Protective device with laser-trimmed soluble elements

Abstract

To provide trimmed parallel element protection devices.SOLUTION: Some protection devices may include a substrate, and a first terminal 104A and a second terminal 104B that are at opposite ends of the substrate. The protection devices may further include a first fusible element 120A and a second fusible element 120B that extend between the first and second terminals, where at least one of the first and second fusible elements includes a trimmed portion 130.SELECTED DRAWING: Figure 1A

Description

Technical Field

[0001] The present disclosure generally relates to circuit protection devices, and more particularly to circuit protection devices having laser trimmed fusible elements.

Background Art

[0002] Fuses are commonly used as electrical circuit protection devices, providing an electrical connection between a power source and circuit components to be protected. In a circuit, when a specific fault condition such as an overcurrent condition occurs, the fusible element melts or separates in other ways to interrupt current flow in the circuit path. Thereby, the protected part of the circuit is electrically insulated, and damage to such a part can be prevented or at least mitigated.

[0003] One problem known for existing fuses is their low accuracy resistance. Thus, there is a need for improved fuses with a higher accuracy resistance tolerance. Considering the above and other matters, this improvement has been needed.

Summary of the Invention

[0004] In some embodiments, the protection device may include a substrate and first and second terminals at opposite ends of the substrate. The protection device may further include a first fusible element and a second fusible element extending between the first and second terminals, wherein at least one of the first and second fusible elements includes a trimming portion.

[0005] In some embodiments, the fusible device may include a substrate and first and second terminals at opposing ends of the substrate. The fusible device may further include a first fusible element and a second fusible element extending between the first and second terminals, wherein at least one of the first and second fusible elements includes a trimming portion comprising one or more recesses formed in the outer surface. [Brief explanation of the drawing]

[0006] The accompanying drawings illustrate exemplary methods of this disclosure, including practical applications of the principles of this disclosure.

[0007] [Figure 1A] This is a perspective view of a protective device according to an exemplary embodiment of the present disclosure.

[0008] [Figure 1B] This is a lateral cross-sectional view along the cutting line BB of the protective device in Figure 1A according to an exemplary embodiment of the present disclosure.

[0009] [Figure 1C] This is a lateral cross-sectional view along the cutting line CC of the protective device in Figure 1A according to an exemplary embodiment of the present disclosure.

[0010] [Figure 2A] This is a perspective view of a protective device according to an exemplary embodiment of the present disclosure.

[0011] [Figure 2B] This is a lateral cross-sectional view of the protective device of Figure 2A along the first cutting line, according to an exemplary embodiment of the present disclosure.

[0012] [Figure 2C] This is a lateral cross-sectional view of the protective device of Figure 2A along a second cutting line, according to an exemplary embodiment of the present disclosure.

[0013] [Figure 3A]Perspective view of a protection device according to an exemplary embodiment of the present disclosure.

[0014] [Figure 3B] Side cross-sectional view of the protection device of FIG. 3A along the first cutting line according to an exemplary embodiment of the present disclosure.

[0015] [Figure 3C] Side cross-sectional view of the protection device of FIG. 3A along the second cutting line according to an exemplary embodiment of the present disclosure.

[0016] [Figure 4A] Perspective view of a protection device according to an exemplary embodiment of the present disclosure.

[0017] [Figure 4B] Side cross-sectional view of the protection device of FIG. 4A along the first cutting line according to an exemplary embodiment of the present disclosure.

[0018] [Figure 4C] Side cross-sectional view of the protection device of FIG. 4A along the second cutting line according to an exemplary embodiment of the present disclosure.

[0019] [Figure 5] Chart depicting the resistance values achievable using the protection device of the present disclosure.

[0020] [Figure 6] Flowchart of a method according to an exemplary embodiment.

[0021] The drawings are not necessarily to scale. The drawings are merely illustrative and are not intended to represent specific parameters of the present disclosure. The drawings are intended to depict typical embodiments of the present disclosure and should not be regarded as limiting the scope. In the drawings, like reference numerals represent like elements.

