KR102201500B1 - Ceramic housing and plating method of ceramic material - Google Patents

Abstract

The present invention includes a form in which a ceramic substrate, a metallization layer, a first plating layer, a second plating layer, and a third plating layer are sequentially stacked, the metallization layer includes molybdenum and manganese, and the first plating layer includes nickel, , The second plating layer and the third plating layer each contain silver, the second plating layer has a thickness of 0.5 to 3 µm, the second plating layer is a plating solution having a lower silver concentration than the third plating layer, and the third plating layer It provides a ceramic housing that is manufactured at a higher current.

Description

Ceramic housing and ceramic substrate plating method {CERAMIC HOUSING AND PLATING METHOD OF CERAMIC MATERIAL}

The present invention relates to a ceramic housing and a method for plating a ceramic substrate.

In the automotive industry, refractory materials such as ceramics are applied in many areas, including wear pads that are bonded to metal parts. In addition, ceramics are used in various electrical and electronic components such as power grid tubes, vacuum circuit breakers, semiconductor packaging, multilayer substrates, ball grid arrays, power loss packaging, and sensor packaging. However, ceramics and metals have a disadvantage in that bonding is difficult. Therefore, conventionally, it is common to metallize the surface of a ceramic and then bond it with a metal.

Specifically, US Patent No. 6,840,429 (Patent Document 1) includes the steps of coating a surface of a material with a coating composition including a binder including a group 4B transition metal, a hydrocarbon resin and a styrene block copolymer, and a fluid carrier; Drying the coated surface; Applying a solder filling material to the dried coating surface; And heating the solder-filled material. A method of treating a non-metallic refractory material is disclosed. However, as in Patent Document 1, when the surface of a ceramic material is coated with a coating composition, a nickel plated layer is formed using electroless plating or electrolytic plating, and then treated by heating after applying a solder filling material, ceramic materials and metal materials There was a problem that the process for joining the was lengthened.

In addition, Korean Patent Application Publication No. 2015-0135155 (Patent Document 2) includes the steps of disposing a metallization layer containing molybdenum on the alumina component portion; Disposing a metal layer comprising nickel and a melting point inhibitor on the metallization layer by screen printing; Sintering the metal layer at a temperature lower than 1,000° C. to form a metal barrier layer; And bonding a portion of the alumina component to the nickel-containing metal component by brazing through a metallization layer and a metal barrier layer. However, as in Patent Document 2, when a metallization layer is disposed on a ceramic substrate and a metal layer containing nickel is disposed on the metallization layer, when a foreign material exists between the metallization layer and the metal layer, the foreign material is caused during brazing. There is a problem in that the metal layer is peeled off from the metallization layer, resulting in a blaster phenomenon.

Accordingly, there is a need for research and development on a plating method for a ceramic substrate having less occurrence of a blasting phenomenon between the metallization layer and the metal layer during brazing and excellent bonding strength between the metallization layer and the metal layer.

US Patent No. 6,840,429 (published on June 17, 2004) Korean Patent Application Publication No. 2015-0135155 (published date: 2015. 12. 2)

Accordingly, the present invention provides a method of plating a ceramic substrate capable of plating a metal layer with a uniform thickness, and a ceramic housing manufactured using the same. I want to.

The present invention includes a form in which a ceramic substrate, a metallization layer, a first plating layer, a second plating layer, and a third plating layer are sequentially stacked, the metallization layer includes molybdenum and manganese, and the first plating layer includes nickel, , The second plating layer and the third plating layer each contain silver, the second plating layer has a thickness of 0.5 to 3 µm, the second plating layer is a plating solution having a lower silver concentration than the third plating layer, and the third plating layer It provides a ceramic housing that is manufactured at a higher current.

In addition, the present invention comprises forming a metallization layer containing molybdenum and manganese on a ceramic substrate; A first plating step of forming a first plating layer containing nickel on the metallization layer; A second plating step of forming a second plating layer containing silver on the first plating layer; And a third plating step of forming a third plating layer containing silver on the second plating layer, wherein the second plating step is performed at a higher current than the third plating step, and the second plating step The plating solution provides a method of plating a ceramic substrate in which the silver concentration is lower than that of the plating solution in the third plating step.

