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Footprint Design for different SMD solder processes

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Inka_One

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Hi Folks,

I have a doubt about footprint design.

Is there any difference design for a SMD pad in wave solder process and reflow solder process?

I hope someone can help me with this question!

Best regards! :smile:
 

Clearly yes. There are detailed IPC specifications for footprints, you can also refer to manufacturer footprint suggestions.

The most important point is to understand the limitations of SMD wave soldering. A lot of modern components (fine pitch, "quad" pin arrangement) can't be wave soldered. In my view, the technique is almost legacy today. So you should ask primarly, if wave soldering is applicable for your design at all. For non-SMD components, selective wave can be used.
 

for low cost application ,designer use wave technology.

YES ,there is difference between footprints for wave and reflow technology and there is difference in placement strategy too.

You can refer IPC-SM-782 for some examples
 

abhi002 said:
for low cost application ,designer use wave technology.

YES ,there is difference between footprints for wave and reflow technology and there is difference in placement strategy too.

You can refer IPC-SM-782 for some examples
Click to expand...

I don't find any reference about difference between footprint design for wave and reflow solder process in IPC-SM-782.

This IPC guide me to design the correct and otimized land pattern for each kind of component package 8-O
 

Second that, IPC-SM-782 is long gone!!
A lot of modern day components will not tolerate wave soldering, selective soldering is more prominent as it does not destroy the SMD parts
 

I can't really believe that wave solder footprint isn't handled by IPC standards. But I don't have it.

As previously mentioned, you can also find masses of manufacturer suggestions for footprints. But you didn't tell about your actual needs.

P.S.: According to the TOC, IPC-7351B seems to be handle the topic https://www.ipc.org/TOC/IPC-7351B.pdf
 
Last edited:

Marce:
As i said Wave soldering is used for some low cost application,it is not totally ruled out. In past i have done some boards which gone for wave soldering + selective soldering. I understand now a days reflow soldering is much in use.
Anonymous_Ricky:
U rightly said ,IPC7351 is newest standard for footprint creation but these IPC standards are generally used by service industry. Major product companies have deployed their own standards for footprint creation and they are doing well.
Inka_One:

Excuse me from deviating the main topic.
Pls see the below link
**broken link removed**
This document deeply explains differences of footprints for wave/reflow solder technology.

Hope it helps you upto some extent
 

IPC-7351 covers wave soldering.
You are totaly wrong about IPC-7351 and who uses is and who developed it, have a look at the members on the working comittee.
As to IPC standards they are the de-facto World standards that ALL PCBs are made to, all PCB manufacturers and competant designers use them.
 

Marce:

I am not saying that footprints created from IPC7351 are wrong , I only talked about the trends in industries.

Take away from this discussion is, only competent designers use IPC 7351.
 

Inka_One

If you need a hard set rule for this I recommend you go talk to the assembly house directly. They can give you a really good answer.
 

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