BGA Assembly
Our experiences handling all types of BGAs from micro BGAs to large size BGAs , and from ceramic BGAs (CBGA) to plastic BGAs (PBGA), and we are capable of placing minimum 0.35 mm pitch BGAs on your PCB board.
Your Premier BGA (Ball Grid Array) Assembly manufacturer
with X-ray Inspection
Venture has great experiences providing BGA assembly services in printed circuit board assembly industry, with our state-of-the-art BGA placement equipment, correct BGA assembly processes, and X-ray test equipment, you can rely on us to build high-quality BGA boards.
When we receive your turnkey order with BGA assembly, our BGA assembly engineer and PCB fabrication engineer will work together to check your PCB Gerber files and BGA datasheet with DFM review, by checking the details such as PCB material, surface finish, maximum warp requirement and solder mask clearance and BGA datasheet, since all these will affect the quality of BGA assembly. Thermal profile is the key importance of the BGA assembly process.
Your Leading BGA Assembly Supplier in China
Before production, our BGA assembly team will carefully check the storage conditions of BGA components, and make an optimized thermal profile for your BGA assembly process, BGA components are highly humidity sensitive and thermal-sensitive components.
Every our BGA assembly board will go through X-ray inspection, from today’s X-ray inspection machines, BGA assembly problems such as excessive voiding, paste bridging, insufficient ball melting or poor placement are immediately detectable with X-ray inspection, in this way we can eliminate soldering problems on the board, and provide you 100% quality guarantee.
No matter you are an electrical engineer, a product designer, a system integrator or maker looking for BGA assembly manufacturer, Venture BGA assembly team will be your perfect place to go.
Why Choose Venture BGA Assembly
Through our 2 hours rapid response services from our 24/7 sales and tech support team, and excellent after-sales service, we will be your best BGA assembly manufacturer and partner in China.
At Venture we can answer any BGA questions that you may have, pls feel free to contact us anytime for your BGA assembly project
What is the difference between BGA and LGA?
BGA(Ball Grid Array) assembly require special mounting practice experiences. A BGA is an SMD with an array, of solder pads across its bottom side. Instead of using ‘leads’ like normal components use to connect to the PCB, BGA use balls of higher-temperature solder to attach to these pads.
Land Grid Array (LGA) and Ball Grid Gray (BGA) are both surface mount technologies (SMT) for motherboards. They basically define how the CPU is actually mounted on the CPU socket of the motherboard.
Essentially, the most basic difference between the two is that LGA-based CPUs can be inserted and removed from the motherboard, or they can be replaced. BGA-based CPUs, however, are soldered to the motherboard and therefore cannot be inserted or replaced.
Factors Affecting PCB BGA Assembly Quality
1) Feasibility of BGA Pad Design
Due to different pitches, BGA packages are divided into different types.
2)Solder Paste Printing
Solder paste printing is the precise transfer of solder paste from a stencil to a pad with a stencil.
3)Positioning accuracy
The accurate positioning of BGA on the printed circuit board is helpful to improve the reliability of BGA soldering.
4)Soldering Temperature Profile and Soldering Defects
5)BGA Inspection and Rework Technology
How to Clean BGA Package
1. Place the BGA package on a conductive pad and use a lit solder paste on its surface.
2. Use a soldering iron to heat the suction line, melt the solder balls, and then sweep the cleaning line across the BGA surface.
3. Clean the BGA surface with industrial alcohol. Use rubbing motion to remove flux from the surface.
4. Inspect clean pads, damaged pads and unremoved solder balls by using a microscope.
5. Carefully scrub the BGA surface with deionized water and a brush.
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Ball Grid Array Assembly: The Ultimate Guide
Today, you’re going to learn about ball grid array assembly as a popular SMT in PCB assembly.
I will take you through its definition, background, merits, demerits, classification and the assembly process.
We are also going to see how you can test BGA PCB.
And that’s not all…
You’ll also learn how to choose a BGA Assembly machine and main applications of BGA Assembly technique.
So let us begin by defining Ball Grid Array.
- Chapter 1: What is Ball Grid Array?
- Chapter 2: Advantages of Ball Grid Array.
- Chapter 3: Disadvantages of BGA
- Chapter 4: Types of BGAs
- Chapter 5: How does the BGA Assembly Process Work?
- Chapter 6: Preparing for the Soldering Process
- Chapter 7: BGA Assembly Capability
- Chapter 8: How do we Test BGA Assembly Board?
