Plastic splicing piece with convex pressure EMC (Electro Magnetic Compatibility) layer

Abstract

A method for providing an electrically conductive layer for a plastic housing, in particular a splice housing for an electromagnetically shielded cable harness, comprises the following steps: a) providing an electrically conductive film and a mold; b) inserting the film into a mould; c) injection molding a plastic into the mold such that the injected plastic is bonded to the conductive film.

Description

Technical Field

[0001] This invention relates to a method for providing a conductive layer on a plastic housing, and also to splice housings, cable harnesses, and vehicles. Background Technology

[0002] Electromagnetic interference (EMI) can cause significant disruption to electronic equipment and systems, especially when using plastic housings for cable harnesses, leading to malfunctions or performance degradation. To mitigate EMI, the housings of electronic components are typically made of conductive materials to shield them from external electromagnetic fields.

[0003] Traditional methods of providing electromagnetic shielding may involve applying a conductive coating or metal layer to the exterior of a plastic housing. However, these methods can be labor-intensive, costly, and prone to wear and degradation over time. Injecting conductive material directly into the plastic housing offers a more efficient and durable solution, combining the structural advantages of plastic with the conductivity required for effective electromagnetic interference shielding.

[0004] The downside is that existing methods typically involve multiple steps, including the post-molding application of the conductive coating, which can be time-consuming and may not provide a robust or durable solution. Furthermore, ensuring complete and uniform coverage of the conductive material on complex three-dimensional shapes using conventional techniques is challenging. Therefore, there is a need to improve the methods for manufacturing splice housings with electromagnetic interference shielding.

[0005] In view of the above, there is a need to improve the method of manufacturing splice housings with electromagnetic interference shielding. Therefore, the object of the present invention is to overcome some or all of the shortcomings of the prior art. Summary of the Invention

[0006] The above objectives are achieved at least in part by the subject matter of independent claim 1. Preferred embodiments are the subject matter of the dependent claims, and those skilled in the art will find hints of other suitable aspects of the invention within the overall disclosure of this application.

[0007] One aspect of the present invention relates to a method for providing a conductive layer for a plastic housing, particularly for a splice housing for electromagnetically shielded cable harnesses, comprising the steps of: a) providing a conductive film and a mold;

[0008] b) Insert the membrane into the mold; c) Inject plastic into the mold so that the injected plastic bonds with the conductive membrane.

[0009] This method can be used to create housings for high-performance automotive cable systems that require electromagnetic interference (EMI) shielding. By integrating a conductive film during the injection molding process, the resulting plastic housing is both robust and capable of shielding sensitive electronic components from EMI. This method simplifies production, reduces the need for post-processing steps such as applying a conductive coating, and ensures a strong bond between the plastic and the conductive layer, improving durability and performance.

[0010] The method can be improved by having a 3D profile in the mold, and by having the film conform to that profile during step c) due to the injected plastic.

[0011] This method can be used to produce complex-shaped housings for electronic devices. The mold is designed with intricate 3D contours to match the shape of the final product. As plastic is injected, a conductive film is pressed and molded to perfectly fit these contours. This ensures that the entire surface area of ​​the housing is covered by the conductive layer, providing consistent and effective electromagnetic shielding. The advantage of this method is its ability to create detailed and precise shapes without compromising the integrity of the conductive layer, resulting in higher quality and more reliable electronic housings.

[0012] A further improvement could be made by preforming the film to at least partially conform to the contour of the mold before step b).

[0013] This preforming step ensures the film already possesses the basic shape of the final product, thus reducing the risk of wrinkling or misalignment during the injection molding process. The main advantage of preforming the film is improved precision and consistency of the conductive layer in the final product, resulting in better electromagnetic shielding performance and a more aesthetically pleasing surface. Furthermore, this method reduces manufacturing time and costs by minimizing adjustments required during molding.

[0014] Further improvements could be made by using a label inside the mold.

