KR102697962B1 - Plastic resin circuit board manufacturing method using electronic circuit plating process - Google Patents

Abstract

The present invention discloses a compact LED structure and a manufacturing method thereof, wherein a partition wall surrounding an LED light source is formed of a plastic resin equipped with an LED light source and has a structure that simultaneously implements a touch sensing function and a reflection function.

Description

Plastic resin circuit board manufacturing method using electronic circuit plating process {Plastic resin circuit board manufacturing method using electronic circuit plating process}

The present invention relates to a method for manufacturing a plastic resin circuit board using an electronic circuit plating method and a plastic resin circuit board completed by the manufacturing method.

IME (In-mold electronics) technology is a relatively new technology that implements 3D shapes and functions by integrating printed conductive ink and in-mold decoration techniques. In the automotive field, it was first commercialized by Ford in an overhead console in 2012, and has since made rapid progress and is currently expanding into home appliances, medical equipment, consumer electronics, portable electronics, defense, and aviation.

IME technology usually consists of the following steps: 1) printing decoration, touch control parts or antennas on a plastic film; 2) surface mounting various electronic parts on the film; 3) thermoforming the film into a 3D shape; and 4) integrating the 3D film with a plastic resin through insert molding. The finished product manufactured in this way can be installed as an attractive exterior film on, for example, a dashboard or door trim in the automobile industry, and the car door can be opened or the window raised or lowered by touching the film with an operation similar to the touch or push operation of a smartphone screen. IME products can provide most of the electrical and electronic functions required for automobiles, and have various advantages such as not requiring mechanical parts such as buttons, knobs, links, shafts or motors, saving space, and providing exterior parts with excellent design.

Looking at prior patents related to IME, Korean Patent Publication No. 10-2016-0094936 discloses the content of creating a film, forming a conductor and graphics on the film, attaching electronic components on the film, and then injection molding it to form a three-dimensional shape. Korean Patent Publication No. 10-2017-0130395 discloses the content of screen-printing a conductor on a substrate, mounting electronic components, and then injection molding it into a three-dimensional shape. US Patent Publication No. 2018-0213651 discloses a process of forming a conductive circuit on a film, mounting electronic components, and thermoforming the film to create a three-dimensional structure. These patents have the limitation that they disclose general content of mounting electronic circuit patterns and electronic components on a single film and forming the film.

The inventors, taking into consideration the above prior art and patents, proposed an IME structure in Patent Application No. 10-2020-0174369 filed on December 14, 2020, including a film having a design formed thereon, a first plastic resin positioned below the film, and a second plastic resin positioned below the first plastic resin, wherein an electronic circuit is formed on the upper surface or both surfaces of the second plastic resin by a plating method and an electronic component is mounted thereon, thereby integrating the film, the first plastic resin, and the second plastic resin having the electronic circuit and the electronic component formed thereon.

Furthermore, the inventors have embarked on the development of a technology in which a multi-IME structure has a lighting function. And, as a structure that performs such a lighting (light-emitting) function and a manufacturing method thereof, the technology disclosed and described in Patent Application No. 10-2021-0094326 on July 19, 2021 has been proposed. FIG. 6 of the above patent application shows that an LED element (L) arranged between light guides (200) on the upper surface of a second plastic resin is surrounded by a sealing material (50) to form a capsule structure. Also, FIG. 7 shows that an LED element (L) arranged between light guides (200) on the upper surface of a second plastic resin is surrounded by a lens (60) to form a capsule structure. This capsule structure has the advantage of protecting components including the LED element (L) from heat or pressure and imparting a light diffusion function.

The present application has been made to further improve and extend the above patent application while maintaining the advantages of a multi-IME structure and providing a touch sensing function.

Therefore, the present invention aims to provide a strong and durable IME structure that can be widely applied to automobiles and home appliances, and in particular, a plastic resin using an electronic circuit plating method that can efficiently guide light emitted from an LED element and perform a touch function, and a method for manufacturing the same.

