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Interesting, the cost breakdown to make an iPhone:
http://tinyurl.com/28v49e8
Somewhere else (I lost it now) they mention assembly costs are around $9.50.
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On 14/10/2010 12:02 PM, scott wrote:
> Interesting, the cost breakdown to make an iPhone:
Interesting indeed.
I note that with all the sophisticated technology in this device, the
single most expensive component is... the display?! (And that's not even
including the touch feature, just the actual display itself.) Closely
followed by... the flash RAM?? Everything else is peanuts compared to
these two items.
I'm quite surprised at how cheap some of the items are. You would have
thought the processor would be expensive... but no. (The RAM is more
expensive than the CPU?!) You would have thought the 5 megapixel camera
would be expensive... but no. You would have thought the custom battery
would be expensive... but yet again, no.
I'm also surprised at just how cheap the casing is; you would have
thought making something that can survive being sat on, dropped on the
pavement, rained on or flushed down a toilet would be very expensive.
But apparently not.
(Strictly, they list the cost of the materials, not the cost of actually
assembling them.)
I also note with some amusement that it has a 960x640 pixel screen.
That's slightly higher than the Amiga 1200 "Super-Hires Interlaced"
video mode, at 960x480 visible pixels. (Well what did you expect with <
2MB of video RAM?) And today you can do that for £30? (I'm presuming
that includes the backlight...)
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> I note that with all the sophisticated technology in this device, the
> single most expensive component is... the display?!
It's a nice display though :-)
> I'm also surprised at just how cheap the casing is; you would have thought
> making something that can survive being sat on, dropped on the pavement,
> rained on or flushed down a toilet would be very expensive. But apparently
> not.
Those parts are typically quite cheap to produce in high volume, once you
have the tooling done it's just injecting cheap plastic into a mould or
cutting and folding sheets of cheap metal.
> (Strictly, they list the cost of the materials, not the cost of actually
> assembling them.)
The list is the amount you pay to buy those components (which includes the
sub-assembly needed for those individual components), on top of that price
there is about another $10 to assemble that lot together into an iPhone.
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>> I note that with all the sophisticated technology in this device, the
>> single most expensive component is... the display?!
>
> It's a nice display though :-)
I saw an iPhone in real life for the very first time on Saturday. It is
actually a nice display. If you can see through all the fingerprints. ;-)
>> I'm also surprised at just how cheap the casing is; you would have
>> thought making something that can survive being sat on, dropped on the
>> pavement, rained on or flushed down a toilet would be very expensive.
>> But apparently not.
>
> Those parts are typically quite cheap to produce in high volume, once
> you have the tooling done it's just injecting cheap plastic into a mould
> or cutting and folding sheets of cheap metal.
If metal and plastic are "cheap", then why does everything get made out
of the most skimpy amounts of material the manufacturers can get away
with so that it's only just barely strong enough to not break?
>> (Strictly, they list the cost of the materials, not the cost of
>> actually assembling them.)
>
> The list is the amount you pay to buy those components (which includes
> the sub-assembly needed for those individual components), on top of that
> price there is about another $10 to assemble that lot together into an
> iPhone.
Now, see, I would have thought just surface-mounting the 2,157
individual resistors would cost more than $10... But what do I know
about anything?
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> If metal and plastic are "cheap", then why does everything get made out of
> the most skimpy amounts of material the manufacturers can get away with so
> that it's only just barely strong enough to not break?
Why waste money making it stronger and thicker than it reasonably needs to
be? Even just 5 or 10 cents extra spent on each iPhone would equal quite a
big amount of money overall.
> Now, see, I would have thought just surface-mounting the 2,157 individual
> resistors would cost more than $10... But what do I know about anything?
I suspect the cost of mounting the resistors can be worked out by the
depreciation of the SMD mounting machines over the lifetime of the product,
plus the cost of running the machine. It's surely not very much though,
given that you can buy loads of consumer devices with populated PCBs inside
them for well under $10.
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>> If metal and plastic are "cheap", then why does everything get made
>> out of the most skimpy amounts of material the manufacturers can get
>> away with so that it's only just barely strong enough to not break?