[0015] This in-mold label not only provides the required conductivity but can also include other information, such as branding or functional graphics. The use of in-mold labels simplifies the manufacturing process by combining labeling and conductive layer application into a single step. This approach enhances the label's durability, ensuring it remains intact and functional throughout the product's lifecycle. Furthermore, it provides a high-quality finished appearance without requiring additional labeling or printing steps after molding.

[0016] Further improvements can be made by including aluminum in the membrane.

[0017] This aluminum-encapsulated membrane ensures effective electromagnetic shielding while minimizing the added weight to the plastic housing. This is beneficial for applications where weight reduction is critical. Furthermore, the durability and corrosion resistance of aluminum improve product lifespan and reliability. This method leverages the properties of aluminum to produce high-performance electromagnetic shielding housings that are both robust and lightweight.

[0018] Further improvements can be made by having a membrane thickness in the range of 0.1 mm to 5 mm, preferably in the range of 0.1 mm to 4 mm, more preferably in the range of 0.2 mm to 3 mm, and most preferably 0.35 mm.

[0019] For example, a specific thickness of 0.35 mm provides an optimal balance between flexibility and durability, ensuring the membrane conforms to the mold profile while maintaining its structural integrity and conductivity. Membranes within this thickness range ensure effective electromagnetic shielding without adding unnecessary bulk to the plastic housing. This precise thickness specification can improve performance and reliability in demanding applications, such as in electronic enclosures and automotive components where space and weight are critical factors.

[0020] Further improvements can be made by ensuring that, after step c), the ratio of the thickness of the plastic layer to the thickness of the conductive film is in the range of 1 to 10, preferably in the range of 3 to 7, and most preferably 5.

[0021] According to this method, after the plastic is injection molded and bonded to the aluminum conductive film, the thickness of the plastic layer is five times the thickness of the conductive film. This specific ratio ensures that the plastic housing provides sufficient mechanical strength and durability while maintaining effective electromagnetic shielding. A ratio of 5 strikes a balance between robust structural support and lightweight design. This optimized ratio contributes to achieving high performance and reliability in the final product, ensuring that it effectively meets both mechanical and shielding requirements.

[0022] Further improvements can be made by including a fixing device suitable for forming a shape with the plastic, preferably wherein the fixing device includes teeth.

[0023] This type of tooth can be designed to embed into the plastic during the injection molding process, creating a strong mechanical bond between the film and the plastic. This form-fit connection enhances adhesion between layers, prevents delamination, and ensures long-term durability. This method is useful in applications where the housing may be subjected to mechanical stress or thermal expansion, such as in the automotive environment. The tooth provides additional anchoring points, thereby improving the structural integrity and reliability of the final product.

[0024] Further improvements can be made to the membrane, including perforations.

[0025] This conductive film can have tiny perforations across its entire surface. These perforations allow injected plastic to flow through the film, creating a stronger bond between the plastic and the film as it cures. The perforations also enhance flexibility, making the film easier to adapt to complex mold shapes. This approach is advantageous for applications requiring highly durable and flexible conductive layers, such as in complex electronic housings or automotive parts. The perforations ensure strong adhesion, preventing the layer from delaminating under mechanical stress, thus improving the overall durability and performance of the product.

[0026] A further improvement could be made after step c), where the membrane completely covers the contour of the mold.

[0027] This conductive film can be designed to completely cover the 3D contours of the mold. Following the injection molding process, the film forms a continuous layer across the entire surface of the plastic housing. This ensures the entire housing benefits from the film's conductivity, providing comprehensive electromagnetic shielding. Furthermore, the complete coverage enhances the aesthetic appeal of the final product, providing a uniform surface without gaps or exposed plastic areas. This makes the product more reliable, visually appealing, and effectively meets both functional and design requirements.

[0028] Conversely, a further improvement can be made if the membrane does not completely cover the contour of the mold after step c).

[0029] In this method, the conductive film can be strategically placed to cover only specific areas of the mold outline. After the injection molding process, the film adheres to the designated portion of the plastic housing, leaving other areas uncovered. This method allows for targeted electromagnetic shielding, which is useful in applications where shielding is only required in certain areas, such as around critical electronic components. Furthermore, this method reduces material costs and weight due to the smaller amount of conductive film used. Selective coverage also provides design flexibility, allowing for the creation of housings with varying functional and aesthetic requirements.