- Chapter 9: How to choose BGA assembly machines
- Chapter 10: Application of BGA Assembling Techniques
Chapter 1: What is Ball Grid Array?
Ball grid array is a surface mount type of packaging. It is used in integrated circuits to mount devices like microprocessors permanently.
Look at this:
BGA Assembly
1.1.Background
BGA is dated back in 1989 when Motorola and citizen developed a plastic BGA.
Later, they were used to package jewelry and some other electronic devices like radio and mobile phones among others.
BGA had some challenges just like many new technologies though as time went by, solutions to those challenges have been found.
The discovery of the answers to these challenges has promoted the reliability of BGA packages since high-quality inspection is now guaranteed.
Chapter 2: Advantages of Ball Grid Array.
What is the benefit of using Ball Grid Array?
Like any other PCB assembly package, BGA has its pros and cons. When you choose BGA, you have to put into consideration its merits and demerits.
Below are some key reasons why we can choose to develop a device using BGA assembly technique.
BGA PCB Assembly
- High density
Because more solder balls are used in Ball Grid Array Assembly, the connection in between the balls increase creating a higher density of connections.
Numerous solder balls are used and this, in turn, lessens space on the circuit board.
This gives BGA an outstanding ability to conduct heat; hence better quality of devices are created through BGA.
The high-density characteristic of BGA package allows it to be used in assembling devices which are required to have high-speed performance.
- Easy to assemble and manage
It is easier to assemble and manage BGA on to the circuit board than in other PCB assembly techniques.
This is because the soldering balls are directly used to solder the package onto the circuit board.
We just place the solder balls and melt it using soldering bit simultaneously. Within a period of a few seconds, a joint is created.
- Soldering balls align themselves
As we solder, the soldering balls align themselves during the soldering process.
Due to high utilization of the space on the printed circuit board, Soldering balls align up beneath the board.
We can view it better when we look at the Printed circuit board from the opposite side.
With BGA, the whole circuit board is utilized. Since the through holes on the board are lined up, all the balls will appear aligned.
- Lower thermal resistance
In addition to these, the BGA package and the circuit board has lower thermal resistance.
This allows dissipation which helps in preventing the device from being overheated.
BGA overheating is not good because it can sometimes damage other board components other than the solder balls.
Lower thermal resistance quality of BGA helps to minimize this particular damage.
- Better electrical conductivity
Due to a shorter path between the die and the circuit board, BGA gives better electrical conductivity. When soldering the balls, no through hole is left.
This means the solder balls and other components occupy the whole circuit board. Therefore vacant spaces are reduced.
Chapter 3: Disadvantages of BGA
Ball Grid Array Assembly also has its shortcomings like any other technique of assembly.
The disadvantages of using BGA are explained below.
BGA Component assembly
· Negative reaction
When a BGA PCB bends, it experiences some negative response from the circuit board. These negative reactions are sometimes called stress.
When there is stress in joints, they may develop some cracks which may cause damage to some components on the board.
Therefore, a lot of care is needed to solder the balls accurately as much as possible if we desire good results.
To reduce this stress, soldering begins by attaching the solder balls loosely until after inspection has confirmed good quality joint.
- Inspection difficulty
One of the challenges of using BGA is difficulty in inspecting the BGA Package. This is because soldering balls are placed very close to one another.
When they are close to each other as it is, it is difficult to carry out a proper joint inspection of BGA packages.
Because of this, it is not easy to identify if the device assembled has some setbacks.
Without the use of advanced machines like X-ray machines, inspection is tough.
- BGA is expensive
The equipment for packaging BGA is costly. For example, an X-ray machine that is used for inspecting BGA package is very expensive.
Soldering using hands can be used though it has proved to be very difficult and undependable.
Should we choose to mount a printed circuit board using the BGA package, then we must be ready to shoulder the cost.
It requires that you use a soldering iron that has a thermostat, which is also very expensive.
So for better, finer and high-quality devices, the cost of manufacturing will go higher.
Therefore in general BGA assembly is expensive for manufacturers; even though devices packaged through it have better performance.
- BGA connections at times may not be reliable
Because solder balls don’t bend, when there is vibration, solder joints develop cracks in between the joints.
For this reason, you should start by fixing the balls loosely and make them firm and strong later during the final stages of soldering.
