SMD (Surface Mount Device) electronic component

Abstract

The invention relates to the technical field of electronic components, in particular to an SMD (Surface Mount Device) electronic component, which overcomes the problems that the existing SMD electronic component possibly damages a circuit board, is not firmly welded with the circuit board and is not beneficial to automatic suction. The upper pin and the lower pin are respectively welded on the upper electrode and the lower electrode and extend out of the functional ceramic body, and the encapsulating layer wraps the functional ceramic body, the upper electrode, the lower electrode and the wrapping part of the upper pin and the lower pin. The parts, exposed out of the encapsulation layer, of the upper pin and the lower pin respectively comprise an initial section extending out of the functional ceramic body, a lower folding section bent downwards from the initial section and a transverse folding section bent to the lower part of the functional ceramic body from the lower folding section, and the transverse folding section continuously extends to form a supporting part which is in contact with or tends to be in contact with the bottom surface of the encapsulation layer; the bottoms of the upper and lower pin transverse folding sections are positioned on the same plane, and at least parts of the upper and lower pin transverse folding sections are welding parts of the electronic element on the circuit board.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic components, in particular to a surface mount electronic component. Background Art

[0002] The advantages of surface-mount electronic components over plug-in electronic components are: 1. They can achieve flattening of printed circuit board (PCB) products; 2. The components are suitable for soldering to the circuit board using the reflow soldering process, which improves soldering efficiency; 3. The components are more convenient for automated absorption, which increases production speed. However, existing surface-mount electronic components also have shortcomings due to structural reasons.

[0003] The structure of existing chip electronic components is roughly similar to that of a chip-coated varistor disclosed in Chinese Patent Publication No. CN207217208U in April 2018. The protruding ends of the upper and lower pins of the varistor extend in the same direction and are bent in a Z-shape so that the lower surfaces of the protruding ends of the upper and lower pins are on the same plane. The main disadvantages of such chip electronic components are:

[0004] 1. The component body is directly attached to the PCB surface. For example, when thermistor is powered on, its body temperature may rise to 150-250°C. Prolonged high-temperature operation of the component will cause the PCB to be heated and baked, posing the risk of carbonization or aging.

[0005] Second, because the center of gravity is significantly deviated from the geometric center, it is difficult for the two pins of the thermistor to maintain a coplanar surface, which can easily cause the pins to tilt, thereby increasing the risk of incomplete solder joints or cold solder joints during the soldering process.

[0006] Third, because the center of gravity obviously deviates from the geometric center, the state of the component body is not stable enough, which affects the suction nozzle of the automated device to absorb the component. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a patch type electronic component to overcome the problems that the existing patch electronic components may damage the circuit board, are not firmly welded to the circuit board and are not conducive to automatic absorption.

[0008] The technical solution adopted by the present invention to solve its technical problems is: a chip-type electronic component, comprising a functional ceramic body, wherein upper and lower electrodes are respectively provided on the upper and lower surfaces of the functional ceramic body, and upper and lower pins are respectively welded to the upper and lower electrodes and extend from the functional ceramic body, and further comprising an encapsulation layer, wherein the encapsulation layer wraps the functional ceramic body, the upper electrode, the lower electrode and the upper and lower pins of the wrapped portion, and the portions of the upper and lower pins exposed from the encapsulation layer respectively comprise a starting section extending from the functional ceramic body, a lower folding section bent downward from the starting section and a transverse folding section folded from the lower folding section toward the bottom of the functional ceramic body, the transverse folding section continues to extend to form a support portion that contacts or tends to contact the bottom surface of the encapsulation layer, the bottoms of the transverse folding sections of the upper and lower pins are in the same plane, and at least part of the transverse folding sections of the upper and lower pins are the welding portions of the electronic component and the circuit board.

[0009] Specifically, the support portion is composed of two diagonal braces connected at the top ends.

[0010] Specifically, the included angle between the two diagonal braces of the support portion is 30 to 150 degrees.

[0011] Specifically, the oblique braces on the support portion formed by extending from the transverse folding section that are not connected to the transverse folding section further extend into a stabilizing section, and the bottoms of the stabilizing sections of the upper and lower pins are respectively in the same plane.

[0012] Specifically, the bottom plane of the stabilizing section is 0.1 to 0.3 mm higher than the bottom plane of the transverse folding section.

