A plastic package patch pressure sensitive resistor and a production process thereof

Abstract

The application discloses a plastic package patch pressure sensitive resistor and a production process thereof. The production process of the plastic package patch pressure sensitive resistor comprises the following steps: step one, one-time cutting; step two, bending; step three, inserting; step four, welding; step five, two-time cutting; and step six, packaging. The plastic package patch pressure sensitive resistor is obtained through the above production process and comprises a shell, a multilayer ceramic element packaged in the shell, a left electrode sheet and a right electrode sheet welded at two ends of the multilayer ceramic element respectively, and wherein the left electrode sheet and the right electrode sheet are bent to form leads after being led out from the inside of the shell to the outside of the shell. The plastic package patch pressure sensitive resistor and the production process thereof improve the utilization rate of the whole-page electrode material to reduce material waste on the basis of improving the production efficiency based on whole-page production.

Description

Technical Field

[0001] This invention relates to the field of plastic-encapsulated surface mount varistors, and in particular to a plastic-encapsulated surface mount varistor and its manufacturing process. Background Technology

[0002] The plastic-encapsulated surface mount varistor is a multilayer ceramic element (with alternating semiconductor ceramic layers and internal metal electrode layers). Electrode plates are provided at both ends of the multilayer ceramic element. The multilayer ceramic element is encapsulated in a housing. The electrode plates are led out from the inside of the housing and adaptively bent to form leads. The leads of the plastic-encapsulated surface mount varistor are soldered to the pads on the circuit board using surface mount technology (SMT).

[0003] In the production process of plastic-encapsulated surface mount varistors, electrode plates need to be welded to both ends of the multilayer ceramic element. On the one hand, since the multilayer ceramic element and electrode plates are relatively small in size, production efficiency needs to be considered in the process of large-scale mechanized production. On the other hand, in order to improve the utilization rate of the whole plate of electrode material, the layout of the whole plate of electrode material also needs to be considered, so as to reduce the waste of electrode material. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a plastic-encapsulated chip varistor and its manufacturing process, which improves the utilization rate of the whole plate electrode material to reduce material waste on the basis of improving production efficiency based on whole plate production.

[0005] The objective of this invention is achieved through the following technical solution: A manufacturing process for a plastic-encapsulated surface mount varistor includes the following steps: Step 1: Cut once; Provide a whole plate of electrode material, cut the whole plate of electrode material once to obtain the frame body and several sets of electrode pairs. The several sets of electrode pairs are arranged in a rectangular array along the X-axis and Y-axis of the frame body. Each electrode pair includes a left electrode plate and a right electrode plate. The left electrode plate has a left connecting end that is connected to the frame body, and the right electrode plate has a right connecting end that is connected to the frame body. Step 2: Bending; The left and right electrode pieces in the electrode pair are bent so that the left electrode piece has a left flat part and a left bent part, and the right electrode piece has a right flat part and a right bent part; the left and right bent parts in the same electrode pair have the same bending direction; in the X-axis direction of the frame body, the left and right bent parts in adjacent electrode pairs have opposite bending directions. Step 3: Connect; Several multilayer ceramic elements are provided, and each multilayer ceramic element is correspondingly inserted into each electrode pair. The two ends of the multilayer ceramic elements are respectively held against the left and right bends by solder paste. Step 4: Welding; The entire electrode plate with inserted multi-layer ceramic components is welded so that the two ends of the multi-layer ceramic components are welded to the left and right bends respectively. Step 5: Secondary cutting; The whole plate electrode material is cut twice to separate the left and right connecting ends from the frame body to obtain several semi-finished products. Each semi-finished product includes a multi-layer ceramic element and a left electrode plate and a right electrode plate respectively welded to its two ends. Step 6: Packaging; The semi-finished product is encapsulated in a housing. The left and right electrode plates of the semi-finished product are led out from inside the housing to the outside of the housing and bent to form leads, thus obtaining a plastic-encapsulated chip varistor.

