IC substrate factories China mainland condition

IC Substrate is a technology developed with the continuous progress of semiconductor packaging technology. In the mid-1990s, a new IC high-density packaging form represented by ball grid array packaging and chip size packaging came out, and IC carrier emerged as a new packaging carrier.  IC substrate is developed on the basis of HDI board. As a high-end PCB board, it has the characteristics of high density, high precision, miniaturization and thin shape.  IC substrate is also called packaging substrate, in the field of high order packaging, IC board has replaced the traditional lead frame, become an indispensable part of the chip packaging, not only to provide support for the chip, heat dissipation and protection, at the same time to provide electronic connection between the chip and PCB motherboard, plays a "link" role;  Passive and active devices can even be embedded to achieve certain system functions.  IC carrier products can be roughly divided into five categories, including memory chip IC carrier, MICRO-electromechanical system IC substrate, RF module IC substrate, processor chip IC substrate and high-speed communication IC substrate, which are mainly used in mobile intelligent terminals, services/storage, etc.  In short, THE IC substrate is the key base material for advanced integrated circuit packaging, the "special" PCB. 

1. The technical barriers are much higher than ordinary PCBs, and there are few industry players

Developed from HDI, the technical barriers are much higher than HDI and ordinary PCB. The IC carrier board is developed on the basis of the HDI board, and there is a certain correlation between the two, but the technical threshold of the IC carrier board is much higher than that of the HDI and ordinary PCB. IC carrier board can be understood as a high-end PCB, which has the characteristics of high density, high precision, high pin count, high performance, miniaturization and thinning, etc. It has higher requirements on various technical parameters, especially the core line Width/line spacing parameters. Taking the chip packaging substrate of mobile product processor as an example, its line width/line spacing is 20μm/20μm, and will continue to decrease to 15μm/15μm, 10μm/10μm in the next 2-3 years, while the general PCB line width / The line spacing should be more than 50μm/50μm.

Compared with ordinary PCB, IC carrier board has many technical difficulties. These technical difficulties are the biggest industry entry barriers for IC carrier board. The following summarizes the technical difficulties of IC carrier board.

1) Core board manufacturing technology. The core board of the IC carrier board is very thin and easily deformed. Only when the process technologies such as board expansion and shrinkage and lamination parameters have made breakthroughs, can the warpage and lamination thickness of the ultra-thin core board be effectively controlled.

2) Microporous technology. The aperture of the micropore is generally about 30 μm, which is much smaller than that of ordinary PCB and HDI, and the number of stacked holes reaches 3, 4 and 5.

3) Pattern formation and copper plating technology. The uniformity of copper plating thickness is high, and the flash corrosion requirements for fine circuits are high. The current line width and spacing requirements are 10-30μm. The thickness uniformity of copper plating is required to be 18±3 microns, and the etching uniformity is ≥90%.

4) Solder mask process. The height difference between the solder mask surface of the IC carrier board is less than 10μm, and the surface height difference between the solder mask and the pad is not more than 15μm.

5) Detection capability and product reliability testing technology. IC substrate factories need to be equipped with a number of different testing equipment/instruments from traditional PCB factories, and also need to master different reliability testing technologies from conventional ones.

At present, there are three main manufacturing processes for IC substrates and PCBs, namely, the subtractive method, the additive method (SAP) and the modified semi-additive method (MSAP).

Subtraction method: The most traditional PCB manufacturing process, firstly, a copper layer of a certain thickness is plated on the copper clad plate, and then the lines and vias are protected by dry film, and the unnecessary copper skin is etched away. The biggest problem with this method is that during the etching process, a part of the side of the copper layer will also be etched (undercut). The existence of side etching makes the minimum line width/spacing of the PCB only greater than 50μm (2mil), so it can only be used on ordinary PCB and HDI products.

Addition method (SAP): First, circuit exposure is performed on an insulating substrate containing a photosensitive catalyst, and then selective electroless copper deposition is performed on the exposed circuit to obtain a complete PCB. Since this method does not require post-etching, high precision can be achieved, and the fabrication can reach below 20 μm. At present, this method has high requirements on the substrate and process flow, high cost and small output.

Modified Semi-Additive Method (MSAP): First, a thin layer of copper is plated on the CCL, then the areas that do not need plating are protected, the plating is performed again and a resist layer is applied, and then the excess chemical is removed by flash etching. The copper layer is removed, and what remains is the required copper layer circuit. Since the copper layer plated at the beginning is very thin, the flash etching time is very short, so the effect of side etching is very small. Compared with the subtractive method and the additive method, the MSAP process greatly improves the production yield and reduces the production cost when the manufacturing accuracy is not much different from that of the SAP. It is currently the most mainstream manufacturing method for fine circuit substrates.

