阅读说明：本技术 用于制造具有包裹物料的电气装置的方法 (Method for producing an electrical device with a packaging material ) 是由 M.哈默-阿尔特曼 于 2018-04-25 设计创作，主要内容包括：本发明涉及一种用于制造具有电气或电子构件(12)的电气装置(10)的方法,其中该构件(12)被具有水泥的包裹物料(14)至少部分地包裹,所述方法具有以下步骤：-将包裹物料(14)施加到电气或电子构件(12)上；和-如此处理包裹物料(14),使得在包裹物料(14)的表面(28)上有针对性地进行水泥的碳化。(The invention relates to a method for producing an electrical device (10) having an electrical or electronic component (12), wherein the component (12) is at least partially encased by a casing compound (14) having cement, comprising the following steps: -applying a wrapping material (14) onto the electrical or electronic component (12); and-treating the packaging material (14) in such a way that the cement is specifically carbonized on the surface (28) of the packaging material (14).)

1. Method for producing an electrical device (10) having an electrical or electronic component (12), wherein the component (12) is at least partially encased by a casing material (14) having cement, having the following steps:

-applying (102) a wrapping material (14) onto the electrical or electronic component (12); and

-treating (104) the packaging material (14) in such a way that a targeted carbonization of the cement takes place on the surface (28) of the packaging material (14).

2. The method (100) according to claim 1, wherein the step of treating the coating material (14) for targeted cement carbonation on the surface (28) comprises the steps of:

-subjecting the wrapping material (14) to a first heat treatment (106);

-forming (108) a moisture film (32) on the surface (28) of the wrapping material (14); and

-subjecting the wrapping material (14) to a second heat treatment (110) under a defined atmosphere having a carbon dioxide content greater than or equal to 0.039% by volume or a carbon dioxide partial pressure greater than 0.039 kPa or equal to 0.039 kPa to less than 0.01 kPa.

3. The method (100) according to claim 2, wherein the step of first heat treating (106) is stopped before the cement of the coating material (14) is fully hydrated.

4. The method (100) according to claim 2 or 3, wherein the step of forming (108) the moisture film (32) comprises cooling the wrapping material (14), in particular to about room temperature, or applying water onto the surface (28) of the wrapping material (14) under a defined atmosphere with a relative humidity of greater than or equal to 60% to less than or equal to 80%, preferably substantially 65%.

5. The method (100) according to any one of claims 2 to 4, wherein in the step of second heat treatment (110), the wrapping material (14) is heated to greater than or equal to 100 ℃.

6. The method (100) according to any one of the preceding claims, wherein the surface (28) of the coating material (14) is the entire outer surface (28) of the coating material (14) which can be subjected to a fluid from the atmosphere (26) surrounding the device (10), wherein the cement on the entire surface (28) is specifically carbonized during the treatment (104) of the coating material (14).

7. The method (100) according to any one of the preceding claims, wherein the cement is an alumina cement.

8. The method (100) according to any one of the preceding claims, wherein the electrical or electronic component (12) is selected from: semiconductor structure element (12), sensor element, inductor, capacitor, battery cell, battery module, circuit.

9. The method (100) according to any one of the preceding claims, wherein the device (10) has at least one further element (16, 18, 20, 24) selected from: an electrode, a component contact (24), a carrier substrate (18), a connecting element (16, 20), in particular a component connecting element (16) and/or a carrier substrate connecting element (20).

10. The method (100) according to any one of the preceding claims, wherein the component (12) and/or the further element (16, 18, 20, 24) has a metallic region on the contact surface with the coating mass (14), wherein the metallic region is free of metals which are substantially not corrosion-resistant in environments with a pH value of greater than or equal to 7 to less than or equal to 9.

11. The method (100) according to any one of the preceding claims, wherein the component (12) and/or the further element (16, 18, 20, 24) has a metal region on the contact surface with the coating mass (14), wherein the metal region has only a metal selected from the group consisting of: copper, copper alloys, copper tin alloys and/or copper nickel alloys.

12. The method (100) according to claim 10 or 11, wherein the contact surface is the entire contact surface between the component (12) and the wrapping material (14) and the further element (16, 18, 20, 24) and the wrapping material (14).