>
> Why waste money making it stronger and thicker than it reasonably needs
> to be? Even just 5 or 10 cents extra spent on each iPhone would equal
> quite a big amount of money overall.
Making something stronger than it needs to be would indeed be a waste of
money. But it seems that these days, everything is made *weaker* than it
actually should be.
Then again, maybe that's because I'm still thinking like a consumer.
When I buy something, I want it to *not* brake. The manufacturer, on the
other hand, has a vested interest in making it so flimsy that it won't
last 5 minutes. That way they get more repeat business. (In addition to
the materials savings, obviously.)
Personally it makes me angry that somebody would deliberately design
something to be defective so that they can make more money out of me.
But I guess we can put that down to market forces. There will always be
people who make expensive high-quality goods, and other people who make
cheap low-quality goods. What kinds of product you find in the shops
depends on what people buy the most of. And today's mentality seems to
be "buy the cheapest thing on the shelf, no matter how defective it is".
>> Now, see, I would have thought just surface-mounting the 2,157
>> individual resistors would cost more than $10... But what do I know
>> about anything?
>
> I suspect the cost of mounting the resistors can be worked out by the
> depreciation of the SMD mounting machines over the lifetime of the
> product, plus the cost of running the machine.
How about the cost of the resistors themselves?
Oh, mind you, that's already in the BoM...
> It's surely not very much
> though, given that you can buy loads of consumer devices with populated
> PCBs inside them for well under $10.
True. I have a 4GB flash RAM device in my pocket that cost 99p.
(I still don't understand why digital devices *need* thousands of
analogue components in them in the first place, but anyway...)
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> Then again, maybe that's because I'm still thinking like a consumer. When
> I buy something, I want it to *not* brake. The manufacturer, on the other
> hand, has a vested interest in making it so flimsy that it won't last 5
> minutes. That way they get more repeat business. (In addition to the
> materials savings, obviously.)
I think more people would steer away from a brand if it got a reputation for
breaking all the time, usually manufacturers have exact targets for how many
devices are returned failed after certain amounts of time. They are
carefully calculated (to produce a device that doesn't break too often, but
is also sensible to manufacture) and then the product is carefully designed
and tested to meet these targets. The bad reputations usually come from
mistakes rather than deliberate design intention. Still this is usually a
result of poor design/testing procedures, which are obviously related to
cost.
> Personally it makes me angry that somebody would deliberately design
> something to be defective so that they can make more money out of me.
I doubt anyone designs something intentionally to fail, no matter what it
might seem like as a consumer. It's quite hard to design something to be
fine within warranty but then to fail just after, you risk a huge
replacement bill if you try that tactic, plus you'll get a very bad
reputation.
> (I still don't understand why digital devices *need* thousands of analogue
> components in them in the first place, but anyway...)
On our boards nearly all of the discrete components are part of the power
supply or to round off the data signals to improve EMI/EMC performance.
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scott wrote:
> Interesting, the cost breakdown to make an iPhone:
>
> http://tinyurl.com/28v49e8
>
> Somewhere else (I lost it now) they mention assembly costs are around
> $9.50.
Tht's not the cost of making an iPhone. That's the cost of the hardware that
goes into making an iPhone. It leaves out stuff like patent licenses, and of
course the sunk design costs etc.
--
Darren New, San Diego CA, USA (PST)
Serving Suggestion:
"Don't serve this any more. It's awful."
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On 10/14/2010 7:53 AM, Invisible wrote:
> Now, see, I would have thought just surface-mounting the 2,157
> individual resistors would cost more than $10... But what do I know
> about anything?
Well... once you buy the machine to do it, it doesn't really use too
much electricity (except, maybe the heater to keep the solder bath warm,
and only takes a few minutes to pick and place the components. But the
initial outlay for the cost of the machine is a high cost.
--
~Mike
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On 10/14/2010 9:46 AM, scott wrote:
> On our boards nearly all of the discrete components are part of the
> power supply or to round off the data signals to improve EMI/EMC
> performance.
[A large chunk of this response is mostly directed at invisible]
Right. Filtering the signals. Caps are used a lot of time in digital
circuits to prevent switching noise from corrupting signals via ground.
