alright everyone and good morning and welcome to the
webinar this morning my name is mark mousetrap
I am senior sales
engineer here at the fr solutions on the line with me
today is Dr greg hilman the ceo of the fr solutions
today's webinar will be on
common mistakes by electronic design teams
and this is part Ⅰ of a two part series
and we just want to go over some ground
rules before we get started here for the webinar
so all lines are muted so only
craig and I will be able to speak this morning
if you have any questions for us
just go to the
questions tab on your go to webinar window
right in your question
and will be addressing them
at the end of the presentation
in addition this webinar is being recorded
and we will be posting it to dfr solutions
com at
a a date to be determined later
it should be in a few days
usually takes about two or three to post the website
but you can get a copy for me sooner than that
and at the end of the webinar
there will be a slide in which my email information
will pop up on screen so just go ahead and record that
and
send me an email and I can go ahead and get you the
copy of the webinar today
so with that I'm going to let craig take it away
go ahead
greg I believe you may be on mute
thank you mark
I want to thank everyone today
for attending our webbing
greatly appreciate you taking time
out of your busy schedule
to kind of learn
some of the comm mistakes that we here at dr
kind of observe with design teams
initiate and engage with them in regards to
making sure that they kind of hit
their customers or market expectations
of quality and reliability
for those who are not familiar with dr
just want to give you a couple slide
indication of
who we are and why we exist
so for solutions that you've not heard of us
before is the industry leader
in quality reliability and durability of electronics
we're a very focused organization
we are not journalists
we only focus on electronic
materials components products and larger systems
and we don't compete against our customers
we're really
about supporting our customers
through the new product introduction process
and being very aggressive and proactive
ensuring that we hit reliability goals
as early in the design process as possible
we think we've kind of hit a growing need industry
to kind of be aggressive with reliability up front
and being aggressive with revealing designs
whether in house
or outsource to a third party
we've been doing this for 12 years
we've grown every year we've been in business
we've actually built up a really nice team here at dr
we're approaching 50 individuals
into a variety of areas and
in engagements with our customers
and really it results in one thing
which is we are able to provide our customers
kind of end and expertise again
the kind of quality and reliability of electronics
but as you know
quality reliability touches is
has multiple touch points in the process
we make sure that we provide our customers
to support they need
in each of those
gates in the process
so we do it by providing a range of activity and
support engagement
we also do it by having
experts in a broad variety of areas
and I like to highlight three
that I think I'm most proud of
and are kind of some of our newest areas
of support
and that includes batteries and increasingly important
aspect of electronic systems
especially with it
power supplies
thermal and electrical designs of power supplies
and some of the challenges they have
in terms of affecting reliability of larger systems
and in housing a chassis both in metal and plastics
we built the burial expertise in terms of
brightening guidance
especially in regards to how to water
best waterproof and chock proof your product
so today we're going to talk about con mistakes and
electronic design teams make
and the motivation in some respects is a positive one
if you really think about it
technology electronic hardware has kind of one
right it is really
one of the largest
and fastest growing markets in the world
right if we compare it to like
furniture and
cars and housing and roads and food and clothing
and all this thing
electronics is up there $2 trillion a year
and not only is one of the largest markets
in the world
it's still one of the fastest growings right
so a huge opportunity for all of us
on the line who are involved electronic hardware
congratulations you've picked the right industry right
and we want to keep growing
we want to be part of a growing
infrastructure of growing organization
and so where are the biggest growth opportunities
we look kind of out in the next five to 10 years
and there's two key ones
what we hear dfr
well there's we call economist transportation
so not just the time this vehicle
but atom planes the time it's drones
the thomas railway
anywhere where there is more
computer engagement in terms of controlling
the transportation structure
and also not just internet of things
but most specifically what we call industrial iot
that's where it's really more
b to b business to business
really more kind of
how it is helping the business infrastructure
and what that
subsidiarity is simply typically called m2m
or machine to machine communication
so when we think about these two
areas that are really going to be the growth drivers
for electronic hardware and technology
over the next kind of five
to 10 years
what special about those two areas
is to remember that winners in these areas
people who will win the contract
who will design the right things
that will stay pace with expectations
are not going to win solely on price
both of those areas because
well we're talking about transportation No.1
and we're talking about industrial
industrial things
that with our safety issues and lots of
money at stake
quality reliability are paramount
you've got to demonstrate you yourself
your team your organization
if you're releasing a product
either directly to the market
or to a customer who is part of that market
you got to hit those quality reliability targets
