Archive for the ‘Ceramic PCB’ Category

Ceramic PCB is suitable for UVC-LED

Wednesday, September 8th, 2021

Due to COVID-2019, UVC-LED is becoming more and more popular.

The wavelength of UVC-LED is 100-275nm, 265 nm is the best!

Why UVC-LED is becoming more and more popular?

Because UVC-LED has a lot of advantages for sterilization.

High efficiency: The UVC segment ultraviolet light emitted by UVC-LED generally kills bacteria and viruses within a few seconds.

Extensive bactericidal effect: UVC-LED can kill a lot of bacteria.

Safety and environmental protection (without mercury): The most obvious advantage of UVC-LED devices over traditional mercury-excited ultraviolet lamps is that the germicidal light source does not contain mercury or heavy metals, and is simple to operate, safer and more reliable.

Small size, flexible design, easy installation: UVC-LED devices are small in size, and the sterilization device is flexible in design. It can be used in small spaces where traditional ultraviolet mercury lamps cannot be used. It is more in line with the future development trend of high efficiency, small size and integration.

Why ceramic PCB is suitable for UVC-LED?

Because UVC-LED is sensitive to heat.

Due to the low external quantum efficiency (EQE) of UVC-LEDs, only about 1-3% of the input power is converted into light, while the remaining 97% is basically converted into heat. If the heat cannot be dissipated in time and the LED chip is kept below its maximum operating temperature, it will directly affect the service life of the chip, and it may even be unusable.

Due to the small size of UVC-LED, most of the heat cannot be dissipated from the surface, so the back of the LED becomes the only way to effectively dissipate heat. After years of development, UVC-LED is basically based on a flip-chip solution with a high thermal conductivity aluminum nitride substrate. Aluminum nitride (AlN) PCB made by Best Technology has high thermal conductivity (thermal conductivity 180 W/(mK) ~ 260 W/(mK)), which meets the needs of high heat dissipation of UVC-LED and effectively extends the service life of UVC-LED.

Please feel free to contact sales@bestpcbs.com to know more about ceramic PCB for UVC-LED.

Ceramic PCB for UVC LED
AlN Ceramic PCB

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Why use ceramic circuit boards

Wednesday, August 11th, 2021

With the continuous upgrading and optimization of electronic products, the PCBs as the carrier of components have also been continuously improved, and ceramic circuit boards have appeared. So, compared with traditional glass fiber (FR-4), aluminum-based and copper-based, what’s the advantages of ceramic PCB?

1. Stable flatness

Ordinary PCB is usually made by bonding copper foil and substrate, and the substrate material is mostly glass fiber (FR-4), phenolic resin (FR-3), aluminum-based, copper-based, PTFE, composite ceramics and other materials. The mixture is usually phenolic, epoxy, etc. Due to thermal stress, chemical factors, improper production technology and other reasons during PCB processing, or due to asymmetric copper paving on both sides during the design process, it is easy to cause the PCB board to warp to varying degrees.
The ceramic circuit board is hard with good heat dissipation performance, and low thermal expansion coefficient. At the same time, the ceramic circuit board is bonded to the base material by magnetron/vacuum sputtering. The bonding force is strong and the copper foil will not fall off. High reliability, thus avoiding the

2. Large current carrying capacity:

100A current continuously passes through the 1mm 0.3mm copper board, and the temperature rise is about 17℃; 100A current continuously passes through the 2mm 0.3mm board, and the temperature rise is only about 5℃.

3. Thermal conductivity:

The thermal conductivity of alumina can reach 15~35, and that of aluminum nitride can reach 170~230. Because in the case of high bonding strength, its thermal expansion coefficient will be more matched, and the tested tensile value can reach 45 MPa.

4. Thermal conductivity:

The thermal conductivity of the high thermal conductivity aluminum substrate is generally 1-4W/M. K, and the thermal conductivity of the ceramic substrate can reach about 220W/M. K depending on its preparation method and material formula.

5. Low thermal resistance:

The thermal resistance of a 10×10mm ceramic substrate is 0.63mm thick. The thermal resistance of a ceramic substrate is 0.31K/W, the thermal resistance of a 0.38mm thick ceramic substrate is 0.19K/W, and the thermal resistance of a 0.25mm thick ceramic substrate is 0.14K /W.
 

