Footprints are the CAD representations of the pads (and other physical/mechanical features) of a board-level component.
Questions tagged [footprint]
353 questions
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Can you place vias inside a QFN footprint?
I am designing a very dense PCB containing a 0.4mm pitch QFN chip. In parts it is proving very difficult to fan out. It is made all the more difficult by the huge thermal pad that all QFNs have for some reason.
It is reasonable to place tiny vias…
Rocketmagnet
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Why would metal from a pad be *underneath* the solder mask in a footprint specification?
One of TI's new regulators has a rather unusual footprint, with several pads (7-13 in this instance) requiring that the pad metal extend under the solder mask.
This is in contrast to the usual case where the solder mark starts some distance…
Damien
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17
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4 answers
Why is it so hard to find component footprints?
When designing PCB's, I find myself very often having to make footprints for a significant portion of the components on my board. This tends to be very time-consuming, as (in Altium at least), dimensioning out land patterns for strange connectors or…
zplizzi
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17
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The "right" 0805 footprint land pattern
My PCB design software comes with some libraries that include some common components, like chip resistors and capacitors. I have noticed, however, that the footprint land pattern for the 0805 resistor is not identical to the 0805 capacitor.
I then…
ajs410
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How can I indicate pin 1 on a SMT package footprint without silkscreen
Sometimes when I order PCBs from a board house, I omit the bottom silkscreen for budgetary reasons. When I place surface-mount chips on the bottom of the board, I then end up with a footprint that doesn't indicate the chip orientation. This is…
W5VO
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What are the advantages of larger SMD pads at the ends of a SOIC land pattern?
I was looking at this NXP TSSOP8 footprint and was wondering why the end pads were 0.600 mm, and the non-end pads were 0.450 mm.
What advantages does this have?
PDug
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13
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‘One for all’ standardized land pattern v.s. specified land pattern in datasheet
I’ve designed lot of ‘simple’ PCBs for hobby and proof-of-concept purposes, but never for (mass)manufacturing. In order to do so in the future, and further expanding my design skills and knowledge, I’m exploring the different package outline…
Julien Roels
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SMD LED polarity marking: is the cathode marking standardized?
SMD LEDs normally have some kind of marking like the following image from here indicates:
The site states
The CATHODE lead is always the lead to be identified with ALL LEDs, including surface-mount LEDs.
There are definitely manufactures that do…
Rev
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13
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KiCad : How can I create a footprint with thermal vias?
I have a SMD chip that gets pretty warm when operating and I want to try and design a footprint that allows more ventilation and extra copper to keep it in range.
Does anyone know of a tutorial that covers how to make footprints (MOD files) with…
Bertus Kruger
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What component does the 'coupon' label refer to in terms of PCBs?
I was looking at a motherboard recently and I found a couple interestingly labelled component footprints. They're two through-hole mounted components right next to the CPU, and they seem to be called COUPON1 and COUPON2. The problem is, the two…
HotelCalifornia
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Pads in IC's corners
One can sometimes observe rectangle pads in the corners of some IC's footprints:
What are they for?
Łukasz Przeniosło
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9
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Mounting DIL8 package on SO8 footprint
As you might know, it is hard to get components these days. That's why we engineers have to get creative sometimes ;-)
The company I'm working for has a shortage of a Zener-type voltage reference which comes in a SO8 package. We have found about…
Stefan Wyss
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9
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3 answers
Unrecognized IC Package Style
I'm implementing the NXP TDA19988 HDMI transmitter IC in one of my projects and I am currently in the PCB design stage. I am building my component library and when I came across this part I wasn't sure how to proceed. I am familiar with standard…
DerStrom8
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9
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Create Altium footprint from scratch for Molex connector?
I'm trying to create a footprint for a Molex connector but I don't think it is possible to do with the wizards inside Altium, so I guess I have to do it by hand, but I am completely lost. Any help, tips, tricks, tutorial, video or whatever would…
Gustavo Corona
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Why do KiCad's library footprints for 0402 resistors and capacitors have different pad sizes?
KiCad's default library footprint for C_0402 is longer than R_0402. Why?
pericynthion
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