1. What is Diamond Wire Saw for Cutting Silicon Wafer?

Diamond wire saw for cutting silicon wafer is used to cut silicon ingots with diamond wire.

It is different from normal blade cutting method.

The cutting tool is made of wire.

The wire is coated with diamond grains which cuts away silicon when it moves.

So you can get a relatively small kerf width.

Also the diamond wire can cut silicon wafer with higher precision because it is very hard and brittle material.

When producing silicon wafer we need to have a uniform dimension and surface quality.

Which means that if we can cut the silicon more accurately it will benefit our next process.

Most silicon wafer factory will use diamond wire saw to cut monocrystal and poly crystal silicon.

If your machine can fit your needs you can also cut other advance material.

Such as silicon carbide, sapphire, quartz, ceramics.

Diamond wire cutting has many advantages for the silicon wafer industry.

Less kerf, higher utilization of silicon and mass production of silicon wafers.

With a multi wire saw you can produce many wafers at once.

Which makes it great for the silicon wafer industry.

2. How Diamond Wire Saw Technology Works

Diamond wire saw works by abrasive cutting.

You place the silicon ingot inside the diamond wire saw machine.

The diamond wire will be moved by a wire drive system.

It will maintain a certain amount of tension from the tension system.

The silicon ingot will then feed towards the diamond wire at a set rate.

The diamond grains will come in contact with the silicon.

And cut away a small portion of the silicon.

The cutting fluid will also remove heat and silicon debris.

Helping keep the process at a more constant temperature.

This will continue until the desired amount of wafers are cut.

2.1 Abrasive Cutting With Diamond

Diamond has one of the highest hardness known.

Allowing it to easily cut through silicon.

Instead of having one point like a tooth it has many points of diamond.

Which can cut very accurately through hard and brittle materials.

Depending on how fast your wire is moving and other factors you can obtain different results.

Wire speed, wire tension and feed rate all play a factor.

2.2 Wire Travel

Diamond wire saws can travel wire continuously or back and forth.

Some diamond wire saws will have the ability to travel the wire around a circle.

Others will only go back and forth.

Either way they can both be used to cut silicon.

2.3 Feed Rate

Feed rate will control how fast the silicon is fed towards the diamond wire.

It is important to feed the silicon at a constant rate.

Feeding too fast can cause the wire to deflect.

Where as not feeding enough can lower your production.

Having a servo feed can be very helpful.

3. Why Use Diamond Wire To Cut Silicon Wafer

Cutting silicon wafers is an expensive process.

You want to make sure that you are getting the most out of your silicon.

By using diamond wire you can cut smaller channels between each wafer.

Allowing you to gain more from your silicon.

Especially when producing large batches of wafers.

As mentioned before silicon is a hard and brittle material.

So we want to make sure that we don’t damage it while cutting.

Diamond wire saws allow us to cut the silicon with less force.

And newer diamond wire saw machines can automatically adjust the tension and feed rate.

Keeping the process running at optimal levels.

Cutting can effect the rest of your silicon wafer process as well.

If you cut your silicon with too much damage you may need to grind more off of it.

Or if your wafer isn’t a consistent thickness it could effect your polishing process.

Which is why you want to cut your silicon accurately.

4. What Does A Diamond Wire Saw Machine Consist Of?

There are many parts that go into a diamond wire saw.

4.1 Diamond Wire

As we know the diamond wire is what cuts the silicon.

You want to choose the correct diameter to fit your needs.

4.2 Drive System

This will control how fast your wire travels.

Usually with servo motors.

4.3 Guide Rollers

Will determine where your wire travels.

If you have a multi wire machine you can space out your wires.

4.4 Auto Tension

Your tension will affect how straight your wire stays while cutting.

Too much tension can cause your wire to break.

Not enough tension can cause your wire to deflect.

4.5 Feed System

Will control how fast your silicon feeds into the wire.

Can be done manually or with a servo feed.

4.6 Filter and Coolant

Coolant will help keep your process cool while removing silicon debris.

Your filter will keep your coolant clean.

4.7 PLC

You can program your diamond wire saw with PLC and use a HMI to set up different cutting programs.

5. How To Cut Silicon Wafer

Step 1: Prepare your silicon ingot.

Step 2: Place your silicon ingot on your holder of choice.

Step 3: Make sure your diamond wire is traveling correctly.

Step 4: Program your machine with the right speed and feed rate.

Step 5: Start cutting.

Step 6: Continue to cut with your cutting fluid.

Step 7: Remove your wafers.

Step 8: Process your wafers.

6. Single Wire Saw vs Multi Wire Saw

There are two types of diamond wire saws that can be used to cut silicon.

They both use diamond wire to cut the silicon.

But serve different purposes.

Single Wire Saw

A single wire saw can be used to cut silicon with one path of wire.

It can be used for specific applications and cut smaller pieces of silicon.

Multi Wire Saw

A multi wire saw will have multiple paths of wire to cut your silicon.

Allowing you to cut more wafers per cycle.

This is a huge benefit for the silicon wafer industry.

