1. What is Silicon Ingot Cutting Machine?

Silicon ingot cutting machine can crop silicon or cut silicon into wafers.

It could be used before wafering or while wafering process is taking place.

It can crop, section, square or cut wafer out of silicon depending on what kind of machine it is.

With the advancement of silicon cutting there is now diamond wire cutting available.

Which allows you to cut through silicon which is very brittle. With a smaller cutting area.

As well as cut through silicon with less waste.

This can become beneficial when working with good silicon for semiconductor application.

A typical silicon ingot will consist of a big chunk of mono or poly silicon.

It will need to be prepared to make wafers.

Depending on how the wafer needs to be cut. There could be silicon cropping done before the wafering process.

Once the ingot is ready it can be sliced into many thin wafers using a multi wire saw.

There are many types of silicon ingot cutting machines that can do different things.

All with advanced features such as servo drives, wire tensioning and automatic processes.

To allow for more repeatability and increase efficiency of the process.

2. How Does Silicon Ingot Cutting Machine Work?

A silicon ingot cutting machine will use a wire that moves to cut through silicon.

An operator will first place the silicon on the cutting machine.

There will be a positioner that will line up the silicon with the path of the wire.

Wire tension is then set to the correct value.

The wire drive will then spin the wire up to speed.

The feed system will advance the silicon into the wire.

The diamond particles on the wire will grind away the silicon.

The cutting fluid will also help remove heat and silicon particles.

Keeping the area being cut more consistent.

Once the desired length has been reached the cutting will stop.

If you are cutting wafer you would have many wires to slice silicon into.

Many wafers can be made at once with a multi wire saw.

Whereas if you are cropping silicon you may only be cutting once at a time.

Depending on what your looking to achieve will depend on what type of machine you will need.

3. Why does cutting silicon ingot matter?

When cutting silicon for wafer it’s important that your cuts are correct.

Having an inaccurate cut will affect many downstream processes.

Grinding could take longer if the wafer was not cut correctly.

Or you may end up removing too much material later on in the process.

Also you want to keep the cutting width as small as possible.

Because silicon can be expensive you don’t want to waste material by making large kerfs.

You also want your silicon ingot cutting machine to be productive.

By having consistent throughput over long periods of time.

Solar cell companies cut very high amounts of wafer each day.

Having your cutting machine run efficiently is crucial to their process.

When finding a silicon ingot cutting machine you want to look at.

• Accuracy
• Low kerf
• Wire movement
• Efficiency
• Quality of silicon after cut

Each of these factors play a role into why your silicon may be cut poorly. You want to make sure you get the best out of your machine and not just the fastest cutting speed.

4. Components of the machine

4.1 Diamond Wire

As stated earlier the diamond wire is what will be cutting your silicon.

Diamond can cut through silicon due to its hard nature.

4.2 Wire Drive System

Will control the speed and movement of your diamond wire.

By having the ability to control your wire with servo motors you can vary your speed.

4.3 Guide Roller System

Guide rollers are what will determine where your diamond wire will travel.

If you have a multi wire system they will allow you to have many wires to cut through your ingot.

4.4 Automatic Wire Tensioning

You will want your wire to be at the right tension while cutting.

Too low can cause issues with cutting and too high can cause your wire to break.

Having your wire tension controlled is a plus to your silicon ingot cutting machine.

4.5 Ingot Feed System

The feed system is what will advance the silicon into the diamond wire.

Allowing for smooth feed of silicon. You can change speeds to better suit your application.

4.6 Fixture

Your fixture will hold your silicon while cutting.

You want to make sure your fixture can hold your silicon without any play.

Also being able to load and unload easily.

4.7 Cutting Fluid

You will always have heat being created when cutting. Having a way to circulate your cutting fluid will help keep your machine clean.

Having filtration on your machine is also helpful.

4.8 PLC/HMI

You want your machine to be automated and able to store recipes for your different types of silicon.

5. How to cut a silicon ingot?

It depends on what your trying to achieve with your silicon.

