一、The birth of BGA chip background
In the course of rapid development of electronic technology, the demand for chip packaging form has been evolving. As electronic equipment increasingly towards miniaturisation, high performance and multifunctionality in the direction of progress, the traditional chip packaging gradually exposed a number of limitations. For example, the limited number of pins is difficult to meet the needs of complex circuit connections, and there are also shortcomings in the use of space and electrical performance.
It is in this context, BGA (Ball Grid Array) chip came into being. It is a new packaging architecture, to solve these problems provides an excellent programme, and quickly occupy an important position in the electronics industry.
二、The structure of the BGA chip analysis
1、The core of the chip
The core of BGA chip is of course its internal integrated circuit chip, which is the key to the whole chip to achieve a variety of functions. It consists of a large number of transistors, capacitors, resistors and other electronic components through the fine photolithography, etching and other semiconductor manufacturing processes integrated in a small piece of silicon, capable of completing such complex functions as data processing, signal conversion, logic operations.
2、Substrate components
Surrounding the core of the chip around the substrate, which plays a key role in the beginning and end. The substrate is usually a multi-layer printed circuit board (PCB) structure, with intricate internal wiring channels, for the chip’s internal signals are accurately transmitted to the external pins. At the same time, the substrate also provides a certain physical support for the chip to ensure that the chip can be stable in a variety of environments.
3、Spherical solder joint array
The most unique and eye-catching is located on the bottom of the substrate of the spherical solder joints array. These tiny spherical solder joints are arranged in a regular grid, densely distributed on the bottom surface of the substrate. They are like a ‘small tentacle’ connecting the chip to the outside world, and are connected to the corresponding pads on the external circuit board through processes such as reflow soldering. Compared with the traditional inline or flat package pins, the spherical solder joints have a smaller pitch and higher density, which enables the BGA chip to accommodate more pins in a limited package area, thus achieving more complex circuit connections and function expansion.
三、The excellent performance advantages of BGA chips
1、High pin density and multi-function integration
With its tightly arranged array of spherical solder joints, BGA chips have a very high pin density. This means that in the same size package size, it can achieve much more than the traditional package chip pin number. More pins can achieve more input and output interfaces, so that the chip can interact with external circuits for richer and more complex signals, and then achieve such as high-speed data transmission, multi-channel audio and video processing and other functions of the integration, which greatly enhances the chip’s scope of application and practicality.
2、Excellent electrical performance
The structural design of the BGA chip optimises the electrical performance to a large extent. Due to the relatively short and uniform connection between the spherical solder joints and the external circuit board, this effectively reduces the impact of inductance, capacitance and other parasitic parameters in the signal transmission process, thus reducing the delay and distortion of the signal transmission. In high-speed digital circuit applications, such as modern 5G communication equipment, high-performance computers, etc., to ensure high-speed and accurate data transmission, providing a strong guarantee for the efficient operation of the entire system.
3、Excellent heat dissipation characteristics
Electronic chips will inevitably generate heat in the working process, and the heat dissipation effect is directly related to the performance and service life of the chip.BGA chips are excellent in this regard, on the one hand, its substrate is usually made of materials with good thermal conductivity, which can quickly conduct the heat generated by the chip; on the other hand, the spherical soldering point array also contributes to a certain degree to the dissemination of heat through heat transfer and thermal conductivity of the external circuit boards and the external circuit boards, as well as the thermal conductivity of the chip. On the other hand, the array of spherical solder joints also contributes to heat dissipation to a certain extent, through heat conduction with the external circuit boards and natural air convection, etc., so that the heat can be effectively dispersed. In addition, for some high-power BGA chips, you can also be equipped with special heat sinks, such as heat sinks, heat pipes, etc., to further strengthen the heat dissipation effect, to ensure that the chip in the high load working condition can also be stable operation.
4、Help electronic equipment miniaturisation
With the increasingly demanding requirements of modern society on the volume and weight of electronic equipment, the advantages of BGA chips are becoming more and more prominent. Its high pin density and compact package structure makes in the case of not increasing or even reducing the overall volume of the device, you can integrate more functions and higher performance. For example, in smart phones, tablet PCs and other portable electronic devices, the application of BGA chips make these devices can be achieved in a small body, such as powerful processor performance, high-definition camera function, high-speed wireless network connection and many other functions, to meet the people on the portability and high performance of the double demand.
四、The BGA chip manufacturing process
1、Chip manufacturing stage
First of all, the chip manufacturing, which is a highly complex and sophisticated process. Semiconductor manufacturing plant will use a series of advanced semiconductor manufacturing processes, such as photolithography, etching, doping, diffusion and other technologies, on a silicon chip to gradually build up integrated circuits with specific functions. This process needs to be carried out in an extremely clean environment, because even the smallest dust particles can lead to chip failure, affecting its performance and quality.