7. What To Look For When Buying A Diamond Wire Saw

Wire Diameter

The diameter of your wire will determine your kerf.

So if you want to cut with a smaller kerf you need to buy a smaller wire.

Wire Speed

You want to have your wire moving at a good speed to cut efficiently.

Wire Tension

Make sure you have your wire tension set correctly to avoid breaking your wire.

Feed Rate

How fast you feed your silicon can play a big role in how well your machine cuts.

You want to feed fast enough to be productive but slow enough to not put too much stress on your wire.

Coolant

Make sure you have enough coolant flowing through your machine to keep it cool.

Diamond Wire Saw Frame

Make sure your diamond wire saw frame is rigid.

So your wire can travel without any vibrations.

8. What is Kerf and How To Improve Your Utilization of Silicon

Kerf is the amount of silicon that is cut away when slicing your wafers.

You always want to try and cut your wafers with as little kerf as possible.

To help you get the most out of your silicon.

Diamond wire saws allow you to do this by using thinner diameters of wire.

Of course its not just the wire diameter that can affect your kerf.

Deflection of your wire and vibration in your machine can play a role.

You want to make sure your machine is cutting with as little kerf as possible.

By adjusting your wire tension, feed rate, guides and overall rigidity of the machine.

9. Wafer Thickness and TTV

When cutting silicon wafers you want to make sure your thickness is consistent.

Another term that you may hear is TTV.

Total Thickness Variation.

This is how much variation there is on your wafer.

You want to keep this as low as possible when slicing your wafers.

By having good wire guides, tension and feed rate you can improve your TTV.

Just like your machine being rigid will help with your TTV.

You will also want to keep in mind that when you slice your wafers they will have marks on them.

Which is why we grind and polish them.

10. Why Use Diamond Wire Saw Machines

There are many reasons why manufacturers use diamond wire saws to cut silicon.

10.1 Lower Kerf Loss

Smaller wire diameters can cut less material away from the silicon.

This allows higher yields of silicon.

10.2 Fast Production Rates

Using many wires at once allows for more wafers to be cut per blade pass.

Which leads to faster overall production rates.

10.3 Ability to Control Cut

Servo driven feed and tension control can move blades accurately.

Allowing manufacturers to increase their yield rates.

10.4 Can Cut Hard Materials

Since the diamonds can cut silicon. Other hard materials can be sliced as well.

Depending on the machine SiC and Sapphire can also be cut.

10.5 Programming Controls

Diamond wire saw machines are now run by PLC’s and cut recipes.

Allowing operators to replicate process steps easily.

10.6 Inline Machine Connectivity

Diamond wire saw machines can link to other silicon wafer machines.

This allows manufacturers to create inline silicon production lines.

11. Industry Uses of Diamond Wire Saw Machines

There are many industries that benefit from diamond wire saw technology.

Silicon Wafer Cutting

Silicon Wafer manufacturers use diamond wire to cut ingots into wafers.

As seen earlier this is a critical first step in producing silicon wafers.

PV (Photovoltaic)

Manufacturers need silicon wafers to produce solar cells.

Which require many wafers to be cut at high rates with high yields.

Power Electronics

Similar to silicon wafer cutting power electronics requires advanced material cutting.

R&D

Silicon R&D labs will use diamond wire machines to cut sample pieces of silicon.

By using our versatile diamond wire saw machines these applications are possible.

12. Problems With Cutting Silicon Wafers

While there are many benefits to using diamond wire machines to cut silicon there are some common problems that manufacturers encounter.

Broken Wires

Too high or low wire tension can lead to wire breaking.

Make sure your wire tension is within specified guidelines.

Bending Wires

If the feed rate is too high it can cause your wires to deflect.

Which can lead to uneven wafer thickness.

Surface Damage

Too much material being cut can lead to surface damage.

Your feed rate and wire speed will have an effect on your wafer surface.

Dirty Cutting Fluid

Since you are removing silicon from the wafer your cutting fluid will get dirty.

You will need to change or filter your cutting fluid on a periodic basis.

Vibrating Machines

Any vibration in the machine will travel to your wire.

Ensure that your machine is built to minimize vibrations and check wear points on your machine.

Wafer Thickness Variation

There are many reasons why your wafer thickness may vary.

Check all of your wire control components for any variation in tension or deflection.

13. What To Consider When Buying A Diamond Wire Saw

Now that you know more about how diamond wire saw machines work here are a few things to consider when buying one.

How big of silicon wafers do you want to cut?

What are your max ingot lengths?

How thick of wafers do you need and what are your TTV specs?

What is your desired production capacity?

If you are looking to cut at high rates of production we recommend using a multi wire machine.

Although a single wire machine may fit your needs better.

Below are some specs to consider when buying a diamond wire saw machine.

• Max Workpiece Length
• Max Workpiece Diameter
• Max Wire Diameter
• Max Wire Speed
• Wire Tension
• Feed Rate
• Cutting Accuracy
• Kerf
• TTV
• Surface Finish
• Rigidity of Machine
• Level of Automation
• Cooling System
• Filtering System
• Required Maintenance
• Support From Manufacturer
• Ability To Customize Machine

Also consider how many production lines you plan on having in the future.