[0022] Furthermore, certain elements in some figures may be omitted for the sake of clarity, or may not be shown to scale. Sectional views may be in the form of "slices" or "myopic" sections, and certain backgrounds that would normally be visible in a "true" section may be omitted for the sake of clarity. Additionally, some reference numerals may be omitted in certain drawings for clarity. [Modes for carrying out the invention]

[0023] The fuse devices and fuse assemblies described herein will be further described below with reference to the accompanying drawings illustrating embodiments of the system and method. However, the fuse devices and fuse assemblies may be embodied in a number of different forms and should not be construed as being limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure may be thorough and complete and so as to convey the scope of the system and method to those skilled in the art.

[0024] The method described herein provides a protective device comprising a hard substrate (e.g., a glaze ceramic substrate) printed with two parallel fusible elements, at least one of which may be trimmed to a precision. As a result, the protective device of this disclosure maintains i2t or a larger difference between the two parallel fusible elements while maintaining higher resistance precision (+ / - 5% tolerance).

[0025] Referring to Figures 1A to 1C, exemplary embodiments of a fuse device / assembly / device (hereinafter referred to as "device") 100 according to the present disclosure are shown. The exemplary device 100 may include a substrate 102, which may be a hard glaze ceramic substrate defined by opposing first main surfaces 103A and second main surfaces 103B, opposing first side surfaces 105A and second side surfaces 105B, and opposing first end surfaces 107A and second end surfaces 107B. As shown, the device 100 may further include a first terminal 104A formed around the first end surface 107A and a second terminal 104B formed around the second end surface 107B. In some embodiments, the first and second terminals 104A and 104B may be coupled to a printed circuit board (not shown).

[0026] The device 100 may further include a first fusible element 120A arranged along a first main surface 103A of the substrate 102, and a second fusible element 120B arranged along a second main surface 103B of the substrate 102. As shown, the first fusible element 120A may be connected to a first terminal 104A by a first lead portion 122 and to a second terminal 104B by a second lead portion 124. Similarly, the second fusible element 120B may be connected to a first terminal 104A by a third lead portion 126 and to a second terminal 104B by a fourth lead portion 128. The first and second fusible elements 120A and 120B may be electrically connected in parallel.

[0027] As most clearly shown in Figure 1A, the first and / or second fusible elements 120A, 120B may include a trimming portion 130 formed therein. The trimming portion 130 may include one or more recesses 132 formed within the outer surface 134. The recesses 132 may be formed by laser trimming (e.g., ablation) so that the resistance value of the device 100 can be adjusted as desired. Non-limitingly, the first and / or second fusible elements 120A, 120B may be trimmed in situ, for example, under operating conditions during implementation. For example, the exact resistance value may not be known or even a consideration initially, but fine-tuning may be required later. In one non-limiting embodiment, a customer, user, and / or manufacturer may incorporate a device 100 with, for example, intentionally high resistance, and then form recesses 132 within the first and / or second fusible elements 120A, 120B until the exact resistance based on customer requirements is obtained.

[0028] As most clearly shown in Figures 1B and 1C, the first fusible element 120A may be formed directly on the first main surface 103A of the substrate 102, the first lead portion 122 and the second lead portion 124 may be formed directly on the first fusible element 120, and the first glass layer 138 may be formed directly on the first and second lead portions 122 and 124 and the first fusible element 120A. As shown, the first terminal 104A and the second terminal 104B may be formed above a portion of the first glass layer 138. Although not shown, in some embodiments, the first and second lead portions 122 and 124 may be connected to the first and second terminals 104A and 104B by solder. In some embodiments, the first and second fusible elements 120A and 120B are made of gold.

[0029] The third lead portion 126 and the fourth lead portion 128 may be formed along the second main surface 103B of the device, along the outside / below of the second fusible element 120B, and the second glass layer 142 may be formed along the outside / below of the third and fourth lead portions 126, 128 and along the second fusible element 120B. As shown, the first terminal 104A and the second terminal 104B may be formed above a portion of the second glass layer 142.

