LTCC Ceramic PCB

LTCC Ceramic PCB

LTCC is also known as low temperature co-fired multilayer ceramic substrate. This technology requires inorganic alumina powder and about 30%~50% glass material to be added with an organic binder to make it evenly mixed into a mud-like slurry, and then Use a scraper to scrape the slurry into flakes, and then go through a drying process to form the flakes of slurry into thin green embryos, and then drill via holes according to the design of each layer to transmit the signals of each layer. The internal circuit of LTCC The screen printing technology is used to fill the holes and print the circuit on the green body respectively. The inner and outer electrodes can use silver, copper, gold and other metals respectively. Finally, each layer is laminated and placed in a room at 850~900°C. Sintering in the sintering furnace can be completed.

 

LTCC (Low Temperature Co-fired Ceramic) is a multilayer circuit made by laminating unsintered cast ceramic materials with printed interconnecting conductors, components and circuits, and sintering the structure into an integrated Ceramic multilayer material. It mainly includes LTCC substrate materials, packaging materials and microwave device materials.

 

LTCC Ceramic PCB technology has been widely used in wireless communications, consumer electronics, medical machinery, automotive electronics, aerospace, and national defense industries.

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LTCC Ceramic PCB Material

Ceramic materials for LTCC ceramic substrates mainly include three systems: glass-ceramic composite system, glass-ceramic system and amorphous glass system.

Glass-ceramic composite system

With the ceramic material as the matrix, the glass with low melting point can reduce the sintering temperature of the ceramic material to below 900°C. Glass-ceramic systems can obtain good electrical properties and compactness by conventional methods. This material can be used in laminated dielectric capacitors, laminated dielectric antennas and laminated dielectric filters, etc. Typical materials for fillers in glass-ceramic systems include: Al2O3, AlN, ZrO2, SiC, spinel, titanate, etc.; representative glasses include: PbO-B2O3-SiO2, Al2O3-B2O3-SiO2, CaO-B2O3-SiO2 , K2O-B2O3-SiO2, etc. 

Glass-ceramic system

Through glass crystallization, polycrystals with a grain size of less than 10μm can be obtained. This material can be used for high-frequency laminated inductors that do not require high electrical performance. The CaO-B2O3-SiO2 (CBS) system glass-ceramic has wollastonite as the main crystal phase, has low dielectric constant and low thermal expansion coefficient, and can be co-fired with noble metal electrodes, making it an important dielectric material. By adjusting the proportion of each component, its linear expansion coefficient can be adjusted.

The main crystal phase of MgO-Al2O3-SiO2 (MAS) glass-ceramics is cordierite, which has high mechanical strength, excellent dielectric properties, good thermal stability and thermal shock resistance, and is stable when co-fired with copper conductors in nitrogen.

Amorphous glass system

Aluminum nitride ceramic substrate material, high mechanical strength, high thermal conductivity

LTCC Ceramic PCB ProcessingTechnology

The process flow of LTCC ceramic pcb manufacturing mainly includes mixing, casting, punching, filling, screen printing, lamination, isostatic pressing, debinding and sintering and other main processes.

LTCC ceramic PCB Advantages  

 

1. Ceramic materials have excellent high frequency, high speed transmission and wide passband characteristics;

LTCC ceramic PCB can adapt to the requirements of high current and high temperature resistance, and has better thermal conductivity than ordinary PCB circuit substrates, which greatly optimizes the heat dissipation design of electronic equipment, has high reliability, can be used in harsh environments, and prolongs its service life;

2. LTCC ceramic PCB can meet the production requirements of multilayer ceramic substrates, and can embed multiple passive components in LTCC ceramic substrate, eliminating the cost of packaging components, and realizing passive and active integration on a three-dimensional circuit substrate with a high number of layers , which is beneficial to increase the assembly density of the circuit and further reduce the volume and weight.

3. Good compatibility with other multilayer wiring technologies, such as hybrid multilayer substrates and hybrid multichip components that can achieve higher packing density and better performance by combining LTCC with thin film wiring technology.

4. The LTCC ceramic PCB discontinuous production process is convenient for quality inspection of each layer of wiring and interconnection holes before the finished product is manufactured, which is conducive to improving the yield and quality of multi-layer substrates, shortening the production cycle and reducing costs.

