Motherboard design

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I was looking at some Gigabyte and ASUS motherboards. I was amazed at the design. The average component count must easily be 300+. How do they design these? How do they design for signal integrities at GHz frequencies?

One such board claims to have a 2oz Copper layer. What is that?
[url]
http://www.newegg.com/Product/Pr...
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139$ is a very low price, but..... think that you can buy it at a lower price, with a screen and buttons + phone. This is called 3G mobile phone.

What did you say???????

Michael.

User of:
IAR Embedded Workbench C/C++ Compiler
Altium Designer

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High volume and design for manufacturability (DFM).

You can continue to be amazed of more complex boards, ie 16 layers and 2000+ components, but those boards cost more than $150.

High frequency design require some knowledge in physics like magnetics and transmission line theory.

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Yes, but compare this with a full blown motherboard with a GP GPU, CPU and other peripherals.

My point is a $100 board which may easily have 5K components (passive+active) comes up to an average of about 20 cents a part. This is not counting the board material (i.e. layers), manufacturing and testing costs. How do board manufacturers make any kind of profit on these?

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Possibly by low wages and not taking the environment into consideration ;-)

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Somehow I have to agree. It's not the price but how much do we have to pay for it.

At least in here things are going so that manufacturing goes to countries with lower wages and here unemployment rises. Maybe soon it will be so that there are no jobs of any kind because it is not worth it to do anything.

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Where do these boards get designed? I would love to be part of the team that does that. I mean you go through the design of one of those boards and it works, and you have mastered not only electronics but physics, chemistry and mechanical engineering.

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One thing also not to forget is that the whole manufacturing of the board and all its components is highly automated too. Populating 100 parts or 800 (or layers) is only a matter of time and how fast the automation can move.

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Quote:
Where do these boards get designed? I would love to be part of the team that does that.

South Korea and Thailand are the main centers, with Vietnam up and coming and of course China in the background. There are companies like Asus that make everything themselves from chips to finished computers, and a constellation of contract manufacturers around them that will take a schematic and deliver finished boards, providing the quantity is enough. I don't think low wages can account for it, because the Asian designers I've encountered are well paid by American standards, and the manufacturing process is highly automated. I think it reflects heavy investment in plant and machinery, concentration on high volume, and emphasis on the long-term instead of keeping Wall Street happy with the next quarter's results.

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Peret, I think you meant Taiwan rather than Thailand.

2oz copper - just a thicker copper layer. The 'standard' is 1oz, which equates to 1oz per square foot or something. I believe they can either use a thicker copper layer or plate it up to the desired thickness in the fabrication. As for design, the high end pcb design tools do most of the work for you. You'll see many squiggly lines used to equalise track length etc - the high end design tools do this for you. I saw a schematic recently that specified tracks to a ddr memory device to be within 3mm of each other.

You get enormous economies of scale when you talk of making 100,000+ boards. Once that production line is fired up, the boards pop out every minute or so. High volume - low margin.

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I think computer motherboards give more bang for the buck than anything I know of. I pay around $60 for "open box" mobos (socket 775) from NewEgg. The motherboard BIOS is another story. I just installed version 90 of the BIOS for the Intel mobo I bought 4 months ago. It looks like they may have finally got it right. :)

I wonder why the CPU needs 1156 connections to the motherboard, and how they can make a socket with 1156 pins that works.

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I wonder why the CPU needs 1156 connections to the motherboard, and how they can make a socket with 1156 pins that works.
At 1.2 volts and about 70-100W power, I'd guess that 40%+ of them are for power, not data :-D

There are pointy haired bald people.
Time flies when you have a bad prescaler selected.

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I too marvel at the cost/capability - technology ratio with some hardware. Goodness, I marvel at the boards I buy from Futurlec when I spend $400 on a project:)

Just some guy

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So what are some high end PCB design tools? Could MG Pads and Layout possibly be one of them?

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peret wrote:
Quote:
emphasis on the long-term instead of keeping Wall Street happy with the next quarter's results.