[0030] Referring to Figures 2A to 2C, exemplary embodiments of a fuse device / assembly / device (hereinafter referred to as "device") 200 according to the present disclosure are shown. The exemplary device 200 may include a substrate 202, which may be a hard glaze ceramic substrate defined by opposing first main surfaces 203A and second main surfaces 203B, opposing first side surfaces 205A and second side surfaces 205B, and opposing first end surfaces 207A and second end surfaces 207B. As shown, the device 200 may further include a first terminal 204A formed around the first end surface 207A and a second terminal 204B formed around the second end surface 207B. In some embodiments, the first and second terminals 204A and 204B may be coupled to a printed circuit board (not shown).

[0031] The device 200 may further include a first fusible element 220A and a second fusible element 220B, both of which are arranged along the first main surface 203A of the substrate 202. In some embodiments, the second fusible element 220B may be formed directly on the substrate 202. As shown, the first fusible element 220A may be connected to the first terminal 204A by a first lead portion 222 and to the second terminal 204B by a second lead portion 224. Similarly, the second fusible element 220B may be connected to the first terminal 204A by a third lead portion 226 and to the second terminal 204B by a fourth lead portion 228. The first and third lead portions 222 and 226 may be electrically connected by the first fusible element 220A, while the second and fourth lead portions 224 and 228 may also be similarly connected by the first fusible element 220A. Although not shown, solder may be present to form an electrical connection between the first and second fusible elements 220A and 220B so that they are electrically connected in parallel. In some embodiments, the first and second fusible elements 220A and 220B are made of gold.

[0032] As is most clearly shown in Figure 2A, the first and / or second fusible elements 220A, 220B may include a trimming portion 230 formed therein. The trimming portion 230 may include one or more recesses 232 formed within the outer surface 234. The recesses 232 may be formed by laser trimming (e.g., ablation) so that the resistance value of the device 200 can be adjusted as desired.

[0033] As most clearly shown in Figures 2B and 2C, the second fusible element 220B may be formed directly on the first main surface 203A of the substrate 202, while the third and fourth lead portions 226 and 228 may be formed above a portion of the second fusible element 220B. The second glass layer 242 may be formed above the third lead portion 226, the fourth lead portion 228, and the second fusible element 220B, while the first and second lead portions 222 and 224 are formed on the second glass layer 242. The first glass layer 238 may be formed above the first and second lead portions 222 and 224 and above a portion of the first fusible element 220A. As shown, the first and second terminals 204A and 204B may be wound around the first lead portion 222, the second lead portion 224, and the first glass layer 238.

[0034] Referring to Figures 3A to 3C, exemplary embodiments of a fuse device / assembly / device (hereinafter referred to as "device") 300 according to the present disclosure are shown. The exemplary device 300 may include a substrate 302, which may be a hard glaze ceramic substrate defined by opposing first main surfaces 303A and second main surfaces 303B, opposing first side surfaces 305A and second side surfaces 305B, and opposing first end surfaces 307A and second end surfaces 307B. As shown, the device 300 may further include a first terminal 304A formed around the first end surface 307A and a second terminal 304B formed around the second end surface 307B.

[0035] The device 300 may further include a first fusible element 320A and a second fusible element 320B, both of which are arranged along the first main surface 303A of the substrate 302. In some embodiments, the second fusible element 320B may be formed directly on the substrate 302. As shown, the first fusible element 320A may be connected to the first terminal 304A by a first lead portion 322 and to the second terminal 304B by a second lead portion 324. In this embodiment, the second fusible element 320B may be directly connected to the first terminal 304A and the second terminal 304B, for example, by solder. In some embodiments, the first and second fusible elements 320A, 320B are made of gold.

