Questions tagged [clearance]

Clearance denotes the shortest distance between two conductive parts as measured through the air.

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5
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1answer
69 views

Barrier and slot within reduced area on a PCB

Imagine this situation in a little area of your PCB: According to the worst case and used material, I need a creepage distance = 30mm. According some tables, clearance must be 30mm. First Red banana ...
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5answers
134 views

When to use slots instead of barriers in high voltage design?

I have read a lot of information about the clearance and creepage strategies, distances, materials, etc.. I am designing my first HV PCB, main LV circuit will be on TOP and HV (6KV) on the bottom. ...
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66 views

Altium designer 19 short-circuit constraint question

I am keeping get the DRC about the short-circuit constraint. I uploaded the picture of the settings. I double clicked the pad and trace. They are all on the same net "Vsys". And there is no other ...
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1answer
131 views

crossing 240 V traces on both top and bottom sides of a 2 layer PCB

My situation is the same as the crossings encircled in white from Can I place 220V Live traces on top and bottom of PCB? Therefore, running Line traces on the top layer and Neutral traces on the ...
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1answer
145 views

Altium: how to assign a net class to unconnected pins?

I have PCB with a clearance rule for nets that can be exposed for higher voltages: In the schematic I put a blanket around the area I need to be assigned as higher voltages nets (I called this class "...
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1answer
44 views

Clearance distance and resin filler

I'm designing a circuit to detect presence of AC line voltage. It's actually a very simple device with AC side made up of a 200Kohm 1W resistor and an optocoupler and a protection diode. There will be ...
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2answers
135 views

Constrain plane clearance from annular ring in Altium

I need to constrain a plane from shorting to the annular rings of a number of vias. The dialog found at ...
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2answers
63 views

Isolating main power traces on backside of the PCB

I am currently making a build-in PSU for my own audio-effect-rack-thing. The internal PSU consists of two print-transformers(THT), one for 6VAC and the second one for 9VAC. These are also pretty low ...
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1answer
191 views

UL 840 clearances

The table 8.1 in UL840 doesn't consider clearances for voltages less than 50V (for example). I have to use a clearance of 0.2 mm on the PCB for the case of overvoltage category 1 and pollution degree ...
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0answers
39 views

Altium Design rule check 45° to pads for AOI

I would like to create a PCB component clearance rule for the AOI which looks from 45° above onto the board to optically inspect all the soldered pads. I can manually set it but that would lead to one ...
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1answer
192 views

Maximum allowable voltage between PCB traces

I have some confusion regarding the guidelines for clearance between surface uncoated PCB traces (specifically component pads). IPC-2221 guidelines and other guidelines and standards indicate spacings ...
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2answers
210 views

High Voltage Capacitor Lead Clearance

I am designing a high voltage board, 10,000 VDC. I wish to use a suitably rated capacitor such as the DHR4E4A102K2BB. When I have been studying the ...
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3answers
93 views

Electrical isolation problems when routing between pads of SMT resistors/caps

According to answers to this previous question, routing traces between the pads of SMD caps/resistors, as shown in the picture, is not dangerous as long as trace to pad clearances are obeyed and the ...
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2answers
360 views

Creepage distance over pcb

How to measure creepage distance over pcb ? Is creepage and clearance distance measure by pbc layout or soldering?
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1answer
59 views

Insulation of SiC Diode

I am reading about creepage distance and clearance and came across a T0-247-3 SiC diode (IDW20G120C5B). This diode is rated for 1.2kV which would mean that it won't break down at let's say 800V, which ...
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2answers
242 views

Cleaning up GND/PWR-plane air wire errors in EAGLE + bonus questions

So I've just finished up my first complete PCB board. The layout is 4-layer based, set up as ((1*2)*(15*16)) ---not sure if it should be ((1+2)*(15+16)) or ((1*2)+(15*16)) instead, please advise--- ...
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1answer
664 views

KiCAD Component Pad Clearances

I'm using KiCAD version 5, and I have an issue with it. Previously, I've been using OrCAD up until the point to where I needed multiple layers for my board. So, I redesigned my components, but I'm ...
2
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1answer
360 views

Altium individual clearance for polygonpour

I want to use a poured plane in my design, but i need more clearance on the bigger pads. If i increase the clearance in the rules, all the spaces between pads, will increase. Is there a way to specify,...
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2answers
2k views

How is clearance affected by altitude (air pressure)?