you got surpass those quality reliability targets
and that's going to be difficult
because the environments where your product is going
to sit
in those two markets are extremely challenging
higher temperatures a lot of shaking a lot of faking
a lot of corrosion all this kind of good stuff
so the days of where we can
you know this idea of consumer electronics right
or price win prices
paramount right
is changing least when it comes to electronic hardware
so if we want to compete in these growth areas
right quality reliability is really critical
in order for me hit my quality reliability targets
right well
we afar started thinking about
and how we put together
this presentation was
we got to avoid the most common mistakes
and those those common mistakes can happen really
at almost the early
stage of the hardware design process
almost at concept in fact
I had a meeting with gentlemen who talked about
concept reliability planning
the talking about reliability at concept stage
a very rare technique very rarely implemented
but really things to think about
and really almost the key justifications why
people I want you to say reliability engineers
but people with a bent towards reliability
whether they're electrical
mechanical thermal materials
program managers whoever need
to be kind of bringing reliability
into the conversation
in the earliest stages
so when we look to comm mistakes among our customers
that we have observed
we saw the kind of congroupt them into four
key categories
we call who controls what
make versus by
right sizing and thermal
and so I'm going to try to touch on each one of those
as best I can
you guys are actually in luck
congratulations
because this is actually only half the presentation
as mark was indicating
so we'll be able to go through these kind of mistakes
in relatively short order
so harbor design who controls what
for those who are involved in the harbor design process
this should look really similar to you right
sometimes it's marketing in sales right
you're building a product for a larger market right
and so it's marking job to go out there
and know the market
know what the customers want right
but the question becomes is can you really build it
right sometimes
you're building a product just for a single customer
right maybe your
design manufacturer
maybe you're a captured design team
right so you're building it for a particular program
right so customers always right right
but you do miss something
is there something being lost in translation
that's going to kind of cause issues in the future
and then there's engineering
right in the day engineering right
you can entering always can build something right
but the question is will the marketing
will the market or the customer buy it
right and when they build it
are they satisfying or mitigating
the common kind of trade off
and tug of wars that can happen
between the electrical and mechanical side
the two
key elements of the design team that really kind of
make the product but kind of have to
not get into each other's way so to speak
so how do we kind of mitigate the mistakes right
in terms of this
engagement with all three of these parties
so the first thing we also recommend is
when we look at the product requirement
document that's typically
being created
we really are looking at it from a early critical
in terms of does it
actually represent actual use cases
have people have the design team the marketing or even
the customer ask the question
who's going to be using it
how is it going to be used where it will be used
how long does it need to work right
are those critical elements
in the product requirement document document
either specifically or
those questions have been answered
and they've kind of influenced assets
the product requirement document
many of my cow called best practice customers
even use a checklist at this stage
and the key thing is to avoid what you don't know
you don't know
right I didn't know the customer really needed this
and typically we don't know that
because we didn't ask that question
typically we spent a lot of time focusing on specs
right fishing in the military space
transportation area right did it meet spec
right marketing knows all about specs typically
may have it like specs because it
believes they hit the specs
they can sell the product right
but specs have a limited value
when it comes to quality reliability right it
means specs doesn't mean effect quality reliability
expectations
right limit those investigations
to kind of we call communication protocols right
if they're seeing the iot space
you go be able to talk to something right
if you're not speaking the same language
that's not going to work
right and compliance requirements right emc safety ul
all the good things
and so if
we make sure we hit the fact we always do that right
but if we don't spend too much time on that
and say focus on product requirements and use case
and develop that
internal checklist
we're really going to get ourselves well set up
and so what does an internal checklist kind of look
like
I thought I would just kind of give one example
because I said I want to spend
evidence here to kind of ramble on in these
presentations
and I'm sure your time is very valuable
but I thought I would just give kind of one
example of this
this is in terms of environment right
so this is actually a common checklist that we
push out to our customers
when we're doing designer views
or we kind of implement internally
have we talked about temperature
right how temperature changes
or how temperature is constant
how we talked about humidity levels and
water and moisture is humidity controlled
is there risk of condensation right
is it a small box it's just on a large metal structure
and there's no heat in the box
right hell we talked about other corrosive risks
saw crossover gases
have we talked about electrical issues
power cycling
electrical loads
transient conditions
electrical noise
have we talked about mechanical effects