In addition to this, BGA connections may be considered unreliable due to the complicated nature of inspection.
However various machines are currently in place to thoroughly inspect the faults on the board if there be any.
Chapter 4: Types of BGAs
There are different types of BGAs.
These differences come as a result of how the BGA assembly package is developed.
Below are some of the types of BGA assembly which are commonly used.
4.1. Molded Array Process Ball Grid Array
With MAPBGA, solder balls are used to mount electrical network on the surface of the circuit board.
This allows for alignment of the solder balls on the circuit board where they are molded together.
MAPBGA
These solder balls once placed are then separated by sawing. MAPBGA enables the solder balls to appear aligned after the completion of mounting.
A better view can be accessed when you look at it from the opposite side of the board. It uses a solder ball for electrical connectivity.
Remember, solder joints are formed underneath the package.
It is advised that inspection should be done using either X-ray machine or Optical magnifier.
This will help in discovering if there is any short-circuit on the package.
There are some of the shortcomings that have been identified when molded array process BGA is used.
For example, some of the solder paste and solder balls may melt but fail to join.
Another defect that has been discovered in MAPBGA is that Solder paste and solder ball merge during reflow from poor paste printing
MAPBGA is not recommended for repair because it may lead to the damage of other components on the board.
Instead, we can do reworking. Here, the whole device is removed and thereafter replaced by a new one.
A good reworking for MAPBGA comprises of six stages for us to get good joints.
These stages include Preparation of the tools, removal of the whole package, redressing the site, solder paste printing, remounting the package and reflow soldering.
4.2. Plastic Ball Grid Array
This is a standardized printed card or circuit board which is used to construct modules. Its surface is thin. It is about > than0.03 inches.
Plastic ball grid array
A chip and the surface where the soldering takes place are connected using wires. Even though this is so, a dice six of sides of the Flip-chip can still be directly connected to PBGA.
It could be either 2 or 4 layers of substrates. It is usually laminated using copper substrates
4.3. Tape Ball Grid Array
Unlike the old BGA, TBGA can easily bend, are lighter in weight and offers better content for electrical manufacturers.
Tape ball grid array – Photo courtesy: PCB CART
Tape Ball Grid Array PCBs do not form fracture since they don’t develop stress. They are flexible and can easily bend.
Because of this characteristic, it is preferred by electrical device manufacturers who assemble lighter devices.
4.4. Package to Package BGA
Here the related links are molded on the circuit board. The detached logic is then vertically molded together with the Ball Grid Array.
Package on package BGA – Photo courtesy: Wikimedia
More than one package can be mounted on each other and separated using a standardized surface to indicate signals between the packages.
Integrated circuits are used to put together vertical discrete logic and memory BGA packages.
For example, digital cameras, mobile phones, and personal digital assistants are packaged using Package on Package BGA assembly technique.
PBGA has been used widely in only two configurations. These include:
- Pure memory stacking where only two or more memory packaged are joined together
- Mixed logic package where memory package is placed on top and logic which is CPU is situated at the bottom.
The benefit of Package to Package is that it possesses the benefits of traditional packaging and the die-stacking techniques.
This helps in reducing the shortcomings of Package to Package.
Package to Package technic can be useful in smaller packages with shorter electric connections.
Most semiconductor engineering companies which are advanced prefer to use Package to Package technology.
4.5. Thermally Enhanced Plastic Ball Grid Arrays
This type of BGA has an in-built heat sink which is very critical to devices with high heat dissipation.
Thermally conductive BGA – Photo courtesy: Electronics cooling
For example, television, automobile, and other industrial electronics.
This thermally enhanced plastic Ball Grid Array helps in regulating the heat so that the solder balls may not overheat.
Overheating can cause dry joints, cracking of the joints and damage to other components on the board.
4.6. Micro BGA
This is also one of the types of Ball Grid Array packaging. Primarily it is made up of 0.04-millimetre dimensions in between the solder balls.
Sometimes the measurements between the balls are less than the 0.04 mm.
Because of this closer package of the balls, the entire package is minimized.
Micro BGA packages placed closer to each other enhances efficiency in the use of the circuit board.
Chapter 5: How does the BGA Assembly Process Work?
BGA assembly process can also be referred to as thermal profiling. Thermal profile is very critical in the PCB assembly process.
Effective thermal profile is achieved by taking into consideration BGA size and BGA balls. These could be either leaded or lead-free.
