Godamned 0603...

[server]

Lasse Langwadt Christensen <langwadt@fonz.dk> wrote in news:4ecce2c8-
24f2-491a-9b47-d1a29e02df0dn@googlegroups.com:

fredag den 18. februar 2022 kl. 09.32.02 UTC+1 skrev Sylvia Else:
I\'ve got a board made that includes pads for some 0603 smds.

How was I expected to know that 0603 is used for both imperial and
metric sizes? No wonder there\'s no way I can put my imperial 0603
components onto the metric 0603 landing pads.

0603 appears to be the only size where this trap arises, and I fell
right into it.

also 0402 metric which is 01005 imperial

<https://en.wikipedia.org/wiki/File:SMT_sizes,
_based_on_original_by_Zureks.svg>

I always used the metric designations and perform my purchases and my
layouts in metric as well. Much easier. I have been \'metrisized\'
since the \'70s.

 

[server]

Jeroen Belleman <jeroen@nospam.please> wrote in news:sunu9q$1l2u$1
@gioia.aioe.org:

On 2022-02-18 11:11, Lasse Langwadt Christensen wrote:
fredag den 18. februar 2022 kl. 09.32.02 UTC+1 skrev Sylvia Else:
I\'ve got a board made that includes pads for some 0603 smds.

How was I expected to know that 0603 is used for both imperial and
metric sizes? No wonder there\'s no way I can put my imperial 0603
components onto the metric 0603 landing pads.

0603 appears to be the only size where this trap arises, and I fell
right into it.

also 0402 metric which is 01005 imperial


Designed to confuse. Why do people do that?

Jeroen Belleman

Anti-metric much? You anti-mask as well?

 

[Rick C]

On Friday, February 18, 2022 at 1:51:04 PM UTC-5, whit3rd wrote:

On Friday, February 18, 2022 at 6:45:50 AM UTC-8, gnuarm.del...@gmail.com wrote:
On Friday, February 18, 2022 at 6:01:25 AM UTC-5, Jeroen Belleman wrote:
On 2022-02-18 11:11, Lasse Langwadt Christensen wrote:
fredag den 18. februar 2022 kl. 09.32.02 UTC+1 skrev Sylvia Else:
I\'ve got a board made that includes pads for some 0603 smds.

How was I expected to know that 0603 is used for both imperial and
metric sizes? No wonder there\'s no way I can put my imperial 0603
components onto the metric 0603 landing pads.
Designed to confuse. Why do people do that?

You mean why do people use the measuring system that everyone else in their country use? I guess this is a more pointed question at the US community. I remember working with a mechanical engineer at a military contractor and was surprised they still did everything using inches. 90% of electronic components are in mm as the primary unit. I guess I expect the mechanical community would have converted by now, but, no.
Pre-NATO, all US military machinery would have been inches; even now,
NATO has standard 7.62 mm ammo, which is just a soft-conversion
from .30 caliber...

I would hope you\'d understand the difference in changing nomenclature and changing measurement systems. Caliber is not an actual measurement of anything, rather a nominal use. Same as 12 inch wafers or a 19 inch rack cabinet. I guess something on a 19 inch rack cabinet is actually 19 inches, but in reality, it\'s just a name we use.

Conversion is a slow process. In the print industries, inches have been the norm; in
science, it has been SI (metric) units for decades. So early semiconductor designs
had diffusion depths in microns, and emitter areas in... square micro-inches.
Because the emitters were printed.

Yeah, whoever does a thing first gets to name it and set the measurements, but they can get changed. You still see references to angstroms in measuring wavelengths. Doesn\'t mean it isn\'t stupid.

Eventually it gets sorted out... but I\'ve got a century-old machine tool
that has inch-standard parts everywhere except one lefthand metric screw....
so don\'t expect the conversion-in-progress phase to be complete in your
lifetime. Digitization, if anything, will impede the progress; your calipers
are made with a \'convert to\' button, so the multiple standards don\'t
bother one so much.