[0006] In one embodiment, in step one, the left electrode sheet is separated from the frame body except for the portion of the left connecting end, and the right electrode sheet is separated from the frame body except for the portion of the right connecting end; the extension line of the left electrode sheet is in the same direction as the Y-axis of the frame body, and the extension line of the right electrode sheet is in the same direction as the Y-axis of the frame body; in each electrode pair, the extension lines of the left electrode sheet and the right electrode sheet are on the same straight line.

[0007] In one embodiment, in step two, the left and right flush portions are on the same plane as the frame body, and the left and right bent portions form an angle with the frame body.

[0008] In one embodiment, the left and right bends are perpendicular to the frame body.

[0009] In one embodiment, in step four, a reflow soldering process is used to solder the two ends of the multilayer ceramic element to the left bend and the right bend, respectively.

[0010] In one embodiment, in step six, the housing includes an upper housing and a lower housing, which are fastened together; the outer side wall of the lower housing is provided with an electrode receiving groove for accommodating the left electrode plate and the right electrode plate.

[0011] In one embodiment, in step six, the shell is a tank structure with one end open and the other end closed. The semi-finished product is first placed in the tank and the left and right electrode plates are led out. Then, glue is poured into the tank to allow it to solidify.

[0012] In one embodiment, in step one, the whole plate of electrode material is cut once using laser cutting technology to obtain the frame body and several sets of electrode pairs; in step five, the left connecting end and the right connecting end are cut off from the frame body using laser cutting technology.

[0013] A plastic-encapsulated surface mount varistor, obtained through the above-described manufacturing process, includes: a housing, a multilayer ceramic element encapsulated within the housing, and a left electrode and a right electrode respectively soldered to its two ends; wherein the left electrode and the right electrode are led out from inside the housing to outside the housing and bent to form leads.

[0014] The plastic-encapsulated patch varistor and its manufacturing process of the present invention, based on the whole-plate production to improve production efficiency, improves the utilization rate of whole-plate electrode materials to reduce material waste. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of cutting a whole sheet of electrode material in one operation. Figure 2 This is a schematic diagram of bending a whole sheet of electrode material after one cut. Figure 3 This is a schematic diagram showing how several multilayer ceramic elements are correspondingly inserted into each electrode pair. Figure 4 This is an exploded view of a plastic-encapsulated surface mount varistor according to an embodiment of the present invention; Figure 5 This is a cross-sectional view of a plastic-encapsulated surface mount varistor according to an embodiment of the present invention. Detailed Implementation