In order to achieve the above-described object, the present invention provides a plastic resin having an electronic circuit formed thereon, wherein the electronic circuit is formed on an upper surface, a lower surface, or both surfaces of the plastic resin, the resin providing a receiving portion in which an LED element is placed, and a partition wall adjacent to the receiving portion and surrounding the receiving portion and convex upward, wherein a touch electrode for detecting a touch that presses the plastic resin and a reflective member for reflecting light emitted from the LED element are formed on the partition wall.

The above-mentioned bulkhead may include a first inclined portion that slopes downward toward the LED element, a ridge that is integrally formed and extended from one end of the first inclined portion, and a second inclined portion that slopes gently downward from one end of the ridge in a direction opposite to the first inclined portion.

The above reflective member can be formed at least in the first slope.

The above reflective member may be included in the touch electrode.

In addition, the present invention provides a process for manufacturing a plastic resin having an electronic circuit formed therein, the process comprising: a step of injection-molding a plastic resin including an upwardly convex partition wall; a step of etching a portion of the plastic resin where an electronic circuit is to be arranged by laser etching; a step of forming an electronic circuit in the etched portion, the step including a step of forming a touch electrode that detects a touch that presses the plastic resin and a reflective member that reflects light on the partition wall, the step being performed by a plating process; and a step including a step of mounting an electronic component.

The step of mounting the above electronic component includes joining by soldering, and the soldering may be any one of reflow soldering, wire soldering, selective soldering, wave soldering, laser spot soldering, laser wire soldering, and laser-jet soldering.

In addition, the present invention provides an IME structure, wherein the IME structure includes: a lower plastic resin made of the above plastic resin; and an upper plastic resin mounted from above to cover an LED element of the lower plastic resin and combined with the lower plastic resin, wherein an inner surface is formed on a lower surface of the upper plastic resin to provide a space for accommodating the LED element, a touch portion that comes into contact with the lower surface of the upper plastic resin is formed on the partition wall, and a touch electrode is formed on at least a portion of the touch portion.

The above lower plastic may be equipped with a connector for power supply.

The present invention provides an improved IME structure that minimizes restrictions on the shape of a product by implementing an electronic circuit on a plastic resin surface by applying a plating method, is sturdy, has good bonding strength, and is durable, and can guide and adjust light when the electronic component is an LED light source, thereby realizing various light patterns.

According to the present invention, a part in which a touch electrode and a reflective member are formed in a plastic resin is provided to accurately sense a touch caused by external pressure and to improve the lighting intensity by reflecting light emitted from an LED light source.

According to the present invention, since a touch portion and a reflective portion can be formed simultaneously in the same structure, it is possible to produce a plastic resin having an economical space utilization and a compact structure.

Figure 1 is a cross-sectional view showing components of the IME structure of the present invention before assembly;
Fig. 2 is a cross-sectional view after assembly of Fig. 1;
Figure 3 is an enlarged view centered on a bulkhead forming a characteristic of the present invention;
FIG. 4 is an enlarged view of another embodiment of a bulkhead forming a feature of the present invention;
FIG. 5 is a drawing illustrating a method for manufacturing a second plastic resin and related parts of the present invention;
Figure 6 is a drawing of a member including an LED light source as shown in the applicant's prior application; and
Figure 7 is another drawing of a member including an LED light source as shown in the applicant's prior application.

Each embodiment according to the present invention is only one example to help understanding of the present invention, and the present invention is not limited to these embodiments. The present invention can be configured by a combination of at least one or more of the individual configurations and individual functions included in each embodiment.

Fig. 1 is a cross-sectional view showing components of the IME structure (1) of the present invention before assembly, and Fig. 2 is a cross-sectional view after assembly. The IME structure (1) can be applied to any field, such as automobiles, home appliances, and mobile phones, but the following description mainly assumes automobiles.