[0036] As is most clearly shown in Figure 3A, the first and / or second fusible elements 320A, 320B may include a trimming portion 330 formed therein. The trimming portion 330 may include one or more recesses 332 formed within the outer surface 334. The recesses 332 may be formed by laser trimming (e.g., ablation) so that the resistance value of the device 300 can be adjusted as desired.

[0037] As is most clearly shown in Figures 3B to 3C, the second fusible element 320B may be formed directly on the first main surface 303A of the substrate 302, while the second glass layer 342 may be formed above the second fusible element 320B. The first fusible element 320A may be formed above the second glass layer 342. As shown, the first and second fusible elements 320A and 320B may be in direct electrical and physical contact with each other. The first and second lead portions 322 and 324 may be formed on a portion of the first fusible element 320A, and the first glass layer 338 may be formed above the first fusible element 320A and portions of the first and second lead portions 322 and 324. As shown, the first and second terminals 304A and 304B may be wound around the first lead portion 322, the second lead portion 324, and the first glass layer 338.

[0038] Referring to Figures 4A to 4C, exemplary embodiments of a fuse device / assembly / device (hereinafter referred to as "device") 400 according to the present disclosure are shown. The exemplary device 400 may include a substrate 402, which may be a hard glaze ceramic substrate defined by opposing first main surfaces 403A and second main surfaces 403B, opposing first side surfaces 405A and second side surfaces 405B, and opposing first end surfaces 407A and second end surfaces 407B. As shown, the device 400 may further include a first terminal 404A formed around the first end surface 407A and a second terminal 404B formed around the second end surface 407B.

[0039] The device 400 may further include a first fusible element 420A and a second fusible element 420B, both of which are arranged along the first main surface 403A of the substrate 402. In some embodiments, the second fusible element 420B may be formed directly on the substrate 402. As shown, the first fusible element 420A may be connected to the first terminal 404A by a first lead portion 422 and to the second terminal 404B by a second lead portion 424. In this embodiment, the second fusible element 420B may be directly connected to the first terminal 404A and the second terminal 404B, for example, by solder. In some embodiments, the first fusible element 420A is made of gold and the second fusible element 420B is made of silver.

[0040] As is most clearly shown in Figure 4A, the first and / or second fusible elements 420A, 420B may include a trimming portion 430 formed therein. The trimming portion 430 may include one or more recesses 432 formed within the outer surface 434. The recesses 432 may be formed by laser trimming (e.g., ablation) so that the resistance value of the device 400 can be adjusted as desired.

[0041] As is most clearly shown in Figures 4B to 4C, the second fusible element 420B may be formed directly on the first main surface 403A of the substrate 402, while the second glass layer 442 may be formed above the second fusible element 420B. The first fusible element 420A may be formed above the second glass layer 420. As shown, the first and second fusible elements 420A and 420B may be in direct electrical and physical contact with each other. The first and second lead portions 422 and 424 may be formed on a portion of the first fusible element 420A, and the first glass layer 438 may be formed above the first fusible element 420A and portions of the first and second lead portions 422 and 424. As shown, the first and second terminals 404A and 404B may be wound around the first lead portion 422, the second lead portion 424, and the first glass layer 438.

[0042] Here, with reference to Figures 5(A) to 5(C), the improvement of the resistance of the devices of this disclosure will be further explained. In Figure 5(A), a chart 501 is shown demonstrating the average resistance of a pair of fusible elements 520A and 520B. The fusible elements 520A and 520B may be the same as the fusible elements described herein for devices 100, 200, 300, and 400. The initial distribution 505 of the first fusible element 520A shown in Figure 5(B) is more extensive when using an accuracy limit of ±5%. After printing the second fusible element 520B, the first and second fusible elements 520A and 520B are in parallel, and therefore the resistance is significantly lower. A laser trimming process may be used on the pair of fusible elements 520A and 520B to trim the resistance to within an accuracy limit of ±5%. As demonstrated in the distribution 511 in Figure 5(C), the trimmed resistance is lower than the initial resistance of the first element 520A, resulting in a higher rating.