bending vibration mechanical shock right
sometimes there
are application environments where you are surprised
that some of the environments
actually do exist in our concern
do you actually give me a great example
we work a lot with companies in the set top box space
right cable
files horizon right how we get our movies to our tv
right
we had no idea how hot the temperature is
inside that box
these stay the art technology
right nobody likes to have their movie
be held up by their watching it
so you need to have stuff that's screaming fast
high resolution
right but no fan
right now we want to hear a fan
when they're watching their favorite movie
and sometimes
these set up boxes are on on top of the tv anymore
because the tv is a flat screen right
but it's kind of inside and enclosed
it's not kind of cabinet right
so no air flow write really stuffy temperatures
7080 90 degrees celsius sometimes inside that box
when we talk about who controls what also
the key thing is also to embrace
in case I drew a little arrow
if you guys didn't get the
thing with snoopy and woodstock
but embrace design checks and embrace analysis tools
I know as a manager myself
and as those who are managers on the phone right
you can be really
concerned about what we call paralysis by analysis
but that really is very much last century
the analysis
tools that are available to engineers nowadays
are really impressive
and can provide information amazingly rapidly
right
and what's great about design analysis tools
it allows us to be to kind of create a product
an agile development process that our suffer
cousins have embraced with
extensive fever and passion
over the last kind of 10 to 15 years
right in some respects
software is agile development
hardware is still waterfall
part of is because the amount of effort
and money committed
once you lock that design in place right
so if we kind of do a lot of analysis
while the design is still
flexible
right electrical analysis mechanical
thermal manufacturing reliability
it brings a lot more agility into that design process
and what's also great is about design alice's tools
we can move away from design rules
which unfortunately
are often arbitrary
and are often the most
common source of conflict between
engineering and marketing right
I mean we understand why design rules exist
there's some product in the past where you guys did
something right it didn't work
right
people are worried that they'll have the problem again
they don't really understand what happened
this is not made from a quantitative perspective
so the implemented design rule all right
we can't have any
silicon carbide fats we can have
any connectors with
palladium we can't have anything closer
to the edge than x amount
we can have
junction temperatures higher than 72 degrees celsius
right and so what ends up happening especially the way
technology evolves is at some point
that design rule is going to be a source of conflict
and it can be difficult for ensuring to justify it
or it can be difficult for marketing to get around it
right and so both sides are going to be unhappy
but if you use these design else's tools right
you can talk about trade offs
okay if we run the strict temperature at 76 72
okay it's going to do x in terms of performance
it's going to do y in terms of reliability right
if I put the component here it means
this the yields will go from x to y right
on the number of information
mortalities will change five
this amount this all gets down to
understanding what the real bottom line effects are
and we can get all this information
before we finalize the build
it's a really powerful opportunity we find
in terms of this who controls what process
but you can see for example
you need these diagnosis tools at this stage
in order to mitigate these kind of mistakes
it's also very important odyssey
the design is only as good as it's supply chain
and that really often goes to manufacture ability
right you want to make sure that
in fact I've seen one of the mystics you seen is again
these design rules arbitrary design rules
have no context
right
as we actually I think one of my fellow
experts talked about in a great internal presentation
right
I can have pcv shops that can do
two mill lines and two mill spaces
or I can they can do six mo line in six no spaces
it all depends on
the equipment that they decided to buy
the process easy to eye to invest in right
the more high end the equipment
the more people of the equipment the more expensive
right costs go up
right
so you pick the supply chain
probably driven by cost and availability right
make sure that what they have decided to focus on
their areas of expertise
is incorporated in terms of your design capabilities
so we've defined the market who's controlling
what how we're resolving that right
now that we've identified the market
or the needs or the product requirements
now we gotta say how do we satisfy that
and there's a number of ways you can do that and that's
the classic make versus by so we can do off the shelf
right buying motherboards enclosures peripherals
you can outsource the design
for what they call odm or original design manufacturer
right dell and hp
are this kind of secondary
option the outsource their design
and there's lots of debates and differentiations
both between dell and hp and lenovo
but even within those organizations about
how much control they have over that design
what kind of suspect do they do
do they fully out source the schematic and the layout
to the only outsource to layout
do the outsource all aspects of it some aspects of it
how much controlled do they establish
and then all I see you can do it all yourself
you have a comprehensive design team
you can design the schematic to layout that pick
the connectors fix the enclosure
decide the cabling
or even some combination of all
three impart in terms of a larger system
we've seen this actually with
with some classic avionics boxes
right there'll be 10 boards
in an avion xbox
two of them will be able to be off the shelf
