An LED encapsulation device

Abstract

The utility model discloses a kind of LED packaging devices, it is related to LED packaging technical field, the LED packaging device includes: support, the support includes cup body and part is arranged in the metal lead-out frame of cup body, the metal lead-out frame includes first lead-out frame and second lead-out frame;The top surface of first lead-out frame is first solder pad, and the top surface of second lead-out frame is second solder pad;First solder pad and second solder pad are along the geometric center of the top surface of support symmetry distribution, and S-shaped insulating river is formed between first solder pad and second solder pad.In the cup body structure of support, staggered distribution is set to solder pad structure, and S-shaped insulating river is formed, improve the contact area between solder pad and support, can effectively improve the binding force between support and solder pad, reduce the influence of external force to support solder pad, improve the structural connection stability between support and solder pad.

Description

Technical Field

[0001] This utility model relates to the field of LED packaging technology, and specifically to an LED packaging device. Background Technology

[0002] Figure 1 A top view of the structure of an LED packaging device in the prior art is shown, with reference to... Figure 1 The existing LED packaging device generally adopts an axisymmetric distribution structure for the pad structure, that is, two pads 20 are symmetrically distributed along the length of the support 10 based on the central axis, so that a straight insulating channel is formed between the two pads 20, and the LED chip 30 is die-bonded on the two pads 20. When the packaging device is affected by external forces, the connection between the pads 20 and the support 10 is prone to breakage, resulting in the pads 20 falling off or breaking, which affects the structural stability of the LED packaging device. Utility Model Content

[0003] The purpose of this invention is to overcome the shortcomings of the prior art. This invention provides an LED packaging device that forms an S-shaped insulating channel in the cup of the bracket by setting a first pad and a second pad symmetrically distributed along the geometric center, thereby increasing the contact area between the pad and the bracket, thus improving the bonding force between the pad and the bracket, and effectively improving the structural stability of the LED packaging device.

[0004] This invention provides an LED packaging device, which includes a support, comprising a cup body and a metal lead-out bracket partially disposed within the cup body.

[0005] The metal lead-out frame includes a first lead-out frame and a second lead-out frame;

[0006] The top surface of the first lead-out bracket is the first pad, and the top surface of the second lead-out bracket is the second pad;

[0007] The first pad and the second pad are symmetrically distributed along the geometric center of the top surface of the bracket, and an S-shaped insulating channel is formed between the first pad and the second pad.

[0008] Furthermore, the first pad is provided with a first finger extending toward the second pad, and the second pad is provided with a second finger extending toward the first pad, with the first finger and the second finger interleaved to form a staggered distribution.

[0009] Furthermore, the metal lead-out frame is configured as a rectangular structure, and the S-shaped insulated channel includes a first section, a second section, and a third section;

[0010] The first segment and the third segment are parallel to the wide side of the rectangular structure, and the second segment is parallel to the long side of the rectangular structure.

[0011] Furthermore, the LED packaging device also includes a white wall disposed inside the cup body, the white wall covering the periphery of the LED chip.

[0012] Furthermore, the white wall is configured as an inclined slope structure, and the white wall forms a preset angle with the top surface of the support.

[0013] The preset included angle is θ, and the value range of θ is: 0° < θ < 25°.

[0014] Furthermore, the white wall is made of silicone.

[0015] Furthermore, the cup tilt angle of the bracket of the LED packaging device is in the range of α, and the value of α is in the range of 25°≤α≤35°.

[0016] Furthermore, the cup structure of the bracket covers an area of ​​S1 on the plane where the S-shaped insulating channel is located, and the area of ​​the plane where the S-shaped insulating channel is located is S2.

[0017] The constraint relationship between S1 and S2 is: 0.3*S2≤S1≤0.8*S2.

[0018] Furthermore, the metal lead-out bracket is provided with a connection hole, and the connection hole extends through the metal lead-out.

[0019] The cup of the bracket fills the connection hole.

[0020] The bottom surface of the bracket forms two or more bottom pads based on the metal lead-out frame. The two or more bottom pads include a third pad and a fourth pad, and an S-shaped insulating channel is formed between the third pad and the fourth pad.

