Powering Smart Mobility with Semiconductors | Dr. Kwok Wai Ma, Infineon | Urban Infra 2025

[Music] Well, what a fantastic beginning to the day two of the Rail Trans Expo 2025.

With this we are now headed towards technical presentations to talk about infinian technologies power solution IGBT

sic for India's future mobility. Joining

us on stage is the senior principal engineer industrial and consumer power at Infinian technologies. Please put

your hands together for Dr. walk by Mark.

[Applause] >> Thank you for the introduction and thank you for joining this section. I'm very

happy to have the financing section before a technical section because for two reason technology always need finance. Okay, no money, no technology.

finance. Okay, no money, no technology.

So therefore uh it's good that the the concept of finance is put before so that people understand why why we meet need more money to invest in the finance. And

second point is also important is technology bring back revenue the revenue that technology bring back should also be recognized in the finance

model. So therefore also counted into

model. So therefore also counted into the total cost uh calculation. So that

is a kind of opening. Okay. So today my topic is talking about uh next generation of power semiconductor

driving next generation of train. Okay.

So I'm going to explain um next generation of power seam conctor in railway. I'm coming from Infinian. So

railway. I'm coming from Infinian. So

probably you may not heard about the name Infinian which is very understandable and probably you may also not understand why we talk about

semiconductor in train. Okay.

some simple and important explanation.

Uh, Inven is the uh, one of the biggest semicond manufacturer in Europe. So, we

are based in in Germany. Our headquarter

is in Munich, but we are very global.

So, we have office um, uh, sales office, technical lab, manufacturing location all over the world and in India we have office in uh, Bangalore uh, Delhi and

Pune. So we are doing um all the

Pune. So we are doing um all the different type of semiconductors covering uh safety and security industrial power and automotive. So my

division is working on power semiconductor and actually in Finland is the biggest power semiconductor manufacturer in the world. So why we

talk about power semiconductor in this context? The reason is also very simple.

context? The reason is also very simple.

Now day in a modern society everything work with power. It start from your mobile phone with your computer and at your home with the air conditioner with your washing machine and when you go out

you drive a electric vehicle and you need electrical wheel charging and we talk about renewable energy that come from the wind turbine as we hear the

presentation yesterday and we also talk about uh uh uh power transmission. So

all these are power and to control this power that can change from meow watt to gawatt you need power semiconductor. So

that is the background for today's presentation and today most of the semiconductor is make of silicon. So

silicon is the basis for the semiconductor today including power sector.

But there is a big uh revolution in power semiconductor technology that is underway uh what we call wideband gap power semiconductor. This is completely

power semiconductor. This is completely changing the game by using very unique material which offer us very

uh surprisingly good uh behavior that allow us to make power semiconductor that can switch faster with lower loss

and higher blocking capability and that is the basis for the use of such semiconductor into railway application.

So before the powerp point I can also briefly explain. So

briefly explain. So the key benefit of power semiconductor is switching. So we switch to control

is switching. So we switch to control power. Thank you. Okay. Finally come. So

power. Thank you. Okay. Finally come. So

it's just at the right point. Okay. So

this is how power semiconductor is used in every part of the uh application. So

you see consumer application like uh um phones or computer. You see industrial applications like motor drive, electric

vehicle and then renewable energy and then you see the the always we have a trade-off between power and and frequency. So the faster you switch the

frequency. So the faster you switch the the lower power and train railway is a very high power application. So

therefore you see on the top left corner you you see the rail the railways logo here. The use of Yband gap epic device

here. The use of Yband gap epic device allow us to switch much faster nearly 10 times faster than today and that is the

motivation why we want to use silicon carbide device in railway application.

The benefit that can bring from silicon carbide device is it can switch faster with lower loss. So therefore we can use

this device to make converter which is smaller and lighter. We can also use this this benefit to drive higher power.

It all depends on the design of the train.

So this is showing the um functional block diagram in a in a train propulsion system where you have the input circuit

that take either AC power or DC power from the cinery and then you have the transformer or filter circuit and then with a rectifier. On the output side you

have the motor circuit which with inverter to drive the the PMSM motor in the boogie and in certain multi system

you may have DC or using battery to drive the train. So you may have a hybrid circuit in all this system when we using certain carbide device you can

generate the benefit of lower switching loss uh lighter and smaller converter and no one loses. So therefore this benefit will be reflected into the

train's performance and comfort.

