News | INNOVACERA

What’s new about the laminated planar oxygen sensor?

The advocated global environmental preservation has brought the increasing stringent on emission regulations. How to reduce hydrocarbon (HC) emission at engine cold start is essential for an automotive, therefore, it’s necessary to control engine exhaust air to fuel (A/F) ratio and warm up the catalyst as quickly as possible. Oxygen sensors are widely used to control the A/F ratio at around the stoichiometric point, where three-way catalysts are most effective.

The traditional oxygen sensor is made of alumina and inserts into a zirconia ceramic tube and commonly takes some 20 seconds to activate.

New laminated planar oxygen sensor combined alumina and zirconia together, heater element was embedded in the zirconia substrate of the sensor element adopting alumina for the heater substrate material, solve the problem of low thermal conductivity of zirconia while guarantee the good heating:

– High thermal conductivity and superior dielectric characteristic, by the direct joining of the alumina ceramic heater substrate and the sensor element zirconia electrolyte.
– Low heat stress at temperature rise, due to optimized heater design.
– Superior sensor protection from water droplets, and improved sensor response, due to optimized arrangement of intake holes in the sensor cover.

With these characteristics, the oxygen sensor can be activated in 10 seconds after a cold start.

Porous Ceramics Cleaning and Machining Guidance and Precautions

1. Machining guidance and precautions:

The porous ceramic plate is soaked in clean tap water for 5 minutes, and then processed.
So as to prevent the oil from penetrating into the dry ceramic plate and not being washed away.
The porous ceramic is cut by a diamond blade and uses a grinding wheel or grinding head to grind.
After processing, use neutral detergent and ultrasonic cleaning. Pls avoid processing with oily coolant, otherwise, it will be difficult to clean.
Last step: drying natural or drying water with an electric fan.

2. To clean the porous ceramic plate:

Using ultrasonic cleaning with neutral detergent to clean. The neutral detergent is not strong acid or alkaline, that is fine. Like washing powder, dishwashing liquid.
After cleaning, drying natural, or drying water with an electric fan. Please don’t use oven dry for avoiding deformation.

Process Comparison of the Ceramic Substrate

The metallized ceramic substrate is a kind of circuit board. It has a thermal expansion coefficient close to that of semiconductors and high heat resistance. It is suitable for products with high heat generation (high-brightness LED, solar energy), and its excellent weather resistance is more suitable for harsh outdoor environments. Because it has the characteristics of lead-free, non-toxic, and good chemical stability, it will not cause harm to environmental protection, so it is more and more widely accepted by the public.

Due to different processes, the ceramic substrate is mainly divided into DBC (Direct Bonded Copper), DPC (Direct Plated Copper), AMB (Active Metal Brazing), and Thick film.

We will introduce each of the processes and the advantages, disadvantages of each process.

DBC (Direct Bonded Copper)

It is composed of the ceramic substrate, bonding layer, and conductive layer. It refers to the special process of copper foil directly bonding to alumina or aluminum nitride ceramic substrate surface at high temperature.

The advantages are as below:

The copper layer is thick;
The processing is fast;
The price is cheap;
Can make multilayer;
Suitable for large area consumption;
High thermal conductivity;
High adhesion strength;
Excellent soft brazing;
Excellent electrical insulation

The disadvantages are as below:

Can not pass through the hole;
Poor accuracy;
Low flatness (surface roughness);
Suitable for the device in the large distance of the product, can not be done in the precise occupation.

DPC (Direct Plated Copper)

Mainly by evaporation, magnetron sputtering and other surface deposition process to carry on the substrate surface metallization, first under the condition of vacuum sputtering, titanium, and then is copper particles, the plating thickness, then finish making line with ordinary PCB craft, and then to plating/electroless deposition way to increase the thickness of the line, the preparation of DPC way contains vacuum coating, wet deposition, Exposure development, etching, and other processes.

The advantages are as below:

In terms of shape processing, DPC ceramic plate needs to be cut by laser, the traditional drilling and milling machine, and punch machine can not be accurately processed, so the combined force and line width are also finer.
The crystal performance of the metal is good;
The flatness is good;
The line is not easy to fall off;
The line position is more accurate, the line distance is smaller, reliable, and stable, can be through the hole and other advantages.

The disadvantages are as below:

It can only make a thin plate (thickness < 300μm), and its cost is high, the output value is limited, resulting in frequent shipment time can not be on time.

