DELAWARE DIAMOND KNIVES

PHASE 4 REPORT

December 10, 2010

By Jeff LeBlanc, Nnamdi Ibeka, David Kim, and Matthew Lindemer

Table of Contents Updated Project Scope ................................................................................................................................. 3

New Project Information .............................................................................................................................. 3

Prototype Fabrication ................................................................................................................................... 6

Subsystem A: Shaft Collar ......................................................................................................................... 6

Subsystem B: Lead Screws ........................................................................................................................ 6

Subsystem C: Guide Rails .......................................................................................................................... 7

Subsystem D: Digital Indicator and Laser Mount ...................................................................................... 7

Subsystem E: Leg Supports ....................................................................................................................... 8

Testing Results & Analysis ............................................................................................................................. 8

Broad Measurement Range (Area) ........................................................................................................... 8

Broad Measurement Range (Thickness) ................................................................................................. 10

Measurement Accuracy .......................................................................................................................... 12

Assembly Time ........................................................................................................................................ 13

Mobility ................................................................................................................................................... 15

Finite Element Analysis ............................................................................................................................ 16

Future Process Design Changes .................................................................................................................. 20

Chemical Mechanical Grinding ................................................................................................................... 20

Path Forward ............................................................................................................................................... 21

Appendix A: Cost Analysis ........................................................................................................................... 22

Appendix B: Design Specification ................................................................................................................ 23

Appendix C: Gantt Chart ............................................................................................................................. 24

Appendix D: Design Package ....................................................................................................................... 24

Updated Project Scope The purpose of this project is to design and manufacture a measuring device that is sensitive enough to precisely measure the thickness of diamond slabs manufactured by Delaware Diamond Knives within an accuracy of 1 micron. The current measurement tools used by Delaware Diamond Knives require the diamond specimens to be removed from their apparatuses which consequently results in measurement inaccuracy due to bow, glue-line thickness, and taper. To combat this issue the new measuring device will be designed to measure the diamond wafers while they remain in their respective positions on the grinding apparatus.

New Project Information Since the end of Phase 3, there have been design changes to the grinding arm. The assembled grinding

head has been changed from a stationary head to a head that swivels in place. This design has added

some difficulty and variables into our Final Concept Design. Since the head of the grinding arm now has

the ability to swivel, our Final Concept Design had to attach to the shaft of the head, because the

surrounding parts have become moving parts. Also there were new clearance heights around the shaft

and the overall dimensions have changed slightly.

Updated Design Changes

Figure 1: New Rail System Design

90° Joining Plate

After our Phase 3 presentation with our sponsor, we found a design flaw in our rail system. The

Phase 3 Design Package had assembled our rails using pin connections (connection locations

circled in Figure 1). These pin connections would cause our rail system to become a

parallelogram over time, because the pin would allow for two degrees of freedom. Our new

design uses 90° Joining Plates, which we modeled from any common bridge or truss connection

that sustains loading over time. This new connection will provide a more rigid structure and

perform better over time than pins would have.

Figure 2: Additional Design to Acme Screw

Another design change that was made since Phase 3 is the addition of knobs [Figure 2] to the end of our

Acme Screws. It is difficult to turn the Acme Screws by hand in the prototype, because of the small

diameter rod, the grease added to provide extra lubrication to the flange, and the fine thread. The

knobs have a knurled radius that provide extra grip when working with the prototype. Another reason

why the knobs were knurled is because the employee’s at DDK are constantly working with machinery

and mechanical devices, so they often have grease on their hands. The knob’s will improve our ease of

use metric and provide better ability to make fine adjustments.

Figure 3: Battery Pack Assembly

One of our original metrics from Phase 2 was to use a battery operated laser. However, the

manufacturer did not specify if the Voltage to our Laser Level was DC or AC, so we waited till we

received the laser before we made our battery pack. The battery back includes 3AA battery in series,

which are wired to an operating switch, which allows the operator to turn the laser on and off [Figure 3].

This battery pack improves the mobility metric and the ease of use metric. It improves the mobility

metric, because the prototype is no longer limited to operational use near an electrical power source.

Also, the ease of use metric is improved, because a switch operated laser will be easier to operate than

plugging and unplugging the laser for operational use.