maybe they're
classic kind of power supply
or maybe some kind of communication board
maybe two more will be what they call kind of
outsource design
so this tier one will go to a tier two or tier three
and so I need you design these relatively simple boards
and then kind of the core ip
they're remaining kind of five or six boards
that's all done in sourced
so when we make these kind of make
versus buy decisions again
there are mistakes that can happen
at this stage of the process
right deciding who does what
and there are ways to mitigate that right so
we think about cots
commercial off the shelf
there are significant benefits
for a plushy firm management perspective
I don't need any money up front right
I'm running a check for
hundreds of thousands or millions of dollars
while I'm winning for a design to be built out right
and sometimes some of that supply chain
that's giving you this cut
already has kind of these agency shirts
right you all certification ce marks
right what have you right
however you have to remember
caught right we're focusing
especially this presentation on where
the areas of growth are
constants and really work well for those growth areas
right because you're really
losing your lacking information on the design
and you have no configuration control right
so if you're going to build
something for autonomous transportation
and rely on I don't know
some graphics board right that you can find on amazon
and you're going to supply
this autonomous control for 10 years
that graphics board is possibly going to change
or not be available
is something that can be difficult or expensive or
not timely to try to make sure whatever you have
acquired viaducts
is 100 compatible with the larger
system that may be
also outsourced or insourced from a design perspective
right so
at least the areas of big growth electronics hardware
our recommendation would be
constant is really about very common peripherals
right solid state drives don't go out
and design your own solid state drive
right for the most part
my unless you have some very specific
very difficult requirements to me
when we look at outsource versus in source
right
many systems are contained some outsource design work
very common
and we see very common in the military aviation world
as just one example
especially here in the dc area
and there are some
values in terms of out sourcing design work
I especially if you find
a supplier that
has a lot of expertise in this particular area right
it also allows you to kind of offload
management of some supply
chain issues
right counterfeiting and
lead free and all that kind of good stuff
in theoretically if you
have the right contract in place
there's transparency right so again especially
high levels of supply chain
again if there's questions about quality reliability
or
design configuration control
you have visibility into that
those questions
often
the recommendation we make in terms of alfrefore's
in source
is the vendor selection is key as kind of as
indicating and
one way of
getting very kind of informal way of indicating
that you've picked the right vendor
is getting some push back
right if you're asking for certain functions
certain capabilities
certain geometric constraints
and all you're getting back is
thumbs up yes
that's probably a really a big red flag
so we've talked about
who controls what make versus by
right now we're going to ready to actually
design the product
and the two challenges we see are right
sizing and thermal issues
and the two are very much
linked together
so
most of you
when I put this up I get a lot of nodding of heads
in most conferences right
marketing wants the
belief and sleek ipad
and engineering wants to build a tank right
and both of them for obvious reasons
come when we go back to who controls what right
with right sizing
and we've seen this multiple times of dr
we really recommend trying to keep the dimensions
loose as late as possible in the design process
right often what you'll see
especially when you take the classic
v and v approach verification validation
which I'm not a big fan of
and I'll talk about that in a minute right
the size requirements come flowing in 1st
okay it has to be three by four or four by five
or whatever it is right
if you push hard you'll find
these size constraints are somewhat arbitrary
and the flexibility around
those size constraints is not
always clearly communicated to the design team
right and so by forcing you into a pickler sized box
right you get all sorts of
challenges
problems propping up in terms of thermal issues
fragility interconnect strategies
poor choices and component selection
let me give you a little example
so really tiny chick components pretty often stuff
right if you look at that picture there
that's a head of a match
which is hard to see in the first place
now imagine trying to see that 01
05 or if you live in the metric world
0402
really difficult stuff to put down
what you don't mean not realize is
there are tradeoffs there are limitations
when you go from an 0603
to no 1005
especially when it comes to capacitors resistors
maybe not so much
but definitely comes the capacitors capacitors
pretty sophisticated technology
you may not realize
so we had one customers poached again pushed a very
arbitrary dimensional requirement
the way that we resolve this was going to
0201 components now
our capacitors this is going back a few years now
right but major issues across the board
in terms of performance
quality reliability when they made that switch
and part of the challenges
was they were in a relatively
robust environment the acceptation was 10 year life
and when they started making acquiries what they found
out was again at that time
was that the overall
majority of companies have bought o21 capacitors
we're hearing aid manufacturers
six months life
if you're at best because
people constantly dropping these things in the toilet
right
so
not really well aligned with their environmental needs
