There are different methods for BGA (Ball Grid Array) chip ball placement. Today, Silman Tech will explain that they can be classified into different categories:
- Based on the operator, BGA ball placement can be divided into machine ball placement and manual ball placement.
Machine ball placement involves setting up a program, and then the machine autonomously completes the BGA ball placement. The advantages of machine ball placement include high rework yield, saving on labor costs, and high rework efficiency. However, the downside is the expensive price. Currently, automatic ball placement machines like Silman Tech’s BGA ball placement machine are available on the market.
Manual ball placement relies on workers using simple machines to perform BGA ball placement. The advantage of this method is the relatively low cost of BGA, but the disadvantages include low rework efficiency, low rework yield, and high labor costs.
- Based on the materials used, ball placement can be divided into solder paste + solder ball and flux + solder ball methods. There are two popular ball placement methods in the industry today: solder paste + solder ball and flux + solder ball.
Solder paste + solder ball is considered the best and most standard method of ball placement. This method produces solder balls with good solderability, glossiness, and minimizes the risk of solder ball migration during soldering. The specific process involves printing solder paste onto the BGA pads and then placing solder balls on top. The solder paste acts as an adhesive to hold the solder balls in place and increases the contact area between the solder balls and the BGA pads, resulting in better solder joint quality and reduced risk of voids.
Flux + solder ball involves using flux instead of solder paste. However, flux behaves differently from solder paste; it becomes liquid at high temperatures, making the solder balls prone to migration. Additionally, flux has inferior soldering properties compared to solder paste. Therefore, the first method (solder paste + solder ball) is more ideal for ball placement.