[0013] Specifically, the starting section of the upper pin is in a straight line shape, the starting section of the lower pin is in a broken line shape, and the lower broken sections of the upper and lower pins are parallel to each other and have the same length.

[0014] Specifically, the transverse folding sections of the upper and lower pins are parallel to each other and have the same length.

[0015] Specifically, in another structure, the transverse folding sections of the upper and lower pins are parallel to each other but have different lengths.

[0016] Specifically, the support portion is in an upwardly arched arc shape, and the support portion further extends into a stabilizing section, and the bottoms of the stabilizing sections of the upper and lower pins are respectively located in the same plane.

[0017] Specifically, the welding sections where the upper and lower pins are welded to the upper and lower electrodes and / or the welding portions where the electronic components on the transverse folding sections are welded to the circuit board are flat.

[0018] Specifically, in order to prevent the upper and lower pins from being deformed and displaced, the electronic component further includes a clamping block for clamping the upper and lower pins, and the clamping block is made of insulating material.

[0019] The beneficial effects of the present invention are:

[0020] 1. The parts of the upper and lower pins of the component exposed from the encapsulation layer support a space between the encapsulation layer and the circuit board, effectively avoiding contact between the heating element and the circuit board, and preventing the circuit board from carbonizing or aging due to long-term heating;

[0021] Second, when the mechanical suction nozzle contacts the upper surface of the component, the support part can provide a reaction force to effectively prevent tilting, which helps to realize automated suction operations;

[0022] 3. The components have good stability when placed on the circuit board, and the support part can also suppress the warping of the solder joint area between the pin and the circuit board, reducing the risk of defective solder joints and improving welding reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0024] Figure 1 It is a three-dimensional embodiment of the present invention. Figure 1 ;

[0025] Figure 2 It is a three-dimensional embodiment of the present invention. Figure 2 ;

[0026] Figure 3 is a front view of embodiment 1 of the present invention;

[0027] Figure 4 is a perspective view of embodiment 2 of the present invention;

[0028] Figure 5 The three-dimensional embodiment of the present invention Figure 1 ;

[0029] Figure 6 The three-dimensional embodiment of the present invention Figure 2 ;

[0030] Figure 7 is a perspective view of embodiment 4 of the present invention;

[0031] Figure 8 It is a three-dimensional embodiment of the present invention 5 Figure 1 ;

[0032] Figure 9 It is a three-dimensional embodiment of the present invention 5 Figure 2 ;

[0033] Figure 10 This is an enlarged view of the clamping block in Example 5 of the present invention.

[0034] In the figure, 1 is a functional ceramic body, 2 is an upper electrode, 3 is a lower electrode, 4 is an upper pin, 5 is a lower pin, 6 is an encapsulation layer, 7 is a starting section, 8 is a lower folding section, 9 is a horizontal folding section, 10 is a supporting part, 11 is a stabilizing section, 12 is a clamping block, 12-1 is a pin hole, and 12-2 is a pin groove. DETAILED DESCRIPTION

[0035] The present invention will now be described in further detail with reference to the accompanying drawings and preferred embodiments. These drawings are simplified schematic diagrams that only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0036] Example 1:

[0037] Attachment Figure 1 、 2 and 3 are structures of Example 1 of the present invention, and the external shape is as follows Figure 1 and Figure 2 , the internal structure is as follows Figure 3 , having a functional ceramic body 1, which can be a thermosensitive chip, a pressure-sensitive chip, or other electronic chip sintered from a set component and having certain electrical properties, an upper electrode 2 and a lower electrode 3 are respectively provided on the upper and lower surfaces of the functional ceramic body 1, an upper pin 4 and a lower pin 5 are respectively welded on the upper electrode 2 and the lower electrode 3 and extend from the functional ceramic body 1, and further having an encapsulation layer 6, the encapsulation layer 6 wraps the functional ceramic body 1, the upper electrode 2 and the lower electrode 3 and the wrapped portion of the upper and lower pins, and the portions of the upper and lower pins exposed from the encapsulation layer 6 include a starting section 7 extending from the functional ceramic body 1 and a lower folded section 8 bent downward from the starting section 7. and a transverse folding section 9 folded from the lower folding section 8 to the bottom of the functional ceramic body 1, the transverse folding section 9 continues to extend to form a support portion 10 that contacts or tends to contact the bottom surface of the encapsulation layer 6, the bottoms of the transverse folding sections 9 of the upper and lower pins are in the same plane. When the upper and lower pins are conductive round wires, the lower side of the transverse folding section 9 actually corresponds to a contact line closest to the circuit board on the outer surface of the cylindrical conductive wire, that is, the lower edge contact area where its circumferential surface contacts the circuit board, so that the bottoms of the transverse folding sections 9 of the upper and lower pins are in the same plane is equivalent to making the upper and lower pins parallel; at least a portion of the transverse folding sections 9 of the upper and lower pins is the welding portion between the electronic component and the circuit board.