AMB (Active Metal Brazing)

It is a method to realize the bonding of ceramic and metal by reacting a small number of active elements Ti and Zr in filler metal with ceramics to form a reaction layer that can be wetted by liquid filler metal.

The advantages are as below:

The combination is achieved by the chemical reaction between ceramic and active metal solder paste at high temperatures, so its bonding strength is higher and reliability is better.

The disadvantages are as below:

The reliability of the AMB process depends largely on the composition of active filler metal, brazing process, brazing layer structure, and many other key factors.

Thick film

Thick film technology is straight on ceramic substrate printed graphics, then direct sintering process.

The advantages are as below:

The bonding force with ceramic is much greater than that of the DPC process;
It is direct printing of graphics, no etching, and copper plating process, so the cost will be lower;
It is a one-time forming, so the flatness is smoother than that of the DPC.

The disadvantages are as below:

Because the thick film process is printed, it is generally not too thick. Due to different product requirements, different materials have a certain impact on the conductivity of the film.

So it is hard to say which process is best, it depends on the customer’s application and usage, customer could choose each of the processes according to their requirements.

Should you have more interests, pls feel free to contact us at any time.

How Many Oxygen Sensors Does a Car Have?

The oxygen sensor is a car part that you probably never think much about. In fact, you may be unsure of what it even does, yet it is essential for your vehicle to function normally or perform optimally.

An oxygen sensor, which is sometimes abbreviated as an O2 Sensor, generates a reading based on the oxygen level within the automotive exhaust system. The oxygen sensor is made of ceramics and includes a number of pores, which are electrodes coated in platinum and surrounded by a threaded casing. The sensor is effectively screwed into the exhaust pipe with half of it sticking out. Most sensors undergo a heat test, which ensures they can reach their optimal operating temperature promptly.

How Many Oxygen Sensors Does a Car Have?

Most new vehicles are required to have catalytic converters in each exhaust pipe. These catalytic converters take harmful gasses and turn them into less harmful gasses. Every catalytic converter is required to have a couple of oxygen sensors.

So if you have a single exhaust system, you probably have one catalytic converter and, thus, two oxygen sensors. Cars with double exhaust pipes, meanwhile, will be fitted with a total of four oxygen sensors.

The actual number of oxygen sensors for a car depends on the year, make, model and engine. However, most of the later model vehicles have four oxygen sensors. Note the following specific vehicles that have four oxygen sensors:

2013 Honda Civic 1.8L 4 cylinder
2010 Chevrolet Tahoe 6.0 L 8 cylinder
2004 Jeep Wrangler 4.0L 6 cylinder
2000 Toyota Land Cruiser 4.7L 8 cylinder

The number of sensors varies according to engine type:

Traditional V6 and V8 have three oxygen sensors including a left bank and right bank sensor upstream and a downstream O2 sensor
4 cylinder transverse has an upstream and a downstream O2 sensor
V6 and V8 transverse have four oxygen sensors including a left or front bank upstream; right or rear bank upstream; rear of the engine; and a downstream sensor
4 and 6 cylinders in-line have three oxygen sensors including a front and rear bank upstream and a downstream sensor

INNOVACERA specializes in the production of ceramic heating elements in oxygen sensors and has many years of experience. Please feel free to contact me if you need it.

Do you know the car oxygen sensor?

With the development of the automobile industry, especially the increase in the number of automobiles and the frequency of use, the pollution caused by automobile exhaust has attracted more and more attention. Traditional carburetor-type vehicles have not adapted to the new automobile exhaust emission requirements. In this case, electronically controlled fuel injection vehicles have become the mainstream of the development of the automotive industry. The electronically controlled fuel injection adopts a closed-loop control system, which can adjust the fuel injection volume in time according to the different working conditions and emission factors of the engine so that the air-fuel ratio can be maintained at 14.7:1, thereby obtaining ideal power and economy. The oxygen sensor is an important component of the automotive engine electronic control system (EMS)

The role of the oxygen sensor on the car is to measure the oxygen content in the exhaust after the engine burns, and convert the oxygen content into a voltage signal and transmit it to the EMS. Under closed-loop control conditions, the EMS adjusts the engine to make the air to fuel ratio at 14.7:1. Nearby, ensure that the three-way catalytic converter has the greatest conversion efficiency for the three pollutants of hydrocarbons (HC), carbon monoxide (C0), and nitrogen oxides (NOx) in the exhaust gas, which maximizes energy saving and emission reduction Effect.