BGA Assembly Process
When the thermal profile is optimized internally to a local level, there is the prevention of BGA internal heating. This reduces joint stress and potential PCB assembly faults.
When quality management procedures are followed, any void is kept below 25%.
For lead-free BGAs, a special lead-free thermal profile can be used to reduce open ball problems which occur when the temperature is low.
On the other hand, leaded BGAs also undergo a special leaded process which prevents high temperature. The high temperatures cause pins to become shorter than expected.
Currently, the development of electronics is drifting from the ones that were heavier, thicker and less advanced. They have become lighter, thinner and more advanced in performance.
Manufacturers faced challenges like guaranteed dependability, quality, and method of inspection of the device in the olden day.
These challenges compromised the quality of BGA assembly packages until when solutions to these challenges were found.
Therefore, all manufacturers want to know these solutions which are critical for the success of manufacturing all devices.
The assembly of BGA includes:
- BGA rework
- BGA re-balling
Honestly, BGA assembly requires high precision.
This is because once mounted, they become permanent and can only be reworked on. So let me take you through the BGA assembly process.
BGA assembly is done through BGA rework and BGA re-balling. Let us look at them separately in a more detailed manner.
5.1. BGA Rework
Reworking BGA is not an easy task unless you have access to the right equipment. When a problem is discovered in a BGA, this calls for rework.
The following procedure is used during BGA rework:
Figure 10 BGA Rework – Photo courtesy: Circuit Technology Center
- Heating of BGA can be done to melt the solders underneath. You should ensure that as you heat the BGA, other components on the board should have little or no effect. If they are heated, they may be destroyed.
- Before you start re-assembly of BGA, you have to begin by removing all the elements.
- Ensure the site is ready for the new work
- After clearing the site, apply the solder paste on the surface of the circuit board where you want to solder the new balls.
- Change all the old BGAs and instead use the new ones.
You must have all the necessary tools for rework. These include a circuit board, solder iron, hand helper, wire cutters, thin-nosed pliers and solder sucker.
All these tools must be available for rework to be done successfully. These tools include:
5.2. Tools used in soldering
For soldering to be done, there have to be specific tools which must be used in order to get the desired joints.
For this reason, we have different tools used during the soldering process. Among them include:
Soldering iron
They exist in different sizes and for different specifications. Their cost is also different. So you can choose the one you can afford to purchase.
The choice of a soldering iron can also be influenced by the type of work you want to do. Another factor is the surface and the size of the work you intend to do.
For example, for fine and smaller devices, you can opt to use smaller soldering irons.
Some soldering irons have an inbuilt temperature controller while some do not have this component.
For those that don’t have a temperature controller, the cooling effect occurs when solder joints are exposed to the air.
On the other hand, solder iron that has an in-built temperature controller has a thermostat which controls the temperature.
Soldering Iron specifications.
Because there are many soldering irons in the market, it has become difficult to choose one. Some are costly while others are less costly.
Others are big while others are small in size.
Nevertheless, you have to choose one to use. A good soldering iron has specific characteristics engraved in it. The following are some of the features:
a)Size
Choosing the relevant size of iron is dependent on the device and nature of the surface of the board you intend to work on.
For example, fine work only permits the use of smaller irons. On the other hand, less delicate devices can be done using big soldering irons.
b)Use of Power
At 40 watts, non-temperature controlled irons are capable of generating good joints.
This can be done for heavy devices. For small fine work, a watt of between15 to 25 can produce good joint too.
c)Voltage
UK and USA manufacture soldering irons of 230 VAC and 115 VAC respectively. However, some irons can use as low as 12 V.
d)Temperature control
Like we have seen earlier on, less expensive irons have no in-built ability to control the temperature.
Expensive irons have the in-built thermostat regulates the heat depending on the settings of the user. You can set it to a level of heat you desire.
e)Anti-static Protection
Static can destroy some components during soldering. It is therefore vital to consider knowing if the iron you are buying has anti-static protection.
f)Stand
When soldering, you are supposed to have a stand. This stand should be well protected.
g)Maintenance
It is very critical for one to buy a soldering iron that has spare parts so that there can be repair of the iron in the future.
Soldering bit requires regular replacement because it does not last long, though the iron itself may in use for many years.
Even for expensive soldering irons, it is essential to be sure of getting the spare parts once a replacement is prompted.
Wire cutters
Wire cutters can be chosen considering where it is going to be used. Smaller wire cutters are mainly used for finer PCB work.