Knurled Knob

During our sponsor discussion after Phase 3, we re-examined any ways to simplify the fabrication

process of the reference plane. In inspection of the copper face plates [Figure 4] we found that they

were purposely notched to prevent the face plate from rotating in place. The design change we decided

to make was to use this notched piece of the copper faceplate and extended our reference plane from

this point [Figure 5]. In Phase 3, our design package included a drawing to lathe down the head of the

Grinding Arm then insert a plane that would extended in the radial direction beyond the copper

faceplate. The new reference plane required less machining, taking advantage of an existing feature,

and a smaller amount of material added to the Grinding Head. The smaller amount of material will

reduce the risk of changing the performance of the Grinding Head and also improve the metric of ease

of use. The shaft collar will be assembled easier with the new reference plane, because it does not

restrict some on the clearance problems that occurred with the Phase 3 design.

In Phase 3, our design to mount the Digital Indicator to the L-Bracket was done by using the provided

hole pattern that was on the back of the Indicator. This design did not allow for any fine adjustments

Figure 5: Notched Copper Face Plate Figure 4: New Reference Plane

Figure 7: New Digital Indicator Mount Figure 6: Rack and Pinion Provides Track Movement

Pinion

Rack Set Screw

Reference Plane

because in order to bring the Indicator closer or further away from the diamond film, all the lead screws

would have to be adjusted. The new design uses a Rack and Pinion Gear System [Figure 6], where the

black knob turns the pinion and translates the motion of the rack, the Indicator, along the distance of

the rack. This mounting plate also has set screws, seen in [Figure 7] which provides a locking mechanism

to ensure that the Indicator does not freely move.

Prototype Fabrication The main components, including guide rails, acme screws, ball joints, flanges, leveling feet, digital

indicator, and laser, were purchased. Our design team fabricated the remaining parts. The design was

modified in order to simplify machining. All of fabrication and assembly was performed in the Delaware

Diamond Knives’ machine shop. Aluminum sheets were the main fabrication material. The total cost of

aluminum stock was $105.33.

Subsystem A: Shaft Collar The Shaft Collar components were milled by a CNC

Router, including the hole pattern seen in [Figure 8]. The

center arcs in the collar were milled to a radius of 1.35

inches. The three larger holes were milled by the router

to a diameter of 0.5 inches, which is the clearance hole

size for the flange nuts of the acme screws. The hole

pattern around the three holes match the flange hole

pattern for the acme screws. These holes were tapped

using ¼-20 taper tap then the bottom piece was tapped

using 5-40 taps and then deburred.

Subsystem B: Lead Screws Most of parts of this subsystem were purchased, but

some modification was required. The acme screw was

cut using a hack saw to acquire the needed length. Also,

since the ball joint thread angle is different from the

thread angle of the acme screw, the ball joint threads

were bored out with a lathe machine and the acme

screws were connected to them using an epoxy.

[Figure 9].

Figure 8: Shaft Collar

Figure9: Lead Screw

Subsystem C: Guide Rails Three kinds of brackets used in this assembly, two of

the bracket connecting carts and the crossing guide

rail, four joining plates, and three brackets connecting

the guide rails and ball joints. Two alignment rods were

machined on the milling machine for the supporting

frame of the rail system. The lip was also fabricated to

attach to one of alignment rod. The main caution on

this subsystem was keeping the side guide rails parallel

to each other. In order to keep the side guide rail

parallel, a slip hole feature was machined on the

alignment rods so that the rails could be adjusted on the

assembly to make them parallel. After attaching the 90⁰

joining plates with the alignment rods, guide rails were placed on to the opposite side of the joining

plates as seen in [Figure 10] using the holes on the guide rails as a clearance hole, punched on the

joining plates and tapped using #5-40 taper tap. The cart bracket was tapped with M3 size tap to attach

on the carts following the dimensions provided by THK, the guide rail manufacturer. Finally, to mount

the crossing guide rail on top of it, the holes were tapped using #5-40 taps.