6. Good insulation performance, high pressure resistance, protection of personal safety and equipment, strong bonding force, bonding technology, copper foil will not fall off, high reliability, stable performance in high temperature and high humidity environments.

7. Stable high-frequency performance, AK and DK values are lower than its PTFE, in line with ceramics.

In summary, with its advantages, ceramic circuit boards have been used in high-power power electronic modules, solar panel components, high-frequency switching power supplies, solid state relays, automotive electronics, aerospace, military electronics, high-power LED lighting products, and communications Antennas, automotive sensors, refrigeration sheets and other fields are widely used.

DSC-1135
DSC-1186

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Laser drilling and cutting in the production process of ceramic circuit boards

Monday, July 12th, 2021

In the ceramic circuit board processing and production process, laser processing mainly includes laser drilling and laser cutting.

Ceramic materials such as alumina and aluminum nitride have the advantages of high thermal conductivity, high insulation and high temperature resistance, and have a wide range of applications in the fields of electronics and semiconductors. However, ceramic materials have high hardness and brittleness, and its molding and processing are very difficult, especially the processing of micropores. Due to the high power density and good directivity of the laser, lasers are generally used to perforate ceramic plates. Laser ceramic perforation generally uses pulsed lasers or quasi-continuous lasers (fiber lasers). The laser beam is focused on On the workpiece placed perpendicular to the laser axis, a laser beam with high energy density (105-109w/cm2) is emitted to melt and vaporize the material. An air stream coaxial with the beam is ejected by the laser cutting head to remove the melted material from The bottom of the incision is blown out to gradually form a through hole.

Due to the small size and high density of electronic devices and semiconductor components, the precision and speed of laser drilling are required to be high. According to the different requirements of component applications, electronic devices and semiconductor components have small size and high density. Due to its characteristics, the precision and speed of laser drilling are required to be high. According to the different requirements of component applications, the diameter of the micro-hole is in the range of 0.05 to 0.2 mm. For lasers used for ceramic precision processing, generally the focal spot diameter of the laser is less than or equal to 0.05mm. Depending on the thickness and size of the ceramic plate, it is generally possible to control the defocus to achieve through-hole punching of different apertures. For through-holes with a diameter less than 0.15mm, drilling can be achieved by controlling the defocus amount.

There are mainly two types method for cutting ceramic PCB: waterjet cutting and laser cutting. Currently, fiber lasers are mostly used for laser cutting. Fiber laser cutting ceramic circuit boards has the following advantages:

(1) High precision, fast speed, narrow cutting seam, small heat-affected zone, smooth cutting surface without burrs.

(2) The laser cutting head will not touch the surface of the material and will not scratch the workpiece.

(3) The slit is narrow, the heat-affected zone is small, the local deformation of the workpiece is extremely small, and there is no mechanical deformation.

(4) The processing flexibility is good, it can process any graphics, and it can also cut pipes and other special-shaped materials.

Al2O3 PCB with drilling
AlN PCB with drilling

 Under the development trend of light and thin, miniaturization, etc., the traditional cutting processing method has not been able to meet the demand due to the insufficient precision. Laser is a non-contact processing tool, which has obvious advantages over traditional processing methods in cutting process, and plays a very important role in the processing of ceramic substrate PCB.

Please contact sales@bestpcbs.com if you want to know more ceramic PCB.

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The technology and application of DBC ceramic PCB

Thursday, June 17th, 2021

DBC means direct bonding copper, it is a ceramic surface metallization technology.

The copper is bonded on Alumina, Beryllium Oxide and Aluminum Nitride, Packaging applications for power electronic modules, semiconductor refrigeration and LED devices are widely used.

DBC-Ceramic-PCB

96% Al2O3 has good insulation, good chemical stability, high strength, and low price. It is the preferred material for DBC technology, but the thermal conductivity of aluminum oxide is low, and there is a certain thermal mismatch with the thermal expansion coefficient of Si.

BeO is a good ceramic material used in DBC technology. It has high low-temperature thermal conductivity. It can be used for medium and high power devices. In the application field and process, the toxicity caused by it should be properly protected.

AlN material is non-toxic, moderate dielectric constant, thermal conductivity is much higher than aluminum oxide, close to beryllium oxide, and thermal expansion coefficient close to SI. All kinds of chips and high-power devices can be directly attached to the AlN substrate. No transition layer of other materials is used. The prospects currently used in DBC technology are very promising.