The plating method of a ceramic substrate according to the present invention can suppress the occurrence of a blast occurring between the metallization layer and the plating layer, and form the plating layer with a uniform thickness.

In addition, the ceramic housing according to the present invention includes a plating layer having a uniform thickness, and the bonding strength between the metallization layer and the plating layer is strong, so that the occurrence of peeling of the plating layer is reduced.

Hereinafter, the present invention will be described in detail.

Ceramic housing

The ceramic housing according to the present invention includes a ceramic substrate, a metallization layer, a first plating layer, a second plating layer, and a third plating layer sequentially stacked.

Ceramic substrate

The ceramic substrate is not particularly limited as long as it is commonly used as a material for the housing. Specifically, the ceramic substrate may include an electrically insulating ceramic. More specifically, the ceramic substrate may include alumina, yttria, zirconia, yttria stabilized zirconia, yttrium aluminum garnet, magnesia alumina spinel, or yttrium aluminate perovskite.

Metallization layer

The metallization layer is formed on a ceramic substrate, serves as an intermediate crosslinking between ceramic and metal, and has conductive properties, so that plating is possible.

The metallization layer includes molybdenum and manganese. In addition, the metallization layer may further include at least one metal selected from the group consisting of tungsten, niobium, and tantalum.

The metallization layer may have a thickness of 10 to 50 μm, for example, 15 to 40 μm. When the thickness of the metallization layer is within the above range, it is possible to combine the ceramic substrate with a different material, and there is an effect of having an appropriate bonding force, vacuum degree, and conductivity.

1st plating layer

The first plating layer is formed on the metallization layer to increase the bonding strength between the metallization layer and the second plating layer, and serves to reduce the problem that the thermal expansion coefficient (CTE) of the metallization layer and the second plating layer is inconsistent.

The first plating layer contains nickel. In addition, the first plating layer may further include a metal selected from the group consisting of cobalt, chromium, boron, phosphorus, zinc, tin, and iron.

The first plating layer may have a thickness of 1 to 20 µm, for example, 2 to 10 µm. When the thickness of the first plating layer is within the above range, a healthy nickel plating layer (first plating layer) having excellent bonding strength and no appearance defect is formed, and corrosion of the metallization layer is prevented.

2nd plating layer

The second plating layer is formed on the first plating layer and serves to increase the bonding strength between the first plating layer and the third plating layer.

The second plating layer contains silver. In addition, the second plating layer may further include a metal selected from the group consisting of gold, platinum, bismuth, cobalt, nickel, indium, and tin.

The second plating layer may have a thickness of 0.5 to 3 µm, for example, 1 to 3 µm. When the thickness of the second plating layer is within the above range, a plating layer having a uniform thickness may be formed to form a sound third plating layer without a blaster on the first plating layer.

Further, the second plating layer is made of a plating solution having a lower silver concentration than the third plating layer, and is manufactured at a higher current than that of the third plating layer. For this reason, the second plating layer may have an average thickness thinner than that of the third plating layer. As described above, when the second plating layer uses a plating solution having a lower silver concentration than the third plating layer and is manufactured at a higher current than the third plating layer, so that the second plating layer has a thinner average thickness than the third plating layer, the second plating layer is formed into the third plating layer. It is possible to increase the bonding strength between the plating layer and the first plating layer.

3rd plating layer

The third plating layer is formed on the second plating layer and serves to be bonded to the metal housing portion without a solder material in a subsequent process.

The third plating layer contains silver. In addition, the third plating layer may further include a metal selected from the group consisting of gold, platinum, bismuth, cobalt, nickel, indium, and tin.

The thickness of the third plating layer may be appropriately adjusted according to the target and size of the ceramic housing. For example, the third plating layer may have a thickness of 20 to 50 µm, or 25 to 50 µm. When the thickness of the third plating layer is within the above range, a fillet between the ceramic housing and the metal is well formed during brazing, thereby having excellent bonding strength.

