BQ51003: Design and PCB recommandations

sg_34

Part Number: BQ51003
Other Parts Discussed in Thread: PMP11311, TIDA-00668

Hi,

I'm working on a design based on BQ51003 with a low Icc due to usage of a small battery (60mAh) : high constraint about PCB size : very small.

I'll use a 4 layers PCB, but after reading documentation and have a look on reference design, I've few questions :

- PCB thickness : 0.8mm possible? or not recommanded? with the small Icc not necessary to use 1.55mm?

- layer thickness equal 0.036 mm (Tpo, Mid1, Mid2, Bot)

- about via in Pad for BGA footprint :

hole size 0.152mm, diameter =0.254mm ?

via tenting on the bottom mandatory

is it necessary to fill via?

I can't find these informations in reference design, thanks for your help, recommandations and feedback

Best regards

over 7 years ago

0 Bill Johns over 7 years ago

TI__Guru 70006 points

Hi SG_34

You are asking a PCB design question, I am not the best resource for this question. For a BGA part like this it is best to consult your CM that will build the device.

The problem with an open via will be wicking of the solder away from pad. All my designs have the vias closed to prevent this.

0 sg_34 over 7 years ago in reply to Bill Johns

Intellectual 500 points

Hi Bill,

I follow reference design TIDA-0031, PMP11311 & TIDA-00668

On these 3 designs, all vias on BQ51003 are on pad, tenting on bottom side, hole size 0.152mm and diameter =0.254mm

Do you think I can design with a PCB thickness of 0.8mm, with clearance =150µm

To avoid wicking, via tenting on bottom side is enough?

Thanks for your support

Stephane

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BQ51003: Design and PCB recommandations