Laying out a double sided SMT circuit board

[ADWSystems]

Do you know how to set up a PCB layout program and components to layout a double sided PCB (eg., PCB with components on both sides). I am having a problem with the component clearances. Even though one is on the top and the other on the bottom, it detects them as being too close together. Any information is appreciated is welcome from the PCB package you are using. I am still using Protel 99SE, so I will translate if possible. If you remember what the settings are for Protel 99SE, even better.

 

[DerStrom8]

It all depends on your specific design rules. I have not used Protel, i use Eagle and Altium, but Protel should work similarly. What is the clearance error actually saying? Is it saying the components are too close, or that they're too close to traces, or pours? Could you post a screenshot of your board? It sounds like you're not actually putting the components on opposite sides of the board. Simply changing the trace layer does not tell the components to go on that layer as well. Eagle requires that you mirror the component in the PCB layout editor in order to place it on the opposite layer.

How this helps!
Regards,
Matt

PS. Please forgive any typos in this post, I'm typing on my phone which i have never been good at

 

[ADWSystems]

usually, designers will use cam350 or protel 99 to draw pcb file ,but if you dont' know how to change format , i can help you ,just send me your file.

Do you know what the design rule setup is for Protel99SE to pass the design rule check with SMT parts mounted on the bottom?

 

[Colin]

I am still using the first version of Protel, which is a dumb program but has never fallen over and does not refuse ANYTHING.
it was the first one in the world.
I still use it because I still have to import some of the first boards into a panel.
It might be slow but never frustrating.
protel 99 was impossible to use and modify some one elses board.
Moving a few parts on one end of the board, moved components at the other end of the board and these were off the screen !!!!!
It was only when the board was zoomed-out that half the parts were seen to be off the board!!!

 

[William Salinas]

I have used Eagle & Altium because Altium Designer stores files on the hard drive. In case if you want to translate then you can choose one from the above.

 

[ronv]

Do you know how to set up a PCB layout program and components to layout a double sided PCB (eg., PCB with components on both sides). I am having a problem with the component clearances. Even though one is on the top and the other on the bottom, it detects them as being too close together. Any information is appreciated is welcome from the PCB package you are using. I am still using Protel 99SE, so I will translate if possible. If you remember what the settings are for Protel 99SE, even better.

Are you sure you placed them on 2 different sides?

 

[ADWSystems]

Are you sure you placed them on 2 different sides?

Pretty sure. Pin one is 'in the wrong place' (upper left rather than lower left).

 

[ronsimpson]

It have been a long time.....Protel might be set to not place parts on the same spot (top/bottom). In the rules there might be a place to allow top and bottom side parts in the same spot.

 

[ADWSystems]

That was kindof the driver behind the thread. to see if anyone knew which setting in the design rule needs to be set or tweaked to allow components to be placed front and back. I never found the setting and the double sided board ended up single sided. But I would still like to know which design rule needs to be set to allow it.

 

[ronsimpson]

can you send a screen shot of the window where you change the design rules?
Some one might know.

 

[ADWSystems]

can you send a screen shot of the window where you change the design rules?
Some one might know.

That's the problem. There are about 20 design rule related "pages". I have found 2-3 menu options that each lead to different screens dealing with configuration. One screen has 5 or 6 tabs, another screen has a list of categories for settings where category has a bunch of settings. If it had only 2 or 3 screens of settings, I would/could send them along. More likely with that few places to look I probably would have found it by now.

 

[ronsimpson]

ADW Systems,

Many people here want to use a CAD program with out a manual. No training. No reading books. Just jump in and go.

The first thing; "This is hard", "The buttons don't make scene", "It should be easy", "Where can I find a CAD that works", etc.

20 design rule pages is 19.5 pages too many AND 20 design rule pages is 25 too few.

It is hard! It takes a long time. You will spend hours trying things. Hours swearing.

There are many programs and they all are hard. The only one that is easy is the one that you have used for years.

