A non-rectangular pad external chip, wafer, and chip LED structure

Abstract

This invention relates to a non-rectangular pad-external chip, wafer, and chip LED structure. The chip includes a chip body and at least one pad, each pad being connected to any end face of the chip body. The advantages of this invention are its simple structure, reasonable design, and external pad chip structure, which prevents misaligned soldering, ensures consistent contact area between the solder ball and the pad, and reduces the proportion of the pad occupying the top area of ​​the overall chip while maintaining sufficient push-pull force, thereby increasing the light-emitting area.

Description

Technical Field

[0001] This invention relates to the field of LED packaging technology, specifically to a non-rectangular pad external chip, wafer, and chip lamp bead structure. Background Technology

[0002] Automotive chips are typically rectangular or square, and the pads are usually adjacent to the chip surface, which can easily cause misaligned solder lines. Also, the white adhesive applied to the bottom can easily spread to the chip's light-emitting surface. More importantly, the gold ball area occupies 80%-90% of the area of ​​the inscribed circular pad. For an 80µm square pad, the gold ball diameter should be written as 73-75µm. Here it should be 2.5µm; perhaps it can be written smaller, perhaps even larger, at the edges. Summary of the Invention

[0003] This invention addresses the technical problems existing in the prior art by providing a non-rectangular pad external chip, wafer, and chip LED structure.

[0004] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: An external chip with non-rectangular pads includes: a chip body and at least one pad, each of the pads being connected to any end face of the chip body.

[0005] The beneficial effects of the present invention are: the present invention has a simple structure and reasonable design. It adopts a chip structure with external pads to prevent the solder wires from being soldered crookedly, ensures that the contact area between the solder balls and the pads is consistent, and reduces the proportion of the pads occupying the top area of ​​the overall chip while ensuring push-pull force, thereby achieving the purpose of increasing the light-emitting area.

[0006] Based on the above technical solution, the present invention can be further improved as follows.

[0007] Furthermore, the number of the solder pads is one, and the solder pads are distributed at one corner of one end of the chip body; a notch is provided at one corner of the other end of the chip body, and the notch is distributed opposite to the solder pads.

[0008] The advantages of adopting the above-mentioned further solution are that the structure is simple and the design is reasonable. This solution has only one pad, which is distributed at one corner of one end of the chip body. At this time, it is a single-electrode chip structure, which prevents the solder wire from being soldered crooked, ensures that the contact area between the solder ball and the pad is consistent, and reduces the proportion of the pad occupying the top area of ​​the chip while ensuring the push-pull force, thereby achieving the purpose of increasing the light-emitting area.

[0009] Furthermore, the number of the solder pads is one, and the solder pads are distributed in the middle of one end of the chip body; a notch is provided in the middle of the other end of the chip body.

[0010] The advantages of adopting the above-mentioned further solution are that the structure is simple and the design is reasonable. This solution has only one pad, which is distributed in the middle of one end of the chip body. At this time, it is a single-electrode chip structure, which prevents the solder wire from being soldered crooked, ensures that the contact area between the solder ball and the pad is consistent, and reduces the proportion of the pad occupying the top area of ​​the chip while ensuring the push-pull force, thereby achieving the purpose of increasing the light-emitting area.

[0011] Furthermore, there are two pads, which are respectively distributed at one diagonal corner of both ends of the chip body; the other diagonal corner of both ends of the chip body has a stepped structure.

[0012] The advantages of adopting the above-mentioned further solution are that the structure is simple and the design is reasonable. This solution has two pads, which are distributed at one of the diagonal corners at both ends of the chip body. This is a dual-electrode chip structure, which prevents the solder wires from being soldered crooked, ensures that the contact area between the solder ball and the pad is consistent, and reduces the proportion of the pad occupying the top area of ​​the chip while ensuring the push-pull force, thereby achieving the purpose of increasing the light-emitting area.

[0013] Furthermore, there are two pads, which are respectively distributed at two corners of one end of the chip body; and notches are provided at two corners of the other end of the chip body.

