Micro packaging technology is a high-density electronic assembly technology. With the rapid development of miniaturization, light weight, high operating frequency and high reliability electronic products, electronic components have gradually entered the development stage of high density, high function, miniaturization, multi-pin and narrow spacing. In this context, micro packaging technology (MPT) emerged as a new generation of advanced electronic assembly and packaging technology.
This article will explore the micro packaging, micro packaging technology (MPT)core technology, micro assembly technology difficulties and solutions.
What is micro packaging technology (MPT)
Micro packaging technology (MPT), a new generation of advanced electronic assembly technology, is the assembly of various micro components (integrated circuit chips and chip components) that constitute electronic circuits to form high-density, high-performance, high-reliability, micro-miniature and modular circuit products with a 3D structure.
Micro packaging is a high-density electronic assembly technology developed on the basis of SMT and hybrid integration technology, mainly including surface mount technology (SMT), hybrid integrated circuit (HIC) technology and multi-chip module (MCM) technology. Micro packaging (or micro assembly) technology uses advanced methods to assemble micro-miniature electronic components into high-density, high-speed, high-reliability 3D electronic products on high-density multi-layer PCB.
Micro packaging technology (MPT ) has a wide range of applications, including discrete electronic components, hybrid integrated circuits, multi-chip components, SiP, micro-systems, vacuum electronic devices, etc. At present, electronic micro assembly and micro packaging technology has been widely used in many fields such as Micro LED display chips, mobile phone micro components, MEMS devices, radio frequency devices, and hybrid PCB.
What are the features and advantages of micro packaging technology
Micro packaging technology (MPT) is a new generation of electronic assembly, packaging and interconnection technology developed on the basis of SMT and hybrid integration technology. The main production process of micro assembly includes chip and substrate mounting process, interconnection process, and packaging process; auxiliary processes include vacuum baking process, cleaning process, coating process, testing process, etc. The main characteristics are as follows:
1. Circuit function: It is no longer a circuit with a single function, but a complex hybrid integrated multifunctional microelectronic component with components, subsystems and even system-level functions.
2. Structural features: It adopts high-density multi-layer wiring substrate, micro-welding, micro assembly bonding and assembling high-density interconnector composed of highly integrated bare IC and other micro components.
3. Integration scale: It belongs to the category of hybrid large-scale integrated circuit or hybrid very large-scale integrated circuit (HLSI, HVLSI). Multi-chip module (MCM) is a typical micro packaging technology and also a typical advanced hybrid integrated circuit technology.
4. For every 10% increase in assembly density, the volume of the circuit module can be reduced by 40% to 50%, and the mass can be reduced by 20% to 30%. Micro assembly technology is of great significance to reduce the volume and quality of microwave components and meet the requirements of miniaturization, light weight, digitalization and low power consumption of modern electronic weapons and equipment.
Micro assembly technology (or micro packaging technology) is an important technical approach to achieve the goals of miniaturization, light weight, high-density 3D interconnection structure, wide operating frequency band, high operating frequency and high reliability of electronic equipment.
What are differences between MPT and conventional electronic assembly
Conventional electronic assembly is an assembly technology based on general electronic components and ordinary printed circuit boards(PCB). And micro packaging is a comprehensive package based on chips (carriers, tapes, small package components, etc.) Sexual assembly technology.
What are core processes of micro packaging technology equipment
1. SMT process line: Micro assembly equipment is an automated equipment that integrates light, machinery, and electricity. It uses pressure, heating, and ultrasound to complete the wire bonding process between the chip and the IC substrate. Due to the high assembly density of components, the requirements for mounting accuracy and alignment angle accuracy are relatively high.
In addition, many components are fragile and volatile, so it is critical to use precise pressure control during placement to ensure safe component pick-up. In particular, the surface of MEMS devices usually has a bare functional structure. Accurate positioning of the pick-up position on the surface of the component and control of the pick-up and placement pressure have become the difficulty and focus of the placement process.
2. High-precision alignment and placement: Micro-assembly equipment should have high-precision alignment and placement functions to ensure production yield. This requires the device to have a force control accuracy of ±0.01N, a linear repeat positioning accuracy of ±2μm, and a rotational repeat positioning accuracy of ±0.01°. In the high-speed operation state, the equipment can still output stably to ensure the production yield.
3. Fine and controllable bonding pressure: Micro packaging equipment should adopt fine and controllable bonding pressure to reduce loss. Supports programmed setting of speed, acceleration and force control, so that the placement head can touch components with very light pressure, reducing loss.
Difficulties and solutions of micro packaging technology
Precision positioning and registration
In the micro assembly process, the size of components is getting smaller and smaller, and the accuracy requirements for component positioning and registration are getting higher and higher. In order to solve this problem, the following methods can be adopted:
1. Use a high-precision, high-speed vision system for component positioning and registration. The image is collected by the camera and processed in real time to realize automatic identification and positioning.