But here are some steps that you may take when cutting silicon.

Inspect your silicon

Measure your silicon and see what areas need to be cut off.

Mount your ingot on the silicon ingot cutting machine.

Make sure your mounted correctly so your cutting in the right direction.

Place your diamond wire in position.

Set your wire tension to desired level.

Program your wire speed feed and other cutting parameters.

Once everything is set begin your cut.

Diamond wire will cut through your silicon.

Advance your feed to cut silicon.

Control your cutting fluid to remove heat.

Once cut is finished remove silicon from your machine.

Move on to the next step in your process.

6. Diamond wire

Diamond wire can allow you to cut through silicon. Since diamond is very hard it will be able to cut through silicon.

It also can have a smaller wire diameter allowing you to lose less silicon while cutting.

Less silicon being lost while cutting is equal to less kerf.

Which means your cutting machine can be more efficient.

But if you have a thin wire you will want to make sure your tensioning and feed is working properly.

So the wire doesn’t move when your cutting.

Machine will need to be rigid as well to prevent any vibration while cutting.

7. Multi wire saw

A multi wire saw will allow you to slice silicon ingot into many pieces at once.

A long piece of wire is routed through rollers that create multiple wires.

The ingot will be fed through the wires allowing for many cuts at once.

You can slice silicon into many wafers at once.

Allowing for more production out of your machine.

As you can see above you have many wires routing through the machine.

Having many wires also allow for automation in your factory.

Just keep in mind if you change one of your wires tension. It can affect many wires when cutting silicon.

So you will want to make sure your machine can handle this type of process.

8. Single wire saw

You can also cut silicon with a single wire saw.

It will have one wire routing through it and cutting your ingot.

Can be used for cropping silicon or even research purposes.

Single wire saw can also be used on different shapes of silicon.

Can have your wire go back and forth or just one direction.

Depends on what your looking to do with your silicon ingot.

Just keep in mind if your cutting wafer you will need to have a multi wire saw to achieve high quantities of wafer.

9. Cropping squaring and wafering silicon

When buying a silicon ingot cutting machine make sure you know what your looking to do.

Crop silicon ingot

Remove unwanted parts from your crystal. Could be top and bottom of your ingot.

Square silicon ingot

Will shape your ingot to what size you need. Can be seen in many solar applications.

Section silicon ingot

May need to cut your ingot into smaller pieces.

Slice silicon wafer

Will allow you to slice wafer out of your ingot.

10. Things to Keep in Mind When Cutting Silicon

There are many variables when cutting silicon.

Wire Diameter

The diameter of the wire will determine how wide your kerf can be.

So using a thinner wire can help you get more silicon out of your ingot.

The down side to using a thinner wire is you will have to control your tension more precisely.

Wire Speed

The speed at which you are cutting the silicon will determine how the silicon reacts to your cutting wire.

You want to go as fast as possible but stay within your cut recipe.

Too fast of a wire speed can cause problems during the cutting process.

Which is why you want to know your full cut recipe when slicing silicon.

Wire Tension

How much tension your cutting wire has will dictate how your wire travels through the silicon.

If you have too much variation in tension it can cause problems with your dimension accuracy.

That is why automatic tension control is beneficial when slicing silicon.

Feed Rate

Feed rate will determine how fast you are pushing silicon through your cut zone.

If you feed to fast you can put to much pressure on your cutting process.

But you want to make sure you don’t feed so slow that you are not being productive.

Again know your recipe.

Cutting Fluid

Cutting fluid will help keep things cool and flush away any silicon dust.

Make sure your fluid is running steady and that your filter is doing it’s job.

Machine Vibration

Any vibration in your machine will translate to your cutting wire.

Having a rigid machine frame can help you get more consistent cuts.

11. What Can I Do To Decrease Kerf Loss

As mentioned before the kerf is the amount of silicon that gets cut off of your ingot by the cutting tool.

So when slicing silicon you are always losing silicon.

Especially if your silicon is used for semiconductor grade applications.

Using a thinner wire can allow you to cut a narrower width of silicon.