Subsystem D: Digital Indicator and Laser Mount

The L-bracket was fabricated to mount digital indicator and laser on opposite sides of each other as seen

in [Figure 11]. This bracket was also machined on the milling machine with .125 inch thick aluminum

sheet. The battery casing was also modified on the milling machine to allow for the appropriate cavities

for both the wires and switch, which increased the overall mobility of the prototype instead of using a

power cord. [Figure 12]

Figure 10: Guide Rail System

Figure 11: L-bracket with Micrometer and Laser Figure 12: Battery Pack

Subsystem E: Leg Supports Bases of the legs and blocks, which sit on at the end of the rods, were

fabricated on the milling machine with aluminum stock, which came

from the sponsor’s general inventory. The angle at one of corner was

cut at 45⁰ to meet the shaft alignment rod lip at its flat surface. The

length of all four threaded rods were modified using a hack saw, as

shown in [Figure 13].

Figure 13: Leg Supports

Testing Results & Analysis

Broad Measurement Range (Area) Purpose of This Test: The purpose of this test is to prove our measurement area metric. The metric

states that the prototype must have the ability to measure a circular area with the diameter of 50mm or

2 inches.

Method: Center the Digital Indicator in the center of the Linear Guide Rail System. Then move the

Digital Indicator to the furthest position in the X and Y direction. The Laser Leveling System was not

attached beneath the Indicator for this test, but the height and size of the laser was taken into account

when taking measurement. All measurements were taken using high accuracy calipers. The

measurement was completed by measuring from the outer most radius of the shaft collar to the tip on

the Digital Indicator. Since we know that the radius of the Shaft Collar was fabricated with a radius of

1.35inches. So the radius of the Shaft Collar was subtracted from each measurement, which would

ensure that we would be taking our measurement from the center of the collar.

Figure 14.1: Centering the Digital Indicator within the Rail System

Figure 14.2: Indicator to the bottom Y position Figure 4.3: Indicator to the right X position

Figure14.5: Indicator to the top Y position Figure 14.4: Indicator to the left X position

Test Results:

Data Analysis:

Every data point measured must be beyond the radius of 25mm or 1 inch, which shows that the

Indicator can measure on a diameter of 50 mm or 2 inches. The top Y position, right X position, left X

position show that the Indicator satisfies the 50mm requirement and has enough freedom of movement

to go farther than the diamond and reach the reference plane. However, the bottom Y position can only

reach a radius of 1.05 inches or 27mm, this satisfies the 25mm radius requirement, but does not allow

the Indicator to reach the reference plane in the lower Y region of the measuring area.

In conclusion, the prototype satisfies the measurement area requirement. In addition to the

measurement area requirement, the data taken shows that the reference plane can only be found in the

upper Y region of the measuring area because the laser mount below the Indicator allows for less

clearance at the bottom position than the top position.

Broad Measurement Range (Thickness) Purpose of Test: The purpose of this test is to prove the metric for thickness measurement range of the

prototype. The metric states that the prototype must measure a range of 5µm to 2mm.

Method: The way this tested was using known thickness values of materials then testing them by first

leveling the Indicator. Then providing a measuring surface, aluminum plate, and zeroing the Indicator in

this position. Then measuring two materials with known thickness and analyze the results.

1.35” Radius (Shaft Collar)

2.35” (Right X Position)

2.45” (Top Y Position)

2.55” (Left X Position)

1.05” (Bottom Y Position)

X

Y

Test Results:

The first item used for testing was a sheet of paper with a known thickness of 50µm or 0.050mm, this

paper was then replaced with a paper of known thickness of 49µm or 0.049mm. This shows that the

prototype is able to measure a thickness change of 1µm. Our next item that we measured was a gold

diamond film backed by a silicon wafer with the thickness of 3.944mm or 3944µm. This item matches

our metric requirement because the film thickness of this silicon wafer is 1.944mm thick and the silicon

wafer backing it has a thickness of 2mm. So this wafer represents the maximum testing range for the

prototype.

Figure 15.1: Zeroing Indicator on Aluminum Figure 5.2: Measuring Thin Piece of Paper

Figure 16: Gold Colored Diamond Film Figure 17: Measuring Diamond Film

Data Analysis:

This test shows that the prototype satisfies the thickness range requirement of 5µm to 2mm diamond

film. This accuracy can be due to the high tolerance Digital Indicator and also the fine tip that was

special ordered from Mahr. This special tip has a diameter of .040 inches or 40 thousands of an inch.