On the contrary, larger cutters are used for general work. Small wire cutters get damaged when used to cut wires in large general work.
Contrary to this, larger cutters don’t make neat cuttings for printed circuit boards.
Wirecutter
Therefore it is recommended that small wire cutters be used in small and fine work whereas large wire cutters to be used in large general work.
It this if followed, quality devices are manufactured, and maintenance of the soldering BGA tools is managed in the long run.
Pliers
Smaller thin nose pliers are used to work on general circuit board. If you have a heavy duty work, you are advised to use larger thin nosed pliers.
Pliers
This promotes quality and neat job. Don’t use small pliers for heavy-duty work or vice vasa since this will compromise the quality of a device.
Wire Strippers
Stripping wires can be done using wire cutters although wire strippers are specifically meant for that work.
Wire stripper
At times, you can use wire cutters since wire strippers are costly.
Though they are expensive to buy, they make the work much easier. It is much easier to strip wires using wire stripers than by using wire cutters.
Solder sucker
This tool is used to remove a solder that has fault from a joint so that rework can be done.
When you want to carry out rework, one of the tools which are very critical at that particular time is solder sucker.
Solder sucker
It helps to neatly and accurately pull off all the faulty solder balls in readiness to carry out rework. Without this solder sucker, it can be difficult to remove the balls once they are fitted.
Holder
This is a tool used to hold a wire in place while soldering. It is sometimes called “helping hand.”
It consists of an alligator which can be adjusted and a crocodile clip at the two ends. Others have a glass that magnifies the wires for proper viewing during soldering.
Holder
Without this holder, three hands are required to hold the solder, iron and the board. It is, therefore, crucial to have a holder for one to solder accurately and successfully.
5.3. Work area of soldering
It is a key factor to consider if you intend to have a rework. The site of carrying out soldering must have adequate light.
This is to allow the user to see the soldering joints and components clearly.
Also, there should be proper ventilation. High ventilation permits fumes from the solder to exit the room.
It is necessary to use a relatively small fan to clean the fumes from the work area.
Do not work in darkness, less ventilated area and near younger children.
Chapter 6: Preparing for the Soldering Process
When you are ready to carry out soldering you have to make some preparations before you can begin.
Ball grid assembly – Photo courtesy: ThomasNet
- Cleaning both the site and the components of soldering is paramount before you can embark on soldering process.
Ensuring that the surfaces are clean is very paramount.
Wipe the printed circuit board using a solvent to remove any contamination that might be on the board surface.
Meanwhile, you should avoid touching the surface of the board since this can contaminate it. Contamination compromises the quality of the joints.
- Secondly, using pliers, remove any oxidation from the board surface. If oxidation is not removed, the solder joints may not be good enough.
- Make the surface of the connectors rough. It helps in cleaning.
Cleanliness of all the BGA components is essential since it ensures proper joint formation.
- Lastly, clean the soldering tools like soldering bit by wiping them on a wet sponge containing a solvent.
6.1. Making solder joints
With regular practice of soldering, it is easier to make solder joints successfully.
When you understand the process, you can ensure all the required components are in an accessible place.
That is, a place you can easily reach out for them during the soldering process.
Ensure you place components where they are contamination free. It is the only way to get high-quality joints.
Solder joint – Photo courtesy: EE Times
Place the lead components in a through a hole in a printed circuit board before embarking on soldering.
- Begin by initially fixing the solder balls loosely. This will ensure you have ample time when you discover that there is a fault and you want to remove.
When they are fixed firmly, it will be difficult to remove the ones that have not been fixed correctly. Therefore loose fixing is recommended at the initial stage.
Firm fixing leads to damage of other components on the PCB surface at the time when defective ones are being removed.
- The next step is to take a solder on a soldering bit and wipe it using a wet sponge. When soldering and the soldering iron is hot, it gets dirty easily.
Regular wiping of the soldering iron is critical.
- Place the bit with the solder on the joint and melt enough solder onto the joint. If you fail to melt enough solder onto the joint, the joint will not be good enough.
- Soldering takes approximately a few seconds. Excess melting of solder balls also creates a tough and dry joint which is also not good.
This can happen when the soldering iron is placed for a longer time on the joint.
- After making the joint, take off the soldering bit and wait for the joint to cool off. This way, you will be able to make several solder joints on the printed circuit board.