The ceramic housing may have a surface roughness of 2.0 to 6.5 μm. Specifically, the ceramic housing may have a surface roughness of 2.0 to 5.0 μm. When the surface roughness of the ceramic housing is within the above range, it is possible to prevent bonding failure during brazing.

In addition, the ceramic housing may have a bonding strength of 2,000 to 3,000 kgf/cm 2 to metal. Specifically, the ceramic housing may have a bonding strength of 2,500 to 2,800 kgf/cm 2 to metal.

As described above, the ceramic housing according to the present invention includes a plating layer having a uniform thickness, and the bonding strength between the metallization layer and the plating layer is strong, so that the occurrence of peeling of the plating layer is reduced. In addition, the ceramic housing may not form a solder layer including silver and copper, which is typically used to bond a ceramic and a metal.

Ceramic substrate plating method

The method of plating a ceramic substrate according to the present invention comprises the steps of forming a metallization layer containing molybdenum and manganese on the ceramic substrate; A first plating step of forming a first plating layer containing nickel on the metallization layer; A second plating step of forming a second plating layer containing silver on the first plating layer; And a third plating step of forming a third plating layer containing silver on the second plating layer.

Forming a metallization layer

In the step of forming the metallization layer, a metallization layer including molybdenum and manganese is formed on the ceramic substrate.

The material of the ceramic substrate and the metallization layer, and the thickness of the metallization layer are as defined in the ceramic housing.

The formation of the metallization layer may use a method commonly used to laminate a metal layer on the surface of a ceramic substrate. For example, the formation of the metallization layer may be performed by depositing or applying a metal paste containing molybdenum and manganese on a ceramic substrate. The deposition may include, for example, a physical vapor deposition technique, screen printing, and sputtering. Further, the application may include, for example, immersion, spraying, ink printing, syringe or nozzle brushing, or tape transfer.

The surface of the ceramic substrate may be polished to remove surface damage formed during manufacturing and improve surface flatness before forming the metallization layer. In addition, the surface of the ceramic substrate may be chemically cleaned before the metallization layer is formed in order to remove contaminants that may affect the bonding of the metallization layer. Furthermore, the ceramic substrate may be annealed prior to formation of the metallization layer, thereby reducing contaminants and reducing residual stress. That is, the ceramic substrate may be subjected to pretreatment steps such as polishing, chemical cleaning, annealing, etc. before forming the metallization layer.

In addition, the ceramic substrate on which the metallization layer is formed may be subjected to steps of hot water washing, degreasing, ultrasonic washing, pickling, and water washing. The degreasing and pickling may be performed using, for example, an acidic solution, and the hot water washing, ultrasonic washing, and water washing may be performed using water. As described above, the ceramic substrate on which the metallization layer is formed may be subjected to a washing step before the first plating step, and thus, it is possible to more easily form the first plating layer to proceed thereafter.

1st plating step

In the first plating step, a first plating layer containing nickel is formed on the metallization layer. In this case, the material and thickness of the first plating layer are as defined in the ceramic housing.

The first plating may be performed by immersing the ceramic substrate on which the metallization layer is formed in a first plating solution containing nickel and applying a current. In this case, the first plating solution may include nickel and boric acid. Specifically, the first plating solution may contain 50 to 75 g/l, or 55 to 70 g/l of nickel, and 10 to 40 g/l, or 10 to 35 g/l of boric acid. When the nickel concentration of the first plating solution is within the above range, a nickel plating layer can be uniformly formed, and when the boric acid concentration is within the above range, acts as a buffer to alleviate fluctuations in the pH of the plating solution and the effect of alleviating internal stress of the plating solution There is.

In addition, the pH of the first plating solution may be 3.0 to 5.5, or 3.0 to 5.0. When the pH of the first plating solution is within the above range, appearance defects on the surface of the first plating layer are prevented and there is an effect.