The IME structure (1) includes, from the top, a light-transmitting shielding layer (2), a first plastic resin (4) positioned below the light-transmitting shielding layer (2), and a second plastic resin (6) positioned below the first plastic resin (4). An electronic circuit (8) and an electronic component (10) are formed on an upper surface (6a) and/or a lower surface (6b) of the second plastic resin (6). The IME structure (1) is manufactured such that the light-transmitting shielding layer (2), the first plastic resin (4), the electronic circuit (8), and the electronic component (10) are formed integrally with the second plastic resin (6).

The IME structure (1) of the present invention is based on a lighting function, and therefore, the electronic element (10) is described as an LED element (L). However, it is not limited to an LED element (L) as long as it performs a lighting or light-emitting function, and various light-emitting elements can be used.

The light-transmitting shielding layer (2) is exemplified as having an overall disk shape with a convex curve in the center and flat surfaces on both sides, but is not limited thereto. The light-transmitting shielding layer (2) is formed with a light-transmitting portion that allows light to pass through and a shielding portion that does not allow light to pass through. Light from the LED element (L) is emitted through the light-transmitting portion.

The light-shielding layer (2) can be made of a film or sheet, but any material can be used as long as it provides a light-shielding function. Various materials such as PC, PMMA, PET, and TPU can be applied as film materials. In the case of sheets, natural leather, artificial leather, natural wood, or fabric can be applied.

The upper surface (4a) of the first plastic resin (4) has the same shape as the light-transmitting shielding layer (2) so as to be aligned with the lower surface of the light-transmitting shielding layer (2). However, an inner surface (42) is formed at a higher position than other parts on the lower surface (4b) so as to provide a space (S) for accommodating an LED element (L). The thickness of the first plastic resin (4) on which the inner surface (42) is formed is thinner than other parts. Any type of resin, such as PC, acrylic, ABS, AES, PMMA, PI, or PPA, may be appropriately used, and is not limited thereto. The first plastic resin (4) is made of a transparent material for external lighting.

The second plastic resin (6) has a shape opposite to the first plastic resin (4), but is not limited thereto. The second plastic resin (6) may be made of the same material as the first plastic resin (4), but does not necessarily have to be a transparent material, and may be made of a material that is more solid than the first plastic resin (4).

The second plastic resin (6) of the present invention has a shape having a flat portion and an uneven portion. An LED element (L) is placed in a relatively flat receiving portion (16), and a partition wall (60) having a convex shape is surrounded around the receiving portion (16). An electronic circuit (8) is formed on the upper surface (6a) and the lower surface (6b) of the second plastic resin (6). However, the electronic circuit (8) can be formed on only one of the upper surface (6a) or the lower surface (6b).

As can be seen in Fig. 2, when the first and second plastic resins (4, 6) are combined, an empty space (S) is provided between the inner surface (42), the receiving portion (16), and the partition wall (60) to surround the LED element (L). The first and second plastic resins (4, 6) are tightly combined without a gap in the portion excluding the space (S). The side edges of the inner surface (42) are manufactured to match the shape of the outer portion of the partition wall (60), so that the partition wall (60) is provided with a touch portion (T) that comes into contact with the inner surface (42). When the touch portion (T) is pressed, the electronic circuit (8) is energized so that power can be supplied to the LED element (L). When the touch portion (T) is pressed once more, the power supply to the LED element (L) can be cut off. Alternatively, the color of the light source can be changed by operating the touch portion (T). For this purpose, a touch electrode (100a) is formed on the touch portion (T) of the present invention. In a broad sense, the touch electrode (100a) is a member included in the electronic circuit (8). A touch-sensitive sensor such as a piezoelectric sensor may be further arranged on the upper surface (6a).