[0014] The advantages of adopting the above-mentioned further solution are that the structure is simple and the design is reasonable. This solution has two pads, which are distributed at two corners at one end of the chip body. This is a dual-electrode chip structure, which prevents the solder wires from being soldered crooked, ensures that the contact area between the solder ball and the pad is consistent, and reduces the proportion of the pad occupying the top area of ​​the chip while ensuring the push-pull force, thereby achieving the purpose of increasing the light-emitting area.

[0015] Furthermore, each of the pads is elliptical or arc-shaped.

[0016] The advantages of adopting the above-mentioned further solution are that the structure is simple, the shape of the pads is reasonably designed, and the gold wires can be better hidden.

[0017] The present invention also relates to a wafer comprising a plurality of external chips with non-rectangular pads as described above, wherein the plurality of chip bodies are spliced ​​together to form a complete wafer structure.

[0018] The beneficial effect of adopting the above-mentioned further solutions is that the present invention also provides a wafer with a simple structure and reasonable design. It adopts a chip structure with external pads to prevent the solder wires from being soldered crookedly, ensures that the contact area between the solder balls and the pads is consistent, and reduces the proportion of the pads occupying the top area of ​​the overall chip while ensuring the push-pull force, thereby achieving the purpose of increasing the light-emitting area.

[0019] The present invention also relates to a chip lamp structure, including an external chip with a non-rectangular pad as described above.

[0020] The beneficial effect of adopting the above-mentioned further solution is that the present invention also provides a chip lamp bead structure, which has a simple structure and reasonable design. It adopts a chip structure with external pads to prevent the solder wires from being soldered crooked, ensures that the contact area between the solder ball and the pad is consistent, and reduces the proportion of the pad occupying the top area of ​​the overall chip while ensuring the push-pull force, thereby achieving the purpose of increasing the light-emitting area.

[0021] Furthermore, it also includes a substrate and gold wires of the same number as the pads, wherein the substrate is provided with grooves; the chip body and the gold wires are respectively distributed in the grooves, and one end of the gold wires is attached to the pads.

[0022] The advantages of adopting the above-mentioned further solution are that the structure is simple, the design is reasonable, and the chip body and gold wire are assembled using a substrate, making assembly convenient.

[0023] Furthermore, the substrate is a ceramic substrate.

[0024] The advantages of adopting the above-mentioned further scheme are that the structure is simple, the use of ceramic matrix is ​​more reasonable, and the advantages of ceramic matrix are its excellent heat dissipation performance, matching coefficient of thermal expansion and excellent insulation. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the chip in the first embodiment of the present invention; Figure 2 This is a schematic diagram of the second embodiment of the chip in this invention; Figure 3 This is a schematic diagram of the third embodiment of the chip in this invention; Figure 4 This is a schematic diagram of the fourth embodiment of the chip in this invention; Figure 5 This is a schematic diagram of the structure of the wafer in the first embodiment of the present invention; Figure 6 This is a schematic diagram of the structure of the second embodiment of the wafer in this invention; Figure 7 This is one of the structural schematic diagrams of the LED bead in this invention; Figure 8 This is the second schematic diagram of the structure of the LED bead in this invention; Figure 9 This is one of the structural schematic diagrams of the gold wire in this invention; Figure 10 This is the second schematic diagram of the gold wire structure in this invention; Figure 11 This is a schematic diagram showing the distribution of solder pads and gold wires in this invention.

[0026] The attached diagram lists the components represented by each number as follows: 1. Chip body; 2. Solder pad; 3. Substrate; 4. Groove; 5. Gold wire. Detailed Implementation

[0027] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0028] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0029] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this technology based on the specific circumstances.

[0030] In the description of this application, spatial relation terms such as "below," "under," "below," "below," "above," "over," etc., are used herein to describe the relationship between one element or feature shown in the figures and other elements or features. It should be understood that, in addition to the orientation shown in the figures, spatial relation terms also include different orientations of the device in use and operation. For example, if the device in the figures is flipped, an element or feature described as "below" or "under" or "below" of other elements or features will be oriented "above" other elements or features. Therefore, the exemplary terms "below" and "under" can include both upper and lower orientations. Furthermore, the device may also include other orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptive terms used herein are interpreted accordingly.