not really well lined with their reliability needs
and really just a bad fit in general
so I'm a gray example
in terms of michael
right sizing is the toyota approach
now toyota has had some bumps in the road lately
we're kind of ignore that
I think the general
approach to it takes is a major plus right
and what they tried to do
is really try to concentrate efforts
at developing knowledge at the lowest
possible design level
so they don't flow down requirements so
they kind of cut their v in half
in some respects right
they really want to understand that technology really
well right
and based on that understanding they build up a system
so they have the best technology
in each aspect of the system architecture right
the example of the radio design
I think is often perfect
right and there was a book I read many years ago now
about the receipt the release of the 1998
or 2000 model year tourists
right and what they talked about was
the people who drove this for the car designers
they were at the top of the
heap so to speak
and they had
designed this very sleek beautiful taurus
that had a certain size engine
they had a bunch of other people
who looked out on the market and said okay
the torus has to have this amount of horsepower
and these features
and then engineering was told
hit this horsepower hit this features inside this
inside this hood space
this space under the hood
and so there ended up being huge fights over
who got
what amount of volume how much the radiator got
how much the water or pump got how much the engine got
all these crazy things right
and so you could see
in some respect they were very successful
but you could see
the craziness and the wrist and the initial
product delays because of these challenges
whereas toyota said you know what
let me really understand radiators
I want a radiator
expert who's testing radiators of different
technologies
different sizes
understands all that
and then they kind of
pick the radiator that works best
and then kind of ask the designers to design the car
around the best technology
so it's kind of almost like a test and design
right rather than design and test
so the whole right sizing how big something should be
really well lines with thermal issues right
because
I can have
heat in the box I can finish you get that heat
out to the box right
but then the box becomes too small to radiate the heat
right the smaller the box
the hotter o get
and this radiation of heat radiation
or heat radiation or some radiation
is actually really critical
again in these kind of high rail
high growth opportunity applications
because most of them are not going to allow fans
right convection
is out
you might be lucky at conduction
if you're attached to a big pole
right but familiar far convection is out right
worried about reliability of fans
there are possibly of interesting corrosion from
the outside atmosphere
all these issues
so how do I kind of attack the thermal issue saying
and we recommend kind of a three step process right
so step one is again at concept stage
there are some great rules of thumb
they're out there
right even before you really know kind of
what the things going to do
or even you know
only have rough idea what the box is going to be
one of the ones that we use
that we like is actually put out by hoffman
they make enclosures
and they actually give you can see on the right here
this great little kind of
estimation of temperature rise
as a function of watts per square foot
on the outside of the box
right again it starts to give you kind of
a
rough rule of thumb in terms of argue
going to have real problems
you know
40 50 degrees seat temperature rise
or kind of are you you know down more like in the
10 to 15 degrees temperature rise right
where are you in terms of fossil risks
right as you're moving closer
or moving along the mpi process and starting to
develop and build out some aspects of the design
we recommend that everybody learn
just a little bit of cfd
or computational fluid dynamics
it's either than you might think
it can be a little frustrating because of these
reynold and new salt numbers which
give me a headache
but again we've given you a link
not just for the hoffman online
rule of thumb but also as for this little
heat sink calculator again
how to calculate temperature rise
in a sealed enclosure
orientation is more
important than you might imagine now
actually I have that in my next slide
so I'm jumping ahead
and so once you've kind of have your rule of thumb
once you've done some kind of
pen and paper calculations
really that's when you're ready to start using some of
the analysis tools
and naturally true for almost anything to some extent
what we often see
again best practices and what we recommend is
you shouldn't
over rely on analysis tools
like don't go straight to circulation tools like spice
don't go straight to cfd don't go straight to fda
right you want to do some initial
pen and paper calculations yourself
to understand where you are right
but those pen and paper calculations
also don't necessarily substitute
for the more rigorous and robust analysis tools that
eventually are required
and as you're understanding what the temperature rises
by running all these activities
be aware of some of the rules
and approaches to optimize your cereal design
because you want to incorporate that
into some of your analysis activities
right so some nice rule of thumbs
then we can at least put in one single slide
like I said
orientation is more important than you might think
right again especially for convection
behavior again
without fans
right so if you can control it that's great
if you can't control it
you'd better make sure that your thermals are working
under worst case orientations
we've seen these issue with some of our customers
the reality is
there's not much
new under the sun when it comes to thermal solutions
to some extent
and even those that are kind of
some extent new
will have limited effects right
so
things says to go about and again