In the US there is no conversion process. We decided to convert and then decided not to. That\'s on us. I believe we lost a Mars lander because of that. I\'m sure there have been many, many other issues as well. I know that\'s why the Navy won\'t convert from yards to meters for targeting. The two measurements are close, but they are too concerned about what happens during the switchover which would take some decades. Opps, I didn\'t mean to hit *that* ship!

With feature sizes on PCBs using fractions of thousandths of an inch, there isn\'t much reason to stick with it. Get rid of the confusion and convert. Rip the band aid off and be done with it. But PCB manufacturing is one of the least progressive areas of electronics in terms of standards and modernization. They have tried on more than one occasion to incorporate Gerber files into a standard that would provide much more information. I think those attempts have only met with limited acceptance. Is it because there are too many competing standards from different companies?


--

Rick C.

--- Get 1,000 miles of free Supercharging
--- Tesla referral code - https://ts.la/richard11209

 

[server]

Joe Gwinn <joegwinn@comcast.net> wrote in
news:kaov0ht8v1704ljg89q5bo5392a16jhlbq@4ax.com:

On Fri, 18 Feb 2022 15:02:21 +0000, Clive Arthur
clive@nowaytoday.co.uk> wrote:

On 18/02/2022 14:45, Rick C wrote:

snipped

I don\'t get why mil are still used in PCB layout so much.

For a thousandth of an inch, we say \'thou\' (with the th as in
thousandth). A mil is often verbal shorthand for a millimetre or
millilitre, depending on context.

That has caused much confusion too.

Not so fast there. Too Euro-centric?

In the US, traditionally a \"mil\" is 0.001\", and a \"tenth\" is
0.0001\",
and a millimeter is a millimeter (\"mm\") and never a mil.

Joe Gwinn

Yep.... for many many decades.

If I say a number in \'mils\' to an engineer in the US, he or she
automatically knows I refer to thousandths of an inch.

Well.. maybe Larkin is an exception to that. He still thinks you
are supposed to dip in a vapor phase cleaning tank.

 

[server]

Lasse Langwadt Christensen <langwadt@fonz.dk> wrote in
news:845ddacd-f984-4693-b99a-47c9d1fb0064n@googlegroups.com:

fredag den 18. februar 2022 kl. 19.51.04 UTC+1 skrev whit3rd:
On Friday, February 18, 2022 at 6:45:50 AM UTC-8,
gnuarm.del...@gmail.com
wrote:
On Friday, February 18, 2022 at 6:01:25 AM UTC-5, Jeroen
Belleman wrote
:
On 2022-02-18 11:11, Lasse Langwadt Christensen wrote:
fredag den 18. februar 2022 kl. 09.32.02 UTC+1 skrev Sylvia
Else:

I\'ve got a board made that includes pads for some 0603
smds.

How was I expected to know that 0603 is used for both
imperial and

metric sizes? No wonder there\'s no way I can put my
imperial 0603

components onto the metric 0603 landing pads.
Designed to confuse. Why do people do that?

You mean why do people use the measuring system that everyone
else in t
heir country use? I guess this is a more pointed question at the
US community. I remember working with a mechanical engineer at a
military contractor and was surprised they still did everything
using inches. 90% of electronic components are in mm as the
primary unit. I guess I expect the mechanical community would have
converted by now, but, no.
Pre-NATO, all US military machinery would have been inches; even
now, NATO has standard 7.62 mm ammo, which is just a
soft-conversion from .30 caliber...

Conversion is a slow process. In the print industries, inches
have been t
he norm; in
science, it has been SI (metric) units for decades. So early
semiconducto
r designs
had diffusion depths in microns, and emitter areas in... square
micro-inc
hes.
Because the emitters were printed.

Eventually it gets sorted out... but I\'ve got a century-old
machine tool

that has inch-standard parts everywhere except one lefthand
metric screw.
..
so don\'t expect the conversion-in-progress phase to be complete
in your

lifetime. Digitization, if anything, will impede the progress;
your calip
ers
are made with a \'convert to\' button, so the multiple standards
don\'t bother one so much.

or it might help, if all your tools/machines/instruments can only
do one standard switching means throwing it all away. If they can
do both like every CNC or digital caliper switching is just a push
of a button

And a conscious mental effort on the part of the person claiming to
be performing engineering tasks.

