Procesul de asamblare a plăcii de circuite electronicePostat pe 08.06.2020
Procesul de asamblare a plăcilor de circuite electronice Shenzhen China
Today a wide range of electronic devices including Smartphones to electric cars etc, have become an essential part of our day-to-day life. The lifeline of all of these electronic devices is the electronic circuit board fitted in them. Actually, they are printed circuit boards of PCB on which electronic components are installed to make then electronic printed circuit boards or electronic circuit boards. In this write-up, we are going to discuss the process of the ELECTRONIC CIRCUIT BOARD ASSEMBLY.
WHAT IS AN ELECTRONIC CIRCUIT BOARD?
An electronic circuit board is a printed circuit board made of multiple layers of fiberglass insulated with a solder mask and joined together with the help of epoxy. They have lines of copper and other metals on which electronic components are fixed to work as the heart of various electronic devices.
TYPES OF THE ELECTRONIC CIRCUIT BOARD
There three basic types of electronic circuit boards or PCBs like:
RIGID CIRCUIT BOARDS: Most of the assembling services of electronic circuit boards use rigid printed circuit boards due to their thickness and rigidity provided by their solid core. These PCBs are made of different types of materials like FR4 or fiberglass to make them inflexible. In order to make affordable PCBs people also use phenolics or epoxies but they are not as durable as that of FR4 or fiberglass.
FLEXIBLE CIRCUIT BOARDS: As compared to rigid PCBs, flexible PCBs have more elasticity because they are made from Kapton, a kind of plastic, which is bendable on high temperatures.
PCBS WITH THE METAL CORE: The metal core used in these PCBs makes them a good option to the boards made of FR4. These boards are efficient in spreading heat as well as in protecting the heat-sensitive electronic components.
DIFFERENT METHODS OF THE ELECTRONIC CIRCUIT BOARD ASSEMBLY
Normally three types of methods are used for electronic circuit board assembly like:
SMT OR SURFACE MOUNT TECHNOLOGY: This technique is traditionally used by the manufacturers of asamblarea PCB-ului . In this process, electronic components are soldered to the electronic circuit boards with the help of their metal tabs. This technique allows you to assemble PCBs with a higher density as you can fix the electronic components by soldering on both sides.
PTH OR PLATED THROUGH-HOLE TECHNOLOGY: In this process, electronic components with attached leads are used. Holes are drilled on the PCBs used for this purpose. Now the leads of the components are inserted through these holes to assemble the PCB easily.
ELECTRO-MECHANICAL TECHNOLOGY: This method is also known as the method of box-build assembly in which looms, wires, cable assembly, molded plastics, and custom networks are assembled with the electronic components on the PCB.
STEPS FOR ELECTRONIC CIRCUIT ASSEMBLY THROUGH SURFACE MOUNT TECHNOLOGY
APPLICATION OF SOLDER PASTE: Before soldering electronic components on the PCB, solder paste will be applied at the areas to be soldered on the PCB. Solder paste is made by mixing flux and small grains of solder. It is applied to the printed portions of the PCB with the help of a solder screen.
After applying and registering the solder paste in the right position on the PCB by using a solder screen, you will have to move a runner on the screen so that some of the solder paste can be squeezed through the holes on the PCB and the screen. It will help in depositing the solder on the solder pads of the PCB. You must control the amount of solder deposited o the pads so that the right amount of solder is available on the final joints.
CHOOSE AND PLACE: After completing the step of applying the solder paste, you will have to pass your PCB through the process of choose and place. In this step, a pick and place machine is used. This machine is loaded with a roll of electronic components so that you can place them in the right position on the PCB with the help of its dispenser.
The tension of the solder paste applied on the PCB will keep the components placed on it in their position unless the board is shaken.
Some of the machines used for this step also secure the placement of the components on the PCB by adding small drops of glue on it. It is normally used if the wave solder method is used to fix the components on the board. But, the use of glue can make it difficult to repair the PCB if it is not degradable.
You will have to program the machine for pick and place about the type of component and its position as per the information of the design of the PCB. It will allow the machine to place the right components in the right position.
SOLDERING: The next step of the electronic circuit board assembly after placing the components at the right position is to solder the components on the board by passing it through a machine. Various types of soldering machines as used at this stage to solder the components to the PCB like wave soldering machine and reflow soldering machine etc. You should know the pros and cons of each method before using it.
INSPECTION: PCBs are inspected thoroughly after passing them through a soldering machine to ensure that the components are perfectly soldered to the board. Due to the presence of a large number of electronic components on the board manual inspection is not recommended. You can find machines to inspect the boards to find the misplaced components, poor soldering of joints, or wrong placement of the components.
TEST: This step is necessary to ensure the quality of the PCB after the final stage of electronic circuit board assembly. Before leaving the factory PCB can be tested in various ways.
FINAL ASSESSMENT: In order to ensure the proper running of the process of PCB assembly it is essential to check the working of the final product. It will help you in detecting the failures and rectifying them before manufacturing the lot as per the order of your client.
In this way, you can complete the process of ELECTRONIC CIRCUIT BOARD ASSEMBLY perfectly by following the steps discussed in this write-up.