6.2. Soldering Golden rules
There are soldering golden rules which should be put into consideration.
When carrying out soldering, you have to adhere to some specific rules.
These rules are very vital because they ensure your safety as an individual and also guarantees good quality joints.
You need to take various considerations to achieve the desired results. Take for example; solder iron is very hot.
Always use holders when the soldering iron. During the soldering process, be careful not to burn people who might be around you with the iron.
It is recommended that you should avoid soldering when young children are near the site.
Cleanliness for soldering iron is very paramount. When the iron is hot, it gets contaminated very easily.
Use a wet sponge to clean the iron regularly.
Concurrent application of both the solder and the iron is very critical to get better joints.
Placing the solder on the bit and carrying it to the joint does not yield good joints. Therefore, it is advisable that both the bit and the solder be applied together at the same time.
Using too much solder compromises the quality of the joints. Just melt enough solder at the joint. Remember, any temptation to apply more solder results in poor joint formation.
Keeping an iron in one particular place causes rigid and dry joint formation. Once a joint is formed, detach the iron from the joint so that you can allow the joint to cool off.
Last but not least, acquiring skills on how to solder is very critical for anyone who has an interest in soldering electronic devices.
Make sure good joints are created every time. It is a sure way to ensure your circuits work efficiently.
Besides, your joints will look good.
Following these rules promotes reliability of BGA assembled devices.
6.3. Types of Soldering Irons
There are two major categories of soldering irons. They are as illustrated below:
Basic air controlled iron
This type of iron has no temperature controller. It relies on the air for temperature control.
The exposure of the soldered joint to the air aids cooling of the joints during the soldering process.
Also, this type of Iron is very cheap, and it can be used to solder a variety of devices.
Temperature controlled iron
This type has an in-built temperature controller. It uses a thermostat to control the bit temperature.
You can adjust the heat to the desired level.
It produces a good joint. However, it is very expensive compared to the basic one.
6.4. BGA Re-balling
BGA re-balling is the process of removing old solder balls, then replacing with new ones. There are numerous reasons for re-balling.
The following can be a reason for re-balling:
- Where a device is accidentally pulled off a PCB, it is necessary to place it back on the board.
- When the device has been soldered in the wrong alloy, you can carry out re-balling to change solder balls.
- Another reason for re-balling is to allow failure analysis to be done.
The method of re-balling is dependent on the:
- Volume of work to be undertaken
- Type of package
- Alloy being placed on the board.
For small packages, tools small in size should be used. On the other hand, when the work involves heavy duty, larger tools are relevant.
Reballing
Therefore, both rework and re-balling entail all the basic BGA assembly processes.
Chapter 7: BGA Assembly Capability
The capabilities of BGA are many. These are some of the capabilities that make it stand out among other packaging techniques.
High-density circuits are created when the solder balls are accurately soldered into the through holes without any crossover.
There is reduced space between the balls. Because of this, there is a high density of circuit on devices that have been assembled through BGA.
Heat conduction
BGA packages have reduced overheating. This is because BGA allows heat to pass through from integrated circuit to outside.
Heat conduction in BGA PCB
Due to this unique characteristic, BGA is rated among reliable packages.
Also, problems related to interference with circuits are limited when it comes to the use of BGA package.
This is mainly because solder balls are smaller in size. As a result, it possesses a characteristic of lower inductance.
BGA Soldering
A solder is a material that melts around a joint which after cooling is capable of conducting heat.
Soldering is one of the critical processes used in the manufacturing of electronic devices. It allows electronic components to be joined together electronically.
Soldering requires an accurately controlled solder quantity which when heated will melt.
You should choose a solder alloy composition and temperature. It is the only way to promote good separation between the solder balls.
And of course, if you want the right joints, it is important to choose appropriate tools and accessories.
Some of the most common tools include:
- Solder iron
- Wire cutters
- Thin-nosed pliers
- Wire strippers
- Solder suckers
- Wire holders among others
Also, the work area must have enough light and proper ventilation during the soldering process.
BGA Rework
Reworking BGA is not an easy task unless you have access to the right equipment. When a problem is discovered in a BGA, this calls for rework.
The following procedure is used during BGA rework:
- Heating of BGA can be done to melt the solders underneath. You should ensure that as you heat the BGA, other components on the board should have little or no effect.
The components may be destroyed.
- Before you start re-assembly of BGA, you have to begin by removing all the elements.
