Re: PSoC Express: Does it work for semi-analog designs?

Joerg skrev:
> Klaus Kragelund wrote:
>
> > Joerg skrev:
> >
> >>Klaus Kragelund wrote:
> >>
> >>
> >>[...]
> >>
> >>>>>A smaller case is not always cheaper. Smaller means the prodcution
> >>>>>equipment has to be of better precision (more expensive), and the
> >>>>>Pick&Place machine also is more expensive
> >>>>>
> >>>>>For example we have looked at the resistor arrays with 4x0603 in one
> >>>>>1206 pack, but our production cant solder that reliable. The placement
> >>>>>error rate rises dramatically.
> >>>>>
> >>>>
> >>>>That looks like a pricey boutique part. Interesting. Anyhow, I'd make
> >>>>sure your production can at least handle regular 0402 parts. That is
> >>>>pretty much state of the art these days. I just debugged a design I had
> >>>>completed today and it had some of those teeny parts. Luckily there
> >>>>wasn't much debugging needed. My eyes don't get any younger ;-)
> >>>>
> >>>
> >>>
> >>>Mine doesn't either (we are prototyping using 0805 resistors since any
> >>>smaller is a pain to debug/solder out/in)
> >>>
> >>
> >>On one of my latest designs I had a few 0805 and some SOT23. Under the
> >>microscope they looked like huge boulders compared to all the rest.
> >>
> >
> >
> > I have looked at some of the smaller packages, but I often see higher
> > prices for the small stuff. For example:
> >
> > BC847 (SOT-23): 0.17USD
> > BC846BM3T5G (SOT-723): 0.37USD
> >
> > Both prices are from mouser just to compare them fairly. So I think in
> > some cases a larger design is actually cheaper since the parts run in
> > high volume from the manufactor and it is a well known production
> > process
> >
>
> That's if you buy one or two. Else the SOT23 is under $0.02 at Mouser:
> http://www.mouser.com/search/ProductDetail.aspx?R=BC847AMTFvirtualkey51210000virtualkey512-BC847AMTF
>
> Never seen SOT723 though.
>
> >
> >>>Regarding the 4x array, it is fairly cheap (about 15 times a single
> >>>0805, in the 5% version about 3 times a 0805 resistor). So a quad
> >>>respack compares to a 0805 if you can live with the 5% tolerance (we
> >>>often can, since only a portion of a design needs precision resistors)
> >>>
> >>>But here is the point, since our placement costs are high, using a
> >>>resistor array means ony one placement instead of 4 placements and thus
> >>>the total price is much lower. We cannot use them however since the
> >>>production cannot solder them reliable. We have used the standard
> >>>layout from the manufactor and enhanced it further but they could not
> >>>get the failure rate down :-( We can however handle 0402 parts reliably
> >>>
> >>
> >>I guess you really have to work on it to get competitive placement costs.
> >>
> >>Check out these guys for stuff you don't want to move outside Europe:
> >>http://www.jabil.com/
> >>Don't know if they are also in Denmark since their locations page
> >>requires some stupid flash player. Web site designers are .... no, no,
> >>just bit my lips, I am not going to say that.
> >>
> >
> >
> > http://www.jabil.com/ looks very interesting - i will try to get a BOM
> > they can qoute (will be very interesting)
> >
> >
> >>>Another really nice part is the dual BJT: BC847BPN - you should check
> >>>it out (it's cheap also)
> >>>
> >>
> >>Yes, that one is nice. Not exactly cheap, between 3-4c in the US.
> >>
> >
> >
> > The same here - for comparison we give about 1c for a standard BC847B
> > (high volume)
> >
> >
> >>>>>Also using fine pitch devices (TSSOP or smaller), there is an increased
> >>>>>risks of solder bridges.
> >>>>>
> >>>>
> >>>>There I'd really sit down for a chat with the production manager. TSSOP
> >>>>is absolutely standard. There are many parts that you simply cannot
> >>>>obtain in any package larger than TSSOP.
> >>>>
> >
> >
> > Yes - it seems its time to dig deeper into the production problems
> >
>
> This could be a difficult mission. Be prepared for some stone-walling
> and excuses that are brought onto the table. You'll need upper
> management participation and support as well as iron-clad quotes from
> outside assemblers for existing products of your company. Then you'll
> have hard data along the lines of "It costs this much to assemble here
> and XYZ Corporation would charge us only that much to do it outside".