[0021] This invention provides an LED packaging device in which a first pad and a second pad are formed in an alternating manner based on a metal lead frame within the cup structure of the bracket. An S-shaped insulating channel is formed based on the alternating arrangement between the first pad and the second pad, thereby increasing the contact area between the pad and the bracket. This effectively improves the bonding force between the bracket and the pad, reduces the impact of external forces on the bracket pad, and enhances the stability of the structural connection between the bracket and the pad. Attached Figure Description

[0022] Figure 1 This is a top view of the structure of an LED packaging device in the prior art;

[0023] Figure 2This is a schematic diagram of the LED packaging device according to Embodiment 1 of this utility model;

[0024] Figure 3 This is a schematic diagram of another structural state of the LED packaging device according to Embodiment 1 of this utility model;

[0025] Figure 4 This is a schematic diagram of the bottom structure of the support structure of the LED packaging device according to an embodiment of the present invention;

[0026] Figure 5 This is a schematic diagram of the bottom pad with hole structure of the support structure of the LED packaging device according to an embodiment of the present invention;

[0027] Figure 6 This is a schematic diagram of the LED packaging device according to Embodiment 2 of this utility model;

[0028] Figure 7 This is a cross-sectional view of the LED packaging device according to Embodiment 2 of this utility model;

[0029] Figure 8 This is a cross-sectional view of the LED packaging device in another state according to Embodiment 2 of this utility model;

[0030] Figure 9 This is a schematic diagram of the LED packaging device according to Embodiment 3 of this utility model. Detailed Implementation

[0031] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0032] Example 1:

[0033] Please refer to Figures 2 to 5 This utility model provides an LED packaging device, which includes: a support 1, the support 1 including a cup body and a metal lead frame partially disposed in the cup body, the metal lead frame 5 including a first lead frame 51 and a second lead frame 52;

[0034] The top surface of the first lead-out bracket 51 is the first pad 511, and the top surface of the second lead-out bracket 52 is the second pad 521.

[0035] The first pad 511 and the second pad 521 are symmetrically distributed along the geometric center of the top surface of the bracket 1, and an S-shaped insulating channel 3 is formed between the first pad 511 and the second pad 521. Based on the symmetrical distribution of the geometric center, the contact area between the first pad 511 and the second pad 521 and the bracket 1 can be increased, and a staggered distribution state can be formed, thereby effectively improving the bonding force between the first pad 511, the second pad 521 and the bracket 1.

[0036] Specifically, the first pad 511 is provided with a first finger extending towards the second pad 521, and the second pad 521 is provided with a second finger extending towards the first pad 511. The first finger and the second finger are staggered to form a staggered distribution. The first pad 511 and the second pad 521 are respectively located at both ends of the length direction of the bracket 1, so that the first finger and the second finger are arranged along the length direction. By setting the first finger, the first pad 511 can form a large area of ​​contact with the bracket 1 in the length direction. By setting the second finger, the second pad 521 can form a large area of ​​contact with the bracket 1 in the length direction. That is, the shape design of the first pad 511 and the second pad 521 can span across the top surface of the bracket 1 in the length direction, thereby effectively improving the bonding force between the first pad 511 and the second pad 521 and the bracket 1.

[0037] Furthermore, the metal lead-out bracket 5 is configured as a rectangular structure, and the S-shaped insulating channel 3 includes a first section, a second section, and a third section. The first section and the third section are parallel to the wide side of the rectangular structure, and the second section is parallel to the long side of the rectangular structure, so that the first pad 511 and the second pad 521 form an interlaced arrangement structure. The bonding area between the metal lead-out bracket 5 and the support 1 is increased, thereby improving the connection stability between the metal lead-out bracket 5 and the support 1.

[0038] For details, please refer to Figure 3 The cup structure of the bracket 1 can partially cover the first and third sections of the S-shaped insulating channel, thereby increasing the contact area between the cup structure of the bracket 1 and the metal lead-out frame 5, and thus improving the bonding stability between the bracket 1 and the metal lead-out frame 5.

[0039] Specifically, the area covered by the cup structure of the support 1 on the plane of the S-shaped insulating channel 3 is S1, and the area of ​​the plane of the S-shaped insulating channel 3 is S2.