Let's say you have a high-voltage circuit (or any voltage really) and you want to provide appropriate clearance distance for the PCB, connector pins, etc. (Above image from link) There are standards ...
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132 views

Creepage and clearance of through hole resistor

Recently I found a resistor broken on a PCB. It is a MOF type 1/2W through hole resistor. I found that the resistor is directly placing (touching) on a PCB Live trace and I know that the potential ...
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1answer
1k views

minimum trace spacing error

A PCB made with KiCad has a configured clearance of 0.152 (6mil) but when I send it to JLC site I have this warning: "Attention please, the minimum trace spacing is out of our capability, your order ...
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1answer
90 views

What's the name of the Altium designer rule that warns if component “enters” another component area (PCB)?

The trouble is that this PCB is a capacitive pad and needs to stay inside the other component square area. What's the Altium rule to exclude this component?
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0answers
189 views

Becoming crazy with EU LVD regulation in PCB and electric strength

First of all I will explain the design characteristics of my project to make clear what it is and where it enters for regulation. It is a fixed electric/electronic installation in offices so it can'...
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1answer
97 views

TO-277A Package Rated for 1000V

I'm looking at using the following part, S4PM: Datasheet The part has a Vrrm of 1000V. The mounting pad layout shows a separation of 0.81mm between cathode and anode. This is well below IPC2221B ...
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2answers
234 views

Clearance Distance measurement

It is a snapshot from an AC/DC converter. do I need to consider "dist. 1" or "dist. 2 at" the below image to measure the correct clearance space.The caps are both Electrolytic that have an aluminum ...
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0answers
45 views

THT decopling capacitor spacing from the TQFP uC's power pin

simple question - how close can the uC's power pin (TQFP pad) and a ceramic cap's PTH pin can get so the PCB fabrication process or later exploitation would not go wrong ? Some ballpark figures for ...
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1answer
371 views

Altium trace Clearance auto finder (based on ANSI / IPC-2221/IPC-2221A standards)?

I need to make one LED PCB Bord for lighting using SO i have designed my schematic into Altium designer V16, like this (single side ): So according ANSI / IPC-2221/IPC-2221A design standards for My ...
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2answers
374 views

Why does the IPC standard allow for smaller clearance on inner layers than external layers?

Why does the IPC standard allow for smaller clearance on inner layers than external layers? In this thread it is alleged that external layers are susceptible contamination. That makes sense with home-...
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1answer
1k views

How does trace/via clearance affect parasitic inductance if they go to the same net

After reading [Mike DeSimone]'s response regarding good decoupling and bypassing practices I kept wondering about distance between wires (wire = trace or net) . [Mike DeSimone] comments that wires ...
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2answers
1k views

Rotating components in Altium Designer, clearance

I can't find out how to properly rotate 45 degrees components in Altium Designer. I read two topics about that: Rotated component placement in Altium How can I rotate a part in Altium without an ...
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2answers
139 views

UL fire safety clearance requirement

The DUT is a relatively high-power LED driver driven by a SELV high-power +24VDC supply. It'll drive LED voltages up to 55V by specification. So everything is considered safe as far voltages are ...
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2answers
1k views

Altium Microstrip routing

I am currently trying to route a micro strip for a GPS and GSM antenna on Altium which got some constraints on spacing with ground poured plane like the one shown just below: This is currently my ...
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1answer
359 views

Clearance distance in a PCB with an insulated barrier

In the image shown below, why is the distance marked with "??" not considered for clearance? Is there a slot under that barrier, or does the barrier pass through the PCB?
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2answers
2k views

Will a cut or a slot in a PCB change clearance or creepage?