Yes, I have heard the excuses before and since I'm not an expert on
pick & places machines its difficult to figure out if they are real or
not

> >
> >>>
> >>>Good point. I have tried for the last year, but my suspicion is that
> >>>the production guys simply is overbooked with work and also that they
> >>>lack the experience and drive to improve the failure rates of special
> >>>components. Its quite sad to try to optimize a design and being told
> >>>the production cannot use the suggested parts.
> >>>
> >>>I guess another solution would be to find an expert consultant, that
> >>>can bring us further
> >>>
> >>
> >>If you can't get anywhere right now then a consultant might really be
> >>needed. I believe that either your own production needs to buy into the
> >>future or you need to outsource it.
> >>
> >>When it comes to the "convincement meeting" which usually has to include
> >>your corporate top brass a very powerful method of convincing most
> >>everyone is this: Take a modern miniaturized appliance, for example a
> >>cell phone, an iPod, a kids toy. Something that everyone knows. Pry the
> >>circuit board out and pass that around. Or, what we often do, take a
> >>photo with a small coin next it and show it on the projector. Then ask
> >>the magic question "This is the future. If we don't get there the
> >>competition will have us for lunch. So how do we get there?"
> >>
> >
> >
> > Good recommendation. Actually we often buy pumps from Asia competitors
> > to look how they can do it so cheap. Often they still use leaded
> > assembly and cheap FR4 boards (so our quality guys just say they can
> > sell it so cheap because the quality is bad)
> >
>
> Why is FR-4 so bad? Believe it or not but some of my designs were even
> run on good old phenolic. The stuff still lasts decades. There has to be
> a very compelling reason to go beyond FR-4, even for RF designs. Maybe
> if your pump controllers have to work in outer space or something like
> that :-)

Well, I didn't mean FR4 is bad. We use only FR4, but rarther that the
asia manufactors use a cheap FR4 with worse quality (so says the
q-guys) and thus lower price. Perhaps we should try to do an example
design with that....

>
> As for RoHS, well, don't get me started. That was one of the more stupid
> decisions by Eurocrats but that's a whole 'nother topic. The main goal
> should probably be to push for an exemption.
>
Couldn't agree more. Whats more funny is that purchasing and production
has been working on this for litterally years and then they figure out
it really isn't demanded for pump applications
>
> > An iPod would be a good choice since it has to have long durability,
> > but ofcourse it is expensive
> >
>
> Or maybe they added a humongous profit margin. Kids pay whatever it
> takes to be at least as hip as their class mates and the industry knows
> that well. Since you are in Scandinavia you might pick a more local
> example that is not expensive. I have a Nokia 2115i cell phone which
> should definitely contain lots of really tiny parts. Still it cost me
> only about $10 with a $40 usage commitment. Without a long-term plan so
> besides maybe half of those $40 there cannot be any subsidies or loss
> tendering in it.

Will try that out. Many thanks for good comments :-)