 

[John Larkin]

On Fri, 18 Feb 2022 15:02:21 +0000, Clive Arthur
<clive@nowaytoday.co.uk> wrote:

On 18/02/2022 14:45, Rick C wrote:

snipped

I don\'t get why mil are still used in PCB layout so much.

For a thousandth of an inch, we say \'thou\' (with the th as in
thousandth). A mil is often verbal shorthand for a millimetre or
millilitre, depending on context.

That has caused much confusion too.

In the US, machinists usually say thou and engineers most often say
mils, both meaning 0.001 inches.

Surprisingly, some big aerospace companies still use pounds and slugs
and BTUs and things. Creeps me out.

The Gimli Glider was about confusing gallons with liters.

--

If a man will begin with certainties, he shall end with doubts,
but if he will be content to begin with doubts he shall end in certainties.
Francis Bacon

 

[Clive Arthur]

On 18/02/2022 16:06, jlarkin@highlandsniptechnology.com wrote:

<snip>

The early IC designers defined as inch as equal to 25 mm.

Many decades ago I bought some stripboard for a prototype. It was 2.5mm
pitch, which I assumed was really meant to be 0.1\".

It was in fact 2.5mm as claimed, and the pins on my 40 pin DIL processor
were well bent, like a man trying to fit into too small shoes.

I do have a lot of sympathy for some \'imperial\' units. For example, I
have a set of scales in the kitchen with both metric and imperial
weights. The imperial weights have no duplicates. The metric weights
have two of 200g and two of 20g. Yes, I realise that\'s because there
are 2^4 ounces in a pound. Likewise, inches in halves, quarters,
eights, sixteenths etc - very convenient and easy to eyeball.

We need to make 16 the default number base. You know it makes sense.

--
Cheers
Clive

 

[Lasse Langwadt Christensen]

fredag den 18. februar 2022 kl. 23.45.26 UTC+1 skrev John Larkin:

On Fri, 18 Feb 2022 15:02:21 +0000, Clive Arthur
cl...@nowaytoday.co.uk> wrote:
On 18/02/2022 14:45, Rick C wrote:

snipped

I don\'t get why mil are still used in PCB layout so much.

For a thousandth of an inch, we say \'thou\' (with the th as in
thousandth). A mil is often verbal shorthand for a millimetre or
millilitre, depending on context.

That has caused much confusion too.
In the US, machinists usually say thou and engineers most often say
mils, both meaning 0.001 inches.

Surprisingly, some big aerospace companies still use pounds and slugs
and BTUs and things. Creeps me out.

The Gimli Glider was about confusing gallons with liters.

no, it was pounds per liter vs. kg per liter

 

[Joe Gwinn]

On Fri, 18 Feb 2022 23:13:26 +0000, Clive Arthur
<clive@nowaytoday.co.uk> wrote:

On 18/02/2022 16:06, jlarkin@highlandsniptechnology.com wrote:

snip

The early IC designers defined as inch as equal to 25 mm.

Many decades ago I bought some stripboard for a prototype. It was 2.5mm
pitch, which I assumed was really meant to be 0.1\".

It was in fact 2.5mm as claimed, and the pins on my 40 pin DIL processor
were well bent, like a man trying to fit into too small shoes.

I do have a lot of sympathy for some \'imperial\' units. For example, I
have a set of scales in the kitchen with both metric and imperial
weights. The imperial weights have no duplicates. The metric weights
have two of 200g and two of 20g. Yes, I realise that\'s because there
are 2^4 ounces in a pound. Likewise, inches in halves, quarters,
eights, sixteenths etc - very convenient and easy to eyeball.

We need to make 16 the default number base. You know it makes sense.

Hard to count on the fingers?

I knew a woman who had six fingers on each hand, all fingers looking
and working normally. But she didn\'t even attempt to get to eight
fingers per hand.

