CN115956099A

CN115956099A - Tackified composite, method of preparing tackified composite, electrical device, method of manufacturing electrical device

Info

Publication number: CN115956099A
Application number: CN202180051297.2A
Authority: CN
Inventors: T·科勒; E·赫斯; K·罗斯
Original assignee: Fraunhofer Gesellschaft zur Forderung der Angewandten Forschung eV; Robert Bosch GmbH
Current assignee: Fraunhofer Gesellschaft zur Forderung der Angewandten Forschung eV; Robert Bosch GmbH
Priority date: 2020-08-21
Filing date: 2021-08-20
Publication date: 2023-04-11
Also published as: EP4200371A1; KR20230051575A; WO2022038271A1; DE102020210680A1

Abstract

The present invention relates to tackified composites. It is provided that the tackified composite comprises at least one inorganic-organic hybrid polymer and at least one epoxy-polyurethane.

Description

Tackified composite, method of preparing tackified composite, electrical device, method of manufacturing electrical device

The present invention relates to tackified composites.

The invention also relates to a method for preparing the tackified composite.

Furthermore, the invention relates to an electrical device having a coating comprising such a tackified composite.

Furthermore, the invention relates to a method of manufacturing such an electrical device.

Prior Art

Electronic components are typically encapsulated with a castable potting compound. The adhesion of the encapsulating compound to the electrical component is advantageous here for the life of the component or of an electrical device containing the component. Here, an encapsulating material made of a silicone material or an epoxy resin material is generally used. In these cases, sufficient adhesion of the encapsulating material to the electrical component usually results. It is also known to use ceramic materials for encapsulating materials. For example, publication DE 10 2015 223 466 A1 discloses an electrical device having an electrical element partially encapsulated by a ceramic encapsulation material. However, when a ceramic potting material is used, adhesion to electronic components is generally lower than in the case of a potting material made of a silicone material or an epoxy material.

Furthermore, coatings of inorganic-organic hybrid polymers are known in the prior art. For example, patent document AU 2006 274 207 B2 discloses in this respect plastic bottles coated with inorganic-organic hybrid polymers. Such hybrid inorganic-organic polymers are also known as hetero poly (organo) siloxanes and are sold, for example, under the name "Ormocer". As the hybrid polymer, the inorganic-organic hybrid polymer is composed of or composed of a plurality of monomers different from each other.

DISCLOSURE OF THE INVENTION

The adhesion-promoting composite material according to the invention having the features of claim 1 is particularly suitable as an adhesion-promoting layer for improving the adhesion of ceramic encapsulating compounds to electrical components. According to the invention, the adhesive-bonding composite material comprises at least one inorganic-organic hybrid polymer and at least one epoxy-polyurethane. Due to the composition according to the invention, the tackified composite adheres particularly well to polar surfaces, such as glass, ceramic or metal surfaces. In particular, even a reactive bonding of the tackified composite to such surfaces is achieved. Thus, a good adhesion effect on the ceramic encapsulating material and the metal component of the electronic component is achieved. However, the tackified composite according to the present invention is also advantageously suitable as a tackifier for other applications, i.e. for bonding other elements to each other. In addition, the tackified composite according to the present invention may be used as a paint, coating, or other coating. Good adhesion effects or reactive bonding are provided in particular by the silanol groups of the inorganic-organic hybrid polymers. Furthermore, the tackified composite according to the present invention has a substantially constant adhesive effect at temperatures up to 250 ℃. The adhesion-promoting composite preferably comprises Sika Primer-3N epoxy-polyurethane as epoxy-polyurethane. In particular, the tackified composite comprises at least one solvent in addition to the inorganic-organic hybrid polymer and the epoxy-polyurethane. For example, the tackified composite is a solution of an inorganic-organic hybrid polymer and an epoxy-polyurethane in at least one solvent. Such solutions can be easily applied by spraying, printing or dipping. After application, at least a portion of the solvent evaporates or evaporates, thereby increasing the viscosity of the adhered composite. The tackified composite then exists, for example, as a gel, whereby it has a gel-like consistency, or as a solid. The mass of the inorganic-organic hybrid polymer preferably corresponds to a mass proportion of 25% to 40%, based on the total mass of solids in the tackified composite. The mass of the inorganic-organic hybrid polymer preferably corresponds to a mass proportion of 32% to 38%, particularly preferably a mass proportion of 35%. The mass of the epoxy-polyurethane preferably corresponds to a mass proportion of 45% to 70%, based on the total mass of the solids in the tackified composite. The mass of the epoxy-polyurethane preferably corresponds to a mass proportion of 52% to 62%, particularly preferably a mass proportion of 57%. Solids are understood here to be substances which remain as evaporation residues when the tackified composite is heated, for example, to 200 ℃ for 1 hour.

