Isolated pins won't connect to a Polygon...

On 12/24/2011 7:39 PM, Steve Krattiger wrote:

Hi,

 

In the LED library there are symbols for the Cree MX6 LED's that have an isolated pin in the center with thermal vias.

 

When I place a polygon on layer16, they do not connect to the vias as expected; I need to name the polygon to the same signal name.  However, I cannot find the netname used for this center pin, or the signal name associated with these vias. The LED's only have two pins in the sch symbol, but have 3 pads in the lib footprint.

 

Anyone worked with MX6, or know how to get the isolated vias to connect to the polygon?

 

Thanks!

 

Steve

 

Hi Steve,

     I took a look at this part and have a few suggestions that may help.

First use the invoke command to make the thermal vias visible in the

schematic and then connect them together with a net.   Then create your

polygon and name it the same name as the net used to connect the thermal

vias in the sch.    Even after doing these steps I was not able to get

the polygon to connect except by turning thermals off under the polygon

properties.   Lack of thermals may significantly degrade the ability to

get good solder contact between the back of the LED and the thermal vias

and polygon.

Jim

Hi Jim,

Thanks for the quick reply on this.  By using the Invoke command on the schematic symbol, that took me to the next step I needed where at least I could name the center conductor and not be guessing.

I connected a net and named it as LED1_TH to keep it isolated.  Once in the PCB, I also named the polygon LED1_TH.  And it still did not connect through.  But on the polygon properties, I went in and turned OFF the checkmark for "Thermals".  That allowed a complete fill of the thermal polygon on Layer16.

Thanks!

Steve

On 12/26/2011 5:14 PM, Steve Krattiger wrote:

Hi Jim,

 

Thanks for the quick reply on this.  By using the Invoke command on the schematic symbol, that took me to the next step I needed where at least I could name the center conductor and not be guessing.

 

I connected a net and named it as LED1_TH to keep it isolated.  Once in the PCB, I also named the polygon LED1_TH.  And it still did not connect through.  But on the polygon properties, I went in and turned OFF the checkmark for "Thermals".  That allowed a complete fill of the thermal polygon on Layer16.

 

Thanks!

 

Steve

 

Hi Steve,

Glad you got it routed the way you want.   I have worked with some of

the Luxeon Rebel LEDs which also come with an eagle footprint including

a nice matrix of thermal vias.   Do not recall having the challenges

that you experienced so there may be something a little off w/ the MX

library part although I did not see anything amiss when I quickly looked

at it w/ the library editor.

Regards,

Jim