P14311: PCB Isolation Routing SystemFinal Presentation

Team Members:Matthew Clark, Marley Collier Sears, Sarah Duman,

Richard Kalb, Joseph Post, Zoe Rabinowitz, Kevin Richard

Guide:Vincent Burolla

Agenda1. Project Goals and Objective2. Engineering Requirements3. Testing and Analysis4. Current System State5. Suggestions for Improvement6. Project Lessons Learned

Problem Statement and ObjectivesProblem: Develop an in-house prototyping system to create wiring patterns

and component holes on printed circuit boards (PCBs).

Objectives:• Handle boards up to 5” x 5”• Reliably and accurately drill and mill patterns with ± .001”

tolerance• Easy and safe for operator use

Customer and Sponsors

Center for ElectronicsManufacturing and Assembly

Jeff Lonneville, Lab TechnicianDr. Ramkumar, Director Scott Systems

Rob Scott, Owner

Current System State

Engineering RequirementsSpecification (Metric) Unit of Measure Marginal Value Ideal

ValuePhysical Footprint ft^3 40 8Weight of Machine lbs 600 300

Eliminate potential for injuries Binary Pass PassNoise Generation dBA <100 <75

Minimum Width Between Traces Supported inches 0.020 0.016

Manufacturing Cost $ 2800 2000

Minimum Tolerance to locating positions on board inches 0.005 0.001

Feed Rate in/minute 10 100

Required Voltage for Operation Volts 5 ± .5, 12 ± 1.2, 24±2.4 5, 12, 24

Router Speed rpm 15000 30000Debris Removal (Copper and Substrate) mg 11.7 1.7

TIR (Total Indicated Run out) inches <0.0006 <0.0004Vacuum Table Force lbs force 10 20

Successful Test ResultsSpecification (Metric) Unit of

Measure Marginal Value IdealValue Concluded Condition

Physical Footprint ft^3 40 8 Marginal PassWeight of Machine lbs 600 300 Pass

Eliminate potential for injuries Binary Pass Pass Pass

Noise Generation dBA <100 <75 Marginal Pass

Minimum Width Between Traces Supported inches 0.020 0.016 Marginal Pass

Minimum Tolerance to locating positions on board inches 0.005 0.001 Marginal Pass

Feed Rate in/minute 10 100 Marginal Pass

Router Speed rpm 15000 30000 Marginal Pass

TIR (Total Indicated Run out) inches <0.0006 <0.0004 Marginal Pass

Vacuum Table Force lbs force 10 20 Marginal Pass

Successful ResultsTIR Test

Maximum TIR (in)Router 1 0.005Router 2 0.001Router 3 0.0005

PCB 1

PCB 3

PCB 5

788286

Sound Levels per sample PCB

dBA Reading 1dBA Reading 2dBA Reading 3Average

PCB Sample #

dBA

Width Between Traces Test Set 1 Set 2 Set 3

Width at location 1 (in) 0.01 0.011 0.016

Width at location 2 (in) 0.016 0.017 0.023

Width at location 3 (in) 0.019 0.022 0.027

Average Width (in) 0.015 0.01667 0.022Marginal Width (in) 0.020 0.020 0.020

Difference (in) -0.005 -0.003 0.002Average Width (in.) 0.017888889

Vacuum Table Test Average Value Total Force on table (78 holes * force per hole)

Force per hole (lbf) 0.2 15.6

Failures and Undetermined Results

Specification (Metric) Unit of Measure Marginal Value Ideal

Value Concluded Condition

Manufacturing Cost $ 2800 2000 Fail ($3450)

Required Voltage for Operation Volts 5 ± .5, 12 ± 1.2, 24±2.4 5, 12, 24 Marginal Pass for 5V, 24V;

Fail for 12V

Debris Removal (Copper and Substrate) mg 11.7 1.7 ?

Capabilities:Can we do what we set out to do?

Elektor PCBA 110538-1:Radiation Monitor

Suggestions for Improvement Implement automatic functions(no operator involvement)

◦ Homing functions in all three axes◦ Spindle Variable Speed Control

Mach3 Upgrades◦ Create macros in Mach3 to improve system flow◦ Buy full version

Optimize tool path to minimize machining timeMachine a level vacuum table sacrificial layer from non-

porous, non-flexible material

Improvements (continued)

Increased Debris Management◦ We’ll have a better idea of what to improve following remaining testing

Disabled Signal debugging- software or connector issueComputer shut off issueLimit Switches

◦ Recovering from a limit pause- implement hand crank◦ Improve board design

Project Lessons Learned: Technical Items“It’s always more complicated than it seems…”

◦ The design became complex very quicklyRead documentation for purchased parts before

implementingThrough-hole components require solder on

bottom- can’t solder through plastic!Safety is important!

Project Lessons Learned:Project ManagementPlanned expectations vs. Actual results

◦ Scheduling◦ Budget◦ Designs◦ Test Results

Development of Operating Procedures◦ Time-consuming, but necessary and helpful