PCB Common Query (2)

Thickness
1. Lay-up
In DWG, customer mentioned layer order only, but didn’t indicate the dielectric thickness between layers and Copper thickness. So, we suggest you follow the lay-up shown on attached file XX, Please confirm.

2. Mismatch between the lay-up and board thickness
According to the lay-up specified by customer, the overall board thickness will be XXX mil, not the customer nominal requirement of YYY mil. So, we suggest:
A). To follow the lay-up specified by customer and change the overall Rigid-flex pcb thickness to YYY mil +/-10%
B). To modify the lay-up as shown on attached file and control the overall board thickness to be XXX mil per customer requirement.
Please clarify which item (A or B) customer preferred.

3. Relax board thickness tolerance.
Customer required controlling the finished board thickness to be XX%, however, the standard tolerance for board thickness is +/-10%. We can achieve tighter tolerance by ordering non-standard materials; however, it will take a long lead-time and a high price to purchase this special material. So, we suggest you relax the tolerance from XX% to +/-10%. Please confirm.

Cu thickness & Pad
1. Add Cu clearance for NPTH or consider 2nd-drill
The non-plated hole located in ground plane(OR a large pad: DIAXXX), in order to facilitate in production, we suggest we shave Cu and add a 10mil clearance around non-plated holes. Please confirm.

2. Add dummy pattern
As the distribution of Cu pattern is very uneven on outer layers, in order to balance plating and improve quality, we suggest you add some dummy pattern in blank area. The dummy shape and size see attached file. Please confirm.

3. Copper close to board edge
In some locations, copper features are closer than 15mil(10mil) from the outline. This presents the risk of exposed copper at board edges. We suggest we shave copper to get sufficient spacing. Please confirm.

4. Copper extending to unit edge
In some locations, copper has extended to unit edge. If we follow master A/W to build, copper will be exposed at unit edge. So, we suggest we shave copper to get sufficient spacing. Please confirm.

5. Delete NPTH pad
For some non-plated holes(DIA: XX), their pad size(DIA: XXX) is larger than hole size. In order to facilitate in production, we suggest you delete these pads. Please confirm.

6. Distance between two pads less than 4mil
On component side/solder side, the spacing between two pads is too narrow (X mil only). As the two pads have been connected together in inner layer YY. In order to facilitate in production, we suggest we shave the pads and keep 5mil spacing. Please confirm.

7. Pad size is too small
According to master A/W the via hole pad is too small (hole size: MMM, pad size: NNN). As there isn’t enough spacing for us to enlarge these pads. In order to select a smaller drill we suggest you change the tolerance of via hole from XXXX+/-3mil to XXXX+0/-6mil. Please confirm.

8. PTH hole with elliptic pad
Per master artwork, we found some PTH holes (DIA: XXX mil) with elliptic pad (pad size: MM X NN mil) (see attached file).AS the elliptic pad was too small, thus it was ineluctable that hole will be broken on short side if we follow master artwork to proceed We suggest to enlarge the pad suitably to guarantee a 2 mil (min)annular ring on the conjoint area, please confirm.