[0043] Now, with reference to Figure 6, we will describe the method 600 according to the embodiment of this disclosure. In block 601, method 600 may include the step of forming a device by extending first and second fusible elements between first and second terminals, wherein at least one of the first and second fusible elements includes a trimming portion. In some embodiments, the device includes a substrate such as a hard ceramic substrate. In some embodiments, the substrate includes opposing first and second principal surfaces, the first fusible element is positioned along the first principal surface of the substrate, and the second fusible element is positioned along the second principal surface of the substrate. In some embodiments, the first and second fusible elements are positioned along the first principal surface of the substrate. In some embodiments, the first and second fusible elements are arranged electrically in parallel. In some embodiments, the trimming portion may include one or more recesses formed in the outer surface. The recesses may be formed by laser trimming (e.g., ablation) so that the resistance value of the device can be adjusted as desired. In some embodiments, the first and second fusible elements are made of gold. In some embodiments, the first fusible element is made of gold and the second fusible element is made of silver.

[0044] In block 602, method 600 may further include the steps of electrically connecting a first lead to a first fusible element and a first terminal, and electrically connecting a second lead to a first fusible element and a second terminal. In some embodiments, a third lead may electrically connect a second fusible element to a first terminal, while a fourth lead may electrically connect a second fusible element to a second terminal.

[0045] In block 603, the method may further include the step of providing the first and second terminals to opposing ends of the substrate.

[0046] The preceding discussions are provided for illustrative and explanatory purposes and are not intended to limit the disclosure to one or more forms disclosed herein. For example, various features of the disclosure may be combined into one or more aspects, embodiments, or configurations for the purpose of streamlining the disclosure. However, it should be understood that various features of a particular aspect, embodiment, or configuration of the disclosure may be incorporated into alternative aspects, embodiments, or configurations. Furthermore, the appended claims are incorporated herein by reference into a form for carrying out the invention, and each claim stands independently as a separate embodiment of the disclosure.

[0047] When used herein, elements or stages described in the singular form and following the word "a" or "an" should be understood not to exclude multiple elements or stages, 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 that also incorporate the described features.

[0048] The use of “include,” “equip,” or “possess,” and their variations herein, means to include the items listed before them, their equivalents, and any additional items. Thus, the terms “include,” “equip,” or “possess,” and their variations, are open-ended expressions and may be used interchangeably herein.

[0049] As used herein, the phrases “at least one,” “one or more,” and “and / or” are open-ended expressions that function both conjunctively and disjunctively. For example, each of the expressions “at least one of A, B, and C,” “at least one of A, B, or C,” “one or more of A, B, and C,” “one or more of A, B, or C,” and “A, B, and / or C” means A alone, B alone, C alone, a combination of A and B, a combination of A and C, a combination of B and C, or a combination of A, B, and C.

[0050] All references to direction (e.g., proximal, distal, upper, lower, upward, downward, left, right, lateral, longitudinal, forward, backward, top, bottom, above, below, vertical, horizontal, radial, axial, clockwise, and counterclockwise) are used solely for identification purposes to facilitate the reader's understanding of this disclosure and do not imply any limitation on the location, orientation, or use of this disclosure. References to connections (e.g., attached, joined, connected, and joined) should be interpreted broadly and, unless otherwise indicated, may include intermediate members between sets of elements and relative motion between elements. Thus, references to connections do not necessarily imply that two elements are directly connected and fixed to one another.

[0051] Furthermore, any references to identification (e.g., primary, secondary, first, second, third, fourth, etc.) are not intended to imply importance or priority, but are used to distinguish one feature from another. The drawings are for illustrative purposes only, and the dimensions, locations, order, and relative sizes reflected in the drawings accompanying this specification may differ.

[0052] Furthermore, the terms “substantial” or “effectively,” as well as “approximate” or “approximately,” can be used interchangeably in some embodiments and can be described using any relative measure acceptable to those skilled in the art. For example, these terms can serve as a comparison with a reference parameter to indicate a deviation that is capable of providing the intended function. Although not limiting, deviations from a reference parameter can be amounts such as less than 1%, less than 3%, less than 5%, less than 10%, less than 15%, less than 20%, etc.