Regards

Klaus

Klaus Kragelund wrote:
> Joerg skrev:
> 
>>Klaus Kragelund wrote:
>>
>>
>>>Joerg skrev:
>>>
>>>
>>>>Klaus Kragelund wrote:
>>>>
>>>>
>>>>[...]
>>>>
>>>>
>>>>>>>A smaller case is not always cheaper. Smaller means the prodcution
>>>>>>>equipment has to be of better precision (more expensive), and the
>>>>>>>Pick&Place machine also is more expensive
>>>>>>>
>>>>>>>For example we have looked at the resistor arrays with 4x0603 in one
>>>>>>>1206 pack, but our production cant solder that reliable. The placement
>>>>>>>error rate rises dramatically.
>>>>>>>
>>>>>>
>>>>>>That looks like a pricey boutique part. Interesting. Anyhow, I'd make
>>>>>>sure your production can at least handle regular 0402 parts. That is
>>>>>>pretty much state of the art these days. I just debugged a design I had
>>>>>>completed today and it had some of those teeny parts. Luckily there
>>>>>>wasn't much debugging needed. My eyes don't get any younger ;-)
>>>>>>
>>>>>
>>>>>
>>>>>Mine doesn't either (we are prototyping using 0805 resistors since any
>>>>>smaller is a pain to debug/solder out/in)
>>>>>
>>>>
>>>>On one of my latest designs I had a few 0805 and some SOT23. Under the
>>>>microscope they looked like huge boulders compared to all the rest.
>>>>
>>>
>>>
>>>I have looked at some of the smaller packages, but I often see higher
>>>prices for the small stuff. For example:
>>>
>>>BC847 (SOT-23): 0.17USD
>>>BC846BM3T5G (SOT-723): 0.37USD
>>>
>>>Both prices are from mouser just to compare them fairly. So I think in
>>>some cases a larger design is actually cheaper since the parts run in
>>>high volume from the manufactor and it is a well known production
>>>process
>>>
>>
>>That's if you buy one or two. Else the SOT23 is under $0.02 at Mouser:
>>http://www.mouser.com/search/ProductDetail.aspx?R=BC847AMTFvirtualkey51210000virtualkey512-BC847AMTF
>>
>>Never seen SOT723 though.
>>
>>
>>>>>Regarding the 4x array, it is fairly cheap (about 15 times a single
>>>>>0805, in the 5% version about 3 times a 0805 resistor). So a quad
>>>>>respack compares to a 0805 if you can live with the 5% tolerance (we
>>>>>often can, since only a portion of a design needs precision resistors)
>>>>>
>>>>>But here is the point, since our placement costs are high, using a
>>>>>resistor array means ony one placement instead of 4 placements and thus
>>>>>the total price is much lower. We cannot use them however since the
>>>>>production cannot solder them reliable. We have used the standard
>>>>>layout from the manufactor and enhanced it further but they could not
>>>>>get the failure rate down :-( We can however handle 0402 parts reliably
>>>>>
>>>>
>>>>I guess you really have to work on it to get competitive placement costs.
>>>>
>>>>Check out these guys for stuff you don't want to move outside Europe:
>>>>http://www.jabil.com/
>>>>Don't know if they are also in Denmark since their locations page
>>>>requires some stupid flash player. Web site designers are .... no, no,
>>>>just bit my lips, I am not going to say that.
>>>>
>>>
>>>
>>>http://www.jabil.com/ looks very interesting - i will try to get a BOM
>>>they can qoute (will be very interesting)
>>>
>>>
>>>
>>>>>Another really nice part is the dual BJT: BC847BPN - you should check
>>>>>it out (it's cheap also)
>>>>>
>>>>
>>>>Yes, that one is nice. Not exactly cheap, between 3-4c in the US.
>>>>
>>>
>>>
>>>The same here - for comparison we give about 1c for a standard BC847B
>>>(high volume)
>>>
>>>
>>>
>>>>>>>Also using fine pitch devices (TSSOP or smaller), there is an increased
>>>>>>>risks of solder bridges.
>>>>>>>
>>>>>>
>>>>>>There I'd really sit down for a chat with the production manager. TSSOP
>>>>>>is absolutely standard. There are many parts that you simply cannot
>>>>>>obtain in any package larger than TSSOP.
>>>>>>
>>>
>>>
>>>Yes - it seems its time to dig deeper into the production problems
>>>
>>
>>This could be a difficult mission. Be prepared for some stone-walling
>>and excuses that are brought onto the table. You'll need upper
>>management participation and support as well as iron-clad quotes from
>>outside assemblers for existing products of your company. Then you'll
>>have hard data along the lines of "It costs this much to assemble here
>>and XYZ Corporation would charge us only that much to do it outside".
> 
> 
> Yes, I have heard the excuses before and since I'm not an expert on
> pick & places machines its difficult to figure out if they are real or
> not
> 

Well, if other companies are able to handle fine pitch I guess they 
aren't real. If it's budgeting concerns then that would be a clear 
indicator to outsource.