[0031] In the description of this application, the term "for example" is used to mean "used as an example, illustration, or description." Any embodiment described as "for example" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use the invention. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that the invention can be made without using these specific details. In other instances, well-known structures and processes will not be described in detail to avoid obscuring the description of the invention with unnecessary detail. Therefore, the invention is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.

[0032] Example 1 like Figures 1 to 4 As shown, this embodiment provides a non-rectangular pad external chip, including: a chip body 1 and at least one pad 2, each of the pads 2 being connected to any end face of the chip body 1.

[0033] This embodiment has a simple structure and reasonable design. It adopts a chip structure with external pads to prevent the solder wires from being soldered crookedly. It ensures that the contact area between the solder balls and the pads is consistent and reduces the proportion of the top area of ​​the chip occupied by the pads while ensuring the push-pull force, thereby increasing the light-emitting area.

[0034] Example 2 Based on Embodiment 1, in this embodiment, the number of solder pads 2 is one, and the solder pads 2 are distributed at one corner of one end of the chip body 1; a notch is provided at one corner of the other end of the chip body 1, and the notch is distributed opposite to the solder pads 2.

[0035] The scheme has a simple structure and reasonable design. The number of pads 2 is one, which is distributed at one corner of one end of the chip body 1. At this time, it is a single electrode chip structure to prevent the solder wire from being soldered crookedly, ensure that the contact area between the solder ball and the pad is consistent, and reduce the proportion of the pad occupying the top area of ​​the chip while ensuring the push-pull force, thereby achieving the purpose of increasing the light-emitting area.

[0036] Preferably, in this embodiment, the cross-section of the notch is L-shaped.

[0037] Example 3 Based on Embodiment 1, in this embodiment, the number of solder pads 2 is one, and the solder pads 2 are distributed in the middle of one end of the chip body 1; a notch is provided in the middle of the other end of the chip body 1.

[0038] The scheme has a simple structure and reasonable design. The number of pads 2 is one, which is distributed in the middle of one end of the chip body 1. At this time, it is a single electrode chip structure to prevent the solder wire from being soldered crookedly. It ensures that the contact area between the solder ball and the pad is consistent. While ensuring the push-pull force, it reduces the proportion of the pad occupying the top area of ​​the chip, thereby increasing the light-emitting area.

[0039] Preferably, in this embodiment, the cross-section of the notch is U-shaped.

[0040] Example 4 Based on Embodiment 1, in this embodiment, there are two pads 2, and the two pads 2 are respectively distributed at one of the diagonal corners at both ends of the chip body 1; the other diagonal corner at both ends of the chip body 1 has a stepped structure.

[0041] The scheme has a simple structure and reasonable design. The number of pads 2 in this scheme is two, and they are distributed at one of the diagonal corners at both ends of the chip body 1. This is a dual-electrode chip structure, which prevents the solder wires from being soldered crooked, ensures that the contact area between the solder ball and the pad is consistent, and reduces the proportion of the pad occupying the top area of ​​the chip while ensuring the push-pull force, thereby achieving the purpose of increasing the light-emitting area.

[0042] Preferably, in this embodiment, the other diagonal corner of the chip body 1 has a stepped structure, preferably a two-step stepped structure.

[0043] Example 5 Based on Embodiment 1, in this embodiment, there are two pads 2, which are respectively distributed at two corners of one end of the chip body 1; and two notches are respectively provided at two corners of the other end of the chip body 1.

[0044] The scheme has a simple structure and reasonable design. The number of pads 2 in this scheme is two, which are distributed at two corners at one end of the chip body 1. This is a dual-electrode chip structure to prevent the solder wires from being soldered crookedly. It ensures that the contact area between the solder ball and the pad is consistent. While ensuring the push-pull force, it reduces the proportion of the pad occupying the top area of ​​the overall chip, thereby increasing the light-emitting area.

[0045] Preferably, in this embodiment, the cross-sections of the two notches are L-shaped.

[0046] The above embodiments 2, 3, 4 and 5 are parallel schemes, which are chip structures with different implementation methods.

[0047] Example 6 Based on the above embodiments, in this embodiment, each of the pads 2 is elliptical or arc-shaped.

[0048] The solution has a simple structure and the shape of the pad 2 is reasonably designed, which can better hide the gold wire 5.

[0049] Alternatively, the shape of the aforementioned pad 2 can also be rectangular.

