Don't let doubt cross the new year to understand t

Don't let doubt cross the year article to understand those things in the semiconductor circle

● there are many design companies only, which generally become problems. With computers, software and design engineers, you can complete the design, output the design and hand it over to the mask factory, wafer foundry, and packaging and testing factory to produce devices

● those who only do manufacturing become Fab factories with high threshold. The total investment of an 8-inch wafer production line can reach $1billion; In addition, the manufacturing has high requirements for process level, chemical supplies control and cleanliness

● as for the profits of design and manufacturing, the design company produces a version of the design and spends a lot of money to roll out the film. Only when the devices sell well can they make profits, otherwise a design company can go bankrupt with one roll out; Fab factory will not lose money as long as there is an order and the equipment is running

2. What is the packaging test of semiconductors

● semiconductor production process consists of wafer manufacturing, wafer testing, chip packaging and post packaging testing. Semiconductor packaging test refers to the process of processing the tested wafer into an independent chip according to the product model and functional requirements

● packaging process: the wafer from the previous wafer process is cut into small chips (die) through the dicing process, and then the cut wafer is pasted to the island of the corresponding substrate (lead frame) frame with glue, and then the bond pad of the wafer is connected to the corresponding pin (lead) of the substrate with ultra-fine metal (gold, tin, copper, aluminum) wires or conductive resin, And constitute the required circuit; Then, the independent chip is encapsulated and protected with a plastic shell. After plastic packaging, a series of operations are carried out, such as post mold cure, trim form, plating, printing and other processes. The finished products are tested after the anti-wear and wear parts and transmission parts are sealed and assembled. Usually, they go through the processes of incoming inspection, testing and packaging, and finally they are warehoused and shipped. The typical packaging process is: dicing → loading → bonding → plastic packaging → removing flash → electroplating → printing → rib cutting → molding → appearance inspection → finished product testing → packaging and shipping

● semiconductor devices have many packaging forms, which can be divided into pin insertion type, surface mount type and advanced packaging according to the outline, size and structure of the package. From dip, SOP, QFP, PGA and BGA made of carbon fiber reinforced polymer (CFRP), to CSP and then to sip, the technical indicators are more advanced from generation to generation. In general, semiconductor packaging has experienced three major innovations: the first was from pin in packaging to surface mount packaging in the 1980s, which greatly improved the assembly density on printed circuit boards; The second is the emergence of spherical matrix packaging in the 1990s, which meets the market demand for high pins and improves the performance of semiconductor devices; Chip level packaging and system packaging are the products of the third innovation, and their purpose is to minimize the packaging area

● semiconductor packaging forms: metal packaging, ceramic packaging, metal + ceramic packaging, plastic packaging (the most important packaging form)

3. What are the main materials of semiconductors

● semiconductor: material with conductivity between conductor and insulator at room temperature

● main materials

element semiconductors: germanium and silicon are the most commonly used element semiconductors

compound semiconductors: including group III and V compounds (gallium arsenide, gallium phosphide, etc.), group II and VI compounds (cadmium sulfide, zinc sulfide, etc.), oxides (oxides of manganese, chromium, iron, copper), and solid solutions (gallium aluminum arsenic, gallium arsenic phosphorus, etc.) composed of group III-V compounds and group II-VI compounds

● technology research field:

integrated circuit: it is the most active field in the development of semiconductor technology, and has developed to the stage of large-scale integration. Tens of thousands of transistors can be made on a few square millimeters of silicon chip, an information processor can be made on a silicon chip, or other complex circuit functions can be completed. The development direction of integrated circuits is to achieve higher integration and micro power consumption, and make the information processing speed reach picosecond level

microwave devices: semiconductor microwave devices include receiving, control and transmitter devices. Receivers below millimeter wave band have been widely used. In the centimeter band, the power of transmitting devices has reached several watts. People are developing new devices and new technologies to obtain greater output power

optoelectronic devices: the development of semiconductor light-emitting devices, camera devices and laser devices has made optoelectronic devices an important field. Their applications mainly include optical communication, digital display, image reception, optical integration, etc

4. What is semiconductor IP

mainly refers to patented technology and non patented proprietary technology related to semiconductors