[0017] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0018] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0020] This invention discloses a manufacturing process for a plastic-encapsulated surface mount varistor, comprising the following steps: Step 1: Cut once; like Figure 1 As shown, a single-plate electrode material 100 is provided. The single-plate electrode material 100 is cut once to obtain a frame body 200 and several sets of electrode pairs 300. The several sets of electrode pairs 300 are arranged along the X-axis direction of the frame body 200 (e.g., ...). Figure 1 (as shown) and the Y-axis direction (as shown) Figure 1 The electrodes (as shown) are arranged in a rectangular array. Each electrode pair 300 includes a left electrode plate 310 and a right electrode plate 320. The left electrode plate 310 has a left connecting end 301 that connects to the frame body 200 (as shown). Figure 2 As shown), the right electrode plate 320 has a right connecting end 302 that connects to the frame body 200 (as shown). Figure 2 (as shown) like Figure 1 As shown, in step one, the left electrode 310, except for the left connecting end 301, is separated from the frame body 200, and the right electrode 320, except for the right connecting end 302, is separated from the frame body 200. The extension line of the left electrode 310 is in the same direction as the Y-axis of the frame body 200, and the extension line of the right electrode 320 is in the same direction as the Y-axis of the frame body 200. In each electrode pair 300, the extension line of the left electrode 310 and the extension line of the right electrode 320 are on the same straight line. In this way, the left electrode 310 and the right electrode 320 can form an electrode pair. Several groups of electrode pairs 300 are arranged in a rectangular array along the X-axis and Y-axis directions of the frame body 200, such as... Figure 1As shown, in this embodiment, there are a total of 36 groups of electrode pairs 300, which are arranged in 2 rows and 18 columns, that is, 18 columns along the X-axis and 2 rows along the Y-axis; in some embodiments, they can also be arranged in 1 row and multiple columns. Thus, the whole plate electrode material 100 can be regarded as a straight infinitely extended roll strip structure. In step one, the whole plate electrode material 100 is cut once using laser cutting technology to obtain the frame body 200 and several sets of electrode pairs 300. At this time, the left electrode piece 310 and the right electrode piece 320 in the electrode pair 300 are still flush with the frame body 200. Step 2: Bending; like Figure 2 As shown, the left electrode 310 and the right electrode 320 in the electrode pair 300 are bent, so that the left electrode 310 has a left flat portion 311 and a left bent portion 312, and the right electrode 320 has a right flat portion 321 and a right bent portion 322; the bending directions of the left bent portion 312 and the right bent portion 322 in the same electrode pair 300 are the same; in the X-axis direction of the frame body 200, the bending directions of the left bent portion 312 and the right bent portion 322 in adjacent electrode pairs 300 are opposite; like Figure 2 As shown, it should be explained that the whole-plate electrode 100 has two opposing panels; the bending directions of the left bending portion 312 and the right bending portion 322 in the same electrode pair 300 are the same, which should be understood as: the left bending portion 312 and the right bending portion 322 both protrude towards the same panel; the bending directions of the left bending portion 312 and the right bending portion 322 in adjacent electrode pairs 300 are opposite, which should be understood as: the left bending portion 312 and the right bending portion 322 in one electrode pair protrude towards the two panels respectively, as do the left bending portion 312 and the right bending portion 322 in the other electrode pair; like Figure 2 As shown, in step two, the left flush portion 311 and the right flush portion 321 are on the same plane as the frame body 200, and the left bent portion 312 and the right bent portion 322 form an angle with the frame body 200; specifically, in this embodiment, the left bent portion 312 and the right bent portion 322 are perpendicular to the frame body 200.

[0021] It should be noted that, in the X-axis direction of the frame body 200, the bending directions of the left-side bent portion 312 and the right-side bent portion 322 in adjacent electrode pairs 300 are opposite. This process is mainly based on the following considerations: if the bending directions of the left-side bent portion 312 and the right-side bent portion 322 in all electrode pairs 300 were the same, due to the influence of the multilayer ceramic elements 400 (such as... Figure 3Due to size constraints (as shown), more space needs to be allocated between adjacent electrode pairs 300 in the X-axis direction to accommodate multilayer ceramic elements 400. This results in the inefficient use of the entire electrode plate 100, leading to material waste. To fully utilize the entire electrode plate 100, in this invention, the left-side bend 312 and right-side bend 322 of adjacent electrode pairs 300 have opposite bending directions in the X-axis direction of the frame body 200. This effectively allows the multilayer ceramic elements 400 to be "stacked" in the spatial direction of the entire electrode plate 100, thus minimizing the spacing between adjacent electrode pairs 300 in the X-axis direction and ensuring full utilization of the entire electrode plate 100. Step 3: Connect; like Figure 3 As shown, a plurality of multilayer ceramic elements 400 are provided, and each multilayer ceramic element 400 is correspondingly inserted into each electrode pair 300. The two ends of the multilayer ceramic element 400 are respectively held against the left bending portion 312 and the right bending portion 322 by solder paste. The left bending portion 312 and the right bending portion 322 after bending have good elasticity and can hold the multilayer ceramic component 400 well. During the insertion process, the multilayer ceramic component 400 is not easy to fall off. Existing surface mount technology (SMT) equipment can be used to accurately insert multilayer ceramic components 400 into each electrode pair 300, thereby improving production efficiency. Step 4: Welding; The integral electrode plate 100 with the multilayer ceramic element 400 inserted is welded so that the two ends of the multilayer ceramic element 400 are respectively welded to the left bending portion 312 and the right bending portion 322. In this embodiment, a reflow soldering process can be used to weld the two ends of the multilayer ceramic element 400 to the left bending portion 312 and the right bending portion 322 respectively. For example, a fixture can be provided to vertically place multiple integral electrode plates 100 (the plate surface is perpendicular to the horizontal plane), and the edge of the frame body 200 is inserted into the limiting groove opened in the fixture. The fixture containing multiple integral electrode plates 100 is placed in the welding furnace for welding. Step 5: Secondary cutting; like Figure 3 As shown, the whole-plate electrode material 100 is cut twice to separate the left connecting end 301 and the right connecting end 302 from the frame body 200, resulting in several semi-finished products, such as... Figure 3 and Figure 4As shown, each half of the finished product includes a multilayer ceramic element 400 and a left electrode plate 310 and a right electrode plate 320 respectively welded to its two ends; in this embodiment, the left connecting end 301 and the right connecting end 302 can be cut off from the frame body 200 using a laser cutting process. It is understandable that after the left connecting end 301 and the right connecting end 302 are cut off from the frame body 200, the semi-finished product will automatically fall off, thereby obtaining several semi-finished products. The semi-finished product includes a multilayer ceramic element 400 and a left electrode plate 310 and a right electrode plate 320 respectively welded to its two ends. The frame body 200 generates very little waste. Step 6: Packaging; like Figure 4 As shown, the semi-finished product is encapsulated in a housing 500. The left electrode 310 and right electrode 320 of the semi-finished product are led out from inside the housing to the outside of the housing and bent to form leads, thus obtaining a plastic-encapsulated surface mount varistor 10 (e.g., Figure 5 (as shown) like Figure 4 As shown, in this embodiment, the housing 500 includes an upper housing 510 and a lower housing 520, which are fastened together; the outer side wall of the lower housing 520 is provided with an electrode receiving groove 521 for receiving the left electrode plate 310 and the right electrode plate 320.