A connector (90) for supplying power to the LED element (L) is installed on the lower surface (6b) of the second plastic resin (6). One end of an electronic circuit (8) is inserted into the terminal portion (90) for current conduction. In the case where the electronic circuit (8) is formed only on the upper surface of the second plastic resin (6), a through hole penetrating the thickness of the second plastic resin (6) is formed, and one end of the electronic circuit (8) is passed through the through hole to be connected to the connector (90). For this purpose, it is preferable to use a plating process as described below.

Next, the bulkhead (60) that constitutes the feature of the present invention will be described with reference to FIG. 3.

The partition wall (60) of the present invention is implemented in the second plastic resin (6). The partition wall (60) includes a first inclined portion (64) that slopes gently downward toward the LED element (L), a relatively flat ridge (62) that is integrally formed and extended from one end of the first inclined portion (64), and a second inclined portion (66) that slopes gently downward in the opposite direction to the first inclined portion (64) from one end of the ridge (62). The first and second inclined portions (64, 66) are symmetrical with respect to the ridge (62), but are not limited thereto. The first and second inclined portions (64, 66) may include not only an inclined surface but also a flat surface, and the ridge (62) may also be formed as an inclined surface other than a flat surface except for a tip portion of the top.

As illustrated in FIG. 2, the touch portion (T) exists over most of the floor (62) among the bulkhead (60), and since the first inclined surface (64) provides a space (S), it does not provide the touch portion (T), but the touch portion (T) can be formed in some parts adjacent to the floor (62).

In the present invention, a touch electrode (100a) and a reflective member (100b) are formed on the upper surface of a bulkhead (60).

The touch electrode (100a) is a component corresponding to the electronic circuit (8), but for the sake of understanding the present invention, a separate component number is given to distinguish it from the electronic circuit (8). The areas of the touch electrode (100a) and the touch portion (T) do not necessarily have to coincide, but it is preferable that it be formed to include most of the touch portion (T). However, if it is an area that can be pressed and contacted by a user's hand or an electronic tool, the installation area may be reduced, such as by forming it mainly on the floor (62). In Fig. 3, it is assumed that the touch electrode (100a) is formed on most of the upper surface of the partition wall (60).

The reflective member (100b) is formed to reflect light from the LED element (L) to emit light into the space (S), prevent light leakage, and concentrate the light forward (upper surface) to increase the lighting intensity. The reflective member (100b) may be made of materials such as TiO ₂ , CaCO ₃ , BaSO ₄ , or may be made of transparent PET, white PET, or Ag sheet. When the reflective member (100b) contains pigment, it is appropriate to use white pigment to increase reflectivity. The reflective member (100b) is formed to cover at least the first inclined portion (64).

The touch electrode (100a) and the reflective member (100b) can be formed in various ways; for example, the touch electrode (100a) can be formed over most of the upper surface of the partition wall (6), and the reflective member (100b) can also be formed integrally in the same area as the touch electrode (100a). In this case, the reflective member (100b) can be formed on the touch electrode (100a) as a separate coating layer. FIG. 4 illustrates an example in which the reflective member (100b) is applied as a coating layer on the touch electrode (100a).

Alternatively, the touch electrode (100a) may be manufactured by mixing a metallic reflective member into the material forming the touch electrode (100a). In this case, the touch electrode (100a) will be a conductive electrode including a reflective member (100b). In this way, if the touch electrode (100a) includes the reflective member (100b), only a plating process is required and there is no need to form a separate coating layer, so the manufacturing process is very simple (Fig. 3).

The reflective member (100b) can also be formed as a separate coating layer only on the first slope (64) or by including it in the touch electrode (100a) of this part.

The structural feature of the present invention is that the second plastic resin (6) has a configuration in which a convex partition (6) provides a touch sensing area such as a touch portion (T) and at the same time reflects light from an LED element (L), thereby saving space overall and promoting compactness of the IME structure (1). Within the scope of this technical concept, the size and position of the touch electrode (100a) and the reflective member (100b) can be freely changed.

Referring to the following Figure 5, a method for manufacturing the second plastic resin (6) and related parts of the present invention will be described.

