Connecting top and bottom SMD component pads using viaEagle is refusing to tie ground pads of SMD components to the ground planeDipTrace bottom layer pad shapeEagle configure autorouter to solder components (except vias) only on bottom layer of double sided PCBIs every pad in eagle a via?Eagle: polygon pour leaving funny blank areasRouting and placement of decoupling capacitor when using power planeA confusion on using PCB copper pourPlacing the pads of SMD components in different layers (KiCad PCB design)How to prevent tombstoning using via-in-pad with small SMD discretesPastemask for through hole components
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Connecting top and bottom SMD component pads using via
Eagle is refusing to tie ground pads of SMD components to the ground planeDipTrace bottom layer pad shapeEagle configure autorouter to solder components (except vias) only on bottom layer of double sided PCBIs every pad in eagle a via?Eagle: polygon pour leaving funny blank areasRouting and placement of decoupling capacitor when using power planeA confusion on using PCB copper pourPlacing the pads of SMD components in different layers (KiCad PCB design)How to prevent tombstoning using via-in-pad with small SMD discretesPastemask for through hole components
$begingroup$
I am working on a 2 layer board and the PCB will be a double sided job. Some components on the top layer will have exact mirrors on the bottom right under them. My question is, for SMD components, can I just connect those pads with a via right in the center of the pads?
Does this affect electrical performance or production/assembly in any shape or form?
The reason: The bottom layer is a copper pour for ground and I have pads that belong to GND
net so why not?
Please see the picture below (for demonstration porpuses I have moved the top component a little bit higher).
P.S. The components are TVS diodes (SM8J36CA). But my qustion is more general and is about wherever the pad size allows hosting a via in its center!
pcb pcb-design analog pcb-fabrication pcb-assembly
$endgroup$
add a comment |
$begingroup$
I am working on a 2 layer board and the PCB will be a double sided job. Some components on the top layer will have exact mirrors on the bottom right under them. My question is, for SMD components, can I just connect those pads with a via right in the center of the pads?
Does this affect electrical performance or production/assembly in any shape or form?
The reason: The bottom layer is a copper pour for ground and I have pads that belong to GND
net so why not?
Please see the picture below (for demonstration porpuses I have moved the top component a little bit higher).
P.S. The components are TVS diodes (SM8J36CA). But my qustion is more general and is about wherever the pad size allows hosting a via in its center!
pcb pcb-design analog pcb-fabrication pcb-assembly
$endgroup$
2
$begingroup$
Talk to whoever is doing your assembly. Vias-in-pads generally wick solder away from the joint, causing reliability issues.
$endgroup$
– Dave Tweed♦
4 hours ago
2
$begingroup$
I wouldn't try it due to issues that can arise. They do this on BGAs where space is at a premium and it's called "via-in-pad" but they take special measures to make sure it works.
$endgroup$
– Toor
4 hours ago
2
$begingroup$
It's possible, but not recommended. If you're hand-assembling them, it should be okay, if a little harder to keep together. If this is for automated assembly, don't do it unless you really have no other option.
$endgroup$
– Hearth
4 hours ago
add a comment |
$begingroup$
I am working on a 2 layer board and the PCB will be a double sided job. Some components on the top layer will have exact mirrors on the bottom right under them. My question is, for SMD components, can I just connect those pads with a via right in the center of the pads?
Does this affect electrical performance or production/assembly in any shape or form?
The reason: The bottom layer is a copper pour for ground and I have pads that belong to GND
net so why not?
Please see the picture below (for demonstration porpuses I have moved the top component a little bit higher).
P.S. The components are TVS diodes (SM8J36CA). But my qustion is more general and is about wherever the pad size allows hosting a via in its center!
pcb pcb-design analog pcb-fabrication pcb-assembly
$endgroup$
I am working on a 2 layer board and the PCB will be a double sided job. Some components on the top layer will have exact mirrors on the bottom right under them. My question is, for SMD components, can I just connect those pads with a via right in the center of the pads?
Does this affect electrical performance or production/assembly in any shape or form?
The reason: The bottom layer is a copper pour for ground and I have pads that belong to GND
net so why not?