[0040] The constraint relationship between S1 and S2 is: 0.3*S2≤S1≤0.8*S2, that is, the support 1 can cover 30% to 80% of the plane area where the S-shaped insulated channel 3 is located, which can meet the requirement of the connection stability between the support 1 and the metal lead-out frame 5.

[0041] Example 2:

[0042] For details, please refer to Figures 6 to 8 In this embodiment, the LED packaging device further includes a white wall 2 disposed inside the cup body. The white wall 2 covers the periphery of the LED chip 4. The white wall 2 is applied to both ends of the support 1 along the length direction using white wall adhesive. Due to the fluidity of the white wall adhesive, a ring of white wall 2 is formed in the cup body of the support 1 along the circumferential direction. The white wall 2 surrounds the periphery of the LED chip 4, which can further improve the bonding force between the support 1 and the metal lead frame 5, and effectively improve the packaging airtightness of the LED packaging device.

[0043] The white wall 2 can reflect the light emitted by the LED chip 4, so that the light emitted by the LED chip 4 towards both ends of the support 1 can be reflected by the white wall 2, thereby improving the light emission efficiency of the LED chip 4 and enhancing the light emission brightness of the LED package device.

[0044] Furthermore, the white wall 2 can also cover part of the S-shaped insulating channel 3, thereby further improving the structural stability of the LED packaging device and further improving the light output efficiency of the LED packaging device.

[0045] Furthermore, in combination Figure 7 and Figure 8 It can be seen that the amount of adhesive dispensing for the LED packaging device can be adjusted under different support structure states. That is, when the area of ​​the cup body of the support 1 covering the plane of the S-shaped insulating channel 3 increases, the bonding force between the cup body of the support 1 and the metal lead frame 5 can be improved, and the amount of adhesive dispensing on the white wall 2 can be reduced, thereby improving the convenience of dispensing operation and effectively improving dispensing efficiency.

[0046] In this embodiment, the LED chip 4 is die-bonded into the cup of the bracket 1. Adhesive is applied to both ends of the cup of the bracket 1 using a dispensing method, allowing the adhesive to flow from both ends of the cup along the edge of the cup. The adhesive from both ends converges at the edge of the cup to form a white wall 2, which fills the cup and forms a ring structure. The LED chip 4 is then encapsulated within the white wall 2. The white wall 2 reflects and concentrates the light emitted from the LED chip 4, effectively improving the luminous efficacy of the LED packaged device.

[0047] Furthermore, the white walls 2 at both ends of the inside of the cup can be integrally formed, so that the white walls 2 at both ends of the inside of the cup can be formed simultaneously, improving the convenience of the fabrication of the support structure 1.

[0048] Specifically, the white wall 2 is configured as an inclined slope structure, and the white wall 2 forms a preset angle with the top surface of the support 1. The angle of the preset angle is θ, and the value range of θ is 0° < θ < 25°. In this embodiment, the value of θ can be one of 10°, 12°, 15°, 17°, 20°, and 23°. Based on the angle design of the preset angle, the white wall 2 can meet the reflection requirements of the side-emitting light of the LED chip 4 and avoid the white wall 2 from blocking the side-emitting light of the LED chip 4, thus ensuring that the LED package device has a good light emission range.

[0049] Furthermore, by adjusting the cup structure of the bracket 1 based on the white wall 2, the refractive index of the cup structure of the bracket 1 can be increased, thereby improving the overall brightness of the LED packaged device by 0.5% to 1%.

[0050] Specifically, the tilt angle of the cup of the support of the LED packaging device is α, and the value of α is 25°≤α≤35°. Based on the white wall 2, the light emitted by the LED chip 4 in the cup of the support 1 is adjusted to increase the front light emission efficiency of the LED packaging device, thereby effectively improving the light emission efficiency of the LED packaging device.

[0051] Furthermore, the white wall 2 can be made of silicone, which has good thermal stability, chemical stability, and high mechanical strength. By dispensing silicone into the cup structure of the bracket 1 to form the white wall 2 structure, the brightness of the LED packaged device can be improved while the device's anti-sulfurization performance can be enhanced.

[0052] Specifically, the cup body of the bracket 1 is filled with a fluorescent adhesive layer 7, and the LED chip 4 is completely contained within the fluorescent adhesive layer 7, so that the light emitted by the LED chip 4 can pass through the fluorescent adhesive layer 7 and be emitted to the outside to meet the light color requirements of different application devices.

