Tag Archive: surface mount technology

1. Ball Grid Arrays (BGAs) for PCBA

   April 5, 2023 10:13 am Leave a Comment

   What’s the BGA Deal?

   Printed circuit board (PCB) assembly has come a long way since the early days of through-hole components. With the advent of surface mount technology (SMT), components have become smaller and more densely packed, making PCB assembly more challenging. One type of component that has become increasingly popular in recent years is the ball grid array (BGA). In this blog post, we’ll take a closer look at BGAs and how they impact PCB assembly.

   What is a BGA?

   A BGA is a type of surface mount component that uses an array of solder balls to make contact with the PCB. The solder balls are arranged in a grid pattern on the bottom of the component and are typically made of lead-free solder. BGAs can have anywhere from a few dozen to several thousand solder balls, depending on the size and complexity of the component.

   Why use BGAs?

   BGAs have a number of advantages over other types of surface mount components. One of the biggest advantages is their high pin density. Because the solder balls are arranged in a grid pattern, BGAs can accommodate more pins in a smaller area than other types of components. This makes them ideal for use in high-density applications, such as microprocessors and other complex integrated circuits.

   BGAs also have a number of mechanical advantages. Because the solder balls are evenly distributed across the bottom of the component, they provide more uniform stress distribution during thermal cycling. This makes BGAs less prone to solder joint failure than other types of components.

   Challenges of BGA assembly

   While BGAs have many advantages, they also pose some unique challenges during assembly. One of the biggest challenges is ensuring that each solder ball makes good contact with the PCB. Because the solder balls are small and densely packed, it can be difficult to inspect them visually. This is where X-ray inspection comes in. X-ray inspection is a non-destructive way to inspect the solder joints and ensure that each ball has made good contact with the PCB.

   Another challenge with BGA assembly is the need for precise placement. Because the solder balls are arranged in a grid pattern, the component must be placed on the PCB with a high degree of accuracy. This requires specialized equipment and skilled technicians who are familiar with the nuances of BGA assembly.

   Finally, the rework of BGA components can be difficult. Because the solder balls are on the bottom of the component, it can be difficult to access them for rework. In some cases, it may be necessary to remove the entire component and replace it with a new one.

   Tips for successful BGA assembly

   If you’re working with BGAs, there are a few things you can do to ensure successful assembly:

   • Use a high-quality solder paste with the correct viscosity and solder ball size
   • Ensure that your pick-and-place machine is properly calibrated and can handle the size and weight of your BGA components
   • Inspect your solder joints using X-ray or other non-destructive testing methods
   • Train your technicians in the proper handling and placement of BGAs
   • Use a rework station that is specifically designed for BGA rework, if possible

   Conclusion

   BGAs are a popular type of surface mount component that offer many advantages in terms of pin density and mechanical reliability. However, they also pose some unique challenges during assembly, including precise placement and the need for X-ray inspection. By following best practices and using specialized equipment and techniques, you can successfully incorporate BGAs into your PCBA designs.

   To ensure greatness, utilize an experienced PCB Assembly manufacturer like PGF Technology Group. We use all of the latest technology to guarantee high-quality work.

   

2. SMT Assembly Process

   February 22, 2023 6:46 pm Leave a Comment

   Surface Mount Technology (SMT) Process

   Printed Circuit Board Assembly (PCBA) is the process of producing circuit boards with electronic components attached to them. One of the most popular techniques for PCBA is Surface Mount Technology (SMT), which is universal in the electronic industry today. The SMT process involves placing electronic components directly onto the surface of the PCB, rather than inserting them into drilled holes, as is the case with through-hole technology. This process is faster, more efficient, and allows for the use of smaller and more densely packed components.

   Trace the Lines

   The SMT assembly process begins with the PCB itself, which is a thin board of a non-conductive material, such as fiberglass or plastic. Copper traces on the board serve as the pathways for electrical current. A photolithography process etches these traces onto the board, which involves exposing the board to light through a stencil called a mask to create the desired trace pattern.

   Pick & Place

   Once the PCB is ready, the next step is to place the electronic components onto the board. Automated pick-and-place machines quickly and accurately place small components, such as transistors and resistors, onto the board.

   AO-I Must Inspect

   After the component placement, the PCB goes through an Automatic Optical Inspection (AOI) process to ensure that the correct components end up in the correct locations and that there are no missing or incorrectly placed components. AOI uses high-resolution cameras to capture images of the PCB and compares them to a pre-defined image of the PCB, allowing it to detect any discrepancies.

   Leave the Oven On!

   The next step is soldering the components to the board to make electrical connections. A reflow oven melts a small amount of solder on the bottom of each component, allowing the machine to securely attach them to the board. In some cases, selective soldering comes into play, which involves selectively applying solder to specific areas of the PCB, rather than applying it to the entire board. This technique is particularly useful when working with complex or sensitive PCBs that require more precise soldering.

   Test, Test, & Test

   After the reflow process, the PCB goes through another round of AOI inspection to check the quality of the soldering. If there are any defects, the assembler will rework the PCB to correct the problem.

   In some cases, the manufacturing process also includes X-ray evaluation, which is an additional step of quality control to ensure that the solder joints are properly formed. It also allows for checks for hidden defects, such as solder bridges or voids, that would not be visible in a visual inspection. X-ray inspection is particularly useful when working with dense or complex PCBs where it is difficult to visually inspect all the solder joints.

   Cleaned & Packaged

   After the AOI and X-ray inspection, the assembler may use the washer to clean the PCBA and then package it for shipping to the customer. If the PCBA is part of a larger product, the manufacturer will then integrate it into the final product, such as a computer or a mobile phone.

   Summary

   In summary, the PCB assembly process using Surface Mount Technology (SMT) includes several steps: PCB preparation, component placement, Automatic Optical Inspection (AOI), soldering, selective soldering, AOI inspection, X-ray evaluation, cleaning, and packaging. This process is efficient, and reliable, and allows for the use of smaller and more densely packed components. By including inspection steps such as AOI and X-ray evaluation, it ensures that the final product is of high quality and meets all the necessary requirements. With the advancement of technology, the SMT assembly process has become more efficient, accurate, and reliable; however, it still requires skilled labor and attention to detail to produce high-quality circuit boards.

   It is important to use an experienced printed circuit board assembly (PCBA) manufacturer like PGF Technology Group to ensure that your PCBs are made to the highest quality standards and meet your specific requirements. With years of experience and state-of-the-art machinery, PGF Technology Group is well-equipped to handle all your PCBA needs. They have a team of experts who are knowledgeable in all aspects of the PCB assembly process, from design to manufacturing.