[0050] Example 7 Based on the above embodiments, such as Figure 5 and Figure 6 As shown, this embodiment also provides a wafer, including multiple non-rectangular pad external chips as described above, with multiple chip bodies 1 spliced ​​together to form a complete wafer structure.

[0051] Based on the above scheme, taking Example 2 (single electrode chip structure) as the basis, and taking four chip bodies 1 as an example, the four chip bodies 1 are divided into two columns. In each column, the pad 2 of one chip body 1 matches the notch on the other chip body 1 to splice together a complete wafer.

[0052] In addition, based on Example 4 (dual electrode chip structure), and taking four chip bodies 1 as an example, the four chip bodies 1 are divided into two columns. In each column, the pads 2 and the stepped structure at one end of one chip body 1 are respectively matched with the stepped structure and the pads 2 on the other chip body 1 to splice together a complete wafer.

[0053] This embodiment also provides a wafer with a simple and reasonable structure. It adopts a chip structure with external pads to prevent the bonding wires from being soldered crookedly, ensure that the contact area between the solder balls and the pads is consistent, and reduce the proportion of the pads occupying the top area of ​​the overall chip while ensuring push-pull force, thereby increasing the light-emitting area.

[0054] Example 8 Based on the above embodiments, such as Figures 7 to 10 As shown, this embodiment also provides a chip LED structure, including the non-rectangular pad external chip as described above.

[0055] This embodiment also provides a chip lamp structure, which is simple in structure and reasonable in design. It adopts a chip structure with external pads to prevent the solder wires from being soldered crookedly, and ensures that the contact area between the solder ball and the pad is consistent. While ensuring the push-pull force, it reduces the proportion of the pad occupying the top area of ​​the overall chip, thereby increasing the light-emitting area.

[0056] Example 9 Based on embodiment 8, this embodiment also includes a substrate 3 and gold wires 5 in the same number as the pads 2. The substrate 3 is provided with a groove 4. The chip body 1 and the gold wires 5 are respectively distributed in the groove 4, and one end of the gold wires 5 is attached to the pads 2.

[0057] The scheme has a simple structure and reasonable design. It uses the substrate 3 to assemble the chip body 1 and the gold wire 5, which makes assembly convenient.

[0058] Alternatively, the number of gold wires 5 can exceed the number of solder pads 2.

[0059] Preferably, in this embodiment, the substrate 3 is preferably a rectangular block structure.

[0060] In addition, the two ends of the gold wire 5 are hemispherical structures, and the part between the two ends is a cylindrical structure.

[0061] Based on the above scheme, let pad 2 be a rectangle with length L and width W (L≥W). Establish a coordinate system with the bottom left corner of the rectangle as the origin. The four vertices are (0,0), (L,0), (L,W) and (0,W), with the shorter sides being x=0 and x=L. The center of the circle lies on the midline of the left shorter side, i.e., the center coordinates are (a,W / 2), where a>0. The circle passes through the two vertices (0,0) and (0,W) of the left shorter side, therefore the radius r= .

[0062] To maximize the area covered by the circle within the rectangle while minimizing the circle's area, the circle should be tangent to the right shorter side x=L, with the point of tangency at (L, W / 2), satisfying La=r.

[0063] Simultaneous equations: r= , La=r.

[0064] Solving for the problem, a= r= , In this configuration, the circle is tangent to the right shorter side of the rectangle, and the center of the circle lies on the midline of the left shorter side, a distance a = from the left shorter side. At this point, the circle covers a larger area within the rectangle, while the circle's area is relatively smaller, achieving an optimal balance.

[0065] The area of ​​the rectangle covered by the circle is fixed at πP. 2 And given that the area of ​​the circle is minimized, the parameter P is determined as follows:

[0066] For P=80μm, the calculation yields: r≈92.10μm, W≈150.37μm, a≈53.17μm, L≈145.27μm.

[0067] In this method, the area of ​​the circle outside the rectangle divided by the area of ​​the circle is approximately 0.92, which is similar to the original π. 1 / 2 / 2 = 0.785, which is approximately an increase of 0.135. Given that the area of ​​the two electrode pads is approximately 20% of the light-emitting area, the increase in light-emitting area is 2.7% (see appendix). Figure 11 ).