it's almost like a checkbox right
check or checklists are great
process tools to implement
so you can look at package selection
like direct fed is going to be a little bit better
than like a classic t0220
you have interfaced materials to look at
thin authentication of the heat sink
pcb design so number of layers copper sickness
copper coining
thermal vias
and the adhesive material copper versus aluminum
right
paint that color of the surface is
important
only when you're in the radiation played a more
important role
in terms of thermals
and I said to now we're without fans radiation
and you got radiation and convection to some extent
right
and so if you don't have an opportunity for much
for a large heat sink
so it's going to be relatively small heat sinking
right so either it's just a metal box by itself or
can relatively small fins
and you're still seeing a snipping at temperature eyes
it's amazing the improvement you can get by going from
a lighter color to going to black
right so not to forget about
if you're lucky enough in these
growth areas to be able to use fans right
the optimum design is you want some turbulent flow
at the heat source
and then you want laminar everywhere else
right to take that heat away right
if I can get turbo
at the heat source
I can really get almost two
x amount of heat dissipation
that if it's simply laminar everywhere right
laminar flow is very good at taking heat out
but not initially extracting the heat at
the source of the problem
so that's kind of
at the very early stages of crafting that design
right so you can call it conceptual
you can call it functional block
whatever we want to call it
right
now we have developed a kind of conceptual design
now we can move on to kind of picking our components
so
how do we kind of avoid some common states
and picking components
so really important rule of thumbs keep it simple
right new component technology very attractive
hey I fall in love with it sometimes too right
not always very appropriate again for these
high reliability applications
where are we going
after again these growth areas
it's important to be conservative
one of the reasons is
the marketing hype of complement vendors does to
exceed the actual implementation
this is the example of the o201 example
I gave you where everybody was using that 021
with a hearing aid manufacturer
you see this a lot
then part of it is because
the
really really large volumes of very very
small number of applications
really kind of
tweak or warp
kind of really
how many people
or how many companies are really using the product
so we've seen this again to go back to chip components
if you see kind of marketing projections
for chip components you'll see
o21 might be the most
popular chip component out there right now
for example right
but that's because
there are maybe
25 companies using o2 on term capacitors
but each of them
is putting out 1 billion
products a year
or something on those lines right
so electronics industry has a really long tail right
it's that really long tale where most of us live
and need to our applications and expectations
and manufacturing environments
are very challenging and may not necessarily work
for these kind of very new component technologies
and even when you find out that somebody like
you is using that technology
be aware that sometimes modifications are made
that aren't necessarily
kind of projected or communicated
through the rest of the industry
right can be proprietary
when we take our electron components
one of the ways we try to
make sure the components are robust is we do d rating
right very common technique
it's a practice of limiting stress on
the trunk components
right to below the manufacturer's ratings
it's kind of an dishing
concept if you really stand back and think about it
right you're kind of saying the manufacturer
I don't really trust you
it's typically used to do three things
one is to make sure that it stays functional right
it provides the margin of safety from deviate
lots right if you think that
you have some distribution of defects and
electrical stresses
or the thermal stresses is some distribution of stress
if I pull back on the stress
and I have less likelihood of
having those two distributions overlap
and also allow some desired operating lifetime right
temperature does play a critical role in lifetime
wire bonds
dial at your breakdown ultra migration
capacitor electrolyte evaporation
all those good things right
and
the way we make sure that we are hitting our d ratings
is
we typically do some kind of component stress analysis
so
all sounds nice and good and was very familiar with it
so how do we vote to
avoid some of the common mistakes
when it comes to de rating
so
what we see
typically in terms of d rating mistakes is two things
one is
we actually didn't do the d rating we thought we did
and it falls into two categories
when we talk about analog and power designs
degrading is typically
overlooked during transient events
especially turn on turn off
right so we're looking at an aesthetic way
but let's say you may have
an application which turn on
once a day or turn on twice a day
and each one of those turn ons
you have a very quick tree indeed event it could be
microseconds it could be milliseconds
but during that event
voltages are very high or currents are very high
really slams those components
or on the foots I we have digital designs
typically everything is upbringing off
a certain bus
right five old bus a three point three volt bus
things should be much more
controlled in additional arena
right requires a lot less black magic
but then we have issues where there's so
many components and so many connections
people kind of do a lot of shortcutting
they only
look at the most critical aspect of the digital
design or where the biggest changes have been done
and not really
understanding the risks throughout the entire digital
architecture
the 2nd way during mistakes were made is
actually almost the opposite
so it's not that defeating wasn't done