The first plating may be performed at 40 to 60° C. under a current of 1 to 5 A/dm 2. Specifically, the first plating may be performed at 40 to 55 °C under a current of 1.5 to 4 A/dm 2. When the temperature during the first plating is within the above range, the plating speed is uniformly maintained, and when the current is within the above range, the thickness of the first plating layer can be uniformly generated, and a nickel plating layer having a sound surface can be formed. .

2nd plating step

In the second plating step, a second plating layer containing silver is formed on the first plating layer. This step is performed to improve the bonding strength between the third plating layer and the first plating layer during the next step, the third plating, by forming a thin silver plating layer as the second plating layer on the first plating layer.

The material and thickness of the second plating layer are as defined in the ceramic housing.

The second plating may be performed by immersing the ceramic substrate on which the first plating layer and the metallization layer are formed in a second plating solution containing silver and applying a current. In this case, the second plating solution may contain silver and cyan (CN). Specifically, the second plating solution may contain 1 to 15 g/l, or 1.5 to 10 g/l of silver and 45 to 160 g/l, or 50 to 100 g/l of cyanide. When the silver concentration of the second plating solution is within the above range, the plating speed is increased during silver plating and the current density is increased. When the cyan concentration is within the above range, metal complex ions are effectively formed during silver plating, and the anode is formed. By dissolving, silver plating efficiency can be improved.

The second plating may be performed at 15 to 30° C. under a current of 3 to 6 A/dm 2 for 10 to 60 seconds. Specifically, the second plating may be performed for 10 to 50 seconds under a current of 3 to 5.5 A/dm 2 at 18 to 28 °C. When the temperature during the second plating is within the above range, a uniform plating speed can be maintained, and when the current is within the above range, a second plating layer having a uniform thickness can be formed.

The second plating step is performed at a higher current than the third plating step. Specifically, the current used in the second plating step may be 1.1 to 3 times, or 1.3 to 2.5 times greater than the current used in the third plating step. When the current in the second plating step is higher than the current in the third plating step, a thin second plating layer is formed on the entire surface of the first plating layer, thereby improving the bonding strength between the first plating layer and the third plating layer during the next step, the third plating. It is possible to manufacture a ceramic housing with less blister generation.

The plating solution in the second plating step (the second plating solution) has a lower silver concentration than the plating solution in the third plating step (the third plating solution). Specifically, the silver concentration of the plating solution in the third plating step may be 5 to 25 times, or 8 to 20 times greater than the silver concentration of the plating solution in the second plating step. As described above, when the silver concentration of the second plating solution is lower than the silver concentration of the third plating solution, a thin second plating layer is formed on the entire surface of the first plating layer, so that the first plating layer and the third plating layer are formed in the next step of the third plating. It is possible to manufacture a ceramic housing with less blister generation due to improved bonding strength.

3rd plating step

In the third plating step, a third plating layer containing silver is formed on the second plating layer. Specifically, in this step, a silver plating layer may be formed to a target thickness.

The material and thickness of the third plating layer are as defined in the silver plating layer of the ceramic housing.

The third plating may be performed by immersing the ceramic substrate on which the second plating layer, the first plating layer, and the metallization layer are formed in a third plating solution containing silver and applying a current. In this case, the third plating solution may include silver and cyan (CN). Specifically, the third plating solution may contain 20 to 150 g/l, or 20 to 100 g/l of silver and 30 to 150 g/l, or 35 to 145 g/l of cyanide. When the silver concentration of the third plating solution is within the above range, the plating speed is improved and the current density is increased, and when the cyan concentration is within the above range, metal complex ions are formed during plating and the anode is dissolved to improve plating efficiency. It works.

The third plating may be performed at 29 to 45° C. under a current of 0.5 to 3.5 A/dm 2 for 10 to 60 minutes. Specifically, the third plating may be performed at 29 to 40 °C for 20 to 55 minutes under a current of 1 to 3.3 A/dm 2. When the temperature during the third plating is within the above range, there is an effect of maintaining a uniform plating speed. When the current is within the above range, a plating layer having a uniform thickness is formed, and the surface roughness of the plating layer can be appropriately adjusted.