● IP core is a functional module with intellectual property rights, specific functions and standardized interfaces that can be reused in multiple integrated circuits. It is the basic component to realize the system chip. You can simply understand that well-designed functional model enterprises generally seek out technology source blocks. (the [design] here has different forms according to the degree of perfection, and can be divided into three categories: soft core, solid core and hard core)

● soft core: understood as [program code], it describes the functional modules with hardware description language (such as a trigger written in VHDL, which is in text form), and does not contain any physical implementation information. (the soft core is characterized by strong portability, short design cycle and low cost for users. The disadvantage is that the physical implementation performance is uncertain and incomplete, and the property right protection is poor)

● fixed core: in addition to realizing the program code of functional modules, vest also implies the company's strong investment in the earliest production equipment, including design links such as gate level circuit synthesis and timing simulation, which are generally provided to users in the form of gate level circuit table. Fixed core can be understood as not only including soft core program code, but also including [rules between programmer module design intent and hardware physical implementation]

● hard core: it is based on physical description and has passed the process verification. Its performance is guaranteed. It is provided to users (chip manufacturers) in the form of circuit physical structure mask layout and a full set of process documents

5. What are the categories of digital integrated circuits

● according to the circuit structure, it can be divided into two series: TTL and CMOS, and BiCMOS chips that integrate TTL and CMOS

● according to the degree of integration, it can be divided into small scale integration (SSI) circuits, medium scale integration (MSI) circuits, large scale integration (LSI) circuits, very large scale integration (VLSI) circuits, very large scale integration (ULSI) circuits and very large scale integration (glsi)

● according to the function, there are many special integrated circuits, such as gate circuit, trigger, memory, single chip microcomputer, which cannot be listed one by one

6. What is the profit distribution of the integrated circuit industry chain

the integrated circuit industry chain is divided into IC design, chip manufacturing, packaging, EDA, equipment, materials, agents, etc

● IC Design: the profit margin is the highest and the risk is high. The gross profit of European and American companies is generally 50% - 80%, and that of domestic companies is also 35% - 60%

● chip manufacturing: it requires a lot of equipment, with large initial investment and medium profit. The general healthy gross profit is 30% - 50%, and the risk is controllable

● packaging: the relative threshold is low, the competition is fierce, the profit margin is the lowest, the general gross profit is 20% - 40%, making a brand also has added value, the risk is the lowest, and the cash flow turnover is fast

● EDA (tool software): the gross profit margin of software is 99.99%, but it takes a lot of market and R & D funds. At present, the market is basically monopolized by Synopsys, cadence and mentor, and the net profit margin is not low, which is at the same level as the design company. Not long ago, mentor was acquired by Siemens for $4.5 billion

● I won't elaborate on the equipment and materials. It's basically that Zhumen's wine and meat stink road has frozen bones, and those with technical barriers are not bad. New players are hard to catch up

● the apparent profit margin of agents is generally between 5-10%. Once sluggish inventory occurs, it is easy to accompany the profits of one or even several years at a time. Therefore, the trend of merger and integration is very obvious now. Only large agents have the ability to negotiate and get better conditions from the chip manufacturer. At the same time, many agents also have supply chain financial services, and agents with strong financing ability can also bring good profits with the help of interest rate difference

7. What is the relationship and difference between semiconductor integrated circuits and semiconductor chips

● semiconductor integrated circuit: connect active components such as transistors, diodes and passive components such as resistors and capacitors on a single semiconductor chip according to a certain circuit, so as to complete specific circuit or system functions

● semiconductor chip: a semiconductor device that can realize a certain function is made by etching and wiring on the semiconductor sheet. Not only silicon chips, but also common semiconductor materials such as gallium arsenide (gallium arsenide is toxic, so don't be curious about decomposing some inferior circuit boards), germanium, etc

● integrated circuit: a micro electronic device or component. Using a certain process, the transistors, resistors, capacitors, inductors and other components and wiring required in a circuit are interconnected, fabricated on a small or several small semiconductor chips or dielectric substrates, and then packaged in a shell to become a micro structure with the required circuit functions; All the components have formed a whole in structure, making the electronic components a big step towards miniaturization, low power consumption, intelligence and high reliability. It is represented by the letter "IC" in the circuit. The inventors of integrated circuits are Jack Kilby (integrated circuit based on germanium (GE)) and Robert neuth (integrated circuit based on silicon (SI)). Nowadays, silicon-based integrated circuits are widely used in semiconductor industry