13. Apparatus for implementing the method (100) according to any one of the preceding claims.

14. Electrical device (10) produced according to one of claims 1 to 12, having an electrical or electronic component (12) and optionally further elements (16, 18, 20, 24).

15. Electrical device (10) with an electrical or electronic component (12), wherein the component (12) is at least partially surrounded by a surrounding material (14) with cement, characterized in that a surface (28) of the surrounding material (14) has carbonized cement (30), in particular wherein the surface (28) of the surrounding material (14) is the entire outer surface (26) of the surrounding material (14), which can be subjected to a fluid from the atmosphere (26) surrounding the device (10).

Technical Field

The invention relates to a method for producing an electrical device having an electrical or electronic component, wherein the component is at least partially surrounded by a covering material having cement, to such an electrical device and to a device for carrying out the method.

Background

Currently, the improvement of reliability and efficiency of power electronics (LE) modules and robust sensor systems, as well as the reduction of their cost, are of paramount importance. Current encapsulation materials (epoxy, silicone materials) are limited to temperature ranges below 200 ℃. By developing a sheathing material with a temperature range of at most 300 ℃ or 350 ℃, the operating range of modern power semiconductors (e.g. SiC) can be further extended beyond 200 ℃ without having to forego the additional functions of the sheathing material (e.g. protection from environmental influences, improved heat flow).

The LE module consists of a number of material combinations of ceramics and metals that can react with each other under specific conditions. Especially moisture, gases and elevated temperatures, so that the chemical reaction preferably proceeds. Possible corrosion can impair functional performance. Here, corrosion refers to erosion of a material by reaction with its environment, in which material properties deteriorate.

One of the reactions to the damaging effects of metals disposed in the cement or cement-based coating material is the carbonation of the cement in the coating material after setting or hydration. Carbonation is understood to mean the Ca (OH) content of the cement stone caused by the carbon dioxide contained in the air₂And chemical conversion of the alkaline component (and NaOH and KOH) to calcium carbonate:

ca (OH)2+ CO2+ H2O → CaCO3 + 2H2O and 2NaOH + CO2 → Na2CO3 + H2O

And (3) carbonization:

1. the crystallized hydroxycaprote is dissolved in the wet air film on the walls of the pores of the cement material. At the same time, carbon dioxide diffuses from the air into the capillary pores

Ca(OH)2→ Ca2+ + 2OH−

2. CO2 reacts with a small portion of water to produce carbonic acid, which is decomposed in water into H + and CO 2-

CO2+ H2O → H2CO3 → 2H+ + CO2−3

3. Ca (OH)2 neutralized by H2CO3

Ca(OH)2+ H2CO3→ CaCO3+ 2H2O

(CaCO 3 is in the form of calcite, and rarely in the form of vaterite (high basicity) or aragonite (low basicity) → CaCO 3-variant)

4. Carbonizing alkali metal hydroxides NaOH and KOH, and further reacting to calcium carbonate and alkali metal hydroxides

2NaOH + CO2 → Na2CO3 + H2O and Na2CO3 + Ca (OH)2 → CaCO3 + 2 NaOH.

The lack of dissolved ca (oh)2 due to carbonization from the pore solution (i.e. the solution on the walls of the pores) results in dissolution of the crystallized hydroxycalcite. The high pH of the pore solution (about 12.5) is maintained as long as ca (oh)2 and base are present. At pH values above 10, for example for reinforced concrete on steel surfaces in contact with cement, a passivation layer (2 to 20 nm) is formed to protect the steel from corrosion. However, in the case of factors that lead to neutralization of the pore solution, the pH is lowered to about 9, so that there is a risk of corrosion. Thus, carbonization results in a decrease in pH from 12.5 to about 9. The reason is the "consumption" of Ca (OH) 2:

Ca(OH)2 + CO2 → CaCO3 + H2O。

thus, the reduction in basicity due to carburization can lead to corrosion of the steel and certain other metals, which in turn has an effect on the stability of these metals. On the other hand, however, carbonation also results in an increase in the density of the carbonated cement.