Why don't you just do a pilot run at one of the larger SMT assemblers? 
Pick one near you and visit them for a tour together with your 
production managers. Then they'd see what is state of the art.


> 
>>>>>Good point. I have tried for the last year, but my suspicion is that
>>>>>the production guys simply is overbooked with work and also that they
>>>>>lack the experience and drive to improve the failure rates of special
>>>>>components. Its quite sad to try to optimize a design and being told
>>>>>the production cannot use the suggested parts.
>>>>>
>>>>>I guess another solution would be to find an expert consultant, that
>>>>>can bring us further
>>>>>
>>>>
>>>>If you can't get anywhere right now then a consultant might really be
>>>>needed. I believe that either your own production needs to buy into the
>>>>future or you need to outsource it.
>>>>
>>>>When it comes to the "convincement meeting" which usually has to include
>>>>your corporate top brass a very powerful method of convincing most
>>>>everyone is this: Take a modern miniaturized appliance, for example a
>>>>cell phone, an iPod, a kids toy. Something that everyone knows. Pry the
>>>>circuit board out and pass that around. Or, what we often do, take a
>>>>photo with a small coin next it and show it on the projector. Then ask
>>>>the magic question "This is the future. If we don't get there the
>>>>competition will have us for lunch. So how do we get there?"
>>>>
>>>
>>>
>>>Good recommendation. Actually we often buy pumps from Asia competitors
>>>to look how they can do it so cheap. Often they still use leaded
>>>assembly and cheap FR4 boards (so our quality guys just say they can
>>>sell it so cheap because the quality is bad)
>>>
>>
>>Why is FR-4 so bad? Believe it or not but some of my designs were even
>>run on good old phenolic. The stuff still lasts decades. There has to be
>>a very compelling reason to go beyond FR-4, even for RF designs. Maybe
>>if your pump controllers have to work in outer space or something like
>>that :-)
> 
> 
> Well, I didn't mean FR4 is bad. We use only FR4, but rarther that the
> asia manufactors use a cheap FR4 with worse quality (so says the
> q-guys) and thus lower price. Perhaps we should try to do an example
> design with that....
> 

It should be the engineers making materials decisions, not so much QA 
folks. If a certain lower cost kind of FR-4 is good enough with some 
margin, why use a more expensive material?

> 
>>As for RoHS, well, don't get me started. That was one of the more stupid
>>decisions by Eurocrats but that's a whole 'nother topic. The main goal
>>should probably be to push for an exemption.
>>
> 
> Couldn't agree more. Whats more funny is that purchasing and production
> has been working on this for litterally years and then they figure out
> it really isn't demanded for pump applications
> 

Ouch...


>>>An iPod would be a good choice since it has to have long durability,
>>>but ofcourse it is expensive
>>>
>>
>>Or maybe they added a humongous profit margin. Kids pay whatever it
>>takes to be at least as hip as their class mates and the industry knows
>>that well. Since you are in Scandinavia you might pick a more local
>>example that is not expensive. I have a Nokia 2115i cell phone which
>>should definitely contain lots of really tiny parts. Still it cost me
>>only about $10 with a $40 usage commitment. Without a long-term plan so
>>besides maybe half of those $40 there cannot be any subsidies or loss
>>tendering in it.
> 
> 
> Will try that out. Many thanks for good comments :-)
> 

-- 
Regards, Joerg

http://www.analogconsultants.com