2、Packaging preparation stage
When the chip manufacturing is completed, the next step is to prepare for the packaging process. This includes testing the chip to ensure that its function is normal, and then the chip is accurately placed on the substrate. Flip chip (Flip chip) technology is usually used, that is, the active side of the chip down, so that it is aligned with the corresponding pad on the substrate, ready for the subsequent welding.
3、Welding formation stage
In the chip and the substrate alignment, through the reflow soldering and other welding processes, the solder will be heated and melted, so that the chip and the substrate through the spherical solder joints connected. In this process, the welding temperature, time and other parameters should be strictly controlled to ensure the quality of the spherical solder joints, to avoid the emergence of false soldering, short circuit and other welding defects.
4、Follow-up testing stage
After the completion of welding to form the BGA chip, it is also necessary to carry out comprehensive testing. Detection includes pin connectivity, electrical performance, thermal performance, etc., to ensure that the manufactured BGA chip meets the quality standards, can be stable and reliable operation in practical applications.
五、BGA Chip Widely Used Areas
1、Computer industry
In the computer field, BGA chips are everywhere. From the central processing unit (CPU) to the memory chip, from the motherboard chipset to the graphics processing unit (GPU), almost all the key components are a large number of BGA package form. For example, in order to achieve high-speed data transmission and powerful processing capability, most of the CPUs and GPUs of modern high-performance computers are packaged in BGA, which can meet the needs of complex computational tasks and also ensure efficient data transmission between various components within the computer.
2、Smartphone and Tablet PC Industry
Smartphones and tablets are indispensable electronic devices in people’s lives today, and BGA chips play an equally important role in these devices. From the processor chip to the baseband chip, from the camera chip to the sensor chip, are widely used in BGA package. It is because of the application of BGA chips, so that these devices can be integrated in a small body with a wealth of functions, such as high-definition photography, video calls, high-speed Internet access, multi-sensor co-operation, etc., to meet the needs of the people on the portability and multifunctionality.
3、Automotive electronics
With the continuous development of the automotive industry, the degree of intelligence of automotive electronics is getting higher and higher. BGA chip is also widely used in the field of automotive electronics, such as engine control system, in-car entertainment system, automatic driving assistance system. It can operate stably in the harsh working environment of automobiles, including high temperature, vibration, humidity and other conditions, providing a guarantee for the safe driving and comfortable experience of automobiles.
4、Communication equipment field
In the field of communication equipment, such as base stations, routers, switches, etc., BGA chip is also a key component. It can ensure the integrity and accuracy of signals in high-speed data transmission, improve communication efficiency, and meet the growing demand for communication. Especially in the development of 5G and future communication technology, the role of BGA chips will be more prominent, providing strong support for the realisation of high-speed and efficient communication networks.
六、BGA Chip Challenges and future development trend challenges:
1、Higher package density and smaller size
With the acceleration of the trend of miniaturisation of electronic products, the BGA package density and size requirements are increasingly high, which brings great challenges in design, manufacturing and testing, such as finer solder ball spacing and more complex interconnect structure.
2、Higher reliability requirements
Smaller size and higher packaging density means lower fault tolerance, higher reliability requirements for the chip, need to overcome factors such as thermal stress, vibration and shock. This requires more advanced materials and processes.
3、Test and maintenance difficulties
The complexity of the package structure of the BGA chip makes it much more difficult to test and repair, especially for the diagnosis and repair of internal faults. This increases production costs and time.
4、Cost
Advanced BGA packaging technology is expensive to develop and produce, which limits its popularity in some low-cost applications.
5、Thermal management
Highly integrated BGA chips generate a lot of heat and require effective thermal solutions to ensure their reliable operation. Inadequate thermal management may lead to chip overheating or even failure.
Future Development Trends.
1、Smaller solder ball spacing and higher pin counts
Continue to pursue higher packaging density, to achieve finer solder ball pitch and higher pin count to meet the needs of more highly integrated chips.
2、Advanced packaging technology
For example, system-in-package (SiP), 3D packaging, etc., to integrate multiple chips into a package to improve performance and reduce power consumption.
3、New materials and processes
The use of more advanced materials and processes, such as high-performance substrate materials, new types of solder and more sophisticated packaging processes to improve reliability and reduce costs.
4、Automation and Intelligence
The use of automation and intelligent technology to improve productivity, reduce manufacturing costs, and improve the efficiency of testing and maintenance.
5、Enhanced thermal management
Develop more effective thermal management techniques, such as the use of high thermal conductivity materials, microchannel cooling, etc., to meet the heat dissipation needs of high-power chips.
6、Reliability modelling and prediction
Develop more accurate reliability modelling and prediction methods to improve chip reliability and extend its service life.