Does a cut or a slot in a printed circuit board increase clearance, creepage or both? Some say it will increase clearance, but I don't think clearance will change because, even with a cut in the PCB, ...
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1answer
3k views

PCB trace clearance in 220V circuit

This is a pcb layout where I am converting 220V rms to a DC voltage (for microcontroller). The pcb has severe size constraints. This is one design I could come up with: Circuit explanation: Consider ...
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1answer
2k views

How to measure creepage distance?

What points do you need to measure in PCB according to IEC 601? Is it the closest distance between any conductive parts? For example minimum air clearance for means of operator protection in secondary ...
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0answers
357 views

What is the common cause of short circuit in PCB design

In PCB design there is some clearance and creepage distances to respect according to the UL 60950 standard for example, I want to know why this distances need to be respected in PCB design, what is ...
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1answer
1k views

Ethernet LED & Diffpair Clearance

How do you maintain creepage distance between diff pairs and the LED terminals on an Ethernet connector? My understanding is that based on EN60950, for 250V IT equipment, the air clearance is 2mm and ...
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2answers
2k views

How much clearance through air is required for 10 kV DC?

Suppose I have two uninsulated connectors with 10 kV DC between them. How much clearance through air should I have between those connectors? What table is this found in?
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1answer
337 views

Eagle - clearance errors and display errors

I am beginning with eagle, I have not any experience with this program. Could you please tell me, what does it mean clearance error, overlap error and dimension error. How could I avoid it and remove ...
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1answer
360 views

How does a fuse affect creepage reqirements?

I am designing a mains-powered device that has to comply with IEC 60079-15 (Non-incedive industrial eqipment). Creepage distances in this standard are inherited from IEC 60664, pollution degree 3. For ...
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1answer
614 views

pollution degree and creepage distance

I read in some books that pollution degree can influence the creepage distance in electronic circuits, is there any relation (mathematical) between the pollution degree and the creepage distance.
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1answer
2k views

Clearance and creepage requirements in EU

I'm looking for the clearance and creepage requirements between live voltage (230V) and SELV (Safety Extra Low Voltage) in the EU. I had a look at this and other questions, but I rarely see numbers ...
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5answers
14k views

Cleaning PCBs… using water?

I found this video where a technician with a lot of experience seems to clean his PCBs using water, and then he just puts it in the sun so it can dry. I was just amazed to see the circuit keeps ...
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1answer
4k views

Eagle Clearance Error on DS2784

I am using the CAD drawing for the DS2777 from Maxim Integrated. http://www.maximintegrated.com/en/design/packaging/cad/?phase=proc&return_url=http%3A%2F%2Fwww.maximintegrated.com%2Fen%2Fdesign%...
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1answer
13k views

Clearance rules for outer/inner layers?

I found some information about general creepage and clearance distances here but it doesn't mention what is OK for inner layers, which are insulated and not subject to contamination the way outer ...
2
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1answer
432 views

PCB clearance on eagle to make coplanar lines

I need to define a clearance between my signal path and souronding ground of 0.16mm in Eagle PCB layout. I tried to setup the "isolate" at 0.16 and do "ratsnets" but it keeps the same distance as ...
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2answers
333 views

Minimum distance from TQFP to chip cap on PCB assembly?

I want to put decoupling caps (0603) as close as possible to TQFP-48-7x7. So PCB/assembly wise how close I can put them (pad to pad, component to component)? Does the 'court yard' need to be exactly ...
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5answers
29k views

How do I disable clearance check for a layer or for only some certain elements?

I'm designing a PCB in Altium Designer. There is a very large heat sink in my project. When I put it on the PCB, there will be plenty of empty space under it where I can put other small components. I ...
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2answers
973 views

Creepage and clearance when using relays

I'm looking at this 10A, 277VAC relay and wondering if there is sufficient spacing between the low voltage (3.5V, 100mA) and the high voltage(277VAC, 10A). The foot print looks like this: Are the 5V ...