So the use of second carbide device is already being uh understood by many of the uh traction com company and also

very operator. So the question is just

very operator. So the question is just to prove it to demonstrate. So therefore

you can already find uh many reports from from different company to test one uh trains different type of train using

s carbine. So for example uh a few years

s carbine. So for example uh a few years ago uh seammens uh have uh joined with infinion to use 3.3 kilow s carbine

module in a tram in Munich. They try one for one year and then the the operational manager conclude that it

save them about 10% electricity and also give very good p passenger experience of much quieter operation of the train and

meanwhile they're also trying zinc carbide on their hydrogen train which which is also uh demonstrating the benefit of uh high efficiency

uh lower weight and also simplify the cooling system design and also in in Sweden um Bombardia has also tried

silicon carbide in their in their mutual subway and they um quantify even the benefit of efficiency weight and and

size. I think the last example is of the

size. I think the last example is of the most important uh reason to India talk about the highspeed train project from

uh Mumbai to Ahmedaba. Uh the Singansen train is also reported their uh test results using sink carbide device. Again

the the common benefit of uh lower weight, higher power density and also uh more efficient cooling system design was uh understand.

Okay. So this um device characteristic of power sim controller is translated into tangible benefit to a railway propulsion system. For example, you see

propulsion system. For example, you see the the inverter designed using synapa device is typically 20% smaller than uh

the traditional IGBD based design. The

highest switching frequency allow either higher output power, lower power loss or uh smaller system design. And the low

loss also bring in additional benefit of user comfort because you need less cooling effort. for example smaller fan

cooling effort. for example smaller fan and also the there's less vibration in the motor and the converter. So

therefore the noise the audible noise in the train compartment will also be lower. So therefore this is of

lower. So therefore this is of particular importance for passenger train or mutual subway.

[Applause] So we can quantify this benefit because um you you see on the on the right right hand side you have the frequency axis in

the in the x-axis and the uh power on the vertical axis. So the use of second carbide device allow both higher switching frequency and higher output

power. So we we can then map this into

power. So we we can then map this into the design of a propulsion converter as a area for for improvement. So that mean

you can use this benefit provided by Saba device to improve either your system or your uh uh propulsion system

power. So how to translate it because

power. So how to translate it because different railway or different railway application or even different railway operator and customer they have

different preference or different status. So therefore all this benefit

status. So therefore all this benefit can capture the different voice or expectation of customer. So you you will often have some conservative customer

that I don't want to change my system is very good. So I can try to plug and play

very good. So I can try to plug and play the new device to see what happen. So

which is uh the number number two number two here even you don't do anything you are number two you are very conservative you

don't do you don't make any change by by changing from silicon device to sync carba device you already gain you gain

in energy you gain in power power you gain in operation cost because of the energy saving by saying carbine okay if If you are performancedriven, so for

example, if you want to de develop a locomotive that can drive even more heavy load, then you can go for higher output current, which is the number

three. Okay, you can deliver the same

three. Okay, you can deliver the same train with higher power using silicon carbide or you want to deliver the highest performance in the train by

packing more device together then you switch at higher switching frequency put them more in parallel and then you deliver the higher power and at the smaller side. So all the different

smaller side. So all the different expectation can be put into this triangle of improvement.

Okay. So, while I have been talked a lot about so sorry while I've been talking about uh a

lot on performance, one thing that is always most important in w application is reliability. So

is reliability. So sorry.

Yes. Okay. So one thing that is very important is reliability. So um I I think I if you participate the the

presentation yesterday you you listen to one of our speaker telling that the total cost of running a very system 50%

is maintenance.

So this is very very important because a train will run for 20 to 30 years along the way any uh disruption on operation will cause maintenance cost. So

therefore lifetime and reliability is critically important in railway application and reliability is not by chance. You have very strict science and

chance. You have very strict science and and technology behind to achieve high reliability. So let's start from the

reliability. So let's start from the very beginning. Start from a chip. The

very beginning. Start from a chip. The

chip on the top bottom is the basic unit of a power semiconductor that do switching. The failure way requirement

switching. The failure way requirement is extremely low. We are talking about fuel failure per billion hour billion 10

to minus 9. Okay. You may wonder why we need such a uh high reliability. Okay.

Then we do the step up.