[0038] The support portion 10 is formed by two diagonal braces connected at the top, for example, a triangular support portion formed by the two diagonal braces and the bottom. The included angle α of the two diagonal braces of the support portion 10 is 60 degrees. When the included angle α of the diagonal braces is less than 30 degrees or greater than 150 degrees, the supporting function cannot be effectively exerted, which may lead to insufficient structural strength or support failure. Therefore, about 60 degrees is the best. The diagonal braces on the support portion 10 that are not connected to the transverse folding section 9 continue to extend the stabilizing section 11. The bottoms of the stabilizing sections 11 of the upper and lower pins are respectively in the same plane, and the plane where the bottom of the stabilizing section 11 is located is the same as the plane where the bottom of the transverse folding section 9 is located. The plane is parallel to the horizontal folding section 9, and the bottom plane of the stabilizing section 11 is 0.1 to 0.3 mm higher than the bottom plane of the horizontal folding section 9. This ensures reliable contact between the horizontal folding section 9 and the circuit board, and avoids the horizontal folding section 9 not being able to fit tightly against the circuit board due to the presence of the stabilizing section 11. The entire length of the horizontal folding section 9 is not limited to being used for welding connections with the circuit board. Therefore, the shape of the horizontal folding section 9 is not limited to the straight rod form shown in the accompanying drawings, but can also be a bent structure such as an inverted U-shape, or a deformed structure in which one or two short straight rods are provided as the welding portion to meet actual installation and welding requirements.

[0039] The starting section 7 of the upper pin 4 is straight, while the starting section 7 of the lower pin 5 is zigzag-shaped. The starting section 7 of the zigzag-shaped lower pin 5 is Z-shaped. The lower folded sections 8 of the upper and lower pins are parallel to each other and of equal length. This structure facilitates the synchronous bending and forming of the upper and lower pins during subsequent processing, helping to improve the consistency and processing efficiency of the forming. Optionally, the starting section 7 of the lower pin 5 can also be straight. However, under this structure, the forming process of the lower pin 5 may be relatively inconvenient, and may result in inconsistent lengths of the lower folded sections 8 of the upper and lower pins, affecting the overall forming accuracy.

[0040] The transverse folding sections 9 of the upper and lower pins are parallel to each other and equal in length, or they may be in another structure, wherein the transverse folding sections 9 of the upper and lower pins are parallel to each other but have different lengths, so that the supporting parts 10 of the upper and lower pins are staggered front to back, forming another supporting effect.

[0041] Example 2:

[0042] like Figure 4 As shown, the structural difference between Example 2 and Example 1 is that the welding sections of the upper pin 4 and the lower pin 5 welded on the upper electrode 2 and the lower electrode 3 respectively are in the shape of protrusions. The advantage of this structure is that less material is used for the encapsulation layer 6. The disadvantage is that although it can be automatically sucked, the suction reliability is insufficient or the suction nozzle requirements are high.

[0043] Example 3:

[0044] like Figure 5 and Figure 6As shown, the structural differences between Example 3 and Example 1 are that the welding section of the pin on the electrode is in a protruding shape, and the support portion 10 is changed from a triangular support to an upwardly arched arc support.

[0045] Example 4:

[0046] like Figure 7 As shown, the structural difference between Example 4 and Example 1 is that the upper and lower pins are changed from conductive round wires to conductive flat wires.