But there are other ways to decrease your kerf as well.

Tension can play a big role as well. You want to keep your tension at a constant level.

You also want to make sure you aren’t feeding too fast or slow.

Keep vibration at a minimum. And lastly make sure your guide rollers are keeping your wire in line.

As you can see decreasing your kerf takes more than just picking a smaller wire.

12. Wafer Thickness and TTV

When slicing silicon you want your wafers to be as uniform in thickness as possible.

Total Thickness Variation (TTV) is a good way to measure if your wafer thickness is consistent.

Many factors come into play when getting consistent thickness on your silicon.

One factor is your wire guide. Having the proper guides and maintaining them will help keep your thickness uniform.

Your tension and feed rate can play a role as well.

Also having a rigid machine frame can help decrease any vibration in your cut.

When buying a silicon ingot cutting machine you want to make sure you are getting all of these benefits.

Of course there is more processing after you slice your wafers.

Grinding and lapping and polishing can all help you get a more accurate thickness on your wafers.

13. What to Look For in a Cut Surface

After slicing your silicon you will have a surface on your wafers that was created from the cutting process.

You will still need to process your wafers after they are sliced.

But you want to minimize how much you have to grind and lap.

The deeper your saw mark is the more grinding you will have to do.

Same goes for any damage that is created from slicing.

By controlling your wire and making sure you have proper feed rates and cooling.

Along with a rigid machine you can decrease the amount of processing your wafers will need.

14. Uses for Cutting Silicon

Silicon Ingot Cutting Machines are used to slice silicon for many applications.

Semiconductor Wafer Cutting

Cutting silicon ingots for use in making semiconductors.

Once you have sliced your ingot into wafers they can be processed to make semi conductors.

Solar Wafer Cutting

Cutting silicon ingots to make solar wafers.

Again you can cut your ingots into wafers that can then be made into solar cells.

Electronic Wafer Cutting

With electronics becoming more advance we are needing better semiconductor wafers.

By slicing your ingots correctly you can produce better electronic wafers.

Research

Many people research with silicon as well. Cutting these types of crystals can also be done with single wire machines.

15. Why Use Automatic Silicon Ingot Cutting Machines?

There are many benefits to using an automatic silicon ingot cutting machine.

Motion controls that can repeat cuts over and over.

Automatic feed using servo drives to move your machine.

Auto tension to keep your wire at a constant level.

PLC to program your recipes and run the machine.

Ability to run your cutting fluid at desired levels.

All of these features will allow you to:

• Cut your silicon more precise

• Decrease kerf loss

• Increase yield of your silicon

• Maintain a stable wire tension

• Control feed rates

• Produce more efficient cuts

• Programmable recipes

• Less reliance on the operator

• Detect abnormalities in machine

Run your machine inline with rest of your production line.

16. How to Pick Your Silicon Ingot Cutting Machine

When looking for a silicon ingot cutting machine you want to know what you are going to be cutting.

Are you cropping ingots, sectioning ingots or slicing wafers?

There are machines for each application.

What is the largest diameter and length of silicon you will be cutting?

How many wafers will you need to produce?

These are just some questions to ask when choosing a machine.

• Diameter of ingot you will be cutting

• Length of ingot

• Thickness of wafer you want

• Size of wire you will be cutting with

• Speed of wire

• Tension range you will need

• Feed speed

• Precision you need when slicing

• TTV you are looking for

• Kerf you want

• Quality of surface after slicing

• Rigidity of machine frame

• Automation you want

• Fluid system

• Filtering

• PLC/Touch Screen

• Service you can expect

• Future needs

As you can see there are many things to consider when buying a silicon ingot cutting machine.

17. Slicing Your Wafer Inline

When buying your silicon ingot cutting machine you want to think about your whole process.

Here is a basic layout of how a silicon wafer is made.

Grow your crystal – Prep ingot – Crop ingot – Slice ingot – Grind – Lap – Polish – Clean – Inspect.

As you can see your ingot cutting machine will play a role in how your wafers will be made.