When some digital circuits (TTL in particular) switch they create a lot
of noise on the ground plane that must be dealt with. Too much
fluctuation between power and ground, and the circuit begins to behave
erratically. Also, its a good idea to limit current. Resistors are used
to stabilize signals, pull up or pull down an input or output, bleed off
excess voltage so FETs don't retain a charge, etc... You need RC
networks to run a clock crystal, etc... Just connecting together a pile
of digital components won't work. You need supporting components to make
sure everything is stable in the system, especially when dealing with
large-scale digital systems like an iPhone. Keep in mind, that device is
also going to require a oscillators and filters for the RF parts, as well.
It gets even more interesting when you start dealing with designing
circuit boards, where you actively need to avoid traces from running
parallel to each other for too much distance, lest they build a
parasitic capacitance between them. In systems with very tight voltage
and current tolerances, the length of traces and thickness of traces
becomes very important as well. Traces can also act as inductors.
Some of the discrete components may be in there to also counteract some
of these effects caused by the traces themselves on the board. You'll
notice caps and resistors will often be very close to the pins of an IC
to minimize any effect the circuit trace may have.
--
~Mike
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> [A large chunk of this response is mostly directed at invisible]
>
> Right. Filtering the signals. Caps are used a lot of time in digital
> circuits to prevent switching noise from corrupting signals via ground.
> When some digital circuits (TTL in particular) switch they create a lot
> of noise on the ground plane that must be dealt with. Too much
> fluctuation between power and ground, and the circuit begins to behave
> erratically. Also, its a good idea to limit current. Resistors are used
> to stabilize signals, pull up or pull down an input or output, bleed off
> excess voltage so FETs don't retain a charge, etc... You need RC
> networks to run a clock crystal, etc... Just connecting together a pile
> of digital components won't work. You need supporting components to make
> sure everything is stable in the system, especially when dealing with
> large-scale digital systems like an iPhone. Keep in mind, that device is
> also going to require a oscillators and filters for the RF parts, as well.
Well, the iPhone runs on battery power, so yeah, the power supply is
probably a little unstable. I'm thinking more about desktop PC
motherboards. Why do *they* need so many million capacitors?
> It gets even more interesting when you start dealing with designing
> circuit boards, where you actively need to avoid traces from running
> parallel to each other for too much distance, lest they build a
> parasitic capacitance between them. In systems with very tight voltage
> and current tolerances, the length of traces and thickness of traces
> becomes very important as well. Traces can also act as inductors.
>
> Some of the discrete components may be in there to also counteract some
> of these effects caused by the traces themselves on the board. You'll
> notice caps and resistors will often be very close to the pins of an IC
> to minimize any effect the circuit trace may have.
Meh, well, fortunately I don't have to care about such things.
(Presumably a few attofarads only starts to matter once you're operating
into the GHz range anyway...)
--
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*
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Orchid XP v8 wrote:
> I'm thinking more about desktop PC
> motherboards. Why do *they* need so many million capacitors?
That's what *makes* them digital.
--
Darren New, San Diego CA, USA (PST)
Serving Suggestion:
"Don't serve this any more. It's awful."
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Darren New <dne### [at] san rrcom> wrote:
> Orchid XP v8 wrote:
> > I'm thinking more about desktop PC
> > motherboards. Why do *they* need so many million capacitors?
> That's what *makes* them digital.
Capacitors are not digital. You are confusing them with transistors
(which, technically speaking, aren't digital either, but can be used
for that purpose when their multiplying factor is ignored).
--
- Warp
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On 23/10/2010 06:42 AM, Warp wrote:
> Capacitors are not digital.
Perhaps it would be more accurate to say that no single component is
digital, more that a particular circuit design can be digital. (I've
seen logic gates used to make an analogue circuit, for example...)
--
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*
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Warp wrote:
> Darren New <dne### [at] sanrrcom> wrote:
>> Orchid XP v8 wrote:
>>> I'm thinking more about desktop PC
>>> motherboards. Why do *they* need so many million capacitors?
>
>> That's what *makes* them digital.
>
> Capacitors are not digital.
Nothing is digital. Digital is an interpretation of an analog signal. To
"make an analog signal digital" requires analog components. You have to
drive the analog signal so it doesn't linger between the fully-on and
fully-off states (however those may be defined).
