Assembly Drawing

[JohnsonMiller]

Hi,

In Assembly Drawing where do you put the component identifier, inside it or outside? please have a look to screen shot, which form do you recommend?



BR,

[robertferanec]

On the assembly layer we always put reference designator inside the component for two reasons:
- you clearly see which designator belongs to which component
- if we placed designators outside of component, in very busy areas (where components are placed close to each other) there would not be space to place designators ... only to place them far away from the component and then it would not be clear what designator is for what component

[JohnsonMiller]

Thank you Robert,

Frankly, I have doubt about usage of this plots! BOM along pick&place contain all required information, why we need to generate assembly plots?

BR,

[mairomaster]

I always do it just out of habit and because I've automated it and it's not a big effort. However, I find it quite useless for most of the designs.
Sometimes it can perhaps be useful when debugging a board which doesn't have silkscreen designators, to have the assembly drawings printed so you have an idea which component are you looking for.
I have the designators inside the courtyards. I am using AdjustDesignators2 Altium script to format/centre them.

[robertferanec]

Our assembly house always uses assembly drawings. I guess, it's for their people to see where specific components are located (e.g. if they do some manual placement or if they are checking placement).

[JohnsonMiller]

Thank you Robert and Mairomaster,

Mairomaster:
"I am using AdjustDesignators2 Altium script to format/centre them."
I currently have format/center issue, can you explain how to do formating?

BR,

[mairomaster]

I normally use the following settings:



You can set the minimum and maximum allowed size of the designators.

In Layer Options, you can chose the reference for the component size. I am using the courtyard mechanical layer (also used in the assembly drawings) for the purpose. According to the component size determined by the selected layer primitives, the script automatically adjusts the font size of the designators.

In Designators to include, I am modifying only the mechanical designators (the silk screen ones are usually arranged by hand to fit between the components).

The script basically rotates the designators so they are either 0 or 90 degrees according to the orientation of the component, sets the font to True font, adjusts the font size according to the size of the footprint and centres the designators. The only drawback is that the overall component bounding rectangle is used to centre the designators. In some cases this leads to not that perfect alignment, because of none-symmetrically primitives outside of the component body (for example silk screen markings or none-symmetrical component body which extends beyond the courtyard). In such cases you might need to modify those by hand. In the majority of the cases it's alright though.