[0053] This disclosure is not limited in scope by any particular embodiment described herein. In fact, various other embodiments and modifications of this disclosure, in addition to those described herein, will be apparent to those skilled in the art from the foregoing description and accompanying drawings. Such other embodiments and modifications are therefore intended to be included within the scope of this disclosure. Furthermore, this disclosure has been described herein in the context of specific implementations in specific environments for specific purposes. The usefulness is not limited thereto, and those skilled in the art will recognize that this disclosure may be usefully realized in any number of environments for any number of purposes. Accordingly, the claims described below should be interpreted in light of the entirety and spirit of this disclosure as described herein.

Claims

1. A protective device, circuit board and The first terminal and the second terminal located at the opposing ends of the substrate, A first fusible element and a second fusible element extending between the first terminal and the second terminal, wherein at least one of the first fusible element and the second fusible element includes a trimming portion, A first glass layer and a second glass layer are positioned along the first main surface of the substrate, the first glass layer and the second glass layer are positioned on the second fusible element, and the first fusible element is positioned between the first glass layer and the second glass layer, A first lead portion electrically connects the first fusible element to the first terminal, wherein the first lead portion is formed directly on the first fusible element, and the first glass layer is formed directly on the first lead portion, A second lead portion electrically connects the first soluble element to the second terminal, A protective device equipped with these features.

2. A third lead portion electrically connects the second soluble element to the first terminal, A fourth lead portion electrically connects the second soluble element to the second terminal. The protective device according to claim 1, further comprising:

3. The protective device according to claim 2, wherein the substrate includes a second main surface facing the first main surface.

4. The protective device according to claim 3, wherein the first soluble element is positioned along the first main surface of the substrate, and the second soluble element is positioned along the second main surface of the substrate.

5. The protective device according to claim 3, wherein the first soluble element and the second soluble element are positioned along the first main surface of the substrate.

6. The protective device according to any one of claims 3 to 5, wherein the first glass layer is positioned above the first lead portion and the second lead portion.

7. The protective device according to claim 6, wherein the second glass layer is positioned above the third lead portion and the fourth lead portion.

8. The protective device according to any one of claims 1 to 7, wherein the first fusible element and the second fusible element are formed from gold.

9. The protective device according to any one of claims 1 to 7, wherein the first soluble element is formed from gold and the second soluble element is formed from silver.

10. A soluble device, circuit board and The first and second terminals located at opposing ends of the substrate, A first fusible element and a second fusible element extending between the first terminal and the second terminal, wherein at least one of the first fusible element and the second fusible element includes a trimming portion comprising one or more recesses formed within the outer surface, A first glass layer and a second glass layer are positioned along the first main surface of the substrate, the first glass layer and the second glass layer are positioned on the second fusible element, and the first fusible element is positioned between the first glass layer and the second glass layer, A first lead portion electrically connects the first fusible element to the first terminal, wherein the first lead portion is formed directly on the first fusible element, and the first glass layer is formed directly on the first lead portion, A second lead portion electrically connects the first soluble element to the second terminal, A soluble device equipped with [a specific feature / feature].

11. A third lead portion electrically connects the second soluble element to the first terminal, A fourth lead portion electrically connects the second soluble element to the second terminal. The soluble device according to claim 10, further comprising the above.

12. The soluble device according to claim 11, wherein the substrate includes a second main surface facing the first main surface.

13. The soluble device according to claim 12, wherein the second soluble element is positioned along the first main surface or the second main surface of the substrate.

14. The soluble device according to claim 12 or 13, wherein the first glass layer is positioned above the first lead portion and the second lead portion.

15. The soluble device according to claim 14, wherein the second glass layer is positioned below the first soluble element.

16. The soluble device according to any one of claims 10 to 15, wherein the first soluble element is formed from gold, and the second soluble element is formed from gold or silver.

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