We don't we can't make a device by just one chip. We need many chip together to

one chip. We need many chip together to make a module. So for example in the second column which is typically a IHV

module used in the locomotive or in the vital subway. In such module you have 36

vital subway. In such module you have 36 chip. So therefore the failure way will

chip. So therefore the failure way will be roughly 100 fit that mean 100 failure per billion hour which translate into

thousands of year again which is very long or regarding MTP but you need many of this module to construct traction converter. So

typically 14 to to 20. So that mean then the MTPF meanantime between failure of a traction converter is in the range of

hundreds years and for a EMU like like a highspeed train you have um 16 or eight section then you need one traction

converter for each uh EMU. So therefore

the MTPF is about 15 year. So, and for an operator like the Delhi Metro or Bangalore Metro or the National Indian

Railway where you're running hundreds or even thousands of trains, you need to this type of MTBF for 15 years of the train to have a maintenance period of

say few months or few period. So

therefore you really need a very very high reliability for the power semicont to control and minimize your maintenance cost.

So how to how to achieve reliability?

Okay. So as I say reliability is is a subject which is very difficult to demonstrate and also to develop because

it take long time. So I here I show you one example which is from my customer in Korea about 10 years ago. They they come

to me they want to understand the fuel reliability fuel health of the power device for the passenger train running

in Korea. So therefore they take out one

in Korea. So therefore they take out one of the working train take out the power semic control module send to infinion

for analysis. They want to know how

for analysis. They want to know how healthy is this module. So therefore we perform the the same analysis just like a fail module. So therefore you see in

the right hand side we cut away the module checking all the mechanical construction and we go deeper in checking the the shoulder joint contact

and we use out alter uh microscopy to check the solar joint connection which I show in the middle and the right hand side. So maybe you you can only see that

side. So maybe you you can only see that there's some small cracking which I show as a pointer that is the worst part of it. So that will receive some small

it. So that will receive some small cracking and on the uh right hand side you see the the base plate which is

perfectly okay. So if I use a general

perfectly okay. So if I use a general statement I would say the the age the age of this uh device is still a

teenager after working 10 year in field. So this

example demonstrate what a highly reliable semiconductor module should look like for railway application.

Okay. So how to achieve this? Okay. So

to achieve this high reliability you need packaging technology and especially when we are moving to the next generation of power semiconductor using silicon carbide you need a new

technology to achieve a even higher level of lifetime availability.

The packing technology that Infinian developed is called XT which is using copper. So copper is a very rare uh

copper. So copper is a very rare uh packaging technique used in semiconductor and copper can allows the highest connectivity and also the

strongest bonding. We all use cining

strongest bonding. We all use cining instead of soldering to connect the chip to the substrate because can can create

the strongest bonding between the sin carbide chip to the substrate. So with

all this technique we are able to achieve a power cycling lifetime 10 time higher than before. So according to the normal operation we can foresee that

this module can operate 40 years in field.

Another example illustrating the importance of knowledge in reliability is because sin carbide is a new technology that some of the failure mode

is different from silicon. So infin

identify such failure mode and we publish our our knowledge in scientific paper and at the same time we also publish application notes telling our

customer how to design the the power device such that you can minimize such failure and at the same time we push

this knowledge into the standardization organization to put this as a standard way to test and qualify by certain carbide devices. So therefore in the on

carbide devices. So therefore in the on the right hand side you see the latest uh uh uh standard published by JDK. By

the way JDK is the uh international standard organization for semiconductor uh reliability. So the the JDK standard

uh reliability. So the the JDK standard is using invenient uh approach to test

and qualify the the uh aging of the gate by the same testing method.

So the key message of my talk today is sync carbide device is a new and revolution technology that can switch

much faster than the silicon power device today and by that it can reduce the energy loss uh increase the the switching frequency to reduce the size

and the weight and also reduce audible noise and and the designer can take advantage of all these benefit. benefit

to fit the application and the use of doxy technology with copper metallization and centering will increase the lifetime to 40 years. Thank

you for your attention.

[Applause] Thank you for quenching our thirst and adding to our pool of knowledge. With

the same requesting Mr. Surya Sha, executive director at Urban Intra Group to kindly join us on the stage to present a small token of appreciation on our behalf.

Also requesting the entire team to kindly join us on the stage for this special moment.

[Applause] Uh, gentlemen, how about we come that was Dr. Quark Wima, senior principal engineer, industrial and

consumer baba at Infinian Technologies.

Heat. Heat.

[Music]

[Music] Heat up here.

[Music] Heat. Heat.

Heat. Heat.

Heat.

Heat.

Heat up here.

Heat.

Heat.

Heat.

Heat.

It's wonderful uh idea and very thoughtful and a great exhibition.

I really uh congratulate not only for organizing this thing.

Maybe officers.

[Music]

when we had uh installed our stock um we were getting all the supports all the manpower um all the equipments and tools that we needed. It was really pleasant

experience over here.

[Applause]