[0053] Specifically, the bottom surface of the bracket 1 has two or more bottom pads 6 formed on the metal lead-out frame 5. The two or more bottom pads 6 include a third pad 61 and a fourth pad 62. An S-shaped insulating channel 3 is formed between the third pad 61 and the fourth pad 62. The structural arrangement of the two or more bottom pads 6 is the same as that of the two or more first pads 511 and second pads 521. By forming an S-shaped insulating channel 3 between the third pad 61 and the fourth pad 62, the contact area between the bottom pads 6 and the bracket 1 is increased, thereby improving the bonding force between the bottom pads 6 and the bracket 1.

[0054] Furthermore, the third pad 61 is provided with a third finger 611 extending towards the fourth pad 62, and the fourth pad 62 is provided with a fourth finger 621 extending towards the third pad 61. The third finger 611 and the fourth finger 621 are staggered to form a staggered distribution. The third pad 61 and the fourth pad 62 are respectively located at both ends of the length direction of the bracket 1, so that the third finger 611 and the fourth finger 621 are arranged along the length direction. By setting the third finger 611, the third pad 61 can form a large-area contact with the bracket 1 in the length direction. By setting the fourth finger 621, the fourth pad 62 can form a large-area contact with the bracket 1 in the length direction. That is, the shape design of the third pad 61 and the fourth pad 62 can span across the top surface of the bracket 1 in the length direction, thereby effectively improving the bonding force between the third pad 61 and the fourth pad 62 and the bracket 1.

[0055] Specifically, the bottom pad 6 is provided with a connection hole 63. The bottom of the bracket 1 is formed by an integral molding process to fill the connection hole 63. The connection hole 63 is provided in the bottom pad 6 so that the bracket 1 can fill the connection hole 63 during the injection molding process, thereby increasing the contact area between the bracket 1 and the bottom pad 6 and effectively improving the structural fit stability between the bracket 1 and the bottom pad 6.

[0056] Specifically, two or more bottom pads 6 are connected one-to-one with two or more metal lead-out brackets 5. The first pad 511 and the third pad 61 are connected in a corresponding manner, that is, the first pad 511 and the third pad 61 are covered on the surface of the bracket 1 based on the same metal. The second pad 521 and the fourth pad 62 are connected in a corresponding manner, that is, the second pad 521 and the fourth pad 62 are covered on the surface of the bracket 1 based on the same metal. This allows the first pad 511, the second pad 521, the third pad 61 and the fourth pad 62 to meet the electrical connection requirements of the LED chip 4.

[0057] This utility model embodiment provides an LED packaging device. A metal lead-out frame 5 is provided within the cup structure of the bracket 1, and the metal lead-out frame 5 is divided into a first pad 511 and a second pad 521. Based on the staggered distribution between the first pad 511 and the second pad 521, an S-shaped insulating channel 3 is formed, which increases the contact area between the first pad 511 and the second pad 521 and the bracket 1. This can effectively improve the bonding force between the bracket 1 and the pads, reduce the influence of external forces on the pads of the bracket 1, and improve the structural stability between the bracket 1 and the first pad 511 and the second pad 521.

[0058] Example 3:

[0059] Please refer to Figure 9 This utility model provides an LED packaging device, which includes: a bracket 1 with a cup body, and two or more metal lead-out brackets 5 disposed in the cup body of the bracket 1. The bracket 1 is made of plastic integral molding and is formed into an integral structure by mold injection molding. By setting corresponding solder pad metal inside the mold, a solder pad structure can be formed on the surface of the bracket 1 while the bracket 1 is being molded by mold injection molding, so as to meet the die bonding requirements of the LED chip 4.

[0060] Two or more metal lead-out frames 5 are symmetrically distributed along the geometric center of the top surface of the support 1, and an S-shaped insulating channel 3 is formed between the two or more metal lead-out frames 5. Based on the symmetrical distribution of the geometric center, the two or more metal lead-out frames 5 can increase the contact area with the support 1 and form a staggered distribution state, thereby effectively improving the bonding force between the metal lead-out frames 5 and the support 1.