 

[ADWSystems]

ADW Systems,

Many people here want to use a CAD program with out a manual. No training. No reading books. Just jump in and go.

The first thing; "This is hard", "The buttons don't make scene", "It should be easy", "Where can I find a CAD that works", etc.

20 design rule pages is 19.5 pages too many AND 20 design rule pages is 25 too few.

It is hard! It takes a long time. You will spend hours trying things. Hours swearing.

There are many programs and they all are hard. The only one that is easy is the one that you have used for years.

I'm not sure exactly what you are trying to say, but at the same time agree with most of what you have said. After 16 years of using this program, most of that as a primary job function, I find it very easy to use. After hours of searching the design rule screens and the internet, I have not found the setting or combination of settings that allows a successful design rule check with components placed on both sides of the board and exactly opposite one another. I can place parts on both sides and pass the DRC, but only if the parts are spaced as though they are on one side of the board.

 

[jpanhalt]

I'm not sure exactly what you are trying to say, but at the same time agree with most of what you have said. After 16 years of using this program, most of that as a primary job function, I find it very easy to use.

That seems odd in the light of your original question. Was this the first time in 16 years that you dealt with a board with components on both sides?

John

 

[ADWSystems]

That seems odd in the light of your original question. Was this the first time in 16 years that you dealt with a board with components on both sides?

John

Yes and no. I have had layout with parts on both sides, but only connectors on the other side. Since the connectors were through hole, there could not be components overlapping them. The board/circuit that initiated this thread has SMT parts on both sides and overlapping.

(By 'overlapping' I mean a part on the top that aligns or overlaps with a component on the bottom)

 

[DerStrom8]

Did you actually change the layer of the component, or did you simply mirror it?

Speaking as someone who uses Altium as their main design package (which is evolved from Protel), you can't mirror the components and have them automatically go to the bottom layer like you can in Eagle. You have to go through a menu and change the actual layer. I'm not at all familiar with Protel 99SE, but I imagine the idea is very similar.

Can you post some pictures?

Matt

 

[jpanhalt]

I know you are not using Eagle, but I just tested a board I did last year and put two, SMD components that were on opposite sides right over each other. DRC gave no errors using default Eagle settings. With Eagle, the pads of SMD components change color depending on which the side of the board they are placed. Does Protel 99SE do the same? I would be surprised if default settings for a commercial program did not make accommodation for SMD's on opposite sides of the board.

In fact, in Eagle, once two layers are defined by default, there are no other DRC settings that distinguish between the two sides.

John

 

[DerStrom8]

I know you are not using Eagle, but I just tested a board I did last year and put two, SMD components that were on opposite sides right over each other. DRC gave no errors using default Eagle settings. With Eagle, the pads of SMD components change color depending on which the side of the board they are placed. Does Protel 99SE do the same? I would be surprised if default settings for a commercial program did not make accommodation for SMD's on opposite sides of the board.

In fact, in Eagle, once two layers are defined by default, there are no other DRC settings that distinguish between the two sides.

John

If Protel 99SE is anything like Altium, the colors do change depending on which side the component sits. It's probably an obvious mistake that the OP will kick himself for when he finds it (been there, done that!).

 

[ADWSystems]

Did you actually change the layer of the component, or did you simply mirror it?

Speaking as someone who uses Altium as their main design package (which is evolved from Protel), you can't mirror the components and have them automatically go to the bottom layer like you can in Eagle. You have to go through a menu and change the actual layer. I'm not at all familiar with Protel 99SE, but I imagine the idea is very similar.

Can you post some pictures?

Matt

I have made mirrored components outlines to be placed on the top but mounted on the bottom. I did this for the first few bottom mount connectors until I learned how to move/place the parts directly on the bottom layer. For this board due to the SMT parts, the parts must be placed on the bottom. As jpanhalt mentioned, as I change the layer the component is on, the pad colors change. But for some reason I am getting clearance violation between the parts on the top and the bottom.

 

[DerStrom8]

What exactly does the error say?

Again, could you please post some pictures?