Automated Dip Coating Deposition Matthew Adamson, Curtis Eldredge, Shane Shoemaker and Adam Terry

Dr. Mike Scarpulla (Advisor)

Analysis

Project Overview

Horizontal/ Vertical Positional Accuracy

-  Translations were programmed and executed individually.

-  Actual length of translation was measured via digital readout and compared against programmed value.

-  Resulting errors were fit to a normal distribution to asses system accuracy.

-  Reported accuracy = mean +/- 6(STD).

Deflection Due to Dynamic Loading

-  Vertical deflection due to accelerating deposition substrates must be quantified to ensure error < spec in the vertical orientation.

-  In order to size horizontal structural members, deflection was modeled under worst case scenario: beams loaded at geometric center, with 8 lb. load on dipper, withdrawing at 10 in/s. That deflection value was added to error observed in vertical motion testing.

Error Accumulation

Open Loop vs. Closed Loop Control: -  Testing was performed to determine if error(s) from

a single translation would accumulate and result in error > spec after many translations.

-  Random, consecutive displacements were executed in increasing quantities until error > spec was observed.

-  After 200 consecutive random displacements, error = .0014“ (vertical), and error = .0018” (horizontal).

-  The need to incorporate sensor feedback was dismissed based on the testing results.

Introduction What is dip coating deposition? Dip coating deposition is a subset of thin film deposition. The goal is to apply 1 or more successive layers of coating(s) to a substrate in order to enhance or alter desired properties. Current Process: Currently on campus, R&D thin film deposition products are being produced by outsourcing or manually running bath sequences in a lab through dipping of substrates by hand. Problems: Current methods cause problems such as increased cost, decreased product accuracy and repeatability, as well as create exposure hazards. Need: A small scale, adaptable, automated film deposition machine is needed. It must accept a minimum of four deposition baths, allow researchers to input recipes using LabVIEW, run the program, and require no further interaction until the process is complete.

Conclusion - Design team was able to provide a dip coating

deposition system that met all of Dr. Scarpulla’s design requirements. All performance specifications were met and often exceeded. Furthermore, the design team was able to produce a system that incorporates all of the demanded components standard to Dr. Scarpulla’s lab. The total built cost was approximately $1400.00

Recommendations

-  Incorporate limit switches at the extremes of all

axis of motion in order to protect system from stalling due to error in control.

-  Further refinement of the batch initiation procedure is recommended in order to expedite total batch process.

1st  Quartile -­‐0.001075Median 0.0001003rd  Quartile 0.001000Maximum 0.003500

-­‐0.000342 0.000525

-­‐0.000221 0.000514

0.001422 0.002047

A-­‐Squared 0.35P-­‐Value 0.459

Mean 0.000092StDev 0.001678Variance 0.000003Skewness 0.015727Kurtosis -­‐0.490014N 60

Minimum -­‐0.003300

Anderson-­‐Darling  Normality  Test

95%  Confidence  Interval  for  Mean

95%  Confidence  Interval  for  Median

95%  Confidence  Interval  for  StDev

0.00320.00160.0000-­‐0.0016-­‐0.0032

Median

Mean

0.00060.00040.00020.0000-­‐0.0002-­‐0.0004

95%  Confidence  Intervals

Summary  Report  for  Vertical  Motion

1st  Quartile -­‐0.004373Median -­‐0.0001833rd  Quartile 0.002778Maximum 0.010122

-­‐0.001240 0.000949

-­‐0.001099 0.001206

0.003800 0.005374

A-­‐Squared 0.53P-­‐Value 0.166

Mean -­‐0.000145StDev 0.004452Variance 0.000020Skewness 0.310474Kurtosis -­‐0.489299N 66

Minimum -­‐0.007556

Anderson-­‐Darling  Normality  Test

95%  Confidence  Interval  for  Mean

95%  Confidence  Interval  for  Median

95%  Confidence  Interval  for  StDev

0.0080.0040.000-­‐0.004-­‐0.008

Median

Mean

0.00100.00050.0000-­‐0.0005-­‐0.0010-­‐0.0015

95%  Confidence  Intervals

Summary  Report  for  Horizontal  Motion

Customer Need Metric Units Marginal Value Ideal Value Delivered Value

Highly Adaptable System

Range of Motion (vertical) in 6 12 12

Range of Velocity (vertical) in/s .1-5 .1-10 0-10

Range of Motion (horizontal) in >12 >20 23 (x), 13.5 (y)

Range of Velocity (horizontal) in/s 0-3 .5-10 0-5

Payload Capacity lb. 0-1 0-5 0-8 (@ max 𝑉  ) Substrate Capacity # 0-4 0-10 23

Will Fit in Fume Hood N/A Yes N/A Yes

Accurate and Repeatable Accuracy (vertical) in +/- 0.03937 +/- 0.01969 +/- 0.01007

Accuracy (horizontal) in +/- 0.25 0.125 +/- 0.02686

Uses Lab Standard Equipment

JameCO Reliapro Stepper N/A

Yes

N/A

Yes User Interface and Programming w/ LabVIEW

JR KERR PIC-STEP Controllers

Vertical Motion

Components

Controls and Programming

Horizontal Motion Components

Substrate Retention

Motor:

Brand: JameCO Reliapro Type: Unipolar Stepper Step Angle: 1.8 Ambient Temperature: -25 - +400C Voltage: 6.3V Current: 1.5A Resistance: 4.2 ohms Holding Torque: 140 N.cm Rotor Inertia: 440 g.cm2

Belt and Pinion System:

Vendor: Open Builds Type : GT3 Material:

Pinion: Aluminum Belt: Fiberglass reinforced

neoprene

Motor:

Brand: JameCO Reliapro Type: Unipolar Stepper Step Angle: 1.8 Ambient Temperature: -25 - +400C Voltage: 6.3V Current: 1.5A Resistance: 4.2 ohms Holding Torque: 140 N.cm Rotor Inertia: 440 g.cm2

Rack and Pinion System: Vendor: SDP-SI.com Type: Fine Pitch Pressure Angle: 20° Pitch: 24

Components Signal Converter:

Brand: JR Kerr SSA-485 Part Number: KAE-SSA485-BDV2 Type: Serial to RS-485

Motor Controllers:

Brand: JR Kerr PIC-STEP Part Number: KAE-T3V1-BDV1 Motor Type: 2-Phase Stepper (4, 6 or 8 wire) Driver Ratings: 2A per phase, 7.5-46 VDC

Programming Developer: National Instruments Program: LabVIEW Logic Diagram

Customer Needs

The design of the substrate retention system was based around the ability to grasp and transport a standard 1” x 3” microscope slide. After many gripping methods were considered, it was determined that a system which employed a friction fit would offer the best combination of ease of use while ensuring that the deposed substrates were held secure throughout the deposition process. To determine the appropriate level of interference, many dimensions were tested by rapid prototyping components and checking the functionality of each. The final product was 3-D printed using high strength ABS with the dimensions as shown below.