Overmolded PTC device with interdigitated structure

Abstract

The present application provides overmolded PTC devices with interdigitated structures. The overmolded PTC devices can include an interdigitated lead frame that can be disposed in a single layer and located at the center or middle of a monolithic PTC material layer that is molded over and around the interdigitated lead frame.

Description

Cross-references to related applications

[0001] This application claims priority to U.S. Provisional Application Serial No. 63 / 797,242 entitled “Overmolded PTC Device with Interdigitated Structure”, filed April 30, 2025, pursuant to 35 USC §119, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0002] This disclosure generally relates to PTC devices. More specifically, this disclosure relates to overmolded PTC devices having an interdigitated structure. Background Technology

[0003] Positive temperature coefficient (PTC) devices are known in the art. In PTC devices, the resistance increases with increasing temperature. Polymeric PTC (PPTC) devices are particularly suitable for use as temperature sensors, overcurrent protection devices, etc.

[0004] For example, known overcurrent protection devices comprise two metal foil electrode layers and a PPTC material layer laminated between them. The resistance of the PPTC material layer is controlled by the device thickness and the conductive particles and / or conductive fillers (e.g., carbon black, tungsten carbide, nickel, or any other conductive metal) loaded therein. However, the multilayer structure of such devices may not be ideal due to the increased size, manufacturing difficulties, and the inability to control where activation occurs within the PPTC material layer (e.g., center, sides, top, bottom).

[0005] Given the above, there is a continuous and ongoing demand for improved PPTC devices. Summary of the Invention

[0006] This brief overview is provided to present, in a simplified form, the selection of concepts further described in the detailed embodiments below. This brief overview is not intended to identify key or essential features of the claimed subject matter, nor is it intended to help determine the scope of the claimed subject matter.

[0007] In some embodiments, a device may include: a fork guide wire frame; and an integral PTC material layer molded on and around the fork guide wire frame.

[0008] In some embodiments, the fork guide wire frame may be located at the center of the monolithic PTC material layer.

[0009] In some embodiments, the PTC material may be a PPTC material.

[0010] In some embodiments, the PPTC material may include one or more of the following polymers: crystalline polymers, high-density polyethylene (HDPE), polyvinylidene fluoride (PVDF), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), ultra-high-density polyethylene, thermoplastic polyurethane (TPU), ethylene methyl acrylate (EMA), ethylene butyl acrylate (EBA), polypropylene (PP), ethylene tetrafluoroethylene (ETFE), and polyamide (nylon).

[0011] In some embodiments, the PPTC material may include one or more of the following conductive particles: carbon black, graphene, graphite powder, carbon nanotubes (CNTs), metals (including nickel, silver, copper, aluminum and / or silver-plated metals) and / or ceramic conductive fillers, including tungsten carbide, titanium carbide, titanium diboride, zirconium diboride, titanium nitride and / or zirconium nitride.

[0012] In some embodiments, the fork guide line frame can be disposed in a single layer.

[0013] In some embodiments, the device may include: a plurality of parallel circuit paths formed by alternating fingers of a fork-guide frame that can interlock with each other and with PTC material, wherein the fork-guide frame may be open circuit if the integral PTC material layer is not molded on and around the fork-guide frame.

[0014] In some embodiments, the fork guide frame may be copper or a copper alloy.

[0015] In some embodiments, the device may include one or more nodules on opposite sides of the alternating fingers of the fork guide wire frame.

[0016] In some embodiments, one or more nodules may be nickel.

[0017] In some embodiments, a method may include: providing a fork guide frame; and molding an integral PTC material layer on and around the fork guide frame.

[0018] In some embodiments, the method may include: initiating activation of the PTC material from the fork guide wire frame at the center of the monolithic PTC material layer.

[0019] In some embodiments, the PTC material may be a PPTC material.

[0020] In some embodiments, the PPTC material may include one or more of the following polymers: crystalline polymers, high-density polyethylene (HDPE), polyvinylidene fluoride (PVDF), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), ultra-high-density polyethylene, thermoplastic polyurethane (TPU), ethylene methyl acrylate (EMA), ethylene butyl acrylate (EBA), polypropylene (PP), ethylene tetrafluoroethylene (ETFE), and polyamide (nylon).

[0021] In some embodiments, the PPTC material may include one or more of the following conductive particles: carbon black, graphene, graphite powder, carbon nanotubes (CNTs), metals (including nickel, silver, copper, aluminum and / or silver-plated metals) and / or ceramic conductive fillers, including tungsten carbide, titanium carbide, titanium diboride, zirconium diboride, titanium nitride and / or zirconium nitride.

[0022] In some embodiments, the method may include: setting the fork guide line frame in a single layer.