- Ensure the site is ready for the new work.
- After clearing the site, apply the solder paste on the surface of the circuit board where you want to solder the new balls.
- Change all the old BGAs and instead use the new ones.
- Carry out the process of reflow.
BGA Re-balling
It means that old solder balls are removed and instead replaced using the new ones.
The following can be a reason for re-balling:
- When a device is accidentally pulled off a PCB, it is necessary to place it back on the board.
- Also, when the device has been soldered in the wrong alloy, you can carry out re-balling to change solder balls.
- Another reason for re-balling is to allow failure analysis to be done.
The method of re-balling is dependent on the volume of work to be undertaken, the type of package and the alloy being placed on the board.
Chapter 8: How do we Test BGA Assembly Board?
After any PCB assembly and design work, quality testing and evaluation is important.
You can use various machines to identify problems and fix in time.
For example, we have an X-ray machine, Industrial CT scanning machines, special microscopes and endoscopes.
With these inspection machines, problems associated with excess soldering, stealing of solders, misalignment of components, bridging and missing solder balls can all be identified.
This is because these machines can see through solder balls.
Remember, inspection equipment helps in verifying that each solder is placed correctly.
It also reassures every contact with the board remains intact.
Even though the inspection machines are good, it has some setbacks.
For instance, it has become difficult to distinguish between parts that are placed on the same location.
Of course, this exception applies when viewing the board from the opposite side.
Tools used for inspection helps in supplementing the accuracy of the placement of the ball. It also helps to ensure the quality of the device is good.
Let’s look at some of the most common inspection techniques:
BGA Assembly X-ray inspection
Sometimes, paste for soldering can be applied in the wrong way. Also, there can be partially melting of the balls.
All these are problems encountered during assembly and could be identified through an investigation machine of X-ray.
X-ray inspection
The interval between balls can be determined through the calculations made using an x-ray software analysis calculator.
Normally, this calculation aids in soldering the balls within the recommended IPC range.
Optimal Solder joint inspection
This equipment checks the position, presence polarity and solder joint. It assesses the quality of a device once it has been manufactured.
PCB inspection
In this case, a machine is used to visualize the device which has been soldered.
Chapter 9: How to choose BGA assembly machines
Selecting the right BGA assembly machine requires experience, manual dexterity and individual talent.
It is important to have an experienced operator who can handle your BGA rework.
The choice of BGA assembly machines have posed challenges to managers, planners, engineers and rework technician.
In the early days when BGA techniques had just been innovated, simple tools like de-soldering tool and magnifiers were used.
Also, de-soldering tool was used to perform all the rework while magnifiers were used for inspecting the quality of the device packaged.
These were not good enough, and the quality of devices manufactured was not good.
Currently, a BGA machine is recommended instead of a simple rework station that was initially used.
Also, an X-ray machine is recommended for joint inspection instead of the simple microscope or magnifier that was used before the discoveries.
Initially, upper-level assembler was used. However, due to technological development, what you need is a skilled operator.
This personnel must have computer skills.
He or she must be in a position to comprehend issues of solder paste.
BGA Machine
In addition to this, he/she must have good dexterity skills. Besides, be able to operate an X-ray machine during the inspection of solder joints.
Also, the operator should have knowledge of interpreting x-ray images. Thus, he can be in a position to recognize if there are faults made during the soldering process.
First, get the experts who can operate the BGA machines. Then you can now go ahead and choose the BGA assembly machine.
They usually use their previous experience to identify which BGA assembling machine yielded good results in their previous assemblage.
Chapter 10: Application of BGA Assembling Techniques
BGA assembling techniques are common in many applications today.
As indicated earlier, BGA packages produce strong joints. When you inspect the BGA with an X-ray machine, they yield good results of solder joints.
Some of the main applications of BGA technique include:
- An integrated circuit in computers, TVs, mobile phones, and many other electronics.
- Dual in-line or flat electronic systems
- Military airborne applications
- Automotive industry
- Consumer electronics, ,
In short, ball grid assembly plays an important role in many electric and electronics industry.
Conclusion
BGA assembly package is very important in technological development in the current world.
Even though it has some shortcomings, its contribution to industries manufacturing electric devices has proved to be reliable, efficient and of high quality.
Therefore as technology advances, there is hope BGA assembly package will also continue to advance.
This is because there is interest in the use of BGA assembling technology by most electrical manufacturing industrie