but it was done in a way that's not really practical
right
theoretically
it should have a practical scientific foundation right
and there are actually our situations wore
really aggressive derivation
is not always better
and so you have to be aware that
we sometime not only does the d rating that
always have a strong foundation
you should also be aware that the rating
doesn't always have a strong scientific foundation
in fact what I find often really funny is
if I get up myself into a room full of
reliability engineers
there can be rather heated
arguments over what the d rating rules should be
I've customers who constantly are asking me for
dreading handbooks that they can follow
but what they don't understand is
the ratings themselves
are driven more by tradition and market forces
than by science
let's let me give you an example right here
and I've actually another one in my head
so this is
a wonderful load table
released by chemist in one of their
technology
reports that they have on their website
and its purpose was to demonstrate how robust
the new
version of town capacitors with a polymer cathode
was
right
so you can see I kind of cut off part of the table
because I wasn't
relation in the marketing aspect of the polymer
the tail and polymer capacitor
I was not tradition
what this thing was saying about the
traditional capacitors
with manganese dioxide cathodes
and what you'll see is right
what they're trying to show you is
the failure rate for magnesia cathodes is
roughly 10 ppm at startup
but at 50 rating but for the polymer you can get up to
you can get that same silly rate at like not 80 or 90
degrading right
then my question was
why can I get a 10 % rate
at the rated voltage for the old towns passer
since when it is
where does the reading come from that if I use it
100% of rated
0.3 % of the capacitors will fail on startup
let me think about some of the larger
more complex designs
you could have
10 20 30 town capacitors on a board right
so now what we're talking about is
they're going to be a failure rate of like 10 %
of the boards could fill out startup
just because if I'm using
30 kiln capacitors at the paraded voltage right
so where does this come from par
where has come from this
when pounds pastors first came out
there were a new technology there was a lot of defects
the whole kind of
self healing process had not been fully optimized
and the major
vendor of r s render
the major consumer of this technology was military
so how does the military deal with this right
the way they dealt with
this is they developed a de rating system right
and that
became kind of a default way of dealing with things
and that whole military de rating
system kind of actually got
incorporated and adopted by
the commercial world as well
another day
if I can think about it in terms of like you know
tradition and marketing is we were looking at two
component vendors for high temperature
products
both components
from two different vendors rated to 150 degrees c
right
but based on testing of those two components and
conversations with customers
one group decides that 150 degrees c
right had a very limited lifetime
so it was only
designed to be used at 150 degrees c for short
periods of time
and that was primarily because
that component vendor was
selling into our mode of market
right another component vendor running a 150 degree c
was selling into the aviation market and serve them
100 degrees c minute had to be 100 degree c
robust for
tens of thousands of hours so same rating 150 degrees c
right
kind of confirmed and design lifetimes
completely different
based upon
the two different markets they're selling to
and you would never know that
pulling up the duty issue
so something you think about right
what will you offer recommend terms of the d rating
decision tree
I'm trying to d raid based on the compound performance
not the ratings right
best practice
do it all still returns if you can right
ashes the question right is a really a clear difference
if you have one product with
parts running at 60 rate of voltage
another product running at 50 % rate of voltage
right are they coming back to fin the field
the two different failure rates right
you can also do some
work all test to fill your qualification
almost like a halt for components right
these are going to be expensive activities so
if you can do it you probably want to limit to the
critical components
if you can't do that
or if you only do it for a certain number of compost
next stage is
asked to manufacture how you should degrade it
right and that's how we found out this
150c for 1 000 hours there was a 150c for 10
20 or 30 000 hours
was basically asking the question
the amazing how many of my customers
just for some reason
don't pick up the phone and call the component vendor
lots of nice people there
they don't always care whether you're buying
one or 1 million
especially if they're fellow engineers
right
the customer is always right
so if those two things don't work
right the customer remains in front of requirements
and then really
only step four
is when you start working to off the standard right
and even when you're working off the standard
make sure that you're flexible
don't be absolute
we've probably seen more
failures where people were rigid
what their d ring requirements then where people
give themselves a little bit of flexibility right
you know our internal recommendation is 66
but I want with 70 right we don't see a catastrophic
failures when they go up
but when they
switch from an aluminum heat sink to a
copper heat sink because they can't hit
95 degrees heat junction temperature
right that copper heat thing goes flying off
and there's a shock event or where there's
any kind of vibration
the last kind of
common
I'll talk about gets into the electrical world
which islam and I have no degree in
but I actually see this quite often on my team
when they report it back to me when they're doing
these interviews
is power sequencing