If you have a deep saw mark you will spend more time grinding.

If you have a inconsistent thickness you may spend more time polishing.

When choosing your silicon ingot cutting machine you want to think about your process line.

At Nanjing Top Wafer we offer machines for many stages of this process.

Allowing you to build your own process line for semiconductors.

18. Maintaining Your Cutting Process

There are many things you should do to help maintain your cutting process.

Inspect your wire guides.

They will help guide your wire through the cut and can affect how your wafer looks after slicing.

Check your tension system.

Keeping your wire at a constant tension will allow you to have consistent cuts.

Change your filter media or clean your filter.

Your cutting fluid will pick up silicon particles as you are slicing your ingots.

Check your servo’s and moving parts.

Keeping your machine well maintained will allow you to produce better wafers.

By checking these items and monitoring your process you can help keep your silicon cutting process consistent.

19. Nanjing Top Wafer

Nanjing Top Wafer Precision Equipment Co., Ltd. manufactures machines to help process your semiconductor wafers.

We offer wire saw machines to cut silicon and other materials that require precision.

We have many models of wire saws available that can suit your application.

From multi wire machines to single wire.

Not only do we manufacture machines to cut your silicon.

We can provide you with the rest of your process.

Grinding, polishing and cleaning machines as well as other machines that can be run inline with your wire saw machine.

Learn more about our wire saw machines by visiting us here.

Our wire saws can be used to cut many different materials including silicon, SIC, Sapphire, ceramics and more.

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20. FAQ

l What is a silicon ingot cutting machine?

A silicon ingot cutting machine is used to cut silicon for making your wafers. Whether you are cropping your ingot or slicing it into wafers.

l How do I cut my silicon ingot?

Most people will use diamond wire to cut their silicon ingots. Using a wire that is moving across the silicon to cut it.

l What machine can I use to slice my ingot into wafers?

Most silicon ingots are sliced using a multi wire saw.

l What is the difference between cropping and slicing my ingot?

Cropping will allow you to take pieces of your ingot or cut your ingot to length.

Slicing will allow you to cut your ingot into wafers.

l Why do people use diamond wire to cut their silicon?

Diamond wire is very hard and can easily cut through silicon. By using a thin wire you can decrease your kerf loss as well.

l What is kerf loss when cutting silicon?

Kerf loss is the amount of silicon that is removed from your ingot when slicing it. You want to keep your kerf loss as low as possible to increase your yield.

l What is TTV when slicing silicon?

TTV stands for total thickness variation. It will tell you how thick your wafers are after they are sliced.

l Can I slice mono silicon with a silicon ingot wire saw?

Yes you can slice mono silicon with a wire saw machine.

l Can I slice poly silicon with a wire saw machine?

Yes you can also slice poly silicon with a wire saw machine.

l Can I use a wire saw to cut SIC?

You can also use a diamond wire to cut SIC. You will need to adjust some of your cutting parameters though.

l What do I use after my silicon ingot cutting machine?

It depends on your process but you may need a grinding machine, lap machine, polish machine or clean machine.

l How do I choose a silicon ingot cutting machine?

You will want to know how large of an ingot you will be cutting. What you want to use it for, what size wires you will be cutting with, how many wafers you want to produce, kerf, precision, how automated you want it and what your process will be after slicing.

21. Final Thoughts

Silicon ingot cutting machines can help you produce better wafers for your application.

Whether you are cropping your ingot or slicing it into wafers.

By using diamond wire you can cut your ingot and minimize kerf loss.

If you want to slice wafers using a multi wire machine you can slice multiple wafers at once.

There are many variables that will effect how your machine slices your ingot.

Wire size, tension, feed speed, fluid, rigidity of your machine and automation.

You also want to make sure you minimize kerf loss and any damage that occurs when slicing.

By having these things in mind you will produce better wafers that will need less grinding and polishing.

Choosing the right silicon ingot cutting machine will benefit your process line.

Learn more about our products and process lines by visiting Nanjing Top Wafer today.