And yes, capacitors can be digital in a voltage-driven circuit.
--
Darren New, San Diego CA, USA (PST)
Serving Suggestion:
"Don't serve this any more. It's awful."
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Darren New wrote:
> Warp wrote:
>> Darren New <dne### [at] sanrrcom> wrote:
>>> Orchid XP v8 wrote:
>>>> I'm thinking more about desktop PC
>>>> motherboards. Why do *they* need so many million capacitors?
>>
>>> That's what *makes* them digital.
>>
>> Capacitors are not digital.
>
> Nothing is digital.
As an example, even your keyboard needs debounce circuits, and power
supplies have to be careful not to let the inductance fry things when you
toggle the switch.
--
Darren New, San Diego CA, USA (PST)
Serving Suggestion:
"Don't serve this any more. It's awful."
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> Well, the iPhone runs on battery power, so yeah, the power supply is
> probably a little unstable.
Not just that, but from a single voltage (the battery) several very stable
voltages must be generated. This involves lots of analogue components (eg
how do you efficiently make accurate 3.3V, 5V and 8V lines from a LiPo
battery that can be between 3 and 4.5V?).
> I'm thinking more about desktop PC motherboards. Why do *they* need so
> many million capacitors?
Noise reduction, basically they allow everything to run correctly at much
higher frequencies than would be possible without them. It works two ways,
the capacitors around each IC help to keep a smooth voltage level for that
IC, ie shielding it from any noise on the power supply lines. Also the
capacitor then prevents a lot of noise being put back onto the supply line
from the ICs.
There are also a lot of resistors on the signal lines, these in conjunction
with the tiny parasitic capacitances cause a low-pass filter effect on the
signals. This also helps to reduce noise emission from the lines.
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On 25/10/2010 01:02 PM, scott wrote:
>> Well, the iPhone runs on battery power, so yeah, the power supply is
>> probably a little unstable.
>
> Not just that, but from a single voltage (the battery) several very
> stable voltages must be generated. This involves lots of analogue
> components (eg how do you efficiently make accurate 3.3V, 5V and 8V
> lines from a LiPo battery that can be between 3 and 4.5V?).
1. Why do you need several different voltages?
2. I'm not aware of any way to change the voltage of a DC circuit. You
can use a resistor to limit current, but AFAIK there's no way to
actually change voltages.
>> I'm thinking more about desktop PC motherboards. Why do *they* need so
>> many million capacitors?
>
> Noise reduction, basically they allow everything to run correctly at
> much higher frequencies than would be possible without them. It works
> two ways, the capacitors around each IC help to keep a smooth voltage
> level for that IC, ie shielding it from any noise on the power supply
> lines. Also the capacitor then prevents a lot of noise being put back
> onto the supply line from the ICs.
>
> There are also a lot of resistors on the signal lines, these in
> conjunction with the tiny parasitic capacitances cause a low-pass filter
> effect on the signals. This also helps to reduce noise emission from the
> lines.
Mmm, interesting. (And ridiculously complicated.) I wonder how much of
this stuff is to do with electromagnetic radiation? (You don't want EM
interference stopping your motherboard working, and you don't want the
board to radiate EM either...)
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> 1. Why do you need several different voltages?
Different circuits need different voltages. It's why the connector you plug
from the PSU to your motherboard has 20-odd wires and not just 2 big fat
ones. In an iPhone I imagine you'd at least need different voltages for the
digital circuits, the audio circuits, the display and the RF ciruits.
> 2. I'm not aware of any way to change the voltage of a DC circuit.
This is often used for battery powered devices as it's very efficient:
http://en.wikipedia.org/wiki/Charge_pump
> Mmm, interesting. (And ridiculously complicated.) I wonder how much of
> this stuff is to do with electromagnetic radiation? (You don't want EM
> interference stopping your motherboard working, and you don't want the
> board to radiate EM either...)
I assume they must pass certain legal test standards for EM compatibility,
but there are products that require stricter controls, especially ones that
are used near other RF equipment where interference is unwanted (eg medical
equipment, circuits in radio receivers, on planes, near to any
safety-critical device etc).
