementation•This recipe exceeded our expectations in drill vs. quality for this project.Th fi l i th f ll iThe final recipe was the following:

• 40-50 pass solution

• 1.7mJ as measured post line generator aperture.

30MM/S i d• 30MM/Sec moving speed

• 400 Hertz laser repetition rate

• Fluence of approx. 53 J/cm^2 / Power of 0.680 Watts

•7 5 Hour run time•7.5 Hour run time

Page 18TeoSys Engineering LLC Confidential Dana Lee Church

Page 19: Dana Lee Church - Excimer Laser Channel Drilling in LDPE

TeoSys Engineering LLC Capabilities & Review

Requirements & Results for Part #4 200µm Thick LDPE M3Part #4 200µm Thick LDPE Requirements•There was no requirement for TeoSys to drill this part

Part #4 (200µm Thick LDPE Results)•3CM by 3CM part was drilled using 248nm

but we thought it would be good to get a thinner example of 248nm channel drilling for testing

• Channel thickness should be as small as possible with goal of less than 20µms.

3CM by 3CM part was drilled using 248nm wavelength in 4.5 hours significantly reducing the run time for all of the channel drilling

• All of the lessons learned were applied to this part and it came out beautifully.

•Part is 3CM by 3CM, 210 lines each direction. The requirement was 210 lines in each direction but because our line generator loses energy at the ends, we actually ran for 230 lines in each direction in order to provide

and it came out beautifully.

• All of the laser recipe is the same as Parts #2 & #3 except for the number of passes which creates the depth.

the actual 3CM x 3CM.

Page 19TeoSys Engineering LLC Confidential Dana Lee Church

Page 20: Dana Lee Church - Excimer Laser Channel Drilling in LDPE

TeoSys Engineering LLC Capabilities & Review

Part #4 200µm Thick Material - Implementation

Part #4 Implementation•ISO tests & depth optimization tests were all that was p pneeded to be done for this part.

Page 20TeoSys Engineering LLC Confidential Dana Lee Church

Page 21: Dana Lee Church - Excimer Laser Channel Drilling in LDPE

TeoSys Engineering LLC Capabilities & Review

Part Fixturing•Part fixturing was a developmental project of its own. A description is outlined in the pictures.

Page 21TeoSys Engineering LLC Confidential Dana Lee Church

Page 22: Dana Lee Church - Excimer Laser Channel Drilling in LDPE

TeoSys Engineering LLC Capabilities & Review Recommendations

1. Obviously speed of drilling is the key factor in the implementation of channel drilling through this material. The thicker the material, the longer it will take to drill no matter what final solution or wavelength is chosen.

2. Investigation should be performed into why the material drills better at a 45° angle from its manufactured sides because there is still some degradation in the quality of the channel drilling based on this rotation factor We chosebecause there is still some degradation in the quality of the channel drilling based on this rotation factor. We chose a happy medium but there is a better solution out there.

3. 248nm is the optimal wavelength for the speed of channel drilling. We would recommend this wavelength even for the thinner materials. However, when using this wavelength, very, very fast and accurate stages must be used in order to provide for the rapid motion in an opposite direction which is a problem for all motion systems.order to provide for the rapid motion in an opposite direction which is a problem for all motion systems.

4. The speed at which this application can be performed can be increased dramatically with a custom designed system. There is more than enough laser power at 248nm in order to provide a split beam or some other creative solution.

Click on picture for picture for movie of drilling operation.

And as always, TeoSys is here to id ll l iprovide all custom system solutions

whether they be with our own excimer or we integrate a large format excimer. We can almost

Page 22TeoSys Engineering LLC Confidential Dana Lee Church

guarantee a reduction in processing times by a factor of 2-4 times.