5 Key Stages in PCB Manufacturing: From Design to Delivery

Mar 24,2020

The printed circuit board (PCBs) is one integral element of almost all electronics applications. They bring life to electronic and electromechanical devices by routing signals within the circuit and enable their functioning. many people know what PCBs are but only a few know how they are manufactured. Today, PCBs are constructed using the pattern plating process. They will continue through the next phase which mainly includes etching and stripping. This post will effectively take you through various stages in the printed circuit board design process but will focus more on the etching and stripping processes of the circuit board.

Designing and Manufacturing Process of PCBs 

Depending on the manufacturer, the PCB manufacturing process may differ slightly, especially in terms of component mounting techniques, testing methods, and so on. They are manufactured in bulk quantities using various automated machines for drilling, plating, punching, and so on. Except for some small variations, the main stages involved in the PCB manufacturing process are the same.

• Stage 1: 8-Step Guide to Etch Your PCBs

  PCBs are made by bonding a copper layer over the entire substrate. Sometimes, both sides of the substrate are covered using copper layers. The PCB etching process, also called a controlled horizontal process, is carried out to remove excess copper from the PCB panel using a temporary mask. After the etching process, the circuit board is left with the desired copper traces. PCB etching process is done using highly aggressive ammonia-based solutions - ferric chloride or hydrochloric acid. Both the chemicals are considered economical and plentiful. To etch your PCB, you need to follow several steps as given below.

  • Step 1:

    Circuit board designing is the initial stage of the etching process, using any software of your choice. Once the design is ready, get it printed on the transfer paper. Make sure that the design will fit inside the shiny side of the paper.

  • Step 2:

    Now, sand the copper plate neatly, which will make its surface rough enough to hold the circuit board design. There are several things to remember while performing this step:

    • Make use of surgical or safety gloves while handling etching solutions. This will prevent oil from getting transferred to the copper plate and your hand too.
    • While sanding the copper plate, make sure you will cover all the edges of the plate.
    
    
  • Step 3: Clean the copper plate with water and rubbing alcohol. This will remove small copper particles from the plate surface. After washing, allow the plate to dry completely.
  • Step 4: Cut out the PCB design accurately and place the board facing down on the copper plate. Now, the plate is passed through laminators many times until it gets heated.
  • Step 5: Once the plate is heated, take it out from the laminator, and place it in a cold bath. Agitate the plate for a while, so that the paper floats on water.
  • Step 6: Take the circuit design out of the bath, and place it into the etching solution. Again, agitate the plate for half an hour, which will help in dissolving unwanted copper around the design.
  • Step 7: Once the excess copper is washed off in a water bath, allow the plate to dry. Once the copper plate dries completely, rub alcohol to wipe off the ink transferred to the circuit board design.
  • Step 8: Now, you have an etched circuit board ready; however, you need to drill the holes using proper tools. 
  
  
• Stage 2: Stripping Process of PCBs

  Even after the etching process, some amount of copper remains on the circuit board, which gets covered by tin/lead or electroplated tin. Nitric acid removes tin effectively while maintaining the copper circuit cracks below the tin metal. As a result, you will get a clear distinct copper outline on the circuit board, and the circuit board is ready to be passed on to the next process – Solder Resist.

• Stage 3: Solder Resist

  This is one important process in the PCN designing process, which covers unsoldered areas on the circuit boards using solder resist material. As a result, it prevents the solder from forming traces, which can create shortcuts to adjacent component leads.

• Stage 4: PCB Testing

  After the PCB is manufactured, testing becomes crucial to check the functioning and features. In this method, the PCB manufacturer determines whether the circuit board is working as expected. Today, PCBs are tested using several advanced testing equipment. ATG test machine is mainly used for testing high volume PCBs, which include flying probes and fixtureless testers.

• Stage 5: PCB Assembling

  This is the last step of PCB manufacturing which mainly includes the positioning of various electronic components on to their respective holes. This can be carried out by either through-hole technology or surface mount technology. One common aspect of both the techniques is that the leads of the component are fixed electrically as well as mechanically to the circuit board using a molten metal solder.

This is all about the manufacturing process of a PCB. If you are interested to know more about soldering tips or materials used for soldering, you can contact industry-leading manufacturers like Creative Hi-Tech. Their highly skilled and experienced experts assist you throughout the designing process.

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