Initially placed components in "01 Big Components Placement" PcbDoc

[miner_tom]

I purchased the advanced layout course and opened the "01 Big Components Placement" PcbDoc. Although this is a pre layout design, I noticed that several small components, such as capacitors and Xtals, had already been placed. However, they do not disappear when I un-show the top and bottom layers (there are more layers in the finished design).

Why are these components in place before any of the other components, such as the CPU?

Attached is a picture of the layout showing already placed items (very small compared to other components).

Thank You
Tom
​

[robertferanec]

Tom, please could you circle the components you are talking about? In the picture you attached, only placed components are CPU and memories.

[miner_tom]

Thank you for the reply,

Attached is a picture of some of the components that I can not seem to make disappear, by making layers invisible. Also, and perhaps this is a problem on my end, in Altium "view configurations" I can not "undisplay" the mechanical layers, thinking that perhaps these small components are on those layers.

One final thing is: In this portion of the design (lesson 1) I only see two layers in the design, top and bottom. I know that the final design will have several more layers. Will these be added later in the course?

Regards
Tom

[robertferanec]

Tom,

- the components you circled are not placed on PCB. Don't worry about these components, they are not placed. Only the black area is PCB.

- yes, in the first exercise, only the top and bottom exists. Additional layers are added later.