The cement carbonization preconditions are as follows:

contact of cement with carbon dioxide, e.g. with air (carbon dioxide content of air 0.04%)

The presence of capillary pores permeable to carbon dioxide

Sufficient moisture conditions (water does not completely fill the pores, not completely dry).

For this, the following applies to the carbonization depth:

in the open air at higher relative air humidity or rainfall, carbonization proceeds more slowly as the water absorbed by the rainfall prevents the transport of CO2 through the capillary pores;

as the w/z-value (water/cement-value) increases, the capillary pore content increases and thus the gas permeability of the cement stone increases;

during hydration of portland cement, in particular the clinker phases C3S and C2S are hydrated to calcium silicate hydrate and ca (oh)2 is formed. The higher the amount of ca (oh)2, the more CO2 is bound, which reduces the carbonization depth. In addition, the newly formed phases occupy more volume in carbonization, which reduces porosity in the carbonization zone and increases diffusion resistance;

aluminous cements have a2 to 3 times greater depth of carbonation compared to portland cement, since no ca (oh)2 is formed during hydration.

Thus, the depth of carbonation decreases with higher Ca (OH)2 content, lower w/z-values and increased cement density.

In addition, the pH can be further lowered by:

increasing the carbon dioxide concentration in the air

Complete consumption of Ca (OH)2 in the pore solution

Further precipitation of the base from the pore solution by means of, for example, silicic acid SiO 2. nH2O (SiO 2 is only very sparingly soluble in water)

2KOH + SiO2 + n H2O K2SiO3·n H2O。

Disclosure of Invention

The subject of the invention is a method for producing an electrical device having an electrical or electronic component, wherein the component is at least partially encased by a casing material having cement, said method having the following steps:

-applying a wrapping material to the electrical or electronic component; and

the coating material is treated in such a way that the carbonization of the cement takes place or proceeds in a targeted manner on the surface of the coating material.

The subject of the invention is also a device for implementing the above-described method.

Furthermore, the subject of the invention is an electrical device with an electrical or electronic component, wherein the component is at least partially surrounded by a surrounding mass with cement, wherein the surface of the surrounding mass has carbonized cement, in particular wherein the surface of the surrounding mass is the entire outer surface of the surrounding mass, which can be subjected to a fluid from the atmosphere surrounding the device.

The electrical device may be formed as a power electronics module.

The electrical or electronic component may be selected from: semiconductor structure element, sensor element, inductor, capacitor, battery cell, battery module, circuit. In the present invention, however, an electrical or electronic component is understood to mean any active and passive structural element or high-performance structural element. In this regard, the electrical device may have at least one further element selected from: an electrode, a component contact, a carrier substrate, a connection element, in particular a component connection element and/or a carrier substrate connection element.

In the context of the present invention, cement is understood to mean an inorganic, metal-free, hydraulic binder. In this connection, cement is hydraulically set, i.e. it reacts chemically with water to form stable, insoluble compounds. In this regard, the cement may be formed at the beginning of the process or prior to hydration as a ground powder which reacts with water or added water to form hydrates, set and set. In this connection, the hydrates can form needles and/or platelets, which are bonded to one another and thus give the cement a high hardness. In contrast, phosphate cements are not hydraulically setting. It undergoes an acid-base reaction to form a salt gel which subsequently sets into a largely amorphous mass. H + (hydrogen ions) are exchanged in an acid-base reaction.

The cement may consist mainly of calcium aluminate and calcium aluminate hydrates are formed during hydration. The cement may have a w/z-value (water/cement-value) of about 0.35 (for alumina cement) to about 0.4 (for portland cement) prior to hydration.

In the present invention, a packaging material is understood to mean any type of envelope (package). The wrapping material has cement. The coating material is preferably based on cement. The encasement material can be formed into a cementitious composite. That is, the coating material may have a cement matrix with fillers and additives. Before and/or after the treatment step, the wrapping material may have the following composition:

-binder alumina cement: greater than or equal to 8 to less than or equal to 47 wt% (e.g., SECAR 71)

-reactant water: greater than or equal to 10 to less than or equal to 28% by weight

-additives: 3 to 20% by weight

-a filler: greater than or equal to 25 to less than or equal to 82 weight percent.