[0022] In other embodiments, the housing 500 is a groove structure with one end open and the other end closed (which can be understood as a single lower housing 520). The semi-finished product is first placed in the groove and the left electrode plate 310 and the right electrode plate 320 are led out. Then, glue is poured into the groove to solidify, thereby realizing the encapsulation of the component.

[0023] The process described above for this invention is explained as follows: In step two, a specific bending process is used to lay the foundation for the insertion process in step three. Since the left bending portion 312 and the right bending portion 322 have good elasticity after bending, the multilayer ceramic component 400 can be well clamped and is not easy to fall off, thus providing a foundation for subsequent welding. In addition, the multilayer ceramic component 400 can be accurately inserted into each electrode pair 300 using existing surface mount technology, thereby improving production efficiency. In step four, the entire electrode plate 100 with the inserted multilayer ceramic components 400 can be welded, which can greatly improve the welding efficiency and stability. In both steps one and five, cutting is performed on the entire plate. Laser cutting technology can achieve rapid cutting of the entire plate, resulting in high production efficiency. In addition, in step two, due to the size constraints of the multilayer ceramic element 400, in order to improve the utilization rate of materials, the bending directions of the left bending portion 312 and the right bending portion 322 in the adjacent electrode pair 300 are opposite in the X-axis direction of the frame body 200. In this way, it is equivalent to "stacking" the multilayer ceramic element 400 in the spatial direction of the whole plate electrode material 100. Thus, the interval between adjacent electrode pairs 300 in the X-axis direction can be minimized to the greatest extent, so that the whole plate electrode material 100 can be fully utilized.

[0024] like Figure 5 As shown, the present invention also discloses a plastic-encapsulated surface mount varistor 10, which is obtained by the above-described plastic-encapsulated surface mount varistor manufacturing process, including: a housing 500, a multilayer ceramic element 400 encapsulated in the housing 500, and a left electrode 310 and a right electrode 320 respectively welded to its two ends; wherein, the left electrode 310 and the right electrode 320 are led out from inside the housing 500 to outside the housing 500 and bent to form leads.