The IC substrate production process is complex, and the MSAP process is the mainstream. The minimum line width/spacing of the IC carrier board is generally less than 30μm, and the traditional subtractive process has been difficult to meet the requirements of the IC carrier board. MSAP is currently the most common process for IC carrier board manufacturing. In addition to the MSAP process being widely used in the manufacture of IC substrates, Apple has also introduced this process to the production of SLP (substrate-like boards). Current designs use a mix of subtractive etch and MSAP processes, which can be applied to thinner, smaller motherboard designs. The manufacture of SLP is between high-end HDI and IC carrier board, and IC carrier board manufacturers have obvious technical advantages and can easily enter the SLP field. With the continuous improvement of the integration level of consumer electronics, SLP will be adopted by more and more manufacturers. Although the profitability is not as good as that of IC substrates, the market space is considerable.

The IC substrate industry has high barriers, not only limited to technical thresholds. Extremely high technical requirements and numerous patent restrictions have created a high threshold for the IC substrate industry, and the barriers to this industry also include capital and customers.

1) Financial barriers

Because the IC carrier board has extremely high technical barriers, the initial R&D investment is huge and takes a long time, and the development risk of the project is high. The construction and subsequent operation of the IC substrate production line also requires huge capital investment, among which the capital investment in equipment is the largest. The IC substrate production line has many equipment, and the price of a single device may exceed 10 million yuan. The equipment/instrument investment accounts for more than 60% of the total investment in the IC substrate project, which is a heavy burden for traditional PCB manufacturers. Taking HOREXS as an example, the company launched the second IC substrate factory project in 2019. The total investment of the project exceeds 800 million yuan. It is expected to reach production in three years.

2) Customer Barriers

The IC carrier board customer verification system is more stringent than that of the PCB, which is related to the connection quality between the chip and the PCB. The "qualified supplier certification system" is generally adopted in the industry, which requires suppliers to have a sound operation network, efficient information management system, rich industry experience and good brand reputation, and need to pass strict certification procedures. The certification process is complex and longer period. Take HOREXS as an example. After nearly two years of verification and cooperation, the company passed the Samsung certification in June 2020, and it will take some time to supply Samsung on a large scale.

3) Environmental barriers

Similar to PCB, the manufacturing process of IC substrate involves a variety of chemical and electrochemical reactions, and the produced materials also contain heavy metals such as copper, nickel-gold, and silver, which pose certain environmental risks. With the country's increasing emphasis on environmental protection and the continuous introduction of environmental protection policies, the early-stage EIA of IC substrate projects has become more and more difficult, and the stricter environmental protection has further raised the industry's capital threshold. entrance ticket.

2. The core of the upstream material is the substrate, which is widely used in the downstream

Packaging substrate is the largest cost of IC packaging, accounting for more than 30%. The cost of IC packaging includes packaging substrates, packaging materials, equipment depreciation and testing, etc. Among them, the cost of IC carrier board accounts for more than 30%, which is the largest cost of integrated circuit packaging and occupies an important position in integrated circuit packaging. For IC carriers, the substrate materials include copper foil, substrate, dry film (solid photoresist), wet film (liquid photoresist) and metal materials (copper balls, nickel beads and gold salts), of which the substrate accounts for The ratio is more than 30%, which is the largest cost end of IC substrates.

1) One of the main raw materials: copper foil

Similar to the PCB, the copper foil required for the IC carrier board is also electrolytic copper foil, and it needs to be an ultra-thin uniform copper foil with a minimum thickness of 1.5μm, generally 9-25μm, while the thickness of the copper foil used in traditional PCB is 18, 35μm or so. The price of ultra-thin uniform copper foil is higher than that of ordinary electrolytic copper foil, and the processing difficulty is also greater.

2) The second main raw material: substrate

The substrate of the IC carrier board is similar to the copper clad laminate of the PCB. It is mainly divided into three types: hard substrate, flexible film substrate and co-fired ceramic substrate. Among them, hard substrate and flexible substrate have more room for development, while co-fired ceramic substrate Development tends to slow down. The main factors considered for IC carrier substrates include dimensional stability, high-frequency characteristics, heat resistance and thermal conductivity. Currently, there are three main materials for rigid packaging substrates, namely BT material, ABF material and MIS material; The substrate materials of flexible packaging substrates mainly include PI (polyimide) and PE (polyester) resins; the materials of ceramic packaging substrates are mainly ceramic materials such as alumina, aluminum nitride, and silicon carbide.

Hard substrate material: BT, ABF, MIS

1. BT resin

The full name of BT resin is "bismaleimide triazine resin", which was developed by Japan's Mitsubishi Gas Company.