[0068] Example 10 Based on Example 9, in this example, the substrate 3 is a ceramic substrate.

[0069] The scheme has a simple structure, and it is more reasonable to use a ceramic substrate for the substrate 3. The advantages of the ceramic substrate are its excellent heat dissipation performance, matching coefficient of thermal expansion and excellent insulation.

[0070] A bracket can also be used instead of the ceramic mentioned above, but the material of the bracket is not limited.

[0071] This invention provides a non-rectangular pad external chip, wafer, and chip LED structure. The structure is simple and reasonably designed. The external pad chip structure prevents the solder wires from being soldered crooked, ensures that the contact area between the solder ball and the pad is consistent, and reduces the proportion of the pad occupying the top area of ​​the overall chip while ensuring push-pull force, thereby increasing the light-emitting area.

[0072] This invention provides a non-rectangular pad external chip, wafer, and chip LED structure, which has the following advantages: 1. The pads are micro-rectangular, and the edge of the pad is 1.5-15um away from the chip surface (as a safety isolation zone).

[0073] 2. The pads are adjacent to the chip surface on only one side; 3. The overall chip is not rectangular; 4. The entire wafer is inspected for adjacent chips, ensuring no waste; 5. The pad height can be reduced, which better conceals the gold wires for products with bottom filler. 6. The die bond adhesive is circular only at the central chip light-emitting position, and the die bond adhesive area at the bottom of the pad does not exceed 1 / 2. This makes it easier to attach the rectangular phosphor film without the interference of the gold wires on the original pad.

[0074] While embodiments or examples of the invention disclosed herein have been described with reference to the accompanying drawings, it should be understood that the above embodiments are merely exemplary embodiments or examples, and the scope of the invention is not limited by these embodiments or examples, but only by the granted claims and their equivalents. Various elements in the embodiments or examples may be omitted or replaced by their equivalents. Furthermore, the steps may be performed in a different order than that described in this disclosure. Further, various elements in the embodiments or examples may be combined in various ways. Importantly, as the technology evolves, many elements described herein can be replaced by equivalents that appear after this disclosure.

Claims

1. A non-rectangular pad external chip, characterized in that, include: The chip body (1) and at least one pad (2), each of the pads (2) being connected to any end face of the chip body (1).

2. The non-rectangular pad external chip according to claim 1, characterized in that, The number of the pads (2) is one, and the pads (2) are distributed at one corner of one end of the chip body (1); a notch is provided at one corner of the other end of the chip body (1), and the notch is distributed opposite to the pads (2).

3. The non-rectangular pad external chip according to claim 1, characterized in that, The number of the pads (2) is one, and the pads (2) are distributed in the middle of one end of the chip body (1); a notch is provided in the middle of the other end of the chip body (1).

4. The non-rectangular pad external chip according to claim 1, characterized in that, The number of the pads (2) is two, and the two pads (2) are respectively distributed at one of the diagonal corners at both ends of the chip body (1); the other diagonal corner at both ends of the chip body (1) has a stepped structure.

5. The non-rectangular pad external chip according to claim 1, characterized in that, The number of the pads (2) is two, and the two pads (2) are respectively distributed at two corners of one end of the chip body (1); the two corners of the other end of the chip body (1) are respectively provided with notches.

6. The non-rectangular pad external chip according to any one of claims 1-5, characterized in that, Each of the pads (2) is elliptical or arc-shaped.

7. A wafer, characterized in that, It includes multiple non-rectangular pad external chips as described in any one of claims 1-6, and multiple chip bodies (1) are spliced ​​together to form a complete wafer structure.

8. A chip-based LED structure, characterized in that, Includes the non-rectangular pad external chip as described in any one of claims 1-6.

9. The chip lamp bead structure according to claim 8, characterized in that, It also includes a substrate (3) and gold wires (5) in the same number as the pads (2). The substrate (3) has grooves (4). The chip body (1) and the gold wires (5) are respectively distributed in the grooves (4), and one end of the gold wires (5) is attached to the pads (2).

10. The chip lamp bead structure according to claim 9, characterized in that, The substrate (3) is a ceramic substrate.

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