2. Use flexible grippers and precision manipulators. Flexible fixtures can adapt to changes in the shape of tiny components, and precision manipulators can achieve high-precision movement and control.
3. Introduce machine learning and artificial intelligence algorithms to intelligently optimize component positioning and registration to improve assembly accuracy.
Control of micro components
The difficulty of handling micro components increases as the size decreases. Ways to address this issue include:
1. Use non-contact manipulation methods such as electrostatic adsorption and vacuum adsorption to reduce direct contact and damage to micro components.
2. Develop new micro-manipulators and micro-control systems to achieve precise control of micro-components.
3. Using microfluidic technology, micro components are manipulated by controlling the flow of fluids, avoiding damage caused by direct contact.
Micro welding technology
Soldering technology in micro assembly faces requirements such as high precision and low thermal stress. Ways to address this issue include:
1. Non-contact welding technologies such as laser welding and ultrasonic welding are used to achieve high precision and low thermal stress in micro-welding.
2. Optimize the welding process parameters to reduce the influence of thermal stress on micro components.
3. Introduce new micro-welding materials to improve the reliability and performance of micro-welding.
Micro assembly process monitoring
During the micro assembly process, real-time monitoring and quality control are crucial. In order to solve this problem, the following methods can be adopted:
1. Introduce a high-resolution, high-speed online visual inspection system to monitor the micro-assembly process in real time and make timely adjustments.
2. Use sensor technology to collect various data in the micro-assembly process, such as force, temperature, pressure, etc., to achieve real-time monitoring and intelligent diagnosis.
3. Establish a digital twin model of the micro assembly process, and realize the optimization and control of the micro-assembly process through simulation and prediction.
Micro assembly automation
In the micro assembly process, automation is the key to reducing costs and improving production efficiency. Ways to address this issue include:
1. Develop micro assembly automation equipment with high precision, high speed, and high stability, such as micro assembly robots, micro-spraying equipment, etc.
2. Using the Internet of Things, big data and artificial intelligence technology to realize the intelligent scheduling and optimization of the micro-assembly production line.
3. Train professionals and improve the skills of operators in the use and maintenance of micro-assembly automation equipment.
International micro packaging technology circuits standard
The circuit design of micro packaging technology can refer to the following standards :
● IPC-D-859 “Design Standard for Thick Film Multilayer Hybrid Circuits”.
● IPC-HM-860 “Specification for multilayer Hybrid Circuits”.
● IPC-MC-790 “Guidelines for Multichip Module Technology Utilization”.
● IPC-SM-784 “Guidelines for Chip-on-Board Technology Implementation”.
● IPC-6015 “Qualification and Performance Specification for Organic Multichip Module (MCM-L) Mounting and Intercnnecting Structures”
● IPC-6018 “Microwave End Product Board Inspection and Test”
● IPC/JPCA-4104 “Specification for High Density Interconnect (HDI) and Microvia Materials”
Difficulties in electronic micro packaging technology mainly include precision positioning and registration, micro-component manipulation, micro-welding technology, micro packaging, micro assembly process monitoring and automation, etc. These difficulties can be effectively solved by adopting high-precision vision system, non-contact control and welding technology, new micro-control system and welding materials, online detection system and automation equipment.
In addition, combining advanced technologies such as the Internet of Things, big data and artificial intelligence to further improve the intelligence level of electronic micro pachaging technology will help meet the development needs of miniaturization, light weight and high performance of electronic products.
Micro packaging technology (MPT) is a high-density electronic assembly technology developed on the basis of SMT and hybrid integration technology, mainly including surface mount technology (SMT), hybrid integrated circuit (HIC) technology and multi-chip module (MCM) technology.
MPT uses advanced methods to assemble micro-miniature electronic components into high-density, high-speed, high-reliability three-dimensional electronic products on high-density multi-layer interconnected circuit boards.
The assembly and packaging of electronic micro-assembly components using electronic micro packaging technology should have the following four functions:
- Power distribution
- Signal distribution
- Cooling channel
- Mechanical support and environmental protection
- Design and manufacturing technology of high-density multilayer interconnection PCB substrate design and manufacturing technology of high-density multilayer interconnection circuit substrate includes thick-film hybrid integrated circuit design and manufacturing process;
- The basic process of micro-assembly includes epoxy mounting, reflow soldering, eutectic welding, parallel seam welding, laser welding and other micro-welding;
- High-density assembly technology is a first-level assembly process technology based on wire bonding (Wire Bonding), flip chip (Flip Chip) and other bare chip assembly, including first-level packaging SIP, first-level and second-level mixed assembly MCM technology.