There is no any layer between the metal and ceramic substrate, so the thermal diffusion ability is strong; the contact resistance is also low, which is conducive to the connection of high-power and high-frequency devices.     

The linking temperature is lower than the melting point of copper, and the DBC substrate maintains a stable geometric shape during the connection process. In some cases, the copper foil can be made into the required shape before the linking, and then the DBC preparation process is performed, eliminating the need After connecting the etching process.

The copper conductor part has a very high current-carrying capacity, so it has the ability to reduce the size of the intercepting medium and increase the power capacity.

If you want to know more about DBC ceramic PCB, please feel free to contact sales8@bestpcbs.com

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How to do SMT for ceramic PCB

Wednesday, May 19th, 2021

As we all know if ceramic PCB is very fragile, so it is not easy to do SMT for them.

But we can do the SMT for ceramic PCB easily because we do it every day and we have more than 15 years experiences for doing that.

For the almost SMD components (such as SMD rsistors, capacitors, diode etc), normally we will add the solder paste by using SMT stencil, then put the components by machine, finally do the oven reflow.

For some special components, we will need to solder it by hand, such as through connectors, but it can’t be soldered by hand directly, it need to be put on the heating table to keep the temperature is high enough to make the solder past at melt state. Because the ceramic material with very good heat dissipation, the solder paste will be solidification very easily if don’t put the ceramic PCB on heating table

For some small LED, it can’t be put by SMT machine, because no such small feeder to pick it up, then need to put it on board by hand.

We can do very well for the small BGA components too.

Below some photos of ceramic PCB.

If you would like to know more about ceramic and ceramic PCB SMT, please feel free to email me

Ceramic PCB with SMT 1
Ceramic PCB with SMT 2
Ceramic PCB with SMT 3
Ceramic PCB with SMT 4
Ceramic PCB with SMT 5

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What’s the differences between thick film ceramic PCB and DPC ceramic PCB

Wednesday, April 21st, 2021

Ceramic PCB including Alumina PCB (Al2O3 PCB), Aluminum Nitride PCB (AlN), Bryllium Oxide PCB(BeO PCB) etc.

There are other differences except the substrate material is different.

  1. The method of making conductor is different.

The conductor for thick film ceramic is made by printing, but DPC is made by vacuum sputtering and plating.

  • The conductor is different.

The conductor for thick film ceramic PCB is Au or AgPd, but for DPC ceramic PCB, it is copper.

  • The thickness of conductor is different.

Normally, it is 10-20um for thick film ceramic PCB, copper thickness can be 10um-300um for DPC ceramic PCB.

  • The solder mask is different.

It is glass glaze for thick film ceramic PCB, the most popular color is greenish and blue. Glass glaze can withstand very high temperature, up to 850C

It is normal solder mask oil for DPC ceramic PCB, the most popular color is white.

The above is only simple introduction for the difference, if you want to know more differences between thick film ceramic PCB and DPC ceramic PCB or other details about ceramic PCB, please contact us

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Do the vias can be filled for ceramic PCB?

Friday, November 13th, 2020

As everyone knows for FR4 PCB, people like the vias to be tented or filled for some special applications.
Ceramic PCB is more and more popular because of the thermal conductivity is very high and very good for heat dissipation. Most of customers are going to make the PCB with ceramic material, includes Al2O3, AlN, BeO or Si3N4, etc.
So do the vias can be filled for ceramic PCB becomes the frequently asked questions (FAQ).
The answer is YES.
So what’s the material can be filled in vias for DBC/DPC alumina PCB/ Aluminium Nitride PCB?

The material can be solder mask, Dow Corning 1-4173 and copper/Cu.
Normally, customers want the vias/holes to be filled with copper.
Because copper can fill the vias very well and it is easier to do and it looks very good. Please see below photo.
The left one with filling with copper, the right one without filling copper

Why you need to fill the vias with copper?
1.Becuase if let the vias open, they will allow solder to flow through to opposite side of PCB during reflow, this causes bridging under components.
Filling the open vias/holes with copper can prevent from the solder pates into the vias.
2.If you need to pull vacuum around them and a hole would compromise that, so need to fill the vias.
There are also other purposes for filling the vias, if you need such ceramic board with filling the vias, please contact Coco in Best Technology sales@bestpcbs.com

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Why don’t use BeO as substrate to make DBC ceramic PCB?

