Host pcb pads for wroom-02

[RogerFL]

The dimension drawing in the data sheet shows the size of pads on the part (but omitting the cutout half circles on edge pads) as 0.85x0.95mm. Should the host pads be larger on all sides or should host pads extend further outward to allow larger fillet only on outer edge? Or is some other design recommended?

[Espressif_Kelly]

Dear Sir,

The original size of pads on ESP-WROOM-02 is 0.9x0.85mm(omitting the cutout half circles on edge pads).
It is ok that the host pads extend further outward(e.g. 0.9x2mm).

Thanks.

[RogerFL]

Thank you Kelly.

Please can Espressif publish a recommended PCB layout?

I also see there is a large pad on the bottom which is not mentioned in 0C-ESP8266__WROOM_WiFi_Module_Datasheet__EN_v0.4.pdf

What is the exact position and dimension of that? What signal is it, ground? Should the host PCB layout have that?

This is basic info that is required to design host PCB and it makes me concerned whether I'm making a mistake selecting esp8266-wroom-02 for a real product with 10,000+ units per year projected. This is a real product intended for commercial use, right?

Roger

[Espressif_Kelly]

Dear Sir,

You can get the hardware design of ESP-WROOM-02 module at below link.

http://bbs.espressif.com/viewtopic.php?f=51&t=818

Please be noted that the schematic needs to be opened by Orcad Capture16.6 and the PCB layout needs to be opened by Pads Layout 9.5.

Any more questions, please let us know.

Thanks.

[comino]

Thank you Kelly.

Please can Espressif publish a recommended PCB layout?

I also see there is a large pad on the bottom which is not mentioned in 0C-ESP8266__WROOM_WiFi_Module_Datasheet__EN_v0.4.pdf

What is the exact position and dimension of that? What signal is it, ground? Should the host PCB layout have that?

This is basic info that is required to design host PCB and it makes me concerned whether I'm making a mistake selecting esp8266-wroom-02 for a real product with 10,000+ units per year projected. This is a real product intended for commercial use, right?

Roger

I have the same question - I can fin no information about the pad under the ESP8266 in the datasheet. I almoast destroyed the first pcb layout. What is it conencted to? Ground? Can I use it as a heat sink (we can realy need that)?

[Espressif_Kelly]

Hi Roger,

Do you mean pad under the ESP8266EX chip or ESP-WROOM-02 module?

The PAD under ESP8266EX chip is ground PAD (3.7x3.7mm) which must be connected to the ground.

The PAD under ESP-WROOM-02 is also a GND PAD (4.3x4.3mm) which you can connect to ground(for good heat dissipation ) or not, because there are already ground PAD in the pin-out of the ESP-WROOM-02 module.

The Dimension of this GND PAD under ESP-WROOM-02 is as shown below.

Any more questions, please let us know.

Thanks.

[RogerFL]

Perfect! I will add the ground pad for wroom-02 to the next revision of my PCB.

Meanwhile I will look for the software needed to read the footprints. I use a Eagle on a mac so it will take some work. A drawing with the dimensions of the outline and the other pads would still be helpful, but not necessary.

Thank you for the info.

Roger