What types of oxygen sensors are available on the market?

According to the working principle of the oxygen sensor sensitive element, it is mainly divided into: switch type oxygen sensor (concentration type), limiting current type oxygen sensor, and semiconductor resistance type oxygen sensor (TiO2 type oxygen sensor)

Type	Switch type oxygen sensor	Limit current type oxygen sensor	Semiconductor resistance type oxygen sensor
Principle	Determine the electric potential based on the difference in oxygen concentration	Determine the limiting current based on the diffusion of oxygen	Determine the resistance based on the chemical reaction of the semiconductor surface
output signal	voltage signal	current signal	Resistance signal
A/F control range	Narrow range, generally around 14.7	Wide range, generally between 10~23	/
Examples of market products	Bosch: LSH/LSF Denso: O2 oxygen sensor	Bosch: LSU (Five-line wide domain) Denso: A/F oxygen sensor	/

Related concepts and characteristic curves

Theoretical air-fuel ratio: A/F=14.7:1 (λ=1)

Rich mixture: When the actual air-fuel ratio is less than the theoretical air-fuel ratio, the mixture is called rich (λ<1).

Lean mixture: When the actual air-fuel ratio is greater than the theoretical air-fuel ratio, the mixture is called lean mixture (λ>1).

When the mixture becomes rich, that is, the concentration of oxygen in the exhaust decreases (λ<1), the output voltage signal of the oxygen sensor is close to 1V.

When the mixture becomes leaner, that is, the concentration of oxygen in the exhaust increases (λ>1), the output voltage signal of the oxygen sensor will be close to 0V.

Working principle

The crystal structure of ZrO2 material

In order to better meet the needs of market development, INNOVACER has now stably supplied the following planar oxygen sensor heating elements. It has a new design that promotes faster heating of the probe. Beginning the monitoring much faster than the thimble type.

1, Typical structure of switch type oxygen sensor sensitive element

Advantages and disadvantages

	A type (alumina type)	B Type (Zirconium Oxide Type)
Advantages	1) Good insulation 2) Fast heat conduction 3) Simple preparation process	1) The base material is the same, and the mechanical strength is higher. 2) The material is easy to prepare
Disadvantage	1) The product has a certain curve 2) *Need to solve the problem of co-firing of different materials	1) Poor insulation reliability 2) Heat conduction is slow 3) The preparation process of the insulating layer is complicated

* Is the core technology of our company.

2, Concentration Oxygen Sensor

(Schematic diagram of HF sensing element)

If you have any needs or problems with car oxygen sensors, please feel free to contact us and we will definitely give you the most professional assistance.

Rapid and Reliable Ceramic Hot Surface Igniters

INNOVACERA offers ceramic igniters for hot surface ignition systems in heating applications. These high strengths, heat resistant ceramic igniters have become an industry standard in gas heating systems. Their superior materials and rapid heating capabilities provide reliable performance over a long useful life.

Applications include:

Gas heating systems
Ovens/ranges
Dryers
And more

IGNITER PRODUCT FAMILIES

INNOVACERA offers two families of ceramic igniters, each offering different ranges of style, durability, and heat up speed to ignition temperatures — all leveraging strong material properties including:

Low porosity
High operating temperature
Corrosion resistant
Long lasting
Easy to install and retrofit

Alumina Igniter

INNOVACERA’s alumina igniter can reach a permanent working temperature above 900°C. Since air can through and around inside and outside of the heater tube, heat can be transferred from both inside and outside of the heater element. It’s widely used in igniting wood chips, firewood, coal bricks or other fuel.

Advantages of Alumina Igniter:

Permanent operation temperature reaches 1000 degree C-1100 degree C
Extremely long lasting.Operating more than 10,000hours
Extremely Energy-efficient.Rapid Ignition 60%-90%
High Quality and Robust

Applications:

Hot surface igniters (ignition of gas, oil, biomass, pellets)
Hit air generation
Customer-specific heating solutions.

The regular size of Alumina Igniter:
OD10.5*78mm 220V, 160-230W
OD10.5*90mm 220V, 160-250W
OD11.5*108mm 220V, 300-350W

Silicon Nitride Igniter

INNOVACERA’s silicon nitride heating elements are normally rectangular in shape. These heaters have a lot operation zone up to 1000 degree C and a cold zone in the contact area. The encapsulated terminal can prevent short circuit caused by conductive contamination. They can be operated with or without a controller. Silicon nitride heater has several times the durability than that of silicon carbide products.