However, this small tip also showed how sensitive the Indicator was to small amounts of movement. The

combination of the high accuracy Indicator and needle point tip show that operational use of the

Indicator will have to be very precise because of the sensitivity.

Measurement Accuracy Purpose of Test: The purpose of this test is to prove the metric accuracy of the prototype. The metric

states that the prototype must have an accuracy of 1µm.

Method:

The measurement accuracy and repeatability were tested by taking a displacement measurement from

the set reference plane to the top surface of the diamond film wafer each time the prototype was

attached to the grinding arm, a total of 12 times. Before taking the measurements specific steps were

taken to ensure the measurement readings would be as accurate as possible. Using the three lead

screws and the alignment laser, the plane of the prototype was finely adjusted until a parallel was

achieved between the plane of prototype and the face of the diamond film. Observing when the center

point of the cross-hair laser beam shined directly back into its orifice served as an indicator for when

parallel planes were achieved. The results from the measurements are shown in [Table 1]

Figure 18: Measuring Data Point Figure 6: Reference Plane with Diamond Film

Test Results:

Trial # Wafer Displacement (mm)

1 1.895

2 1.892

3 1.894

4 1.896

5 1.888

6 1.895

7 1.899

8 1.889

9 1.901

10 1.891

11 1.903

12 1.893

MEAN 1.895

MODE 1.895

ST. DEV 0.005

Data Analysis:

Based on the data obtained from the measurement trials the measurement prototype was accurate

within +/- 5 microns. According to the metric set in the project scope of +/- 1 micron for measurement

accuracy, the accuracy of the measurement prototype missed the set metric by 4 microns. Due to this

shortcoming an analysis of sources of error were done. After some timely observation the project team

identified a few sources of error that could generate such a small discrepancy. Imperfections in part

fabrication could be a viable source of error and also vigorous vibrations generated from surrounding

machinery also would cause a variance in the accuracy of the prototype. It is also possible that the

parallel positioning set during the measurement processes are not always 100% perfect and in that case

the accuracy of the device would be offset. Vibrations were considered to be the most underlining cause

of in accuracy. Based on these observations the accuracy achieved was deemed acceptable given that it

still improves upon the current accuracy of DDK’s measuring process.

Assembly Time Purpose of Test: The purpose of this test is to test the prototypes assembly time metric. This metric has

been adjusted since Phase 2, because of new information gathered about the current process. Currently

it takes 15 minutes to remove the wafer, dissolve the adhesive backing, then measure and reapply the

Table 1: Displacement Data

wafer to the grinding arm. The target metric is to have the prototype assemble for 12 minutes to

outperform the current solution

Method: The processing time was tested by measuring time durations during two stages of the diamond

film measuring process. The stages observed during the test were the time it takes to attach the

measurement device to the grinding arm and the time it takes to disassemble and remove the device

from the grinding arm. The test was done in a total 12 trials, each member of the project team

completed three trials each. Several people completed multiple time trials in order to generate realistic

variances in assembly times, being that many employees at DDK will use the prototype and the assembly

and disassembly time will vary from person to person. The data in [Table 2] depicts the recorded times

for each of the 12 trials.

Test Results:

Trial # Mount Time (sec) Dismount Time (sec)

1 234 227

2 295 231

3 236 242

4 241 213

5 266 216

6 238 221

7 257 239

8 255 235

9 225 219

10 261 246

11 224 212

12 227 235

Average Time 246.5833333 228

Approx. 4 minutes 7 seconds Approx. 3 minutes 48 seconds

Figure 20: Assembly the Prototype Figure 7: Prototype Fully Assembled

Table2: Assembly Data

Data Analysis:

Based upon the information obtained from DDK machinist, Bill Tabeling, the original preparation time

needed to get the diamond wafer to be measured was approximately 15 minutes. This process included

removing the wafer from the grinding apparatus, soaking it in a solution to soften and dissolve the

adhesive, and cleaning the adhesive from the surface completely. Based on the time it originally took to

prepare the wafer for measurement, an acceptable goal for set up and breakdown time for assembly

time was set at simply achieving a time shorter than the original time it took to prepare the wafer for

measurement. As shown in the data table the average set-up and breakdown time for the measurement

prototype was approximately 8 minutes, which nearly cuts the time in half from the original preparation

time. Based on the given data the assembly time for the prototype is considered acceptable.