The filler may be selected from:

-Al2O 3: fine d50 about 1 μm to coarse d50 about 150-

- α -Si3N4 fine about 1 μm to coarse about 100 μm

-hex. BN: about 15 μm or to about 250 μm fine

-SiC: about 10-50 μm or to about 600 μm fine

-AlN: about 1 μm or to about 100 μm.

The wrapping material may be disposed adjacent to the member and optionally adjacent to the additional element during the applying step. Thus, the wrapping material may have an interface with the member and optionally with further elements.

The processing step may comprise a plurality of sub-steps. The treatment step may comprise a hydration step and/or a setting step and/or a drying step and/or a curing step.

In this case, the surface of the coating material has capillary walls or pores. The surface of the coating material can advantageously be the entire outer surface of the coating material, which can be subjected to a fluid from the atmosphere surrounding the device, wherein the cement is specifically carbonized over the entire surface during the treatment of the coating material. The surface of the encapsulating material is therefore not the interface between the encapsulating material and the electronic component or structural element.

In the context of the present invention, controlled carbonization is understood to mean controlled or regulated carbonization. In this case, the carbonization is carried out in a defined atmosphere. In this case, a targeted carbonization is desirable and intended, with this process taking place or taking place in a regulated manner. In this case, the surface of the coating material is treated in such a way that the specifically carbonized surface reacts substantially uniformly. The entire specifically carbonized surface thus has a substantially uniform carbonization distribution. That is, the entire surface is carbonized evenly or uniformly in the longitudinal and transverse directions thereof. However, the carbonization profile can also vary in the depth direction of the coating material.

In contrast to the methods and efforts known to date for preventing carbonization in cement or reinforced concrete or for minimizing the carbonization depth in cement or reinforced concrete in order to prevent corrosion of iron or steel due to pH reduction, the carbonization of cement in the encapsulating material is carried out and promoted in a targeted manner in the present invention, wherein an undesired pH reduction is deliberately accepted. The advantage of carbonization can thus be utilized by the method according to the invention, so that the surface of the coating material which is specifically carbonized is covered

Increase in density of the cement structure due to the volume increase (V) caused by the newly formed calcium carbonate

Ca(OH)2→ CaCO3 V = +11%

-improving the tightness against water and gases by reducing the total pore volume by 20% to 28%, and

increasing the cement strength by 20 to 50% depending on the type of cement.

The electrical device produced by the method thus has a coating compound with improved tightness to moisture and gases (for example SO2 gas from combustion exhaust gases, which can be converted into sulfurous acid in the presence of moisture and into sulfuric acid by oxidation) on the surface or in the edge region. This in turn leads to acid attack of the concrete, which leads to a decrease in the pH and subsequent corrosion

S + O2 → SO2

SO2 + ½ O2 + H2O → H2SO4。

Further, the strength is improved by improving the sealing property. In order to prevent the risk of corrosion of the metal due to a decrease in the pH value of the encapsulation material and thus ensure the functional performance of the electrical or power electronics module, the metal having a contact surface with the encapsulation material must be selected accordingly, or has corrosion resistance in the pH range, depending on the set pH range.

It is also advantageous if the step of treating the coating material for the targeted carbonization of the cement on the surface comprises the following steps:

-subjecting the wrapping material to a first heat treatment;

-forming a film of moisture on the surface of the wrapping material; and

-subjecting the wrapping material to a second heat treatment under a defined atmosphere having a carbon dioxide content greater than 0.039% by volume or a carbon dioxide partial pressure greater than 0.039 kPa or equal to 0.039 kPa to less than 0.01 kPa.