The ceramic substrate on which the third plating layer is formed may then be washed with water, hot water, and dried. The water washing may be performed using water, and the hot water washing may be performed using water at 70 to 90°C.

As described above, the plating method of a ceramic substrate according to the present invention can suppress the occurrence of blisters occurring between the metallization layer and the plated layer on the metallization layer, and form the plated layer with a uniform thickness. In addition, the plating method may not form a solder layer including silver and copper, which is typically used to bond a ceramic and a metal.

Hereinafter, the present invention will be described in more detail through examples. However, these examples are only intended to aid understanding of the present invention, and the scope of the present invention is not limited to these examples in any sense.

[Example]

Example 1. Plating of ceramic substrate

A sample in which a metallization layer made of molybdenum, manganese and alpha-alumina was formed on a ceramic substrate was washed with water at 75°C. Thereafter, the sample was degreased with 10% by weight of an acidic aqueous solution, and then ultrasonically washed with water and an ultrasonic cleaner, and washed with water. Thereafter, a first plating layer was formed at 45° C. for 10 minutes under a current of 2.5 A/dm 2 using a first plating solution containing 70 g/L of nickel and 35 g/L of boric acid and having a pH of 4.0.

Thereafter, the sample on which the first plating layer was formed was washed with water, and a second plating solution containing 2 g/ℓ of silver and 80 g/ℓ of cyanide (CN) was used for 55 seconds under a current of 4 A/dm 2 at 25 °C. The second plating was performed to form a second plating layer.

Thereafter, the sample on which the second plating layer was formed was washed with water, and a third plating solution containing 40 g/ℓ of silver and 100 g/ℓ of cyanide (CN) was used for 40 minutes under a current of 2.0 A/dm2 at 30°C. The third plating was performed to form a third plating layer. Then, it was washed with water, washed with water at 75° C., and dried to prepare a ceramic housing.

Examples 2 to 4 and Comparative Examples 1 to 4.

As shown in Table 1 below, except that the silver and cyan concentrations of the second plating solution, the plating conditions during the second plating, the silver and cyan concentrations of the third plating solution, and the plating conditions during the third plating were adjusted, Examples The ceramic substrate was plated in the same manner as in 1 to prepare a ceramic housing.

Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Second
Plating amount Silver concentration (g/ℓ) 2 7 10 12 - 20 0.5 10 Cyanide concentration
(g/ℓ) 80 130 95 110 - 60 80 130 Second
Plated Current (A/d㎡) 4 3.5 4.5 4.0 - 4 3 7 time 50 seconds 40 seconds 30 seconds 15 seconds - 50 seconds 20 seconds 70 seconds Temperature 25 ℃ 20 ℃ 25 ℃ 23 ℃ - 25 ℃ 25 ℃ 25 ℃ Third
Plating amount Silver concentration (g/ℓ) 40 60 50 60 40 40 40 50 Cyanide concentration
(g/ℓ) 100 80 125 130 100 100 100 100 Third
Plated Current (A/d㎡) 2.0 3.0 2.0 2.0 2.0 2.0 2.0 2.0 time 40 minutes 25 minutes 40 minutes 40 minutes 40 minutes 40 minutes 40 minutes 40 minutes Temperature 30 ℃ 40 ℃ 32 ℃ 30 ℃ 30 ℃ 30 ℃ 30 ℃ 40 ℃

Test Example 1. Measurement of Bluster Generation

The amount of blister generation was measured for 200 ceramic housings produced in Example 1 and Comparative Example 1, and the incidence rate was calculated from this, and the results are shown in Table 2.

Specifically, for the amount of blasting generated, the ceramic housing was heat-treated at 600° C. for 3 hours, and then the surface of the ceramic housing was visually observed.

Whether to perform the second plating output Bluster generation amount Bluster rate Example 1 U 200 pcs 10 things 5% Comparative Example 1 radish 200 pcs 186 pcs 93%

As shown in Table 2, Example 1, in which the second plating was performed, had a low amount and rate of blasting. On the other hand, Comparative Example 1, in which the second plating was not performed, had a high amount and rate of blasting. Through this, it was found that the second plating layer improves the bonding strength between the first plating layer (nickel plating layer) and the third plating layer.