Wednesday, September 9th, 2020

It is widely known that BeO with high thermal conductivity (200-250W/m.k).

High dielectric constant 6-7 (0.1MHz) and dielectric loss tangent is 10-4 (0.1GHz).

It is ideal material for ceramic PCB, lots of engineers want to use it as DBC ceramic PCB substrate.

But it is unfeasible, the powder of BeO is extremely poisonous.

The poison gas is produced by the reaction between oxygen, Cu and BeO under

1065-1085 degrees Celsius, so it is limited to make cooper on BeO substrate,

it has caused AlN (Aluminium Nitride) is becoming more and more popular.

Though BeO is unfeasible for DBC technology, but it is feasible for thick film technology.

Because when doing the conductor (Au or AgPd) on BeO substrate, we use silk-screen printing, no need to under high temperature environment, there is no chemical reactions.

Below the manufacturing process for your reference.

Here is the photo of BeO with AgPd conductor.

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What’s the advantages for AMB ceramic PCB comparing with DPC, DCB, LTCC, HTCC, thick film ceramic PCB?

Tuesday, August 18th, 2020

As we know, there are all kinds of ceramic PCB, DPC ceramic PCB, DBC ceramic PCB, LTCC ceramic PCB, HTCC ceramic PCB, thick film/thin film ceramic PCB.

Very few people know that there is AMB (Active Metal Bonding) ceramic PCB.

Do you know what’s the advantage for AMB ceramic PCB compare with other ceramic PCB (Al2O3/AlN/BeO/Si3N4 PCB)?

For AMB PCB, the substrate can be AlN ( Aluminium Nitride) and Si3N4 (Silicon Nitride) normally, AlN is the most popular. It is widely known that AlN with very high thermal conductivity ( Theoretical Value is 320W/m.k).

Using AMB technology to combine the oxygen-free copper and AlN material under high temperature, AlN with smaller thermal resistance, lower coefficient of thermal expansion and more stable partial discharge capability.

Compared with the traditional DBC or other substrate, the Aluminum Nitride copper-clad ceramic substrate made by the AMB technology with higher bonding strength of the copper layer and better cold and hot cycling characteristics.

So it  is widely used in the field of IGBT, especially for the high-power device control module.

AMB with competitive price and the copper thickness can be much thicker.

AlN max 300um
Si3N4 max 1200um

For more details, please contact me sales@bestpcbs.com 
I will update the manufacture process at the end of this month.

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Why don’t use BeO as substrate to make DBC ceramic PCB?

Monday, June 22nd, 2020

It is widely known that BeO with high thermal conductivity (200-250W/m.k). High dielectric constant 6-7 (0.1MHz) and dielectric loss tangent is 10-4 (0.1GHz), extremely high working temprature. It is ideal material for ceramic PCB, lots of engineers want to use it as DBC ceramic PCB substrate.

But it is not popular in ceramic PCB market, comparing with Al2O3, AIN, Si3N4, or ZrO2, as the powder of BeO is extremely poisonous.

The poison gas is produced by the reaction between oxygen, Cu and BeO under 1065-1085 degrees Celsius, so it is limited to make cooper on BeO substrate, it has caused ALN (Aluminium Nitride) is becoming more and more popular.

Right now, only few countries are using BeO to make ceramic PCB, such as USA, Russia and China. USA had biggest capability to make BeO , and here in China, there’re still some companies to make BeO raw material and among them, a few companies to produce direct copper bonded (DCB) on BeO because of environment limitation.

Though BeO is not popular for DBC technology, but it is feasible for thick film technology, because when the mentalization of Ceramic PCB, the conductor (Au or AgPd) on BeO substrate was made by silk-screen printing, and drying temperature is only around 850C, no need to under high temperature environment, so there is no chemical reactions, no environment issue.

Below the thick film ceramic PCB manufacturing process for your reference.

https://www.bestpcbs.com/products/thick-film-ceramic-pcb-manufacturing-process.htm

Here is the photo of BeO with AgPd conductor.

BeO with AgPd conductor
BeO with AgPd conductor

Welcome to contact us if you have better idea, or different comments on BeO ceramic PCB, communation will make us becoming better and better.

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