What is BGA stencil？

BGA stencil is an indispensable complex component in electronic products. They provide critical thermal conductivity, packing density, and interference immunity. Unfortunately, when they fail, they are difficult to repair.

Due to thermal damage or mechanical problems, the contact between the chip and the PCB is usually lost. In this case, the best way to restore the BGA pins is to re-solder the ball. After removing the BGA from the PCB, reballing is the process of putting all the pins on the BGA with the help of the soldering station. After reassembly, the defective chip can be used again, or the pins can be placed on a new chip.

The BGA stencil is a key tool to make the reballing process smoother. They are designed to simplify the placement of array devices, thereby saving you up to 50% of the time, otherwise, you will spend the BGA rework.

Below, we provide more information on how to choose and use the correct BGA resolder stencil that suits your unique needs.

Types of BGA stencils

The BGA stencil is essentially a board, usually made of metal with small holes. The size of the hole corresponds to the diameter of the BGA solder ball, and the pitch of the hole corresponds to the pitch of the chip pin surface. There are two different types of BGA templates: dedicated and general.

The general template is a square matrix with holes of the same size. They are very suitable for re-spheroidizing chips with the same pitch and diameter as the template.

The special templates are also square, but their holes are aligned in the same way as the pins on the chip. They are most commonly used in situations where chips of the same type must be re-balled regularly.

Most reballing kits include universal templates, which tend to be the more popular template type.

How to choose the best BGA stencil?

When choosing a BGA stencil, you should keep a few key considerations in mind. First, you need to consider the resistance of the template to deformation during heating. Many templates for refilling computer chips are not heat resistant, which means they can only be used to place balls and should be removed when the chip is heated.

You also need to understand the size requirements of the BGA you are using to ensure that the solder balls are properly fixed. These size requirements include the size and thickness of the BGA.

How to use BGA stencil

To properly fix and use the BGA stencil, follow these steps:

After removing the BGA from the PCB, clean and prepare the template and BGA template rework station. You can use isopropyl alcohol and a lint-free cloth to remove any dust or other contaminants.

Peel off the adhesive from the back of the template and place it. To apply the template correctly, align its holes with the pins on the chip. Place the template in one corner and work slowly to the opposite corner. After placing it, gently flatten it.

Next, you will apply solder paste. You should allow the solder paste to reach room temperature and stir before applying it. To apply, use a micro scraper or brush tool. Place the tool at a 45-degree angle to the template and use enough force to ensure that the solder paste adheres to the chip through the holes in the template.

Using your BGA template rework station, apply hot air to cure the solder paste. This process will form solder balls that stick to the chip.

Wipe off the excess solder paste with a lint-free cloth, and then inspect the workpiece to ensure that the solder is evenly distributed.

Clean the chip with acetone or IPA solution and remove it from the template.

Now you can solder the BGA back to the PCB. Place the chip on the PCB and heat it up.

Benefits of using BGA stencil

Using BGA steel mesh to re-solder the ball, you will simplify the repair process and save your own time. You can expect a low-cost repair method with accurate results, even in narrow or irregularly shaped areas.

When you use a BGA stencil with a size that fits your BGA, you will increase your first-pass yield, thereby achieving higher overall accuracy and reducing scrap costs. The time required to align and place the equipment will also be significantly reduced.

Oriwhiz (Shenzhen DongYe Tengfei Electronics Co., Ltd) is a professional iPhone, iPad, iMac, Mac Book, Xiaomi, Huawei, Samsung, Sony, LG, ASUS repair parts and repair tools supplier. Oriwhiz team aims to provide the best quality cellphone replacement parts and repair tools to all customers. We provide comprehensive solutions for cellphone, digital devices, computer repair shops with powerful and handy cellphone repair packages, repair tools, and repair machines. Browse our product category to select an item you like or contact us for wholesale and distribution issues.