so power single thing is actually quite interesting
it's when I have two integrated circuits
on different power rails so v1v2 right
but they are still connected
in some way
and so if you're not careful about how those
two integrated circuits are powered up
there's a risk you can get high current flow
through one or through both
and then you can have a lacked up condition
the reason why it's one of the most
geological mistakes is
it's kind of an electrical
versus mechanical where we find things get dropped
same situation
it's often a blend of the digital and power design
right so you have a digital architecture person
you have a power architecture person
they're not as always talking to each other
or the digital person is designing the whole thing
but I'm really thinking about power
right
failure is not always immediate
it can be a big reason for one of those
no fault founds
that is very kind of like drive people crazy right
it can be difficult to test
and also difficult to identify when you do have kind of
permanent failures
in can be difficult to identify root cause
all you know is there's an eos event
right
and even when you kind of
know power significance a problem
and you're making a big effort
we find a lot of teams only focus on
half of the problem
they're focusing on what happens during turn on they're
developing really good practices for turn on
not really think about what happens when things
turn off
so
high current foes can damaged ic over time
due to elevate temperature
it can also get the ic to behave erratically
and again if you think about
how this causes failure again
it can consider that's
always being communicated to you
so
one of the classroom cables is
I'm sure we all have technology
in some ways you perform
that for some reason kind of freezes are acts weird
and then we have to do a power cycle
right why is that
why are you ever seek about that
why a Paris lego kind of clears everything out
there's a number of reasons for it
depending upon the technology
but again one of the more common ones
is this latch up situation we're getting
one of the ics is kind of getting
stock in certain positions
depending on the complexity of the ic
and which rails
parts that I see are connected to
it may not be the whole icy
and the only a certain functionality
within that integrated circuit
how do we avoid this common mistake
there are actually our three methodologies
they're called sequential ratiometric or simultase
sequencing
the method to use
and the order the sequence is going to vary
especially for complex integrated circuits
it's really about kind of being
again upfront with that manufacturer
asking them for guidance
and then also kind of the overall circuit design
around those integrated circuits
so this is kind of some integrations of how you do it
so sequential sequencing
each parcel is separately sequenced
so the next supply will not come up
until the first one is regulating right
so that's a little bit easier to implement
right
for ratio metric sequencing
each power supply starts together
ramps up and down at the same time right
that invitation is really good
being upon the power supplies
that are supplying voltages to those rails
which ones are they
it's not really as common
you can also do simultaneous sequencing right
so here each power supply ran up together at the same
voltage until they start regulation
again implementation
not as common right
as the sequential sequencing right begin
there
can be limitations in terms of timing in terms of
space available
that may not actually allow you to do
sequential sequencing
in the first place
so in conclusion
I have a surprise conclusion for everybody
the conclusion is
at 10 part Ⅱ of this presentation
so my colleague michael plateau
we'll be
talking about the second part of the presentation
they'll focus more on the mechanical elements of the
design
housing
physics of failure
and they'll kind of wrap up that presentation with an
overall conclusion in terms of winning
common design mistakes
in the meantime
for myself
I want to thank everybody for attending this
presentation
if you have any questions or comments
feel free to contact myself
our mark was autonomy
and looking forward to seeing you guys
on the presentation
next week
all right thank you craig
for that great presentation
looks like we have just a few questions here rolling in
a couple people thanking you for the training
so that's always good to say
and I see we have a question here
about one will the slides be available
so the slides will be available
as I said at the outset of the webinar
if you want to take down
my email and I am mark mustang
just email me directly
and I can get you a recording of the webinar
right after this
so please feel free to do that if you're interested
as for the slides being posted to our website
that will take a few days
but they should be up there relatively soon
now craig we do have a question for you here
and it's more of a comment
actually it says the d rating looks like something
to investigate more than I
or more of that I initially
though
not
more than I guess
I guess they meant to say more than I initially saw it
so that's good that
people are kind of taken that out of your presentation
if anybody else has any questions
I do want to give you a chance
to write them into the questions bar
so if you'd like to do that you can do that now
as I'm kind of wrapping up the presentation
just as a note
we will have another
another presentation at 2pm eastern time today
if you'd like to attend that
if you feel like you missed anything
or want to sit through and on this again
please feel free to sign up for the 2pm eastern
webinar today
it will be the exact same webinar that craig gave
and then of course
please do follow his advice and join us next week with
michael blotto
on part Ⅱ of this presentation
so I'm not seeing any additional questions
so we're going to go ahead and close
out the presentation
at this point in time
thank you for attending everyone and have a great day