This way you can plan ahead when choosing the right machine for your facility.

14. Putting Diamond Wire Saw Machines Into Your Production Line

As mentioned earlier diamond wire saws are only one piece of your silicon wafer production line.

Here is a basic list of processes involved when creating silicon wafers.

Crystal Growing > Ingots > Diamond Wire Saw > Grinding > Lapping > Polishing > Cleaning

All of these processes can affect each other when cutting silicon wafers.

For example if you create to much slicing damage when cutting your silicon wafers. You will need to grind your wafers thicker to remove this damage.

This is why it’s important to have the right process in place when cutting silicon wafers.

At Nanjing Top Wafer we offer equipment that fits each process involved in cutting silicon wafers.

Giving manufacturers an all inclusive solution when producing semiconductors.

15. Maintaining Your Diamond Wire Saw Machine

There are many things to keep in mind when maintaining your diamond wire saw.

Make sure your diamond wire is following its designated path.

Your guides could be worn which can lead to poor slicing accuracy.

Check that your tension system is running correctly.

To ensure no variance occurs in your wires while cutting.

Keep your cutting fluid clean and flowing.

Change out filters when necessary.

Check that all servo’s and components are working properly on your machine.

Always analyze your machine and its process when running your diamond wire saw.

This can help you avoid costly machine downtime.

16. Diamond Wire Saw Machines At Nanjing Top Wafer

At Nanjing Top Wafer we supply Diamond Wire Saw Machines to manufacturers throughout China.

We carry both Single Wire and Multi Wire Diamond Saw Machines for silicon and other materials.

We also offer equipment to help further process your silicon wafers.

From Grinding Machines to Polishing Machines and beyond we have many options for you to choose from.

Our Diamond Wire Saw Machines can be used to cut:

• Mono Crystalline Silicon

• Poly Crystalline Silicon

• Silicon Carbide

• Sapphire

• Quartz

• Ceramic’s

• And many other advanced crystals.

Depending on your application and material there are different diamond wire saw machines available to meet your needs.

Learn more about our Diamond Wire Saw Machines Here.

For more information on Multi Wire Saw Machines Click Here.

17. Diamond Wire Saw FAQs

l What is a diamond wire saw?

A diamond wire saw is a machine that cuts materials using a wire laced with diamonds.

l How does a diamond wire saw machine work?

Diamond wire saw machines use a set of diamond wires to slice through your material of choice. A feeding system will push the material through the slicing area.

l Why would I use a diamond wire to cut silicon wafers?

Using diamond wire to cut silicon will give you smaller kerf widths and higher accuracy. Also with the use of multi wire machines you can cut wafers at faster production rates.

l What is a multi wire diamond wire saw?

A multi wire diamond wire saw has many wires that allow for more slices to be made at once.

l What’s the difference between a single wire and multi wire diamond wire saw?

A single wire machine only has one wire that is used to make slices through your workpiece. Where as a multi wire machine has many wires that make many slices through your workpiece at the same time.

l Can diamond wire saw machines cut 12″ silicon ingots?

Yes our diamond wire saw machines are capable of cutting silicon for 12″ wafers. Just make sure the machine you purchase can accommodate that size ingot.

l What is kerf when cutting silicon wafers?

Kerf is the amount of silicon you cut away from your wafer. By reducing your kerf you will have a higher yield of usable silicon.

l What is TTV?

TTV stands for Total Thickness Variation and is used to describe how much variation there is in thickness across a wafer.

l Will diamond wire damage my silicon?

When using a diamond wire saw to cut silicon you will experience surface and sub surface damage. Which will need to be ground and polished off after cutting.

l What determines how accurate my diamond wire cutting will be?

There are many factors that play into how accurately your diamond wire saw machine will cut. Wire diameter, wire tension, feed rate, wire speed and guides are just a few that can impact your accuracy.

l How do I know what diamond wire saw machine to buy?

There are many things to consider when purchasing a diamond wire saw. Size of silicon you will be cutting, max ingot length, thickness of your wafers, TTV, kerf and desired production rate are just a few things to think about.

l Where can I buy diamond wire saw machines?

Nanjing Top Wafer Precision Equipment Co.Ltd carries Diamond Wire Saw Machines and many other pieces of equipment to help with your silicon wafer production.

18. Conclusion

There you have it everything you need to know about a diamond wire saw for cutting silicon wafers.

As we learned diamond wire saw machines are very versatile machines that allow us to cut wafers with small kerf losses.

Allowing for more silicon to be used.

Using multi wire machines can also increase your production rate.

Enabling you to cut more wafers per blade pass.

Of course you will want to pay attention to the diameter of your wire and how fast you are cutting your silicon wafers.

All of these factors will impact your ability to create high quality silicon wafers.

At Nanjing Top Wafer we offer many diamond wire saw machines to help you achieve your silicon wafer goals.

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