[0047] Example 5:

[0048] like Figure 8 、 9 As shown in Figure 10, Example 5 is an electronic component formed by adding a clamping block 12 for shaping and positioning the upper and lower pins on the basis of Example 4. The clamping block 12 is an insulating material piece and is provided with a pin hole 12-1 and a pin slot 12-2. There are two pin holes 12-1, which are used for the upper pin 4 and the lower pin 5 respectively, and there are four pin slots 12-2. On the basis that the lower folding section 8 is located in the pin hole 12-1, the pin slots 12-2 at the openings of the pin hole 12-1 at both ends respectively accommodate the part of the starting section 7 close to the lower folding section 8 and the part of the transverse folding section 9 close to the lower folding section 8.

[0049] Of course, the electronic component can also be formed by adding a clamping block 12 on the basis of the structure of embodiments 1-3.

[0050] The shapes of the upper and lower pins of the electronic component of the present invention can be formed by extrusion of a mold.

[0051] In addition, the upper and lower pins can also be made of round wire that has been partially flattened, such as flattening the welding sections of the upper and lower pins welded on the electrodes and / or the welding sections of the electronic components and the circuit board on the transverse folding section 9.

[0052] Finally, the top and bottom of the encapsulation layer 6 can be planes as shown in Example 1, or they can be smooth spherical surfaces with a slightly bulging center. The smooth spherical surface can also well meet the requirements of automated suction.

[0053] The above description only describes specific embodiments of the present invention. Various examples do not limit the essential content of the present invention. After reading the description, ordinary technicians in the relevant technical field can make modifications or variations to the specific embodiments described above without departing from the essence and scope of the invention.

Claims

1. A surface-mount electronic component comprising a functional ceramic body, upper and lower electrodes provided on the upper and lower surfaces of the functional ceramic body, upper and lower leads welded to the upper and lower electrodes and extending from the functional ceramic body, and an encapsulating layer encapsulating the functional ceramic body, the upper and lower electrodes, and the encapsulated portions of the upper and lower leads, wherein: The parts of the upper and lower pins exposed from the encapsulation layer respectively include a starting section extending from the functional ceramic body, a lower folding section bent downward from the starting section, and a transverse folding section folded from the lower folding section to the bottom of the functional ceramic body. The transverse folding section continues to extend to form a supporting portion that contacts or tends to contact the bottom surface of the encapsulation layer. The bottoms of the transverse folding sections of the upper and lower pins are in the same plane, and at least part of the transverse folding sections of the upper and lower pins are the welding parts between the electronic components and the circuit board.

2. The surface-mount electronic component according to claim 1, wherein: The supporting portion is composed of two oblique supports connected at the top ends.

3. The surface-mount electronic component according to claim 2, wherein: The included angle between the two diagonal braces of the supporting part is 30 to 150 degrees.

4. The surface-mount electronic component according to claim 2 or 3, wherein: The oblique support on the support portion formed by extending from the transverse folding section and not connected to the transverse folding section further extends into a stabilizing section, and the bottoms of the stabilizing sections of the upper and lower pins are respectively in the same plane.

5. The surface-mount electronic component according to claim 4, wherein: The bottom of the stabilizing section is located on a plane 0.1 to 0.3 mm higher than the bottom of the transverse folding section.

6. The surface-mount electronic component according to claim 1, wherein: The starting section of the upper pin is in a straight line shape, the starting section of the lower pin is in a broken line shape, and the lower broken sections of the upper and lower pins are parallel to each other and have the same length.

7. The surface-mount electronic component according to claim 1, wherein: The transverse folding sections of the upper and lower pins are parallel to each other and have the same length.

8. The surface-mount electronic component according to claim 1, wherein: The transverse folding sections of the upper and lower pins are parallel to each other but have different lengths.

9. The surface-mount electronic component according to claim 1, wherein: The support portion is in an upwardly arched arc shape, and the support portion further extends into a stabilizing section, and the bottoms of the stabilizing sections of the upper and lower pins are respectively located in the same plane.

10. The surface-mount electronic component according to claim 1, wherein: The welding sections where the upper and lower pins are welded to the upper and lower electrodes and / or the welding sections where the electronic components on the transverse folding sections are welded to the circuit board are flat.

11. The surface-mount electronic component according to claim 1, wherein: The electronic component further comprises a clamping block for clamping the upper pin and the lower pin, and the clamping block is made of insulating material.

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