PCB Labels and Designators

Each PCB to be assembly has a silkscreen layer on both the top and bottom of the PCB. Silkscreens consist of boxes, lettering, and component outlines are used for PCB information, instructions, and references for assembly.

Silkscreens are printed in white on PCBs, except for the white PCB where they are printed in black.

PCB top

All PCBs for the project have the following on the PCB top (silkscreen):

Connector Identification provides end-user assistance in understand the purpose of a connector (sockets, connectors, jumpers, etc.).
Component Outlines to assist in the location and orientation when placing components on the PCB.
IC and Module component names to help with identification
Component Identifiers consisting of a letter followed by a unique number. For example, R1 means resistor one. Identifiers are referenced in the assembly instructions, component listings, and by PCB fabricators providing assembly services. Common component designators are listed below.

PCB bottom

Cards and most Breakout Boards for the project have on the PCB bottom (silkscreen) the board’s name, along with a version number. Some PCBs may provide additional information, such maximum current specifications, etc.

Note that components are not mounted on bottom since most PCB are setup for reflow soldering which can only be performed on side (top)

Component Designators

Below are a list of industry standard component designators used for the project’s PCB:

Designator	Component	Examples
BR	Bridge Rectifier	BR1
C	Capacitor	C1, C1-C5
D	Diodes (includes LEDs)	D1
J	Jack, Socket (male or female)	J1
IR	Infrared-Diode	IR1
JP	Jumper (male pins)	JP1
L	Inductor	L1
OP	Opto-isolator	OP1
Q	Transistor	Q1
R	Resistor	R1, R1-R5
S, SW	Switch	S1, SW1
SG	Buzzer	SG1
U	IC	U1
VR	Voltage Regulator	VR1
Y	Oscillator	Y1
ZD	Zener-Diode	ZD1

Reference

Reference Designators (WikiPedia)