Joe Gwinn

 

[Lasse Langwadt Christensen]

fredag den 18. februar 2022 kl. 23.36.28 UTC+1 skrev gnuarm.del...@gmail.com:

On Friday, February 18, 2022 at 1:51:04 PM UTC-5, whit3rd wrote:
On Friday, February 18, 2022 at 6:45:50 AM UTC-8, gnuarm.del...@gmail.com wrote:
On Friday, February 18, 2022 at 6:01:25 AM UTC-5, Jeroen Belleman wrote:
On 2022-02-18 11:11, Lasse Langwadt Christensen wrote:
fredag den 18. februar 2022 kl. 09.32.02 UTC+1 skrev Sylvia Else:
I\'ve got a board made that includes pads for some 0603 smds.

How was I expected to know that 0603 is used for both imperial and
metric sizes? No wonder there\'s no way I can put my imperial 0603
components onto the metric 0603 landing pads.
Designed to confuse. Why do people do that?

You mean why do people use the measuring system that everyone else in their country use? I guess this is a more pointed question at the US community. I remember working with a mechanical engineer at a military contractor and was surprised they still did everything using inches. 90% of electronic components are in mm as the primary unit. I guess I expect the mechanical community would have converted by now, but, no.
Pre-NATO, all US military machinery would have been inches; even now,
NATO has standard 7.62 mm ammo, which is just a soft-conversion
from .30 caliber...

I would hope you\'d understand the difference in changing nomenclature and changing measurement systems. Caliber is not an actual measurement of anything, rather a nominal use. Same as 12 inch wafers or a 19 inch rack cabinet. I guess something on a 19 inch rack cabinet is actually 19 inches, but in reality, it\'s just a name we use.

a 19\" rack enclosure is 19\" wide including the \"ears\"

in the case of 7.62mm it is land to land diameter of the barrel, the bullet is bigger

 

[Piotr Wyderski]

Jeroen Belleman wrote:

> Designed to confuse. Why do people do that?

Mars Climate Orbiter likes it!

Best regards, Piotr

 

[Piotr Wyderski]

Rick C wrote:

> It\'s a damn good thing they had already developed metric measurements for electricity by the time things got rolling.

Not entirely, decibels still haunt the landscape. Why would I write 60dB
if I mean 1e3 relative something?

Best regards, Piotr

 

[Piotr Wyderski]

John Larkin wrote:

Surprisingly, some big aerospace companies still use pounds and slugs
and BTUs and things. Creeps me out.

Slug\'s a good one, thanks! This is so pervert.

Best regards, Piotr

 

[John Larkin]

On Fri, 18 Feb 2022 18:38:32 -0500, Joe Gwinn <joegwinn@comcast.net>
wrote:

On Fri, 18 Feb 2022 23:13:26 +0000, Clive Arthur
clive@nowaytoday.co.uk> wrote:

On 18/02/2022 16:06, jlarkin@highlandsniptechnology.com wrote:

snip

The early IC designers defined as inch as equal to 25 mm.

Many decades ago I bought some stripboard for a prototype. It was 2.5mm
pitch, which I assumed was really meant to be 0.1\".

It was in fact 2.5mm as claimed, and the pins on my 40 pin DIL processor
were well bent, like a man trying to fit into too small shoes.

I do have a lot of sympathy for some \'imperial\' units. For example, I
have a set of scales in the kitchen with both metric and imperial
weights. The imperial weights have no duplicates. The metric weights
have two of 200g and two of 20g. Yes, I realise that\'s because there
are 2^4 ounces in a pound. Likewise, inches in halves, quarters,
eights, sixteenths etc - very convenient and easy to eyeball.

We need to make 16 the default number base. You know it makes sense.

Hard to count on the fingers?

Hard for kids to learn the addition and multiplication tables.

Most DEC computers were octal, even the 16-bit PDP-11. I can still
assemble some octal instructions from memory.

012737 Move word immediate to absolute location
nnnnn
aaaaa

I knew a woman who had six fingers on each hand, all fingers looking
and working normally. But she didn\'t even attempt to get to eight
fingers per hand.

Joe Gwinn

Base 12 has been proposed to replace 10.

There must be some FOR loop in our DNA that wraps around a subroutine
called FINGER. Maybe one base pair is the index.