In this connection, it is particularly advantageous to stop the first heat treatment step before the cement of the coating material is completely hydrated, so that carbonization can be carried out efficiently. The w/z-value (water/cement-value) of the cement prior to hydration may be from about 0.35 (for alumina cement) to about 0.4 (for portland cement). The first heat treatment may comprise an annealing step in an annealing furnace under a defined atmosphere. The first heat treatment may be performed at a temperature ranging from 40 ℃ or more to 300 ℃ or less. The defined atmosphere may be, for example, air with an elevated air humidity of at most 100%. The defined atmosphere may also have catalyst-or promoter molecules. Furthermore, it is particularly advantageous for the step of forming the moisture film to comprise cooling the wrapper, in particular to about room temperature (20 ℃), or applying water to the surface of the wrapper, under a defined atmosphere with a relative humidity or relative air humidity of greater than or equal to 60% to less than or equal to 80%, preferably substantially 65%. The second heat treatment may comprise an annealing step in an annealing furnace under a defined atmosphere. The second heat treatment may be performed at a temperature ranging from 95 ℃ or more to 300 ℃ or less. The relative humidity or relative air humidity of the defined atmosphere may be greater than or equal to 60% to less than or equal to 80%, preferably substantially 65%. The defined atmosphere may also include catalyst-or promoter molecules. This measure makes it possible in a simple manner to initiate or carry out a targeted carbonization of the cement on the surface of the coating material. On the one hand, a moisture film can form on the surface or on the capillary walls of the surface as a result of the hydration of the cement stopping (i.e. incomplete) in the first heat treatment and subsequent cooling to about room temperature under a defined humidity or air humidity. In a subsequent second heat treatment at a defined carbon dioxide content, carbonization takes place from the outside to the inside on the surface, wherein at the same time a part of the excess water of the cement or from the cement is allowed to evaporate. As a result, the cement slowly loses excess pore water ("dries out") on the surface and the cement structure becomes denser, preventing further penetration of moisture and gases by means of this "protected area". At the same time, the remaining pore solution becomes less alkaline. The maximum carbonization rate is achieved at a relative air humidity of greater than or equal to 60% to less than or equal to 80%.

It is also advantageous if the cement mass comprises, in particular consists of, aluminous cement. Alumina cement (abbreviated CAC) is in accordance with european regulations in DIN EN 14647. Alumina cement is mainly composed of monocalcium aluminate (CaO x Al2O 3).

The alumina cement may, for example, have the following composition:

-Al2O 3: greater than or equal to 67.8% by weight

-CaO: less than or equal to 31.0% by weight

-SiO 2: less than or equal to 0.8% by weight

-Fe2O 3: less than or equal to 0.4 wt%.

Aluminous cements have a2 to 3 times greater depth of carbonation compared to, for example, portland cement, because no ca (oh)2 is formed during hydration. Because of the desire and the targeted carbonization of the cement, the carbonization can take place or be carried out more quickly, more easily and more efficiently on the surface of the coating material by using aluminous cement.

It is also advantageous if the component and/or the further element has a metal region on the contact surface with the coating material, wherein the metal region is free of metals which are substantially not resistant to corrosion in environments or solutions having a pH value of greater than or equal to 7 to less than or equal to 9. That is, the metal region has only a metal that is substantially resistant to corrosion in an environment or solution having a pH of greater than or equal to 7 to less than or equal to 9, or the metal region has only a metal that is substantially resistant to corrosion in an environment or solution having a neutral to slightly alkaline pH. It is advantageous for the component and/or the further element to have a metal region on the contact surface with the packaging material, wherein the metal region has only one metal selected from the group consisting of: copper (Cu), copper alloys, copper tin alloys (CuSn alloys) and/or copper nickel alloys (CuNi alloys). It is particularly advantageous for this purpose if the contact surface is the entire contact surface between the component and the packaging material and between the further element and the packaging material. That is, all metal regions having an interface with the coating material are free of metals that are substantially non-corrosion resistant in environments having a pH greater than or equal to 7 to less than or equal to 9, such as metals selected from the group consisting of: copper, copper alloys, copper tin alloys and/or copper nickel alloys. In this connection, a metallic region is a region having or consisting of at least one metal. However, the metal regions may also have other non-metals that are not susceptible to corrosion. Since the pH value is reduced to a neutral to weakly alkaline value by carbonization, corrosion of all the fragile metals in the coating material can be prevented by this measure, so that the functional performance of the electrical device or power electronics module can be ensured. Copper and copper alloys, such as copper-tin alloys and/or copper-nickel alloys, are good electrical conductors and have good corrosion resistance in neutral and alkaline environments or solutions.