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> 2. I'm not aware of any way to change the voltage of a DC circuit.
I made an example using that Java circuit simulation applet:
http://tinyurl.com/2cplrbn
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On 25/10/2010 02:46 PM, scott wrote:
>> 2. I'm not aware of any way to change the voltage of a DC circuit.
>
> I made an example using that Java circuit simulation applet:
>
> http://tinyurl.com/2cplrbn
Hmm, interesting.
1. It's possible to edit the circuits. I never knew that.
2. It's possible to encode the circuit description in the URL. (I'm
pretty sure you'll quickly hit a limit on the maximum size for a URL!)
3. No matter what values I change, the circuit always stabilises to
exactly 8V.
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scott wrote:
> http://en.wikipedia.org/wiki/Charge_pump
That's freaky.
> I assume they must pass certain legal test standards for EM
> compatibility, but there are products that require stricter controls,
Like, a radio transmitter that's designed to run for hours or days on a
small battery? :-)
--
Darren New, San Diego CA, USA (PST)
Serving Suggestion:
"Don't serve this any more. It's awful."
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On 10/25/2010 7:17 AM, Invisible wrote:
> 1. Why do you need several different voltages?
Different components require different voltages. Sometimes you get lucky
and everything will run all one a single voltage. You may have high
intensity LED's that have a voltage forward of more than 3.3 volts, so 5
volts is a logical choice to power the backlight circuitry allowing the
LED's to function, but pumping 5 volts into a chip requiring 3.3 volts,
would possibly overheat at best or fry at worse, etc...
>
> 2. I'm not aware of any way to change the voltage of a DC circuit. You
> can use a resistor to limit current, but AFAIK there's no way to
> actually change voltages.
>
You're kidding, right?
You can affect voltage by either using a regulator (true, it does this
by altering current) or if you need more voltage than is supplied by the
source you can use a charge pump, which will increase voltage by
alternately charging and discharging a bank of capacitors configured in
a very specific way (lots of caps for that one)
>
> Mmm, interesting. (And ridiculously complicated.) I wonder how much of
> this stuff is to do with electromagnetic radiation? (You don't want EM
> interference stopping your motherboard working, and you don't want the
> board to radiate EM either...)
Filtering probably helps that. But at those timings every little thing
in the design becomes critically important. You can literally have a
parasitic capacitance completely filter out the signal.
--
~Mike
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On 10/25/2010 8:46 AM, scott wrote:
>> 2. I'm not aware of any way to change the voltage of a DC circuit.
>
> I made an example using that Java circuit simulation applet:
>
> http://tinyurl.com/2cplrbn
>
another simple charge pump based on a 555 timer.
http://tinyurl.com/2a8wf2x
--
~Mike
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>> I made an example using that Java circuit simulation applet:
>>
>> http://tinyurl.com/2cplrbn
>>
>
> another simple charge pump based on a 555 timer.
>
> http://tinyurl.com/2a8wf2x
Cool! I know also that you can use a circuit with inductors rather than
capacitors to make it more efficient, but the downside is the inductors need
more physical space than the capacitors on the board (only a problem if
space is very limited).
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On 10/26/2010 3:01 AM, scott wrote:
>>> I made an example using that Java circuit simulation applet:
>>>
>>> http://tinyurl.com/2cplrbn
>>>
>>
>> another simple charge pump based on a 555 timer.
>>
>> http://tinyurl.com/2a8wf2x
>
> Cool! I know also that you can use a circuit with inductors rather than
> capacitors to make it more efficient, but the downside is the inductors
> need more physical space than the capacitors on the board (only a
> problem if space is very limited).
>
>
>
I have yet to attempt a boost converter using an inductor. I should
attempt such a thing one of these days. ;) From what I understand, you
can get some pretty nasty high voltages with such a circuit. Probably
one of the reasons I haven't messed with it.
There's a regulator circuit geared toward LED use that, iirc used a very
small capacity that used the same theory to supply enough voltage to
overcome the high output LED's VF from a very small battery, even when
the battery is nearly spent and has a voltage drop. Something called a
joule thief. Essentially a boost converter using a transformer.
--
~Mike
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