Mobility Purpose of Test: The purpose of this test is to analyze the mobility metric of the prototype. The metric

states that the prototype must weigh less than 5lbs.

Method: This test was conducted by weighing the subsystems of the prototype on a packaging scale

provided by the sponsor. After all the subsystems have been weighed, the combined weight will be

added together.

Test Results: The weight of the prototype in full assembly was measured to be 4.5 pounds.

Data Analysis: The components that comprise what is considered to be the full assembly are as follows:

shaft collar, acme screws (with nuts and flanges), guide rail assembly with carts, digital indictor with an

adjustable mount, alignment laser, a series of brackets used throughout out the assembly, as well as a

variety of screws used to assemble the prototype. The leg supports were not include in the weighing

process during the mobility testing due to the fact they are handled separately when installing the main

measurement device to the grinding arm. As shown by the previously stated results, the weight of the

prototype is within the set weight constraints and therefore meets the mobility requirements.

Figure 22: Weighing Indicator Figure 8: Weighting Guide Rails with Acme Screws

Finite Element Analysis Purpose of Test: The purpose of this test is to analyze the durability and the amount of deflection that

occurs when the acme screws are loaded differently in potential situations

Method: Using SolidWorks and SimulationXpress, a model of the Acme Screw, with the material

property of Stainless Steel, was loaded in compression and in a bending moment.

Bending Moment on Acme Screw

Figure 24: SolidWorks Model of Acme Screw, ¼ inch Diameter, 5 inches Long

Figure 25: Fixing Bottom of Screw to Create Screw in Shaft Collar

Load (lbf) Maximum Deflection (mm)

1.00 8.88E-05

1.50 1.33E-04

2.00 1.78E-04

2.50 2.22E-04

3.00 2.66E-04

3.50 3.11E-04

4.00 3.55E-04

4.50 3.99E-04

5.00 4.44E-04

5.50 4.88E-04

6.00 5.33E-04

6.50 5.77E-04

7.00 6.21E-04

7.50 6.66E-04

8.00 7.10E-04

8.50 7.54E-04

9.00 7.99E-04

9.50 8.43E-04

10.00 8.88E-04

0.00E+00

1.00E-04

2.00E-04

3.00E-04

4.00E-04

5.00E-04

6.00E-04

7.00E-04

8.00E-04

9.00E-04

1.00E-03

0.00 2.00 4.00 6.00 8.00 10.00 12.00

De

fle

ctio

n (

mm

)

Load (lbf)

Acme Screws in Compression Loading

Data Analysis: This testing shows that the screw can be loaded in compression up to 10 lbf, which would

be over the realistic loading limit, and still show no significant deflection. The maximum deflections

occur in the top of the screw, 8.88x10^-4 mm, where the acme screw would be loaded in compression

by the ball joint on the rail system.

Figure 26: Compression Force on top of Screw Simulating Loading from Rails

Figure 27: Compression Loading Results from SimulationXpress

Chart 1: Acme Screw in Compression Table3 Load vs. Max Deflection

0.00E+00

5.00E-01

1.00E+00

1.50E+00

2.00E+00

2.50E+00

0.00 2.00 4.00 6.00 8.00 10.00 12.00

De

fle

ctio

n (

mm

)

Bending Moment (lbf)

Bending Moment on Acme Screw

Data Analysis: The deflection in the screw is the largest at the

location of the bending moment. The maximum deflection that was

seen is 2.12 mm. This is more than expected, but the prototype

should never experience a bending moment of 10 lbf. This also

shows that the rod is still in the elastic region and has some

flexibility. This flexibility will help keep the screw from translating

more force into the shaft collar. It is a concern if the acme screw is

too flexible because it possibly become permanently deformed.