Although the patent period of BT resin has expired, Mitsubishi Gas is still a global leader in the research and development and application of BT resin. BT resin has many advantages such as high Tg, high heat resistance, moisture resistance, low dielectric constant (Dk) and low dispersion factor (Df), but due to the glass fiber yarn layer, it is harder than ABF material FC substrate, And the wiring is more troublesome, the difficulty of laser drilling is high, and it cannot meet the requirements of thin lines, but it can stabilize the size and prevent thermal expansion and contraction from affecting the line yield. Therefore, BT materials are mostly used for networks that require high reliability. Chips and Programmable Logic Chips. At present, BT substrates are mostly used in products such as mobile phone MEMS chips, communication chips and memory chips. With the rapid development of LED chips, the application of BT substrates in LED chip packaging is also developing rapidly.

2. ABF

ABF material is a material developed by Intel and used for the production of high-end carrier boards such as Flip Chip. Compared with BT base material, ABF material can be used as IC with thinner lines, suitable for high pin count and high transmission, and is mostly used for large high-end chips such as CPU, GPU and chipset. ABF is used as a build-up material, and the ABF can be directly attached to the copper foil substrate to make a circuit, and there is no need for a thermocompression bonding process. In the past, ABFFC had the problem of thickness, but due to the more and more advanced technology of copper foil substrate, ABFFC can solve the problem of thickness as long as it uses thin plate. In the early days, ABF carrier boards were mostly used in CPUs of computers and game consoles. With the rise of smart phones and changes in packaging technology, the ABF industry had fallen into a low ebb. However, in recent years, network speed improvements and technological breakthroughs have brought new applications of high-performance computing to the surface. ABF demand is amplified again. From the perspective of industry trends, ABF substrates can keep up with the pace of advanced semiconductor manufacturing processes and meet the requirements of thin lines, thin line widths/spacings, and the future market growth potential can be expected.

3. MIS

MIS substrate packaging technology is a new technology that is currently developing rapidly in analog, power IC, and digital currency markets. Unlike traditional substrates, MIS consists of one or more layers of pre-encapsulated structures, each of which is interconnected by electroplating copper to provide electrical connections during the encapsulation process. MIS can replace some traditional packages such as QFN or lead frame based packages because MIS has finer routing capability, better electrical and thermal performance, and smaller form factor.

Flexible substrate material: PI, PE

PI and PE resins are widely used in flexible PCBs and IC carriers, especially in tape IC carriers. The flexible film substrate is mainly divided into three layers with glue and two layers without glue. The three-layer rubber sheet was originally mainly used for military electronic products such as launch vehicles, cruise missiles, and space satellites, and later expanded to various civilian electronic product chips; , Thinning and thinning have obvious advantages. The products are widely used in consumer electronics, automotive electronics and other fields, and are the main development direction of flexible packaging substrates in the future.

There are many upstream substrate material manufacturers, and domestic technology is relatively weak. There are many types of core material substrates for IC carrier boards, and most upstream manufacturers are foreign-funded enterprises. Taking the most used BT materials and ABF materials as an example, the main global BT resin manufacturers are Japanese companies Mitsubishi Gas Chemical and Hitachi Chemical. There are very few companies involved; ABF material leaders include Nandian, Ibiden, Shinko, Semco, etc. Xinxing is actively catching up with the progress, and domestic enterprises in mainland China are rarely involved. As far as Chinese enterprises are concerned, Shengyi Technology is at the forefront of R&D and production of IC substrate substrates. The company announced in May 2018 that the "annual output of 17 million square meters of copper clad laminates and 22 million meters of commodity adhesive sheet construction projects" will be changed. . The company's layout on the substrate side of IC substrates is expected to break through the technological encirclement of foreign giants and accelerate the process of domestic substitution of PCBs and IC substrates.

IC substrates have a wide range of applications. Mainstream packaging substrate products are roughly divided into five categories, namely memory chip packaging substrates, MEMS packaging substrates, RF module packaging substrates, processor chip packaging substrates and high-speed communication packaging substrates. Substrate packaging solutions, with the continuous improvement of IC integration, the proportion of other chips using IC carrier boards will also increase.

Because of it is so much complicated and special,In China mainland,You still found so many companies says we are professional in it and we are factory,So much fake.

IC substrate technology development very late in China mainland,Mainly in Taiwan,Japan,Korea,Not in CHINA.Only few factories are very professional in IC substrate production,Such as HOREXS,SHENNAN CIRCUITS,ZHUHAI ACCESS etc.No exceed 5 factories in China mainland can do it.

Of course,There's very small,which are only hande the sample or very small orders production,They dont have ability do mass production.Almost of them are trade companies.