Understanding of several layers in drawing PCB

shaorc

When using the IPC footprint wizard wizard that comes with AD2018 to generate a TSSOP package, you will go through the following step, which is to set the mechanical layer Figure 1. In Figure 1, the 15th layer of the mechanical layer is the largest outer frame size of the device package; the 1st layer is the installation and assembly size; the 13th layer is the size of the device itself. However, in the generated figure, as shown in Figure 2-3, the 15th layer of the mechanical layer (green line border) is indeed the largest size of the package area, but the 1st layer of the mechanical layer (pink border, without diagonal lines, just pink border), how can it be the installation size? And the 13th layer of the mechanical layer (with pink diagonal filling inside) refers to the size of the device itself (excluding pins)? Figure 2 Figure 3

曹伟1993

The pink one is the 3D model, which is the three-dimensional model of the device. In PCB mode, press 3 on the keyboard to display the 3D image.

topwon

I think that mechanical 13 layers are the width of the actual chip including the pins, and mechanical 1 layer is the width of the actual chip body plastic package (excluding pins).

qwqwqw2088

In English mode, press the number 3 to understand the three-dimensional packaging boundary. Press 2 again to return to 2D space