Load (lbf)

Maximum Deflection (mm)

1.00 2.12E-01

1.50 3.18E-01

2.00 4.24E-01

2.50 5.24E-01

3.00 6.35E-01

3.50 7.41E-01

4.00 8.47E-01

4.50 9.53E-01

5.00 1.06E+00

5.50 1.17E+00

6.00 1.27E+00

6.50 1.38E+00

7.00 1.48E+00

7.50 1.59E+00

8.00 1.69E+00

8.50 1.80E+00

9.00 1.91E+00

9.50 2.01E+00

10.00 2.12E+00

Figure 28: Force Location to Create Bending Moment Figure 29: Resulting Bending Moment of 1 lbf

Table 4: Load vs. Deflection Chart 2: Bending Moment on Acme Screw

0.00E+00

5.00E-04

1.00E-03

1.50E-03

2.00E-03

2.50E-03

3.00E-03

0.00 2.00 4.00 6.00 8.00 10.00 12.00

Max

imu

m D

efl

ect

ion

(m

m)

Load (lbf)

Bending Moment on Shaft Collar

Bending Moment on Shaft Collar

Table 5: Load vs. Deflection

Load (lbf) Maximum Deflection (mm)

1.00 2.78E-04

1.50 4.17E-04

2.00 5.56E-04

2.50 6.95E-04

3.00 8.33E-04

3.50 9.72E-04

4.00 1.11E-03

4.50 1.25E-03

5.00 1.39E-03

5.50 1.53E-03

6.00 1.67E-03

6.50 1.81E-03

7.00 1.95E-03

7.50 2.08E-03

8.00 2.22E-03

8.50 2.36E-03

9.00 2.50E-03

9.50 2.65E-03

10.00 2.78E-03

Figure 30: Resultant Deformation Diagram Figure 31: Fixed Shaft Collar Center with Bending Moment

Chart 3: Bending Moment on Shaft Collar

Data Analysis: This data shows the possible deformation of the Shaft Collar design. The reason why we

would want to reduce the deformation in the Shaft Collar is because it could possible move the hole

locations. The largest amount of deflection is 2.78E-03 mm, which is not a significant amount of

deflection. Therefore, we are convinced under the loading conditions of the prototype there will be no

significant deformation causing the prototype to lose any performance metrics.

Further Design Development After analyzing the overall design of the measurement prototype there are a few changes that could be

made in the future to improve the quality, versatility, and ease of use of the device. In the future DDK

will look to upgrade the mounting collar’s latching mechanism from screws to toggle clamps. This

change will make it easier to fasten the collar to the grinding shaft and will therefore cut down the time

it takes to mount and dismount the device to and from the grinding arm substantially. Further feasible

design developments also include implementing set screws in the shaft collar which would be used to

adjust the diameter of the collar. Such development would make it possible for the measurement device

to be adaptable to new grinding mechanisms that DDK will design and fabricate in the future as well as

other grinding stations that were not included in the scope of this project. Using set screws would

undoubtedly increase the overall adaptability of the prototype.

Future Process Design Changes Though fabricating a device that allows one to measure the thickness of diamond wafers while they

remain on the grinding arm improves the accuracy and efficiency of the grinding process, it is imperative

to recognize that the accuracy in measurement also depends greatly on the efficiency of the grinding

process itself. With the implication of that notion, it has been determined that there are more efficient

ways to grind CVD diamond films in opposition to the process chosen by Delaware Diamond Knives, such

as, Chemical-Mechanical Planarization.

Chemical Mechanical Grinding Chemical Mechanical Planarization (CMP) defined as a process of

smoothing surfaces by means of both chemical and mechanical forces.

This method of surface grinding/finishing can be used to remove

topography from silicon oxide, metals, and polysilicon surfaces. The

mechanical process currently used by DDK has a much higher surface

damage rate when compared to CMP. The process of grinding by

method of CMP uses abrasive and corrosive chemical slurry, most likely

a colloid, combined with a polishing pad and a retaining ring as shown

in [Figure 32]. Also notable, CMP is capable of grinding surface down to

Angstrom levels.