[0023] In some embodiments, the method may include: forming a plurality of parallel circuit paths by alternating fingers of a fork-guide wire frame that are interlocked with each other and interlocked with PTC material, wherein the fork-guide wire frame may be open circuit if the integral PTC material layer is not molded on and around the fork-guide wire frame.

[0024] In some embodiments, the fork guide frame may be copper or a copper alloy.

[0025] In some embodiments, the method may include providing one or more nodules on opposite sides of the alternating fingers of the forked guide wire frame.

[0026] In some embodiments, one or more nodules may be nickel.

[0027] Other technical features will be apparent to those skilled in the art from the following figures, description and claims. Attached Figure Description

[0028] To facilitate identification of any discussion of a particular element or action, one or more of the most significant digits in the figure references refer to the figure references that first introduced that element.

[0029] Figure 1A This is a schematic diagram illustrating a fork guide line frame according to a disclosed embodiment.

[0030] Figure 1B This is a top view showing a fork guide line frame according to the disclosed embodiment.

[0031] Figure 2 This is a microscopic view showing the nodules of a fork guide wire frame according to the disclosed embodiment.

[0032] Figure 3A This is a perspective view showing a PTC device overmolded according to the disclosed embodiments.

[0033] Figure 3B This is a perspective view showing a PTC device overmolded according to the disclosed embodiments.

[0034] Figure 4 This is a flowchart illustrating a method according to the disclosed embodiments. Detailed Implementation

[0035] Exemplary embodiments of the overmolded PTC device according to the present disclosure will now be described more fully below with reference to the accompanying drawings. However, the overmolded PTC device may be implemented in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will convey certain exemplary aspects of the overmolded PTC device to those skilled in the art.

[0036] According to the disclosed embodiments, the overmolded PTC device may include a fork lead frame structure, which may be located at the center or middle of a monolithic conductive PTC compound layer, the conductive PTC compound being deposited onto the fork lead frame structure, for example, by injection molding, transfer molding, etc. Importantly, the fork lead frame structure can be disposed in a single layer, thereby eliminating the multilayer foil and electrodes found in known devices. However, in some embodiments, the fork lead frame structure may include a single lead frame or multiple lead frames, all disposed in a single layer.

[0037] Advantageously, the fork-lead frame structure disclosed herein can control the resistance of a molded PTC device by creating multiple paths of parallel circuits formed by alternating fingers of the fork-lead frame structure that are interlocked with each other and interlocked with the PTC material. In particular, the fork-lead frame structure can be designed and configured to have more or fewer parallel circuit paths to provide more or fewer paths for current to travel through the fork-lead frame structure, thereby reducing or increasing resistance as needed for a particular application.

[0038] As another advantage, the forked guide wire frame structure disclosed herein can also generate thermal wires at the center or middle of the PTC compound. In particular, the forked guide wire frame structure located at the center or middle of the monolithic PTC compound layer ensures that any activation of the PTC compound, including increases in temperature and resistance, originates at the center or middle of the monolithic PTC compound layer.

[0039] As another advantage, the overmolded PTC devices disclosed herein can have a small form factor, be highly integrated, and enable efficient ion transport.

[0040] Figure 1A This is a schematic diagram illustrating a fork guide wire frame 100a according to a disclosed embodiment. As seen, the fork guide wire frame 100a may include a first set of alternating fingers 102a facing and interlocking with a second set of interlocking alternating fingers 104a, having an open space or gap 106a therebetween. In some embodiments, the fork guide wire frame 100a may be disposed in a single layer, and in some embodiments, the fork guide wire frame 100a may be copper or a copper alloy.

[0041] Similar to Figure 1A , Figure 1BThis is a top view illustrating a fork guide wire frame 100b according to a disclosed embodiment. As seen, the fork guide wire frame 100b may include a first set of alternating fingers 102b facing and interlocking with a second set of interlocking alternating fingers 104b, having an open space or gap 106b therebetween. In some embodiments, the fork guide wire frame 100b may be disposed in a single layer, and in some embodiments, the fork guide wire frame 100b may be copper or a copper alloy.

[0042] In some embodiments, one or more nodules 204 may be disposed on opposite sides of each of the alternating fingers 102a, 104a of the forked lead frame 100a and / or on opposite sides of each of the alternating fingers 102b, 104b of the forked lead frame 100b. For example, nodules 204 may be disposed on one or more sides of each of the alternating fingers 102a, 104a and / or each of the alternating fingers 102b, 104b, and provide protection for the forked lead frame 100a and / or forked lead frame 100b, respectively, for example, by minimizing and / or preventing oxidation. Figure 2 This is a microscopic view showing such nodules 204 disposed on alternating fingers 202 according to the disclosed embodiments, and it should be understood that alternating fingers 202 may be identical or similar to any of alternating fingers 102a, 104a, 102b, 104b. In embodiments where the fork guide wire frames 100a, 100b are copper or a copper alloy, the nodules 204 may be nickel.