Part of it's also due to the mentality kids in this country (the States) have developed. When I went to high school, there were two types of kids: the ones too lazy to learn anything. This type hung out in the parking lot and smoked and seldom took any class more difficult than metal shop, when they bothered to show up for class at all. These people went to work for the local GM assembly plant when they graduated, and complained long and bitterly when GM closed the plant to move production somewhere where the wages were lower.

The other group was too lazy to take any "hard" classes, so they went into fields like investment banking, marketing communications, and the like. In other words, fields that move numbers and words around on paper without actually creating anything.

Very few from my high school class of 1000 went into engineering, science, or related fields--probably 20 or fewer. No wonder we're slowly, but surely, losing our industries to places like Taiwan, China, and India. How long will it take before the people in these countries realize that they don't need an American middleman skimming their profits before they start selling direct to consumers? Where will that leave us then? We can't all be stock brokers and bankers (especially when all the money's moved overseas and the stock of American companies is worthless.)

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The other group was too lazy to take any "hard" classes, so they went into fields like investment banking, marketing communications, and the like. In other words, fields that move numbers and words around on paper without actually creating anything.

Wow, that is a stretch and a pious generalization that relates such a narrow perspective. I can honestly say that I feel sorry for you, truly. You are obviously moving through life without experiencing the vast wonderful diversity of people. Intelligence is measured in so many different ways and to say those that have a proclivity for the sciences are the only hard working people is just so blatantly malice that it makes me feel sad for you.

After I applied to be accepted into the Naval Aviation Cadet Training I had to pass a qualification exam that consisted of two parts. The first part tested us on math and science and the second part tested on aviation. There were six of us waiting to take the examination and we started chatting about "which" college we graduated from. All of these young men graduated from 4 year universities except me. And, when I mentioned that I was attending a local junior college there was an audible chuckle amongst them. Two of us passed the first portion of the test - myself and one other man. I smiled and waved goodbye to the applicants from the 4 year universities as they left the room. They were disqualified and not allowed to take the aviation portion of the test.

And, what did I do before I applied for Navy flight training? I was a union tradesman. I wasn't lazy, I was (like the majority of 18 year old kids) lost. Over the years great men have showed me the way and, I promise you...

You may go through your life living in this narrow view but, I implore you to open your mind, it may actually help you learn and see the value in people.

John

Just some guy

Last Edited: Sun. Sep 13, 2009 - 06:28 PM
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daqq wrote:
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I wonder why the CPU needs 1156 connections to the motherboard, and how they can make a socket with 1156 pins that works.
At 1.2 volts and about 70-100W power, I'd guess that 40%+ of them are for power, not data :-D

At a previous company we made a test chip for a mobile phone (cell phone). It had 1576 pins, and the power pins were kept to the minimum number needed to allow the IC to meet specs. As it was not too high speed the ratio was well in the favour of data. If the hardware team could have had more data pins; they would have, but we became limited by the packaging capabilities of our Fab.

I can tell you, it's not much fun drawing the OrCAD schematic symbols for a device that size. They stretch over many pages. :-(

-Tim

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Quote:
So what are some high end PCB design tools? Could MG Pads and Layout possibly be one of them?
Of the high end I know: Mentor Graphics, Cadence Allegro, Bartels BAE.

There are pointy haired bald people.
Time flies when you have a bad prescaler selected.

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My point is a $100 board which may easily have 5K components (passive+active) comes up to an average of about 20 cents a part

Two cents ;)

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Yes of course. (you can tell I am too used to the 1V = 1000 mV conversion..:)
Thanks for putting your two cents in..

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Maybe they use some professional edition of orcad,and probably design new boards from an already existing project.A job for many people for many months.

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jayjay1974 wrote:
Quote:
My point is a $100 board which may easily have 5K components (passive+active) comes up to an average of about 20 cents a part

Two cents ;)

In my previous working place I did some of the purchasing of electronic and mechanical components. The prices for most electronics is almost nothing. Almost everything is sourced from China and Taiwan (other than specialty components) and let's say that if you think 1000pcs of high quality resistors for $3 is cheap you better think again. :)