What\'s amazing is that the 6th finger actually works, has veins and
nerves and muscles and tendons and stuff.

--

If a man will begin with certainties, he shall end with doubts,
but if he will be content to begin with doubts he shall end in certainties.
Francis Bacon

 

[David Eather]

On 18/02/2022 6:31 pm, Sylvia Else wrote:

I\'ve got a board made that includes pads for some 0603 smds.

How was I expected to know that 0603 is used for both imperial and
metric sizes? No wonder there\'s no way I can put my imperial 0603
components onto the metric 0603 landing pads.

0603 appears to be the only size where this trap arises, and I fell
right into it.

If I\'d printed out the PCB layout at 1:1 scale, I might have realised
that the pads were absurdly small, but of course, I didn\'t.

Sylvia.

I didn\'t know that. Thanks for the heads up. I have a design I need to
check (again) before it goes to JLC.

 

[Joe Gwinn]

On Fri, 18 Feb 2022 16:34:37 -0800, John Larkin
<jlarkin@highland_atwork_technology.com> wrote:

On Fri, 18 Feb 2022 18:38:32 -0500, Joe Gwinn <joegwinn@comcast.net
wrote:

On Fri, 18 Feb 2022 23:13:26 +0000, Clive Arthur
clive@nowaytoday.co.uk> wrote:

On 18/02/2022 16:06, jlarkin@highlandsniptechnology.com wrote:

snip

The early IC designers defined as inch as equal to 25 mm.

Many decades ago I bought some stripboard for a prototype. It was 2.5mm
pitch, which I assumed was really meant to be 0.1\".

It was in fact 2.5mm as claimed, and the pins on my 40 pin DIL processor
were well bent, like a man trying to fit into too small shoes.

I do have a lot of sympathy for some \'imperial\' units. For example, I
have a set of scales in the kitchen with both metric and imperial
weights. The imperial weights have no duplicates. The metric weights
have two of 200g and two of 20g. Yes, I realise that\'s because there
are 2^4 ounces in a pound. Likewise, inches in halves, quarters,
eights, sixteenths etc - very convenient and easy to eyeball.

We need to make 16 the default number base. You know it makes sense.

Hard to count on the fingers?

Hard for kids to learn the addition and multiplication tables.

Most DEC computers were octal, even the 16-bit PDP-11. I can still
assemble some octal instructions from memory.

012737 Move word immediate to absolute location
nnnnn
aaaaa

Actually, there was a time when I was disassembling PDP-11 machine
code manually, and one soon learned the common opcodes.

I knew a woman who had six fingers on each hand, all fingers looking
and working normally. But she didn\'t even attempt to get to eight
fingers per hand.

Joe Gwinn

Base 12 has been proposed to replace 10.

There must be some FOR loop in our DNA that wraps around a subroutine
called FINGER. Maybe one base pair is the index.

Well, it\'s mechanistic, but way more interesting than DO loops:
Sonic Hedgehog and Homeobox genes, specifically HOX genes. The
literature is immense. Here are some summary articles.

..<https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5328949/>

..<https://en.wikipedia.org/wiki/Homeobox#Human_homeobox_genes>

What\'s amazing is that the 6th finger actually works, has veins and
nerves and muscles and tendons and stuff.

Yes, extra fingers are often vestigial, and people usually have them
removed surgically. But not in her case. The only problem, aside
from an occasional quizzical look, was that regular gloves didn\'t fit.

Joe Gwinn

 

[Sylvia Else]

On 18-Feb-22 7:31 pm, Sylvia Else wrote:

I\'ve got a board made that includes pads for some 0603 smds.

How was I expected to know that 0603 is used for both imperial and
metric sizes? No wonder there\'s no way I can put my imperial 0603
components onto the metric 0603 landing pads.

0603 appears to be the only size where this trap arises, and I fell
right into it.

If I\'d printed out the PCB layout at 1:1 scale, I might have realised
that the pads were absurdly small, but of course, I didn\'t.

Sylvia.

Somehow, I managed to connect an imperial 0603 resistor to a metric 0603
pad. The component is skewed, and its top surface is at a 45 degree
angle to the board (!), but it is connected.