[0043] In themselves, the fork-guide wire frames 100a and 100b are open circuits. However, when molded with PTC materials 302a and 302b as disclosed herein, multiple paths of the parallel circuit can be formed by alternating fingers 102a and 104a of the fork-guide wire frame 100a that are interlocked with and interlocked with PTC materials 302a and 302b, and / or alternating fingers 102b and 104b of the fork-guide wire frame 100b that are interlocked with and interlocked with PTC materials 302a and 302b.

[0044] In some embodiments, PTC materials 302a and 302b may be PPTC materials. For example, in some embodiments, PPTC materials may include one or more PPTC polymers and / or one or more conductive particles or conductive fillers. In particular, in some embodiments, these polymers may include any of the following in various combinations: crystalline polymers, high-density polyethylene (HDPE), polyvinylidene fluoride (PVDF), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), ultra-high-density polyethylene, thermoplastic polyurethane (TPU), ethylene methyl acrylate (EMA), ethylene butyl acrylate (EBA), polypropylene (PP), ethylene tetrafluoroethylene (ETFE), and / or polyamide (nylon). Furthermore, in some embodiments, these conductive particles or conductive fillers may include any of the following in various combinations: carbon black, graphene, graphite powder, carbon nanotubes (CNTs), metals (including nickel, silver, copper, aluminum, and / or silver-plated metals) and / or ceramic conductive fillers, including tungsten carbide, titanium carbide, titanium diboride, zirconium diboride, titanium nitride, and / or zirconium nitride.

[0045] Figure 3A This is a perspective view showing a PTC device 300a with a first termination design, molded according to a disclosed embodiment, and Figure 3B This is a perspective view illustrating an overmolded PTC device 300b with a second termination design according to a disclosed embodiment. Specifically, the overmolded PTC device 300a may include a fork guide frame 100a and a monolithic PTC material 302a layer molded on and around the fork guide frame 100a. Similarly, the overmolded PTC device 300b may include a fork guide frame 100b and a monolithic PTC material 302b layer molded on and around the fork guide frame 100b. In some embodiments, the fork guide frame 100a may be located at the center of the monolithic PTC material 302a layer, and in these embodiments, activation of the PTC material 302a may originate from the center of the monolithic PTC material 302a layer. Similarly, in some embodiments, the fork guide frame 100b may be located at the center of the monolithic PTC material 302b layer, and in these embodiments, activation of the PTC material 302b may originate from the center of the monolithic PTC material 302b layer.

[0046] As described above, in some embodiments, PTC material 302a may be molded on and / or around the fork guide frame 100a, and PTC material 302b may be molded on and / or around the fork guide frame 100b. In these embodiments, the fork guide frames 100a, 100b may be placed in a suitable mold and, for example, utilize... Figure 1A and Figure 1BThe locking holes 108a and 108b shown (e.g., round holes) are securely locked in to ensure that the fork guide frame 100a and 100b are correctly placed in the PTC material 302a and 302b, respectively.

[0047] As described above, the overmolded PTC devices 300a and 300b can be designed and configured for different applications. In this respect, the overmolded PTC devices 300a and 300b (including those portions of the fork guide wire frames 100a and 100b extending beyond the PTC materials 302a and 302b) can have different form factors suitable for different applications. For example, Figure 3A The overmolded PTC device 300a shown (its fork guide wire frame 100a is in) Figure 1A (As shown) may include a solid connecting mechanism 304 on opposite sides of the PTC material 302a. Specifically, the fork guide wire frame 100a extending on each side of the PTC material 302a may include a single terminal for connection thereto. Conversely, Figure 3B The overmolded PTC device 300b shown (its fork leader frame 100b is in) Figure 1B The PTC device 300a (as shown in the diagram) may include a forked or slotted connection mechanism 110 on opposite sides of the PTC material 302a. Specifically, each of the connection mechanisms 110 may include a portion of a fork guide frame 100b extending beyond the respective side of the PTC material 302a, and may include a fork having multiple terminal branches for connection to the fork, the multiple terminal branches being separated by multiple opening slots. In some embodiments, the overmolded PTC device 300a and / or overmolded PTC device 300b may be used in conjunction with surface mount applications.

[0048] Figure 4 This is a flowchart illustrating a method 400 according to a disclosed embodiment. (As shown) Figure 4 As shown, method 400 may include providing a fork guide frame, as in 402. For example, the fork guide frame may be disposed in a single layer and is itself open-circuited. In some embodiments, method 400 may also include providing one or more nodules on one or more sides of the fork guide frame to protect the fork guide frame. Additionally or alternatively, method 400 may also include covering the fork guide frame with a molded dielectric layer.

