Large Sensors and true LiveView

[BJL]

Now that I think about it, there is almost no cost involved in fact. It would be fairly easy for a company like Canon to identify in advance those perfect wafers and to use these for large chips, while using non perfect wafers for smaller chips. From then on it is just a matter of process control to make sure that at least some wafers are perfect.

This is not a genius idea. Intel does the same with their CPUs.

I am tempted to suggest that the testing for defects and such is done electronically on chips after they are fabricated, not by optical examination of blank wafers in advance. But what does either of us really know about the details?

What we do know is that several companies compete in the market for large sensors (most famously Kodak and Dalsa) and so if it really were as easy as you say, and if we avoid internet cynicism about industry leading companies being more ignorant thus us internet pundits about how to reduce costs or increase quality, or conspiracy theories about Kodak and Dalsa fixing prices and in the price strangling the DMF market to their mutual detriment, then one or more of these competitors would have done what you suggest, and reduced its costs substantially (they both make lots of smaller CCDs too, so your idea fits their situation), and then reduced their prices in order to gain market share, and so on.

The actual evidence of MF sensor competitive market pricing instead indicates that with the current state of the art, the costs of MF sensor design and fabrication is such that the price to customers for even a 44x33mm sensor is well over US$1000, and prices will scale at least in proportion to area. More according to every source I have read on chip yield.

And in case anyone suggest it, large CMOS sensors are not cheaper than equally large CCDs to make; that is an internet myth, based on falsely extrapolating the cost savings for tiny "camera on a chip" cell-phone and web-cam modules. Note well that the last remaining DSLR CCD's are clustered in the cheapest models!


Short version: I do not believe any internet forum proposal about dramatically improving price/performance beyond what competitive market forces are currently producing unless it is backed by evidence of a technological break-through that it too new to have been commercialized yet.

[BernardLanguillier]

What we do know is that several companies compete in the market for large sensors (most famously Kodak and Dalsa) and so if it really were as easy as you say, and if we avoid internet cynicism about industry leading companies being more ignorant thus us internet pundits about how to reduce costs or increase quality, or conspiracy theories about Kodak and Dalsa fixing prices and in the price strangling the DMF market to their mutual detriment, then one or more of these competitors would have done what you suggest, and reduced its costs substantially (they both make lots of smaller CCDs too, so your idea fits their situation), and then reduced their prices in order to gain market share, and so on.

The actual evidence of MF sensor competitive market pricing instead indicates that with the current state of the art, the costs of MF sensor design and fabrication is such that the price to customers for even a 44x33mm sensor is well over US$1000, and prices will scale at least in proportion to area. More according to every source I have read on chip yield.

Short version: I do not believe any internet forum proposal about dramatically improving price/performance beyond what competitive market forces are currently producing unless it is backed by evidence of a technological break-through that it too new to have been commercialized yet.

BJL,

Neither Kodak nor Dalsa produce many imaging chips, even without assuming price fixing (which is most probably happening by the way), they wouldn't be able to deploy the strategy I am suggesting. In the world of consumer electronics they are tiny tiny players compared to Canon, Sony and now probably Nikon if rumors are to be believed about Nikon producing the D3100 chip themselves. Any series less than 1.000.000 parts is not significant in the grand scheme of things.

What I am saying is that producing large chips would have no significant cost for a company producing many small chips.

Cheers,
Bernard

[BJL]

Neither Kodak nor Dalsa produce many imaging chips, even without assuming price fixing (which is most probably happening by the way), they wouldn't be able to deploy the strategy I am suggesting.

Bernard,
    if you scan this product list
http://www.kodak.com:80/global/en/business/ISS/Products/index.jhtml?pq-path=11937/11938
you will see a great variety of smaller CCDs from Kodak, so as I indicated in my previous post, it seems fairly clear that Kodak does make a great many more of those small sensors than it does MF size ones. (There is a lot more to the CCD market than consumer cameras).

But perhaps I should revive my previous comment that, as far as I know, there is no evidence that your idea of testing wafers before deciding which ones to use for big sensors is used, or is usable: all the testing I know of is based on the electronic performance of semi-conductor devices once they have been fabricated. That is true in your example of processors, which are "speed rated" after testing, and Kodak sells evaluation boards for testing some of its sensors, like this one:
http://www.kodak.com:80/global/plugins/acrobat/en/business/ISS/eval/MTD-PS-0881_KAF-39000_User_Manual.pdf

Do you have any evidence that your wafer choice by visual inspection of blank wafers is done, or doable?

[BernardLanguillier]

Bernard,
    if you scan this product list
http://www.kodak.com:80/global/en/business/ISS/Products/index.jhtml?pq-path=11937/11938
you will see a great variety of smaller CCDs from Kodak, so as I indicated in my previous post, it seems fairly clear that Kodak does make a great many more of those small sensors than it does MF size ones. (There is a lot more to the CCD market than consumer cameras).

Does Kodak manufacture the sensors of their compacts, or do they use Sony parts? I was under the impression that they were using Sony parts but I could be wrong in which case my nice theory would become somewhat less credible indeed.