Please see the picture below (for demonstration porpuses I have moved the top component a little bit higher).
P.S. The components are TVS diodes (SM8J36CA). But my qustion is more general and is about wherever the pad size allows hosting a via in its center!
pcb pcb-design analog pcb-fabrication pcb-assembly
pcb pcb-design analog pcb-fabrication pcb-assembly
edited 3 hours ago
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
JRE
22.2k43771
22.2k43771
asked 4 hours ago


Sean87Sean87
1,543123360
1,543123360
2
$begingroup$
Talk to whoever is doing your assembly. Vias-in-pads generally wick solder away from the joint, causing reliability issues.
$endgroup$
– Dave Tweed♦
4 hours ago
2
$begingroup$
I wouldn't try it due to issues that can arise. They do this on BGAs where space is at a premium and it's called "via-in-pad" but they take special measures to make sure it works.
$endgroup$
– Toor
4 hours ago
2
$begingroup$
It's possible, but not recommended. If you're hand-assembling them, it should be okay, if a little harder to keep together. If this is for automated assembly, don't do it unless you really have no other option.
$endgroup$
– Hearth
4 hours ago
add a comment |
2
$begingroup$
Talk to whoever is doing your assembly. Vias-in-pads generally wick solder away from the joint, causing reliability issues.
$endgroup$
– Dave Tweed♦
4 hours ago
2
$begingroup$
I wouldn't try it due to issues that can arise. They do this on BGAs where space is at a premium and it's called "via-in-pad" but they take special measures to make sure it works.
$endgroup$
– Toor
4 hours ago
2
$begingroup$
It's possible, but not recommended. If you're hand-assembling them, it should be okay, if a little harder to keep together. If this is for automated assembly, don't do it unless you really have no other option.
$endgroup$
– Hearth
4 hours ago
2
2
$begingroup$
Talk to whoever is doing your assembly. Vias-in-pads generally wick solder away from the joint, causing reliability issues.
$endgroup$
– Dave Tweed♦
4 hours ago
$begingroup$
Talk to whoever is doing your assembly. Vias-in-pads generally wick solder away from the joint, causing reliability issues.
$endgroup$
– Dave Tweed♦
4 hours ago
2
2
$begingroup$
I wouldn't try it due to issues that can arise. They do this on BGAs where space is at a premium and it's called "via-in-pad" but they take special measures to make sure it works.
$endgroup$
– Toor
4 hours ago
$begingroup$
I wouldn't try it due to issues that can arise. They do this on BGAs where space is at a premium and it's called "via-in-pad" but they take special measures to make sure it works.
$endgroup$
– Toor
4 hours ago
2
2
$begingroup$
It's possible, but not recommended. If you're hand-assembling them, it should be okay, if a little harder to keep together. If this is for automated assembly, don't do it unless you really have no other option.
$endgroup$
– Hearth
4 hours ago
$begingroup$
It's possible, but not recommended. If you're hand-assembling them, it should be okay, if a little harder to keep together. If this is for automated assembly, don't do it unless you really have no other option.
$endgroup$
– Hearth
4 hours ago
add a comment |
1 Answer
1
active
oldest
votes
$begingroup$
I am working on a 2 layer board and the PCB will be a double sided
job. Some components on the top layer will have exact mirrors on the
bottom right under them. My question is, for SMD components, can I
just connect those pads with a VIA right in the center of the pads?
Yes, will the assembly house be happy about it? No. Vias wick solder through them, plus using a stencil will apply the wrong amount of solder for the component because most of it will be in the hole.
If you do this, let the assembly house know (or if your hand soldering them who cares?) They will probably need to hand solder this component.
Does this affect electrical performance or production/assembly in any
shape or form?
If the signals in question aren't running at the +50Mhz speed then no, a few nH of inductance isn't going to make a difference. Vias might slow down very fast ESD events, if this is the only inductor in the current path which is unlikely. if adding a 10's of nH to the design makes a difference then run a PCB via inductance calculator and parallel the vias or do something else.
