PCB Fabrication

pcb creation - history and modern steps of the printed circuit board

by:A-TECH      2020-03-02
Printed circuit boards are an important part of modern technology.
It has two main functions.
First, it contains all the electrical components of the electronic system.
Secondly, it completes the electrical connection between the components.
During PCB production, the copper sheet is laminated in a non-
Conductive board.
In order to turn this \"blank canvas\" into something useful, the unwanted copper is etched to form a connection between various electrical components.
The history of printed circuit boards was developed as a reliable process before PCB creation and mass production, and engineers used very inefficient methods such as point-to-
Point welding and wire packaging.
Previous technologies were time-consuming and error-prone.
In 1936, Paul Eisler made the first printed circuit board as part of the radio.
Less than 10 years later, the technology is widely used in electrical systems.
The first generation of printed circuit boards is used-hole (or leaded)components.
As the name implies, a hole is drilled everywhere on the board and a component lead needs to be inserted.
The component leads in each hole are welded in place.
In order to significantly reduce the assembly time of the circuit board, wave soldering technology was invented.
Modern technology takes advantage of smaller components called surface mounting components.
The leads of these components are very short and do not require drilling.
Stepsstep 1 film production for modern PCB manufacturing: accurate film representation is produced using computer software.
Each layer of the PCB generates a layer of film.
Step 2 cut PCB raw material: cut the board to the right size starting with the copper clad board stock.
Through-step 3 drilling
Hole lead parts: an automated machine that uses a carbide drill bit to drill holes.
Step 4 Chemical copper sink: in order to connect the trace on one side of the circuit board to the other side, thin copper deposits are applied in each hole barrel.
Step 5 image application: apply the sensitivity plate to the bare copper plate . .
Use light sources and film exposure boards.
This image is a negative image.
This will only allow etching of unwanted copper material.
Step 6 Pattern plate: this is an electrolytic process in which copper is placed in traces and holes.
The surface is then plated with tinplate paper. . . tin!
Step 7 Strip & Etch: remove the dry film from Step 5 and then etching the exposed copper.
The tin-protected copper signal path in Step 6 is not etched.
Step 8 solder mask: in addition to the solder mask, apply the solder mask area to the entire board.
Step 9 apply the welding coating: apply the welding coating on the pad by immersing the PCB in the welding slot.
Using a heat knife, the weld is leveled when the circuit board is removed from the tank.
Step 10 labels and identifiers: Apply a white letter mark using a screen printing process.
The bare circuit board can now be welded to the components.
This step is usually performed in different facilities using the \"pick and place\" machine.
These machines use components purchased on reels to automate assembly placement.
There are many companies offering PCB creation and assembly services.
These companies typically offer free motherboard design software that can be downloaded from their website. Give it a try!
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