5. The LTCC ceramic PCB has good temperature characteristics, such as small thermal expansion coefficient and small temperature coefficient of dielectric constant, can make circuit substrates with extremely high layers, and can make thin line structures with line widths less than 50μm.

 

LTCC Ceramic PCB Application

LTCC ceramic circuit boards have been developed earlier and are used in the fields of electrical components, communications, and high-frequency microwaves. LTCC ceramic circuit boards are used in LTCC components, LTCC functional devices, LTCC module substrates and LTCC integrated modules.

 

LTCC component

Passive components produced by LTCC technology are widely used in mobile communication equipment and other fields. For example: mobile phones, WLAN, Bluetooth, power amplifiers, automotive electronics, etc. It has a wide range of products, including filters, duplexers, baluns, couplers, transceiver switch function modules, power dividers, and common mode choke coils, etc.

 

LTCC functional devices

The filters on GSM and CDMA mobile phones have been replaced by surface acoustic filters or embedded in the module substrate, while the filters on PHS mobile phones and cordless phones are mostly LC filters made of LTCC Ceramic pcb with small size and low price Devices, Bluetooth and wireless network cards use LC filters from the beginning.

 

LTCC module substrate

Alternative module substrates include LTCC, HTCC, traditional PCB such as FR4, PTFE, etc. The sintering temperature of HTCC is above 1500°C, and the matching refractory metals such as tungsten, molybdenum/manganese have poor electrical conductivity, and the sintering shrinkage is not as easy to control as LTCC. The dielectric loss of LTCC is an order of magnitude lower than that of RF4. PTFE has lower losses, but both are less insulating. LTCC allows better precision control than most organic substrate materials. No organic material can be compared comprehensively with LTCC substrates in terms of high frequency performance, size and cost.

 

LTCC in High Density Packaging Application

Used in aviation, aerospace and military fields, using LTCC technology to develop satellite control circuit components. Using 9 layers of conductors, the metal line width and line spacing are 125 µm, and the green material is DuPont's A951. Our ceramic factory has LTCC design and manufacturing technology, and has manufactured a variety of LTCCs that can be used in aviation, aerospace and military fields. Ceramic circuit board.

 

Used in fields such as MEMS, actuators and sensors

 

LTCC can form a three-dimensional structure by embedding capacitors, inductors, etc., thereby greatly reducing the circuit volume. Therefore, in high-performance devices such as RF circuit drivers and high-frequency switches, three-dimensional structure circuits are widely used to meet the current requirements for the size and performance of such circuits.

 

Applied in automotive electronics and other fields

Because LTCC has many excellent characteristics, LTCC has been listed as an important technology for making automotive electronic circuits. Our ceramic circuit board customers also need to use LTCC technology to apply it in automotive EPS.

 

Application in Antenna

With the increase of 5G communication frequency, the size of antenna and radio frequency module will be smaller and more integrated. When the working frequency is≥30 GHz, the size of the antenna will be reduced to the millimeter level or even smaller. At this time, the design of the antenna will be changed from the existing single antenna to the array antenna. The application of LTCC technology on the antenna mainly includes 5G Array antennas, ultra-wideband LTCC antennas, Wifi/Bluetooth antennas, GPS antennas, multi-band LTCC antennas, RFID antennas, NFC antennas, integrated package antennas, etc.

 

LTCC Ceramic PCB Structure

LTCC (Low Temperature Co-fired Ceramics) is a multilayer glass-ceramic substrate is also "glass-ceramic" because its composition consists of glass and alumina. LTCC ceramic substrate is co-fired with low-resistance metal conductors at a low firing temperature (less than 1000°C).  The substrate manufactured by the LTCC process has the functions of realizing integrated circuit chip packaging, embedded passive components and high-density circuit assembly.

 

 

LTCC low-temperature co-firing production process can realize multi-layer interconnection and multi-layer wiring. It is a miniaturization technology of passive devices. According to the designed structure, it is a high-quality technology to burn electronic devices and substrate electrode materials at one time. Integrated, high-performance electronic packaging technology.

 

Shenzhen Beton Ceramic PCB Board factory, has been focusing on all kinds of ceramic PCB circuit boardssuch as HTCC ceramic circuit boards, LTCC ceramic substrates, DBC ceramic circuit boards, DPC ceramic PCB substrates. Any Ceramic pcb demands, please contact us at Cathy@beton-tech.com.