[0061] Specifically, the two or more metal lead-out brackets 5 include a first pad 511 and a second pad 521. The first pad 511 is provided with a first finger 511 extending towards the second pad 521, and the second pad 521 is provided with a second finger extending towards the first pad 511. The first finger and the second finger are staggered to form a staggered distribution. The first pad 511 and the second pad 521 are respectively located at both ends of the length direction of the bracket 1, so that the first finger and the second finger are arranged along the length direction. By setting the first finger, the first pad 511 can form a large area of ​​contact with the bracket 1 in the length direction. By setting the second finger, the second pad 521 can form a large area of ​​contact with the bracket 1 in the length direction. That is, the shape design of the first pad 511 and the second pad 521 can span across the top surface of the bracket 1 in the length direction, thereby effectively improving the bonding force between the first pad 511 and the second pad 521 and the bracket 1.

[0062] Specifically, in this embodiment, the cup body of the support 1 and the white wall 2 are integrally formed. The white wall 2 is formed inside the cup body of the support 1 based on the integral molding process. A connecting part is formed between the white walls 2 at both ends inside the cup body. The connecting part is filled in the insulating channel 3 between the first pad 511 and the second pad 521, so that the white walls 2 at both ends inside the cup body can be formed simultaneously, improving the convenience of the support 1 structure preparation.

[0063] Specifically, the white wall 2 is configured as an inclined slope structure, and the white wall 2 forms a preset angle with the top surface of the support 1. The angle of the preset angle is θ, and the value range of θ is 0° < θ < 25°. In this embodiment, the value of θ can be one of 10°, 12°, 15°, 17°, 20°, and 23°. Based on the angle design of the preset angle, the white wall 2 can meet the reflection requirements of the side-emitting light of the LED chip 4 and avoid the white wall 2 from blocking the side-emitting light of the LED chip 4, thus ensuring that the LED package device has a good light emission range.

[0064] Furthermore, by adjusting the cup structure of the bracket 1 based on the white wall 2, the refractive index of the cup structure of the bracket 1 can be increased, thereby improving the overall brightness of the LED packaged device by 0.5% to 1%.

[0065] Furthermore, the white wall 2 can be made of silicone, which has good thermal stability, chemical stability, and high mechanical strength. By dispensing silicone into the cup structure of the bracket 1 to form the white wall 2 structure, the brightness of the LED packaged device can be improved while the device's anti-sulfurization performance can be enhanced.

[0066] Specifically, the cup body of the bracket 1 is filled with a fluorescent adhesive layer 7, and the LED chip 4 is completely contained within the fluorescent adhesive layer 7, so that the light emitted by the LED chip 4 can pass through the fluorescent adhesive layer 7 and be emitted to the outside to meet the light color requirements of different application devices.

[0067] Specifically, the bottom surface of the bracket 1 is provided with two or more bottom pads 6, including a third pad 61 and a fourth pad 62. An S-shaped insulating channel 3 is formed between the third pad 61 and the fourth pad 62. The structural arrangement of the two or more bottom pads 6 is the same as that of the two or more metal lead-out brackets 5. By forming an S-shaped insulating channel 3 between the third pad 61 and the fourth pad 62, the contact area between the bottom pads 6 and the bracket 1 is increased, thereby improving the bonding force between the bottom pads 6 and the bracket 1.

[0068] Furthermore, the third pad 61 is provided with a third finger 611 extending towards the fourth pad 62, and the fourth pad 62 is provided with a fourth finger 621 extending towards the third pad 61. The third finger 611 and the fourth finger 621 are staggered to form a staggered distribution. The third pad 61 and the fourth pad 62 are respectively located at both ends of the length direction of the bracket 1, so that the third finger 611 and the fourth finger 621 are arranged along the length direction. By setting the third finger 611, the third pad 61 can form a large-area contact with the bracket 1 in the length direction. By setting the fourth finger 621, the fourth pad 62 can form a large-area contact with the bracket 1 in the length direction. That is, the shape design of the third pad 61 and the fourth pad 62 can span across the top surface of the bracket 1 in the length direction, thereby effectively improving the bonding force between the third pad 61 and the fourth pad 62 and the bracket 1.