Test Example 2. Measurement of physical properties of ceramic housing

The average thickness, surface roughness, and bonding strength of the silver plating layer (the second plating layer + the third plating layer) were measured and calculated for 100 ceramic housings of Examples 1 to 4 and Comparative Examples 1 to 4, and the results are shown in the following table. It is shown in 3.

Specifically, the thickness of the silver plating layer was measured using XRF (X-ray-Fluorescence), and the surface roughness was measured by a contact method using a simple surface roughness meter. In addition, the bonding strength was measured by bonding the copper pins to the ceramic housings of Examples and Comparative Examples, and then removing the copper pins using a universal testing machine.

Average thickness of silver plating layer (㎛) Surface roughness (㎛) Bonding strength (kgf/㎠) 2nd plating layer 3rd plating layer Example 1 1.0 35.7 3.2 2,780 Example 2 1.5 35.9 3.5 2,510 Example 3 2.1 37.2 3.8 2,600 Example 4 2.8 45.8 4.0 2,250 Comparative Example 1 0.0 35.5 3.8 560 Comparative Example 2 4.3 36.0 7.6 1,110 Comparative Example 3 0.3 34.1 5.2 730 Comparative Example 4 3.5 36.3 8.2 1,420

As shown in Table 3, the ceramic housings of Examples 1 to 4 have appropriate surface roughness and excellent bonding strength, so that a solder layer containing silver and copper, which is commonly used to bond ceramics and metals, may not be formed. have.

On the other hand, it was confirmed that Comparative Example 1 in which the second plating layer was not formed significantly decreased the bonding strength compared to Examples 1 to 4. In addition, in Comparative Examples 2 and 4, it was confirmed that the average thickness of the second plating layer exceeded 3 µm, so that the surface roughness was poor and the bonding strength was also reduced. Further, Comparative Example 3 in which the second plating layer was too thin had a remarkably low bonding strength.

Claims (7)

A ceramic substrate, a metallization layer, a first plating layer, a second plating layer, and a third plating layer are sequentially stacked, and
The metallization layer contains molybdenum and manganese,
The first plating layer includes nickel,
The second plating layer and the third plating layer each contain silver,
The second plating layer has a thickness of 0.5 to 3 µm,
The second plating layer is made of a plating solution having a lower silver concentration than the third plating layer, and is manufactured at a higher current than the third plating layer,
The second plating layer is manufactured by performing plating at a current of 15 to 30° C. and 3 to 6 A/dm ² using a plating solution having a silver concentration of 1 to 15 g/ℓ. The method according to claim 1,
The metallization layer has a thickness of 10 to 50 μm,
The first plating layer has a thickness of 1 to 20 μm,
The third plating layer has a thickness of 20 to 50 μm, a ceramic housing. Forming a metallization layer containing molybdenum and manganese on a ceramic substrate;
A first plating step of forming a first plating layer containing nickel on the metallization layer;
A second plating step of forming a second plating layer containing silver on the first plating layer; And
Including; a third plating step of forming a third plating layer containing silver on the second plating layer,
The second plating step is performed at a higher current than the third plating step, and the plating solution in the second plating step has a lower silver concentration than the plating solution in the third plating step,
In the second plating step, the plating solution has a silver concentration of 1 to 15 g/ℓ, and plating is performed at a current of 15 to 30° C. and 3 to 6 A/dm ² . The method of claim 3,
The plating method of a ceramic substrate, wherein the silver concentration of the plating solution in the third plating step is 5 to 25 times greater than that of the plating solution in the second plating step. The method of claim 3,
The second plating step is performed for 10 to 60 seconds, a method of plating a ceramic substrate. The method of claim 3,
In the third plating step, the plating solution has a silver concentration of 20 to 150 g/ℓ, and is performed for 10 to 60 minutes. The method of claim 3,
The current used in the second plating step is 1.1 to 3 times larger than the current used in the third plating step, a method of plating a ceramic substrate.