According to a preferred embodiment, the adhesive-bonding composite contains at least one bisphenol-based epoxy resin. Advantageous mixtures of epoxy-polyurethanes with inorganic-organic hybrid polymers are achieved in the preparation of tackified composites by means of bisphenol-based epoxy resins. In particular, the chemical compounds of epoxy-polyurethane and inorganic-organic hybrid polymers are formed here by bisphenol-based epoxy resins. The mass of the bisphenol-based epoxy resin preferably corresponds to a mass proportion of 6 to 11%, based on the total mass of the solids in the tackified composite. Preferably, the mass of the bisphenol-based epoxy resin corresponds to a mass proportion of 8% to 9%, particularly preferably of 8.5%.

Preferably, the inorganic-organic hybrid polymer has a metal alkoxide monomer. Thus, inorganic-organic hybrid polymers are made from different monomers, at least one of which is a metal alkoxide monomer. The high strength of the tackifying composite material is realized by constructing the metal alkoxide monomer in the inorganic-organic hybrid polymer. The metal alkoxide monomer is a main group or subgroup metal alkoxide monomer. Preferably, the metal of the metal alkoxide monomer is titanium, aluminum or zirconium. Particularly preferably, the metal alkoxide monomer is Al (OBu) ₃ An EAA. The molar amount of the metal alkoxide monomer preferably corresponds to a molar amount proportion of 15% to 25%, based on the total molar amount of the monomers used to prepare the inorganic-organic hybrid polymer. Particularly preferably, the molar amount of the metal alkoxide monomer corresponds to a molar amount ratio of 20%.

Preferably, the inorganic-organic hybrid polymer has an epoxy silane monomer. The inorganic-organic hybrid polymer is thus made of different monomers, at least one of which is an epoxy silane monomer. Inorganic-organic hybrid polymers can be easily cured at low temperature or UV radiation by epoxy silane monomers. Particularly preferably, the epoxysilane monomer is 3-Glycidoxypropyltrimethoxysilane (GLYMO). The molar amount of the epoxy silane monomer preferably corresponds to a molar amount proportion of 40 to 50%, based on the total molar amount of the monomers used for preparing the inorganic-organic hybrid polymer. Particularly preferably, the molar amount of the epoxysilane monomer corresponds to a molar amount ratio of 45%.

According to a preferred embodiment, the hybrid inorganic-organic polymer has alkylsilane monomers. The inorganic-organic hybrid polymers are thus made from different monomers, at least one of which is an alkylsilane monomer. By means of the alkylsilane monomers, the desired properties of the tackified composite in terms of desired chemical bonding and desired adhesion effect can be provided. Particularly preferably, the alkylsilane monomer is Propyltrimethoxysilane (PTMO). The molar amount of alkylsilane monomer preferably corresponds to a molar amount proportion of from 25% to 35%, based on the total molar amount of monomers used for preparing the inorganic-organic hybrid polymer. Particularly preferably, the molar amount of alkylsilane monomer corresponds to a molar amount ratio of 30%.

According to a preferred embodiment, the hybrid inorganic-organic polymer has aminoalkyl silane monomers. The inorganic-organic hybrid polymer is thus made from different monomers, at least one of which is an aminoalkylsilane monomer. The desired properties of the tackified composite in terms of desired chemical bonding and desired adhesion effects may also be provided by the aminoalkylsilane monomers. Particularly preferably, the aminoalkyl monomer is 3-Aminopropyltriethoxysilane (AMEO). The molar amount of aminoalkyl monomer preferably corresponds to a molar amount proportion of 3 to 8%, based on the total molar amount of monomers used to prepare the inorganic-organic hybrid polymer. Particularly preferably, the molar amount of aminoalkyl monomer corresponds to a molar weight proportion of 5%.

The method according to the invention for producing a tackified composite is characterized by the features of claim 7 by providing an inorganic-organic hybrid polymer and an epoxy-polyurethane and mixing the epoxy-polyurethane with the inorganic-organic hybrid polymer. This also results in the already mentioned advantages. Further preferred features and combinations of features result from what has been described above and from the claims.