$endgroup$
add a comment |
Your Answer
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1 Answer
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1 Answer
1
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oldest
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votes
$begingroup$
I am working on a 2 layer board and the PCB will be a double sided
job. Some components on the top layer will have exact mirrors on the
bottom right under them. My question is, for SMD components, can I
just connect those pads with a VIA right in the center of the pads?
Yes, will the assembly house be happy about it? No. Vias wick solder through them, plus using a stencil will apply the wrong amount of solder for the component because most of it will be in the hole.
If you do this, let the assembly house know (or if your hand soldering them who cares?) They will probably need to hand solder this component.
Does this affect electrical performance or production/assembly in any
shape or form?
If the signals in question aren't running at the +50Mhz speed then no, a few nH of inductance isn't going to make a difference. Vias might slow down very fast ESD events, if this is the only inductor in the current path which is unlikely. if adding a 10's of nH to the design makes a difference then run a PCB via inductance calculator and parallel the vias or do something else.
$endgroup$
add a comment |
$begingroup$
I am working on a 2 layer board and the PCB will be a double sided
job. Some components on the top layer will have exact mirrors on the
bottom right under them. My question is, for SMD components, can I
just connect those pads with a VIA right in the center of the pads?
Yes, will the assembly house be happy about it? No. Vias wick solder through them, plus using a stencil will apply the wrong amount of solder for the component because most of it will be in the hole.
If you do this, let the assembly house know (or if your hand soldering them who cares?) They will probably need to hand solder this component.
Does this affect electrical performance or production/assembly in any
shape or form?
If the signals in question aren't running at the +50Mhz speed then no, a few nH of inductance isn't going to make a difference. Vias might slow down very fast ESD events, if this is the only inductor in the current path which is unlikely. if adding a 10's of nH to the design makes a difference then run a PCB via inductance calculator and parallel the vias or do something else.
$endgroup$
add a comment |
$begingroup$
I am working on a 2 layer board and the PCB will be a double sided
job. Some components on the top layer will have exact mirrors on the
bottom right under them. My question is, for SMD components, can I
just connect those pads with a VIA right in the center of the pads?
Yes, will the assembly house be happy about it? No. Vias wick solder through them, plus using a stencil will apply the wrong amount of solder for the component because most of it will be in the hole.
If you do this, let the assembly house know (or if your hand soldering them who cares?) They will probably need to hand solder this component.
Does this affect electrical performance or production/assembly in any
shape or form?
If the signals in question aren't running at the +50Mhz speed then no, a few nH of inductance isn't going to make a difference. Vias might slow down very fast ESD events, if this is the only inductor in the current path which is unlikely. if adding a 10's of nH to the design makes a difference then run a PCB via inductance calculator and parallel the vias or do something else.
$endgroup$
I am working on a 2 layer board and the PCB will be a double sided
job. Some components on the top layer will have exact mirrors on the
bottom right under them. My question is, for SMD components, can I
just connect those pads with a VIA right in the center of the pads?
Yes, will the assembly house be happy about it? No. Vias wick solder through them, plus using a stencil will apply the wrong amount of solder for the component because most of it will be in the hole.
If you do this, let the assembly house know (or if your hand soldering them who cares?) They will probably need to hand solder this component.
Does this affect electrical performance or production/assembly in any
shape or form?
If the signals in question aren't running at the +50Mhz speed then no, a few nH of inductance isn't going to make a difference. Vias might slow down very fast ESD events, if this is the only inductor in the current path which is unlikely. if adding a 10's of nH to the design makes a difference then run a PCB via inductance calculator and parallel the vias or do something else.
answered 3 hours ago


laptop2dlaptop2d
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26.3k123381
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2
$begingroup$
Talk to whoever is doing your assembly. Vias-in-pads generally wick solder away from the joint, causing reliability issues.
$endgroup$
– Dave Tweed♦
4 hours ago
2
$begingroup$
I wouldn't try it due to issues that can arise. They do this on BGAs where space is at a premium and it's called "via-in-pad" but they take special measures to make sure it works.
$endgroup$
– Toor
4 hours ago
2
$begingroup$
It's possible, but not recommended. If you're hand-assembling them, it should be okay, if a little harder to keep together. If this is for automated assembly, don't do it unless you really have no other option.
$endgroup$
– Hearth
4 hours ago