[0030] Another embodiment of the present invention is a splicing housing for electromagnetically shielded cable harnesses, comprising two halves formed by the method described above.

[0031] This splice housing for electromagnetically shielded cable harnesses consists of two halves created using the method described above. For example, each half can be produced by injection molding plastic onto an aluminum conductive film. These halves are then joined together to enclose the cable splice, ensuring complete electromagnetic shielding. The use of an integrated conductive film during the molding process provides significant protection against electromagnetic interference, improving the reliability of the cable harness. Furthermore, the strong bond between the film and the plastic ensures long-lasting durability, making the splice housing suitable for harsh environments in automotive applications. This method allows for precise manufacturing of the splice housing, ensuring high-quality, effective electromagnetic interference shielding.

[0032] Another embodiment of the present invention is a cable harness that includes the above-described splicing housing.

[0033] This cable harness comprises a splice housing made of two halves created using a specified method. This splice housing provides comprehensive electromagnetic shielding for the cable harness, protecting the enclosed cables from external electromagnetic interference. The use of a conductive film ensures that the housing maintains its shielding effectiveness over time, even in harsh environments. This integration enhances the overall performance and reliability of the cable harness, making it ideal for applications requiring robust EMC. Furthermore, the precisely manufactured splice housing contributes to improved structural integrity and lifespan of the cable harness.

[0034] Another aspect of the invention is a vehicle, preferably an electric vehicle or a hybrid vehicle, which includes the aforementioned cable harness.

[0035] This wiring harness provides excellent electromagnetic shielding, protecting the vehicle's sensitive electronic systems from electromagnetic interference. By ensuring the reliable operation of the vehicle's electronics, this wiring harness improves overall performance and safety. Advanced shielding is beneficial in electric and hybrid vehicles, where electronic components are critical for efficient and effective operation. This integration supports the vehicle's durability and long-term functionality, contributing to higher quality and more reliable transportation solutions.

[0036] Another aspect of the present invention is a splicing housing for an electromagnetically shielded cable harness, the splicing housing comprising an outer shell made of injection-molded plastic and an inner conductive film bonded to the inner wall of the outer shell by an injection molding process.

[0037] This splice housing for electromagnetically shielded cable harnesses comprises an outer shell made of injection-molded plastic and an inner layer of conductive film. During the injection molding process, the conductive film is integrated and firmly bonded to the inner wall of the plastic shell. This design provides robust electromagnetic shielding by ensuring that the conductive film is firmly attached and covers the necessary areas. The plastic shell provides mechanical protection and structural support, while the conductive film prevents electromagnetic interference from affecting the enclosed cable. This construction method results in a durable and reliable splice housing that effectively combines mechanical strength with electromagnetic shielding. Attached Figure Description

[0038] Preferred embodiments of the present disclosure are disclosed below with reference to the accompanying drawings.

[0039] Figure 1 The image shows a three-dimensional view of a half of the splicing housing according to the present invention.

[0040] Figure 2 This illustrates the steps involved in injection molding a film.

[0041] Figure 3 : A photograph depicting a plastic part with a conductive film. Detailed Implementation

[0042] The invention will be described in detail below, with reference to the accompanying drawings for clarity. These descriptions are illustrative only and are not intended to limit the scope of the invention. Throughout the drawings and text, the same reference numerals denote the same parts. These illustrations may not reflect actual dimensions or scale; for better understanding and visual convenience, descriptions of dimensions, scales, and components may be added.

[0043] Figure 1 A half of the splicing housing according to the present invention is shown. The inner surface of the splicing housing half 1 is completely covered by a conductive film 10, which is adhered to the plastic housing 12 by injection molding. Those skilled in the art will understand that a second half of the corresponding shape can be joined to form a complete splicing housing.