According to a preferred embodiment arrangement, the inorganic-organic hybrid polymer is provided by sol-gel synthesis from different monomers. Thus, the different monomers are first dissolved or dispersed in a solvent, preferably water. Then, by sol-gel synthesis, an inorganic-organic hybrid polymer is obtained as a gel or as a substance with a gel-like consistency.

Preferably, the inorganic-organic hybrid polymer is mixed with a bisphenol-based epoxy resin, and then the inorganic-organic hybrid polymer is mixed with the epoxy-polyurethane in step c). As already mentioned, the mixing of epoxy-polyurethanes with inorganic-organic hybrid polymers is improved by means of bisphenol-based epoxy resins.

According to a preferred embodiment, the inorganic-organic hybrid polymer is mixed with a protic organic solvent before being mixed with the bisphenol-based epoxy resin. By mixing the inorganic-organic hybrid polymer with a solvent, subsequent mixing with the bisphenol-based epoxy resin is simplified. When the inorganic-organic hybrid polymer is, for example, a gel, the viscosity of the inorganic-organic hybrid polymer is lowered by mixing with a solvent. Preference is given to using alcohols, particularly preferably 2-butoxyethanol, as protic organic solvents.

Preferably, a solution of the epoxy-polyurethane in an organic solvent is provided as the epoxy-polyurethane. The epoxy-polyurethane solution can be mixed particularly easily and homogeneously with the inorganic-organic hybrid polymer. Furthermore, the tackified composite is at least initially obtained as a solution at this time, and therefore the tackified composite can be easily applied. The organic solvent is particularly preferably ethyl acetate.

The electrical device according to the invention comprises an electrical element and by the features of claim 12 is characterized by a coating covering at least a section of the electrical element and comprising an adhesion promoting composite according to the invention. By means of this coating, the covered section is protected, thereby increasing the lifetime of the component or device. Further preferred features and combinations of features result from what has been described above and from the claims. The electrical component is, for example, an active electrical component or a passive electrical component, such as a transformer.

Preferably, the device comprises an encapsulating compound, in particular a ceramic encapsulating compound, which at least partially encapsulates the electrical component, such that the coating is arranged between the component and the encapsulating compound. Due to the advantageous adhesive effect of the adhesion-promoting composite of the coating, a strong adhesion of the encapsulating material on the component is achieved. In this regard, the coating forms an adhesion promoting layer.

The method according to the invention for producing an electrical device is characterized by the features of claim 14 in that an electrical element is provided and the adhesion-promoting composite according to the invention is applied to the element such that the adhesion-promoting composite covers at least one section of the element as a coating. This also results in the already mentioned advantages. Further preferred features and combinations of features result from what has been described above and from the claims. Preferably, the component is at least partially encapsulated by the encapsulating material, such that the coating is arranged between the component and the encapsulating material. The adhesion promoting composite is preferably first provided in the form of a solution and applied to the electrical component. The electrical component is then encapsulated with an encapsulating material, preferably after partial drying or drying of the adhesion-promoting composite.

According to a preferred embodiment arrangement, the tackified composite is applied to the element by spraying, printing or dip coating. This is advantageously possible due to its low viscosity if the tackified composite is present at least initially as a solution. By spraying, printing or dip coating, a uniform application of the tackified composite in a low layer thickness can be achieved.

The invention is explained in more detail below with reference to the drawings. Wherein

Figure 1 shows an electrical installation which is,

figure 2 shows a further electrical device which is,

figure 3 shows a method of manufacturing the electric device or the further electric device,

FIG. 4 shows different monomers of inorganic-organic hybrid polymers and

fig. 5 shows a part of the structure of an inorganic-organic hybrid polymer.

Fig. 1 shows an electrical device 1 in a schematic view. The electrical device 1 comprises an electrical element 2, which is an active electrical element 2. The electrical element 2 comprises a substrate 3, which is for example a DBC substrate 3 or an AMB substrate 3. A chip 4, which is, for example, a Si chip 4, a SiC chip 4 or a GaN chip 4, is arranged on the substrate 3. The conductor tracks, not shown, of the substrate 3 are electrically connected to the conductor tracks, not shown, of the chip 4 via the bonding wires 5 of the current element 2.