Figure 32: CMP Diagram: http://en.wikipedia.org/wiki/Chemical-mechanical_planarization

By implementing this grinding process in place of their current fully mechanical grinding process DDK

would greatly improve the quality of the diamond films they polish. The faces of the diamond films

would definitely be more even and the rate at which films are cracked and damaged during the actual

grinding process would decrease greatly. Being that reducing the risk of damage to the diamond film

was an essential aspect of the project scope, it would be feasible to propose that DDK look into

optimizing their grinding process in the future.

Path Forward In order to move our design into a fully working item for all grinding devices a few steps to need be

taken. The final design is completed, but to fully implement our design to all of DDK’s grinding machines

new shaft collars and alignment rods would need to be fabricated to fit grinding machines of different

configurations. The manufacturing process is similar to the one used previous. The only differences are

the center arc radius of the shaft collar and the distance between the holes that the acme screws come

out of. The additional design development as noted previously also includes, toggle clamps and

implementing set screws into shaft collar. Finally, the measurement process requires training workers to

calculate exact thicknesses from the measured displacement as well as the mounting and dismounting

process.

QTY Part Brand Order/ Item #

Price Quote

(each)

1 Micrometer Mahr XLI - 20002 $454.75

1 Mounting Bracket Mahr AT - 116

1 Tip Mahr PT - 2265

4 Linear Guide Rail (Cross Section) THK RSR12ZM $86.00

1 Material Stock McMaster-Carr 9246K13 $19.00

1 Material Stock McMaster-Carr 8973K43 $51.14

3 Threaded Rod (Acme) Roton Industries 60760 $18.63

6 Lead Screw Nut Roton Industries 91734 $22.10

6 Lead Screw Flange Roton Industries 89837 $27.07

3 Ball Joint Mid-West Control FMIL250C $3.19

1 Laser Level Cole-Parmer EW-42935-22 $289

1 Laser Battery Sears UPG 5.00v Lithium-Ion Battery$16.99

2 Leveling Foot 80/20 Inc 2194

1 Rod Ends McMaster-Carr 95475A576 $6.74

1 Material Stock McMaster-Carr 9135K261 $31.51

1 Inch Standard Screws McMaster-Carr 91251A080 $3.82

1 Inch Standard Screws McMaster-Carr 91251A126 $8.25 

1 Inch Standard Screws McMaster-Carr 90128A245 $11.12

1 Metric Standard Screws McMaster-Carr 91290A113 $4.32

1 Inch Standard Screws McMaster-Carr 91251A125 $8.44

TOTAL: $1,601.31

Appendix A: Cost Analysis

After looking at the materials and parts costs it is determined that a budget of $2000 would be sufficient

to complete the prototype. The table below is the complete list of all of parts that were purchased. The

two most cost intensive of part were Micrometer and Laser Level. Other purchased products were

comparatively small. Some aluminum materials, acme screw handle, and battery pack were provided by

Sponsor DDK. The final design cost was about $1,600 which is significantly less than the initial target

value of $9,000. Delaware Diamond Knives costs $3,000-$10,000 to grow diamond film on the wafer and

have 5% chance of breaking the diamond film while taking on and off from the grinding arm. The use of

our design will save at least $1,400 on first month and save same amount money as loss by breaking the

diamond film from next month. Over a year, the benefit will be $31,400 at least and $184,000 at most.

Purchased Parts:

Table6: Purchase Sheet

Future Cost

The prototype which was built is only for one type of the grinding machine. The shaft collar and guide

rail system including the alignment rod and the corner bracket will be machined for another grinding

machine. Also, changes of the laser will increase accuracy of the leveling the system.

Part Price

Material Stock $200

Laser $300

Total $500

Appendix B: Design Specification

Final Design Details How the Design Works

The mathematical theory behind the design is very simple. Our idea for the design was to use a Digital Indicator to measure the “change in thickness” of the diamond films. Our sponsor gave us a list of assumptions to base our design around. These assumptions include:

1. While the Diamond Film is grown onto the Silicon Wafer during the Chemical Vapor Deposition process in the High Pressure Microwave Plasma Reactor, the Silicon Wafer will not have any thickness etched away and will remain at 1/8” thickness.

