Dual resistor design

Question

HI, I'm new to Cadsoft Eagle and have been trying it for 3 days now. i want to design a pcb so it can be compatible for the use of a 1/4 watt leaded resistor and a 1206 SMD resistor. Please help.

kovarm · Accepted Answer

Hi Shalen, John's solution with extension of THT pads to accomodate SMD component too is very uncomfortable, especially with a lot of "doubled" components on a board and I mean only possible for hand made boards , it means without soldering mask, paste, glue and usage of SMT automat. Jorge give you an idea how to do it easily, it means put into a schematic all resistors doubled (SMD and THT) and then put them both ideally sharing the same place on the board. This solution has one problem: you must do everything two times (schematic, values and may be names too and then placement on board and connection of pads). More complicated on start, but more comfortable on a usage is my way: make your own library component as SMD and THT combination , it means with pair of pads and pair of SMDs which are connected in device in parallel (possible from version 6 only). Then you have only one component in schematic and one in board with only one name and value. But then may be a problem with newer assembling automats which are able to place both SMD and THT components, but this is not my problem (we use SMT automat and then we place THT components by hands). Ideal solution can be done by Eagle development team by implementing shared components, whitch support assigning more than only one package variant for a component in schematic and then work with this on board as a group or selectable separately. The next level of functionality will be done by enabling of grouping of more packages from devices with the same schematic symbol (by name, pin placement etc.) together. For some smart solutions like this I am waiting a lot of years yet ...

jw0752 · Answer

Hi Shalen, I see where you have requested to be a contact. I am glad to have you but unfortunately I do not use or know much about Eagle. I do believe that I have seen boards that will accomodate throught the hole and SMD resistors, either - or. If I recall correctly they extend the trace past the holes inorder to accomodate the SMD if it is preferred. How one would design this on Eagle I have no clue. Perhaps one of the Eagle experts will pickup on this and give you a better answer. John

autodeskguest · Answer

On 11/17/2014 4:30 AM, Shalen Maharaj wrote:

HI, I'm new to Cadsoft Eagle and have been trying it for 3 days now. i
want to design a pcb so it can be compatible for the use of a 1/4 watt
leaded resistor and a 1206 SMD resistor. Please help.

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Hi Shalen,

One way this could be handled is by putting the resistors in parallel.

So for every resistor in your design you actually have two, one SMD and

one 1/4 watt through-hole.

You could then create two assembly variants, one through hole and the

other SMD. The through hole variant would not place the SMDs and vice versa.

This is how I would handle this.

Let me know if there's anything else I can do for you.

Best Regards,

Jorge Garcia

Dual resistor design

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