The electrical device 1 further comprises a ceramic potting compound 6, which encapsulates a section of the electrical element 2. In order to improve the adhesion of the ceramic potting compound 6 to the electrical component 2, the electrical device 1 comprises a coating 7 or an adhesion-promoting layer 7, which is arranged between the electrical component 2 and the potting compound 6. In the present case, the adhesion-promoting layer 7 is formed such that the encapsulating material 6 is separated from the electrical component 2 by the adhesion-promoting layer 7. Thus, there is no direct physical contact between the electrical component 2 and the encapsulating material 6.

Fig. 2 shows a further electrical device 11 in a schematic view. The further electrical device 11 comprises an electrical element 12 which is a passive electrical element 12, in this case a transformer 12. The electric element 12 includes a copper can 13 having a housing portion. In this receptacle, a transformer core 14 is arranged, which is wound by electrical conductors 15. The further electrical device 11 also comprises a ceramic potting compound 16, which encapsulates a section of the electrical component 12. In order to increase the adhesion of the encapsulating compound 16 to the electrical component 12, a coating 17 or adhesion-promoting layer 17 is also provided in the case of the further electrical device 11 shown in fig. 2, which is arranged between the electrical component 12 and the encapsulating compound 16.

In the following, an advantageous method of manufacturing the electric device 1 or the further electric device 11 is described with reference to fig. 3. Fig. 3 shows the method using a flow chart. Method steps S1 to S5 describe a method for producing a tackified composite for the adhesion-promoting

layer

7 or 17.

In a first step S1, an inorganic-organic hybrid polymer is provided by sol-gel synthesis. For this, various monomers, i.e., metal alkoxide monomer, epoxy silane monomer, alkyl silane monomer and amino alkyl silane monomer, are dissolved or dispersed in distilled water, and the solution or dispersion is stirred to obtain an inorganic-organic hybrid polymer as a gel. In the present case, the monomers 3-Glycidoxypropyltrimethoxysilane (GLYMO), propyltrimethoxysilane (PTMO), 3-Aminopropyltriethoxysilane (AMEO) and Al (OBu) shown in FIG. 4 ₃ EAA was used as the monomer. The masses and molar amounts of the monomers used are listed, for example, in the table below.

Components	Molar weight [ mol]	Molar mass [ g/mol ]]	Mass [ g ]]
				GLYMO	0.45	236.34	106.35
PTMO	0.3	164.28	49.28
				AMEO	0.05	221.37	11.07
Al(OBu)3EAA	0.2	376.47	75.3
				Distillation of H2O	2.8	18.02	50.46
Sum of			292.46

In a second step S2, the inorganic-organic hybrid polymer obtained in step S1 is mixed with a protic organic solvent. For example, 2-butoxy-ethanol is used as a solvent. In this case, 292.46g of the gel obtained in step S1 was mixed with 48.74g of 2-butoxyethanol.

In a third step S3, the inorganic-organic hybrid polymer is mixed with a bisphenol-based epoxy resin. For example, araldit GY 260, a bisphenol-based epoxy resin shown below, was used. In particular, crosslinking of inorganic-organic hybrid polymers is achieved by bisphenol-based epoxy resins.

In this case, 200g of the mixture obtained in step S2 was mixed with 34.29g of Araldit GY 260.

The structure of the inorganic-organic hybrid polymer thus obtained is shown in fig. 5. Here, the letter M denotes a metal ion of the metal alkoxide monomer. The letter R represents an alkyl or aminoalkyl group of an alkylsilane monomer or aminoalkylsilane monomer. As can be seen from fig. 5, the inorganic-organic hybrid polymer has a Si-O network obtained by a condensation reaction between different monomers. The wavy line W represents a chemical bond between Si atoms obtained by the reaction of the reactive group of the epoxy silane monomer with the reactive group of the bisphenol-based epoxy resin.

In a fourth step S4, the mixture obtained in step S3 is mixed with an organic solvent. For example, n-propanol is used. Preferably, the mixture is diluted by adding an organic solvent so that the mass proportion of solids in the mixture is 30%. In the present case, 17.54g of the mixture obtained in step S3 were mixed for this purpose with 12.46g of n-propanol.

In a fifth step S5, the mixture obtained in step S4 is mixed with a solution of epoxy-polyurethane in an organic solvent. Preferably, a 40% solution of Sika 3N epoxy-polyurethane in ethyl acetate is used. In the present case, 30g of the mixture obtained in step S4 are mixed with 30g of a 40% Sika 3N epoxy-polyurethane solution. By mixing the mixture obtained in step S4 with an epoxy-polyurethane solution, a tackified composite is prepared or provided as a solution.