[0049] After providing the fork guide wire frame as in 402, method 400 may include molding an integral PTC material layer on and around the fork guide wire frame as in 404. The combination of the fork guide wire frame and the PTC material can form a closed circuit. In particular, the alternating fingers of the fork guide wire frame can interlock with each other and with the PTC material to form multiple parallel circuit paths.

[0050] In some embodiments, the monolithic PTC material layer can be molded such that the fork guide wire frame can be located at the center of the monolithic PTC material layer. In these embodiments, any activation of the PTC material during use can originate from the fork guide wire frame at the center of the monolithic PTC material layer.

[0051] As used herein, an element or step described in the singular and beginning with the word "a" or "an" should be understood to not exclude multiple elements or steps unless such exclusion is explicitly stated. Furthermore, references to "one embodiment" in this disclosure are not intended to be construed as excluding the existence of additional embodiments also incorporated into the described features.

[0052] While this disclosure references certain embodiments, many modifications, alterations, and variations of the described embodiments are possible without departing from the scope and effect of this disclosure as defined by the appended claims. Therefore, this disclosure is intended to be limited to the described embodiments, but rather to have the full scope defined by the language of the appended claims and their equivalents.

Claims

1. A device comprising: Fork leader line frame; An integral PTC material layer is molded on and around the fork guide line frame.

2. The device according to claim 1, wherein, The fork guide wire frame is located at the center of the integral PTC material layer.

3. The device according to claim 1, wherein, The PTC material is PPTC material.

4. The device according to claim 3, wherein, The PPTC material includes one or more of the following polymers: crystalline polymers, high-density polyethylene (HDPE), polyvinylidene fluoride (PVDF), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), ultra-high-density polyethylene, thermoplastic polyurethane (TPU), ethylene methyl acrylate (EMA), ethylene butyl acrylate (EBA), polypropylene (PP), ethylene tetrafluoroethylene (ETFE), and polyamide (nylon).

5. The device according to claim 3, wherein, The PPTC material includes one or more of the following conductive particles: carbon black, graphene, graphite powder, carbon nanotubes (CNTs), metals including nickel, silver, copper, aluminum and / or silver-plated metals, and / or ceramic conductive fillers including tungsten carbide, titanium carbide, titanium diboride, zirconium diboride, titanium nitride and / or zirconium nitride.

6. The device according to claim 1, wherein, The fork guide line frame is set in a single layer.

7. The device according to claim 1, further comprising: Multiple parallel circuit paths are formed by alternating fingers of a forked guide wire frame that are interlocked with each other and interlocked with the PTC material. Wherein, if the integral PTC material layer is not molded on and around the fork guide wire frame, the fork guide wire frame is open circuit.

8. The device according to claim 1, wherein, The fork guide wire frame is made of copper or a copper alloy.

9. The device according to claim 8, further comprising: One or more nodules on opposite sides of the alternating fingers of the forked guide line frame.

10. The device according to claim 9, wherein, The one or more nodules are nickel.

11. A method comprising: Provides a fork leader line frame; The monolithic PTC material layer is molded onto and around the fork guide line frame.

12. The method of claim 11, further comprising: The activation of the PTC material is initiated from the fork guide wire frame at the center of the integral PTC material layer.

13. The method according to claim 11, wherein, The PTC material is PPTC material.

14. The method according to claim 13, wherein, The PPTC material includes one or more of the following polymers: crystalline polymers, high-density polyethylene (HDPE), polyvinylidene fluoride (PVDF), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), ultra-high-density polyethylene, thermoplastic polyurethane (TPU), ethylene methyl acrylate (EMA), ethylene butyl acrylate (EBA), polypropylene (PP), ethylene tetrafluoroethylene (ETFE), and polyamide (nylon).

15. The method according to claim 13, wherein, The PPTC material includes one or more of the following conductive particles: carbon black, graphene, graphite powder, carbon nanotubes (CNTs), metals including nickel, silver, copper, aluminum and / or silver-plated metals, and / or ceramic conductive fillers including tungsten carbide, titanium carbide, titanium diboride, zirconium diboride, titanium nitride and / or zirconium nitride.

16. The method of claim 11, further comprising: The fork guide line frame is set in a single layer.

17. The method of claim 11, further comprising: Multiple parallel circuit paths are formed by the alternating fingers of the forked guide wire frame that are interlocked with each other and interlocked with the PTC material. Wherein, if the integral PTC material layer is not molded on and around the fork guide wire frame, the fork guide wire frame is open circuit.

18. The method according to claim 11, wherein, The fork guide wire frame is made of copper or a copper alloy.

19. The method of claim 18, further comprising: One or more nodules are provided on opposite sides of the alternating fingers of the forked guide wire frame.

20. The method according to claim 19, wherein, The one or more nodules are nickel.

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