[0044] The conductive film 10 completely covers the inner surface, thus ensuring complete electromagnetic shielding. During the injection molding process, the bonding of the film to the plastic housing 12 creates a robust and durable connection. This continuous integration of the conductive film improves the overall performance and reliability of the spliced ​​housing. This method simplifies manufacturing by combining film application and housing formation in a single step.

[0045] Figure 2 The steps of injection molding the film are shown. In step A), a pre-formed conductive film 20 is inserted into a mold 200. In step B), the mold 200 is closed, and molten plastic 202 is introduced into the mold via injection molding, thereby establishing a bond between the film 20 and the plastic 202. Step C) shows a demolded housing 22 with the conductive film 20 on its outer side.

[0046] This injection molding process ensures precise application and bonding of the conductive film. Step A: Inserting the pre-formed conductive film 20 into the mold 200 ensures the film is correctly positioned before injection molding. Step B: Closing the mold 200 and injecting molten plastic 202 allows the film 20 to bond to the plastic 202 as it solidifies, creating a robust, uniform layer. Step C: The demolded housing 22 reveals the conductive film 20 firmly attached to its exterior, providing effective electromagnetic shielding. This method offers several advantages, including enhanced durability of the bond between the film and the plastic, simplified manufacturing by combining film application and molding in a single step, and the ability to produce complex shapes with integrated electromagnetic shielding.

[0047] Figure 3 A plastic part with a conductive film is depicted. The plastic 32 has an adhered conductive film 30.

[0048] This figure illustrates the effectiveness of the bonding process. The plastic part 32 is uniformly covered by the conductive film 30, indicating strong adhesion between the two materials.

[0049] List of reference numerals

[0050] 1: Splicing component housing half

[0051] 10, 20, 30: Conductive film

[0052] 12,22: Plastic casing

[0053] 32: Plastic

[0054] 200: Mold

[0055] 202: Molten Plastic

Claims

1. A method for providing a conductive layer for a plastic housing, particularly for splicing housings of electromagnetically shielded cable harnesses, the method comprising the following steps: a) Provide conductive films and molds; b) Insert the membrane into the mold; c) Injecting plastic into the mold, such that the injected plastic bonds with the conductive film.

2. The method according to claim 1, characterized in that, The mold has a 3D profile, and the film conforms to the profile during step c) due to the injected plastic.

3. The method according to claim 1 or 2, characterized in that, Prior to step b), the membrane is pre-shaped to at least partially conform to the contour of the mold.

4. The method according to any one of the preceding claims, characterized in that, The film is an in-mold label.

5. The method according to any one of the preceding claims, characterized in that, The membrane comprises aluminum.

6. The method according to any one of the preceding claims, characterized in that, The thickness of the membrane is in the range of 0.1 mm to 5 mm, preferably in the range of 0.1 mm to 4 mm, more preferably in the range of 0.2 mm to 3 mm, and most preferably 0.35 mm.

7. The method according to any one of the preceding claims, Its features are, After step c), the ratio of the thickness of the plastic layer to the thickness of the conductive film is in the range of 1 to 10, preferably in the range of 3 to 7, and most preferably 5.

8. The method according to any one of the preceding claims, Its features are, The membrane includes a fastening device adapted to form a shape with the plastic, preferably wherein the fastening device includes teeth.

9. The method according to any one of the preceding claims, characterized in that, The membrane includes perforations.

10. The method according to any one of the preceding claims, characterized in that, After step c), the membrane completely covers the outline of the mold.

11. The method according to any one of claims 1 to 9, characterized in that, The membrane after step c) does not completely cover the outline of the mold.

12. A splicing housing for electromagnetically shielded cable harnesses, comprising two halves formed by the method according to claims 1 to 11.

13. A cable harness comprising a splicing housing according to claim 12.

14. A vehicle, preferably an electric vehicle or a hybrid vehicle, comprising the cable harness according to claim 13.

15. A splicing housing for an electromagnetically shielded cable harness, the splicing housing comprising an outer shell made of injection-molded plastic and an inner conductive film bonded to the inner wall of the outer shell by an injection molding process.

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