In a sixth step S6, an electrical element is provided. If the electrical device 1 should be manufactured by this method, an element 2 is provided. However, if the further electrical device 11 should be manufactured, an element 12 is provided.

In a seventh step S7, an adhesion-promoting composite material present as a solution is applied to at least one section of the electrical element. For example, application is by spraying, printing or dipping.

In an eighth step S8, the applied tackified composite is dried or partially dried. Thereby increasing the viscosity of the tackified composite. In particular, the tackified composite exists as a gel after drying or partial drying. In particular, in step S8, the tackified composite is heated, for example to 100-140 ℃ for 1-10 minutes, for drying or partial drying. As an alternative to this, heating is eliminated so that the tackified composite is dried or partially dried by evaporation of the solvent. The tackified composite then forms a

coating

7 or 17 that covers at least a section of the element 2 or 12.

In a ninth step S9, a castable ceramic potting compound is provided.

In a tenth step S10, the electrical component 2 or 12 is encapsulated with the

ceramic encapsulating material

6 or 16 using a casting method, such that an adhesion-promoting composite material is arranged as an adhesion-promoting

layer

7 or 17 between the component 2 or 12 and the encapsulating

material

6 or 16. Thereby, the device 1 shown in fig. 1 or the device 11 shown in fig. 2 is finally obtained.

Claims

1. A tackified composite comprising

At least one inorganic-organic hybrid polymer and

at least one epoxy-polyurethane.

2. The tackified composite of claim 1, wherein the tackified composite comprises at least one bisphenol based epoxy resin.

3. Tackified composite according to any of the preceding claims, characterized in that the inorganic-organic hybrid polymer has a metal alkoxide monomer (Al (OBu) ₃ EAA)。

4. Tackified composite according to any of the preceding claims, characterized in that the inorganic-organic hybrid polymer has an epoxy silane monomer, in particular 3-Glycidoxypropyltrimethoxysilane (GLYMO).

5. Tackified composite according to any of the preceding claims, characterized in that the inorganic-organic hybrid polymer has alkylsilane monomers, in particular Propyltrimethoxysilane (PTMO).

6. Tackified composite according to any of the preceding claims, characterized in that the inorganic-organic hybrid polymer has aminoalkylsilane monomers, in particular 3-Aminopropyltriethoxysilane (AMEO).

7. A method of preparing a tackified composite, comprising the steps of:

a) An inorganic-organic hybrid polymer is provided,

b) There is provided an epoxy-polyurethane composition comprising an epoxy-polyurethane,

c) Epoxy-polyurethane is mixed with an inorganic-organic hybrid polymer.

8. The method according to claim 7, characterized in that the inorganic-organic hybrid polymer is provided by sol-gel synthesis from different monomers.

9. The method according to any one of claims 7 and 8, characterized in that the inorganic-organic hybrid polymer is mixed with a bisphenol-based epoxy resin and then mixed with an epoxy-polyurethane in step c).

10. Method according to claim 9, characterized in that the inorganic-organic hybrid polymer is mixed with a protic organic solvent, in particular 2-butoxyethanol, before being mixed with the bisphenol-based epoxy resin.

11. The method according to any one of claims 7 to 10, characterized in that a solution of epoxy-polyurethane in an organic solvent, in particular ethyl acetate, is provided as epoxy-polyurethane.

12. Electrical device with an electrical component (2, 12), characterized by a coating (7, 17) covering at least a section of the electrical component (2, 12) and comprising an adhesion promoting composite material according to any of claims 1 to 6.

13. An electric device according to claim 12, characterized in that an encapsulating material (6, 16), in particular a ceramic encapsulating material (6, 16), at least partly encapsulates the electric element (2, 12) such that the coating (7, 17) is arranged between the element (2, 12) and the encapsulating material (6, 16).

14. Method of manufacturing an electrical device, wherein an electrical element (2, 12) is provided, and wherein an adhesion promoting composite according to any of claims 1 to 6 is applied onto the electrical element (2, 12) such that the adhesion promoting composite covers at least a section of the element (2, 12) as a coating (7, 17).

15. Method according to claim 14, characterized in that the tackified composite is applied to the element (2, 12) by spraying, by printing or by dip coating.