First, the second plastic resin (6) including the bulkhead (60) is injection-molded into a predetermined shape.

Next, the part where the electronic circuit (8) is to be placed is etched using laser etching in the second plastic resin (6).

Next, an electronic circuit (8) is formed on the etched portion. The electronic circuit (8) includes a touch electrode (100a). The touch electrode (100a) and the reflective member (100b) are formed on the partition wall (60). It is preferable that the process utilize a plating process. For example, in the process of manufacturing the touch electrode (100a), other parts of the electronic circuit (8) are masked, the portion where the touch electrode (100a) is to be formed is exposed, and the circuit pattern material and the reflective material are plated on this portion.

Next, the electronic component, the LED component (L), is mounted.

The mounting operation involves joining by soldering, and the soldering can be appropriately selected from reflow soldering, wire soldering, selective soldering, wave soldering, laser spot soldering, laser wire soldering, and laser-jet soldering.
Alternatively, thermal or infrared curing using an electrically conductive adhesive containing silver (Ag) paste is also possible.

Next, a connector (90) is mounted and connected to the lower surface of the second plastic resin (6).

The second plastic resin (6) completed in this manner is mechanically bonded or injection-molded with the first plastic resin (4) to form an IME structure (1).

It can be understood that in the present invention, the IME structure (1) is particularly characterized by the second plastic resin (6). As long as the second plastic resin (6) is used, either the first plastic resin (4) or the light-transmitting shielding layer (2) can be freely and appropriately selected.

Although the embodiments of the present invention have been described above, they do not limit the present invention, and various modifications and variations are possible for the present invention. It is obvious that the scope of the rights of the present invention extends to a scope identical or equivalent to the claims described below.

Claims (8)

A plastic resin having an electronic circuit formed thereon, wherein the electronic circuit is formed on the upper surface, lower surface, or both surfaces of the plastic resin, wherein the resin provides a receiving portion in which an LED element is placed, and a partition wall adjacent to the receiving portion and surrounding the receiving portion and convex upward, and wherein a touch electrode for detecting a touch that presses the plastic resin and a reflective member for reflecting light emitted from the LED element are formed on the partition wall. In paragraph 1,
The above bulkhead comprises a plastic resin, which comprises a first inclined portion that slopes downward toward the LED element, a ridge that is formed integrally and extended from one end of the first inclined portion, and a second inclined portion that slopes downward in a direction opposite to the first inclined portion from one end of the ridge. In the second paragraph,
The above reflective member is formed of a plastic resin at least in the first inclined portion. In the third paragraph,
The above reflective member is a plastic resin included in the touch electrode. A process for manufacturing a plastic resin having an electronic circuit formed therein, said process comprising:
A step of injection molding a plastic resin including a receiving portion in which a light source is to be placed and a baffle body having an upward convex shape surrounding the receiving portion;
A step of etching by laser the part where the electronic circuit is to be placed in the plastic resin;
A step of forming an electronic circuit in an etched portion, the step including a step of forming a touch electrode that detects a touch that presses a plastic resin and a reflective member that reflects light in a barrier wall, the step being a step performed by a plating process; and
A process including the step of mounting electronic components. In paragraph 5,
The step of mounting the above electronic component includes joining by soldering, and the soldering is one of reflow soldering, wire soldering, selective soldering, wave soldering, laser spot soldering, laser wire soldering, and laser-jet soldering. As an IME structure, the above IME structure is:
A lower plastic resin comprising a plastic resin according to any one of claims 1 to 4; and
An IME structure comprising an upper plastic resin mounted from above to cover an LED element of the lower plastic resin and bonded to the lower plastic resin, an inner surface formed on a lower surface of the upper plastic resin to provide a space for accommodating the LED element, a touch portion formed on the partition wall to come into contact with the lower surface of the upper plastic resin, and the touch electrode formed on at least a portion of the touch portion. In Article 7,
The IME structure has a connector for power supply mounted on the lower plastic part.