2. The current Micrometer at DDK’s facility has the ability to map the thickness profile of the Diamond Film after the Diamond is grown onto the Silicon and before the Silicon and Diamond Wafer is placed onto the Grinding Arm. Thus the sponsors current solution with give us an initial thickness profile for the Diamond.

3. The Diamond Film backed with the Silicon Wafer is placed onto the Grinding Arm using a light adhesive. This adhesive is a paste material that is applied by hand, and does not have a uniform thickness profile. Also the lightweight strength of this adhesive cause the diamond to spin in place while it is being grinded because the wheel with physically spin the Diamond and the adhesive does not stop the diamond from rotating.

The first things to be done to begin is put the shaft collar over the shaft, and secure the bottom of the collar using ¼-20 screws to pull the collar tight to the shaft. Then level a diamond film measurement is to ensure that the frame of our design and the Digital Indicator is square with the Diamond Film. To do this we will use our laser leveling system, which is backed by the Digital Indicator to ensure we are parallel with the Indicator. Then we will use the three lead screws to make fine adjustments in the angle of the frame. The theory behind this leveling system is that you need three points to create a plane; therefore we need three adjustments to ensure that the digital indicator is on a square plane with the diamond.

The purpose of the Digital Indicator is to use the New Surface (which will be added using the lathe), as a reference point that will be permanent. If we directly attach a surface to the shaft of the Grinding Head, we know that it will be an unchanging reference point and square to the diamond.

Table6: Estimated Future Cost

The Digital Indicator will measure the distance to the New Surface, and Zero that position. This will be done every time before a measurement is taken. The Digital Indicator will map the height of the diamond film, using the same mapping technique the sponsor uses, and this will be a measurement of the initial height.

So after the initial height around the diamond is mapped. The structure will be reattached, leveled, and zeroed. Then the Diamond Film with be mapped again, and the change in height around the Diamond Film will be the resulting thickness change in the Film. Since the initial thickness of the Film is known, we can calculate what the current thickness of the diamond.

Appendix C: Gantt Chart The project schedule will be uploaded onto Sakai

File Name: “Updated Gantt Chart Phase 4_Appendix C”

Appendix D: Design Package

Bill of Materials

Table 7: Bill of Materials

DWG NO. PART NAME PART NUMBER DESCRIPTION QTY.

1 Lead Screw 60760 ¼”-20 Diameter 3

2 Lead Nut 91734 Bronze Nut 3

3 Ball Joint FMIL250C ¼” - 20 3

4 Flange 89837 3

5 Cart 1 RSR12ZM 3

6 Rail 220mm RSR12ZM 1

7 Alignment Rod 1

8 Alignment Rod with Lip 1

9 Rail 160mm RSR12ZM 2

10 Cart Bracket 2

11 Bracket for Block 2

12 Shaft Collar 1 1

13 Shaft Collar 2 1

14 Leveling feet 2515T15 2

15 Leg to Collar Shaft 2

16 Leg to Guide Rail 2

17 Base of the Leg 2

18 L-Bracket 1

19 Laser LTM2HKD 1

20 Standard Screw 90128A242 ¼”-20 1/2" length 1

21 Standard Screw 91251A173 #5- 40 1 - 1/4" length

1

22 Bracket to Cart 92196A459 ,

92196A459 #1 – 64 1/4" Length

1

23 Standard Screw, 91251A096

91251A096 #3-48 1/2" Length

1

24 Set Screw 91375A124 91375A124 #5-401/4" Length

1

25 Micrometer XLI-20002 Digital-1” Stroke

1

Part List

Figure 1: Fully Assembled Prototype with Numbers Referencing Bill of Materials in previous page

Full Assembly Drawing

Figure 2: Assembly Drawing with instructions

Sub Assembly Drawings

Sub Assembly Drawing #1: Lead Screw

Figure 3: Sub Assembly Drawing #1: Lead Screw

Sub Assembly Drawing #2: Guide Rail System

Figure 4: Sub Assembly Drawing #2 for Guide Rail System

Sub Assembly Drawing #3: Collar Shaft

Sub Assembly Drawings #4: Support Legs

Part Drawings

Parts in Sub Assembly #1

Parts in Sub Assembly #2

Parts in Sub Assembly #3

Parts in Sub Assembly #4

Remaining Parts