Performances & Characteristics:

Electrical safety. The current leakage after the break is less than 10 mA
High temperature resistance. Dry point up to 1300 ℃
High surface load. Heating liquid surface load up to 78w/cm2
Small size
The thermal inertia is small, faster heating up.
Long service life
Acid and alkali corrosion resistance

Hot Pressed Aluminum Nitride Ceramic Overview

Hot pressed aluminum nitride ceramic is used in applications requiring high electrical resistivity in addition to exceptional thermal conductivity. The applications for hot-pressed AlN typically involve rigorous or abrasive environments and high-temperature thermal cycling.

Below are the properties of the pressed aluminum nitride.

Property	Units	Value
Flexural Strength, MOR (20 °C)	MPa	300-460
Fracture Toughness	MPa m1/2	2.75-6.0
Thermal Conductivity (20 °C)	W/m K	80-100
Coefficient of Thermal Expansion	1 x 10-6/°C	3.3-5.5
Maximum Use Temperature	°C	800
Dielectric Strength (6.35mm)	ac-kV/mm	16.0-19.7
Dielectric Loss	1MHz, 25 °C	1 x 10^-4 to 5 x 10^-4
Volume Resistivity (25°C)	Ω-cm	10¹³ to 10¹⁴

The information provided on this chart is for general material property reference only.

Example Applications:

Semiconductor heaters
Ballistics armor

Should you have any inquiries, please feel free to contact us.

Ceramics For The Textile Machinery Industry

Innovacera manufactures ceramics for the textile machinery industry. The products are ceramic friction discs for texturing yarns, thread guides for fiber production, ceramic navels for Yarn spinning, and ceramic cutters for the textiles industry.

: ceramic eyelet

The advantages of using alumina ceramic is as below:

Lowest possible yarn breakage rates
Highest yarn cleanliness
Low yarn tension
Excellent package build
High quality and cost effectiveness

It is new hard-wearing material with an excellent surface finish for higher yarn quality. The extreme hardness of ceramic also ensures superior process stability in spinning.

Properties of Ceramic Parts for Textile:

Good wear and corrosion resistance
96% & 99.7% Al2O3 alumina ceramics
Precision manufacturing
Good surfaces finished for different applications

We have also developed a high-performance yttrium-reinforces zirconium oxide ceramic(TZP) for cutting yarns and textiles. It stands out from other materials with its extremely high cutting edge strength and excellent flexural strength and hardness. The use of Y-TZP cutters improves efficiency in cutting textile threads, which ultimately increases profitability.

Technical Advantages of Y-TZP Zirconium Oxide Cutters

Faster cutting rates
Consistently good cutting quality, e.g. improved strength of spliced connections
No corrosion
Smooth running
Extended maintenance intervals
Universal cleaning possibilities using acids, alkaline solutions and organic solvents.

If you have any inquiries, pls feel free to contact us.

Zirconia Ceramic Heating Element-New generation of Oxygen Sensor Chip!

The concentration of oxygen sensor is measured to test the oxygen content in the gas emission released by the engine, send corresponding voltage signals and provide real-time monitoring for the Electronic Control Unit(ECU), optimize the system control strategy, reduce fuel consumption and exhaust emissions.

The core component inside an oxygen sensor is the zirconia ceramic heating element, which will heat the O2 concentration on each side, turn the O2 to the voltage signals and send to the ECU.

Innovacera provides three types of oxygen sensor chip that can help to improve the performance of the oxygen sensor:
1. SWITCH TYPE OXYGEN SENSOR
2. WIDE BAND OXYGEN SENSOR
3. AIR-FUEL RATIO SENSOR

Till now, those zirconia ceramic heating element has been used on the automotive such as TOYOTA, LEXUS, AUDI, Santana, Magotan, etc.

Alumina Ceramic Ball Valves Dye Penetrant Test

In the Innovacera each ceramic ball valves production, after product finish producing, Innovacera arranges to put the alumina ceramic ball valves in the dye penetrant to test any cracked inside of the product and make sure every ball valves quality is qualified.

After confirming the dye penetrant test is qualified, then Innovacera arranges to clean the ceramic ball valves.