[0069] Specifically, the bottom pad 6 is provided with a connection hole 63. The bottom of the bracket 1 is formed by an integral molding process to fill the connection hole 63. The connection hole 63 is provided in the bottom pad 6 so that the bracket 1 can fill the connection hole 63 during the injection molding process, thereby increasing the contact area between the bracket 1 and the bottom pad 6 and effectively improving the structural fit stability between the bracket 1 and the bottom pad 6.

[0070] Specifically, two or more bottom pads 6 are connected one-to-one with two or more metal lead-out brackets 5. The first pad 511 and the third pad 61 are connected in a corresponding manner, that is, the first pad 511 and the third pad 61 are covered on the surface of the bracket 1 based on the same metal. The second pad 521 and the fourth pad 62 are connected in a corresponding manner, that is, the second pad 521 and the fourth pad 62 are covered on the surface of the bracket 1 based on the same metal. This allows the first pad 511, the second pad 521, the third pad 61 and the fourth pad 62 to meet the electrical connection requirements of the LED chip 4.

[0071] This embodiment of the invention provides an LED packaging device. A plurality of pad structures are formed on the surface of a support 1, and S-shaped insulating channels 3 are formed between a plurality of metal lead-out frames 5 and a plurality of bottom pads 6. This increases the contact area between the metal lead-out frames 5 and the bottom pads 6 and the surface of the support 1, thereby improving the bonding force between the pad structures and the support 1 and reducing the risk of pad detachment and cracking. By forming a white wall 2 within the cup of the support 1 during its fabrication process, the light emitted from the LED chip 4 can be reflected and converged based on the white wall 2, thereby improving the luminous efficacy of the LED packaging device.

[0072] Furthermore, the above description provides a detailed overview of an LED packaging device provided by the embodiments of this utility model. Specific examples have been used to illustrate the principles and implementation methods of this utility model. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. An LED package device, comprising: The LED packaging device includes a bracket, which comprises a cup body and a metal lead-out bracket partially disposed within the cup body. The metal lead-out frame includes a first lead-out frame and a second lead-out frame; The top surface of the first lead-out bracket is the first pad, and the top surface of the second lead-out bracket is the second pad; The first pad and the second pad are symmetrically distributed along the geometric center of the top surface of the bracket, and an S-shaped insulating channel is formed between the first pad and the second pad.

2. The LED packaging device according to claim 1, wherein, The first pad is provided with a first finger extending toward the second pad, and the second pad is provided with a second finger extending toward the first pad. The first finger and the second finger are staggered to form a misaligned distribution.

3. The LED packaging device according to claim 1, wherein, The metal lead-out frame is configured as a rectangular structure, and the S-shaped insulated channel includes a first section, a second section, and a third section; The first segment and the third segment are parallel to the wide side of the rectangular structure, and the second segment is parallel to the long side of the rectangular structure.

4. The LED packaging device according to claim 3, wherein, The LED packaging device also includes a white wall disposed inside the cup body, which covers the periphery of the LED chip.

5. The LED packaging device as described in claim 3, characterized in that, The white wall is configured as an inclined slope structure, and the white wall forms a preset angle with the top surface of the support. The preset included angle is θ, and the value range of θ is: 0° < θ < 25°.

6. The LED packaging device as described in claim 3, characterized in that, The white walls are made of silicone.

7. The LED packaging device as described in claim 3, characterized in that, The tilt angle of the cup of the bracket of the LED packaging device is α, and the value of α is 25°≤α≤35°.

8. The LED packaging device as described in claim 1, characterized in that, The cup structure of the bracket covers an area of ​​S1 on the plane where the S-shaped insulating channel is located, and the area of ​​the plane where the S-shaped insulating channel is located is S2. The constraint relationship between S1 and S2 is: 0.3*S2≤S1≤0.8*S2.

9. The LED packaging device as described in claim 1, characterized in that, The metal lead-out bracket is provided with a connection hole, and the connection hole extends through the metal lead-out. The cup of the bracket fills the connection hole.

10. The LED packaging device as described in claim 1, characterized in that, The bottom surface of the bracket forms two or more bottom pads based on the metal lead-out frame. The two or more bottom pads include a third pad and a fourth pad, and an S-shaped insulating channel is formed between the third pad and the fourth pad.

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