[0025] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A manufacturing process for a plastic-encapsulated surface mount varistor, characterized in that, Includes the following steps: Step 1: Cut once; Provide a whole plate of electrode material, cut the whole plate of electrode material once to obtain the frame body and several sets of electrode pairs. The several sets of electrode pairs are arranged in a rectangular array along the X-axis and Y-axis of the frame body. Each electrode pair includes a left electrode plate and a right electrode plate. The left electrode plate has a left connecting end that is connected to the frame body, and the right electrode plate has a right connecting end that is connected to the frame body. Step 2: Bending; The left and right electrode pieces in the electrode pair are bent so that the left electrode piece has a left flat part and a left bent part, and the right electrode piece has a right flat part and a right bent part; the left and right bent parts in the same electrode pair have the same bending direction; in the X-axis direction of the frame body, the left and right bent parts in adjacent electrode pairs have opposite bending directions. Step 3: Connect; Several multilayer ceramic elements are provided, and each multilayer ceramic element is correspondingly inserted into each electrode pair. The two ends of the multilayer ceramic elements are respectively held against the left and right bends by solder paste. Step 4: Welding; The entire electrode plate with inserted multi-layer ceramic components is welded so that the two ends of the multi-layer ceramic components are welded to the left and right bends respectively. Step 5: Secondary cutting; The whole plate electrode material is cut twice to separate the left and right connecting ends from the frame body to obtain several semi-finished products. Each semi-finished product includes a multi-layer ceramic element and a left electrode plate and a right electrode plate respectively welded to its two ends. Step 6: Packaging; The semi-finished product is encapsulated in a housing. The left and right electrode plates of the semi-finished product are led out from inside the housing to the outside of the housing and bent to form leads, thus obtaining a plastic-encapsulated chip varistor.

2. The manufacturing process of the plastic-encapsulated surface mount varistor according to claim 1, characterized in that, In step one, the left electrode plate is separated from the frame body except for the left connecting end, and the right electrode plate is separated from the frame body except for the right connecting end; the extension line of the left electrode plate is in the same direction as the Y-axis of the frame body, and the extension line of the right electrode plate is in the same direction as the Y-axis of the frame body; in each electrode pair, the extension lines of the left electrode plate and the right electrode plate are on the same straight line.

3. The manufacturing process of the plastic-encapsulated surface mount varistor according to claim 1, characterized in that, In step two, the left and right flush parts are on the same plane as the main frame, and the left and right bent parts form an angle with the main frame.

4. The manufacturing process of the plastic-encapsulated surface mount varistor according to claim 3, characterized in that, The left and right bends are perpendicular to the main frame.

5. The manufacturing process of the plastic-encapsulated surface mount varistor according to claim 1, characterized in that, In step four, a reflow soldering process is used to solder the two ends of the multilayer ceramic component to the left and right bends, respectively.

6. The manufacturing process of the plastic-encapsulated surface mount varistor according to claim 1, characterized in that, In step six, the housing includes an upper housing and a lower housing, which are fastened together; the outer side wall of the lower housing is provided with an electrode receiving groove for accommodating the left electrode plate and the right electrode plate.

7. The manufacturing process of the plastic-encapsulated surface mount varistor according to claim 1, characterized in that, In step six, the shell is a tank structure with one end open and the other end closed. First, the semi-finished product is placed in the tank and the left and right electrode plates are led out. Then, glue is poured into the tank to allow it to solidify.

8. The manufacturing process of the plastic-encapsulated surface mount varistor according to claim 1, characterized in that, In step one, the whole plate of electrode material is cut once using laser cutting technology to obtain the frame body and several sets of electrode pairs; in step five, the left connecting end and the right connecting end are cut off from the frame body using laser cutting technology.

9. A plastic-encapsulated surface mount varistor, characterized in that, The plastic-encapsulated surface mount varistor is manufactured using the production process described in any one of claims 1 to 8, comprising: a housing, a multilayer ceramic element encapsulated within the housing, and a left electrode plate and a right electrode plate respectively welded to its two ends; wherein the left electrode plate and the right electrode plate are led out from inside the housing to outside the housing and bent to form leads.

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