But perhaps I should revive my previous comment that, as far as I know, there is no evidence that your idea of testing wafers before deciding which ones to use for big sensors is used, or is usable: all the testing I know of is based on the electronic performance of semi-conductor devices once they have been fabricated. That is true in your example of processors, which are "speed rated" after testing, and Kodak sells evaluation boards for testing some of its sensors, like this one:
http://www.kodak.com:80/global/plugins/acrobat/en/business/ISS/eval/MTD-PS-0881_KAF-39000_User_Manual.pdf

Do you have any evidence that your wafer choice by visual inspection of blank wafers is done, or doable?

Nope, but I'll ask some contacts knowledgeable in the field.

If this cannot be done yet it does for sure look like a tremendous business opportinity if you are right about the current extremely high costs of perfect wafers. Jee, do I hate this forum software.

Cheers,
Bernard

[LKaven]

I've been told the Kodak chip used in the Pentax 645D costs $1000 in quantity.

[BJL]

Does Kodak manufacture the sensors of their compacts, or do they use Sony parts?

That question is irrelevant to your idea about using lesser wafers for less critical needs like smaller sensors; all that matters is that Kodak has a use for lots of those lesser wafers, which it does because it make lots of small CCD's, as indicated by its product list.

Kodak gives some details of where its sensors are used at http://www.kodak.com/global/en/business/ISS/Applications/
where the headings are, in order, "industrial, medical, photography, scientific and security"; photography only ranks third place! As I said previously, there is a wide range of markets for CCDs other than consumer cameras.

Let me know what you find out about wafer/chip inspection!

[BernardLanguillier]

That question is irrelevant to your idea about using lesser wafers for less critical needs like smaller sensors; all that matters is that Kodak has a use for lots of those lesser wafers, which it does because it make lots of small CCD's, as indicated by its product list.

Kodak gives some details of where its sensors are used at http://www.kodak.com/global/en/business/ISS/Applications/
where the headings are, in order, "industrial, medical, photography, scientific and security"; photography only ranks third place! As I said previously, there is a wide range of markets for CCDs other than consumer cameras.

There is a difference between selling a wide array of speciality products and producing many parts.

I'll let you know what I find out.

Cheers,
Bernard

[BJL]

There is a difference between selling a wide array of speciality products and producing many parts.

What matters for your "wafer pre-selection" idea is that the larger sensors are a small enough proportion of total production, which only requires that Kodak's very numerous smaller CCDs outsell it larger CCDs by a sufficiently large ratio. I do not have the numbers, but that seems a very good bet: when you look through the various applications described and sensors suggested for each, it looks as if most of the work would be handled by the smaller, far more affordable sensor models.

Look at it this way: Kodak cannot be selling more than about 5,000 sensor for MF back each year, given that the whole MF back market is only about that size, and Dalsa has a healthy share of it. It needs to be selling many hundreds of times as many of its smaller sensors for that smaller sensor business to have vaguely competitive economies of scale. (Total annual sensor sales are well over one billion!) And that means many wafers full of small sensors for every one "perfect" wafer needed for your high yield scheme.

[BernardLanguillier]

What matters for your "wafer pre-selection" idea is that the larger sensors are a small enough proportion of total production, which only requires that Kodak's very numerous smaller CCDs outsell it larger CCDs by a sufficiently large ratio. I do not have the numbers, but that seems a very good bet: when you look through the various applications described and sensors suggested for each, it looks as if most of the work would be handled by the smaller, far more affordable sensor models.

Look at it this way: Kodak cannot be selling more than about 5,000 sensor for MF back each year, given that the whole MF back market is only about that size, and Dalsa has a healthy share of it. It needs to be selling many hundreds of times as many of its smaller sensors for that smaller sensor business to have vaguely competitive economies of scale. (Total annual sensor sales are well over one billion!) And that means many wafers full of small sensors for every one "perfect" wafer needed for your high yield scheme.

Yep, that is indeed correct. Now it is probably easier to implement when you produce many sensors of the same type instead of having a large portfolio of small series items that might not always fully use full wafers. But anyway, the idea remains applicable if you move enough wafers around.

Cheers,
Bernard

[ErikKaffehr]

Bernard and JBL,

Just a few comments to the ongoing discussion..

1) Michael Reichmann had an interview with Claus Molgaard, (Phase One VP R&D) and also with Jesper Sandager, VP Manufacturing - Phase One, LLVJ 13 & 14. I got the impression that Phase One had a significant reject rate on sensors (from Kodak). Also I got the impression that many of the sensors within specs still could have dead pixel columns, which were taken care of in postprocessing. This is from memory, I have not re-viewed the videos.

2) I guess that cost is not that much dependent silicon wafer prices. The process is applied to the wafer and the chip is tested. So it's not the wafers that are rejected but the complete chip.

At that time Phase indicated that the sensor cost was about half of the cost of the back. Now, cost and value is not the same. And that was a few years ago.

Best regards
Erik