I don\'t expect that it\'s something I can repeat though.

Sylvia.

 

[Sylvia Else]

On 19-Feb-22 1:45 am, Rick C wrote:

On Friday, February 18, 2022 at 6:01:25 AM UTC-5, Jeroen Belleman wrote:
On 2022-02-18 11:11, Lasse Langwadt Christensen wrote:
fredag den 18. februar 2022 kl. 09.32.02 UTC+1 skrev Sylvia Else:
I\'ve got a board made that includes pads for some 0603 smds.

How was I expected to know that 0603 is used for both imperial and
metric sizes? No wonder there\'s no way I can put my imperial 0603
components onto the metric 0603 landing pads.

0603 appears to be the only size where this trap arises, and I fell
right into it.

also 0402 metric which is 01005 imperial

Designed to confuse. Why do people do that?

You mean why do people use the measuring system that everyone else in their country use?

No, I think the question was why was a size code needlessly duplicated?
The numbers are only an approximation to the size anyway. Whichever came
second could have been named 0604, without any other impact whatsoever.

Sylvia.

 

[server]

On Sat, 19 Feb 2022 14:27:37 +1100, Sylvia Else <sylvia@email.invalid>
wrote:

On 19-Feb-22 1:45 am, Rick C wrote:
On Friday, February 18, 2022 at 6:01:25 AM UTC-5, Jeroen Belleman wrote:
On 2022-02-18 11:11, Lasse Langwadt Christensen wrote:
fredag den 18. februar 2022 kl. 09.32.02 UTC+1 skrev Sylvia Else:
I\'ve got a board made that includes pads for some 0603 smds.

How was I expected to know that 0603 is used for both imperial and
metric sizes? No wonder there\'s no way I can put my imperial 0603
components onto the metric 0603 landing pads.

0603 appears to be the only size where this trap arises, and I fell
right into it.

also 0402 metric which is 01005 imperial

Designed to confuse. Why do people do that?

You mean why do people use the measuring system that everyone else in their country use?

No, I think the question was why was a size code needlessly duplicated?
The numbers are only an approximation to the size anyway. Whichever came
second could have been named 0604, without any other impact whatsoever.

Sylvia.

Then there are the sideways caps, like 0306.



--

I yam what I yam - Popeye

 

[Rick C]

On Friday, February 18, 2022 at 10:27:51 PM UTC-5, Sylvia Else wrote:

On 19-Feb-22 1:45 am, Rick C wrote:
On Friday, February 18, 2022 at 6:01:25 AM UTC-5, Jeroen Belleman wrote:
On 2022-02-18 11:11, Lasse Langwadt Christensen wrote:
fredag den 18. februar 2022 kl. 09.32.02 UTC+1 skrev Sylvia Else:
I\'ve got a board made that includes pads for some 0603 smds.

How was I expected to know that 0603 is used for both imperial and
metric sizes? No wonder there\'s no way I can put my imperial 0603
components onto the metric 0603 landing pads.

0603 appears to be the only size where this trap arises, and I fell
right into it.

also 0402 metric which is 01005 imperial

Designed to confuse. Why do people do that?

You mean why do people use the measuring system that everyone else in their country use?
No, I think the question was why was a size code needlessly duplicated?
The numbers are only an approximation to the size anyway. Whichever came
second could have been named 0604, without any other impact whatsoever.

It\'s not about first or second. The convention is to name the part by its size. If you are using metric the size will be named by the approximate metric values.

People need to learn this is a metric world. Do you really think the rest of the world is bound by the mistakes made in the US fifty years ago?

While anyone can make a mistake, in reality, this is your mistake. I sympathize with your problem, but it is not the responsibility of the people who make the parts. Have you figured out exactly how it happened? Did an engineer specify the wrong part? Or was it an error in the layout where someone didn\'t understand the names of the footprints in their system?

If you can\'t get the SMT parts to solder properly, you might try using small wires to connect the parts.

--

Rick C.

--+ Get 1,000 miles of free Supercharging
--+ Tesla referral code - https://ts.la/richard11209