WO2021189877A1 - Pin, power device, method for manufacturing power device, and packaging mould - Google Patents

Abstract

A pin (102), a power device (100), a method for manufacturing a power device, and a packaging mould (200). The pin (102) comprises a first section (102a), a second section (102b) and a third section (102c), which are sequentially arranged, wherein the second section (102b) is composed of a rotating body; the distances between points on a rotating curved surface of the rotating body and a rotating shaft of the rotating body progressively increase or decrease in the axial direction; the first section (102a) is composed of a first columnar body; a bottom surface of the first columnar body is connected to a bottom surface, which has small area, of the second section (102b); and the cross-sectional area of the first columnar body is less than or equal to the area of a bottom surface, which has small area, of the rotating body. The pin (102) is constructed to be the rotating body at the second section (102b), which is located at a middle part, such that the pin (102) can be in sealing contact with the inner surface of an avoidance hole (204) of the packaging mould (200) by means of the rotating body, and in this case, even if the actual size of the existing circular avoidance hole (204) is greater than a design size, the pin (102) can also prevent a plastic packaging material from overflowing from the packaging mould (200) via the avoidance hole (204) during a packaging process of the power device (100).

Description

Pin, power device, power device manufacturing method and packaging mold

This disclosure is based on the patent document filed on March 23, 2020 with an application number of 202010209711.5 and titled "Pin, Power Device, Power Device Manufacturing Method and Packaging Mold" and the application number filed on March 23, 2020. 202020380049.5 and the name "pins, power devices and packaging molds" are priority documents, and the entire contents of the two are incorporated into the present disclosure by reference.

Technical field

The present disclosure belongs to the technical field of electronic power devices, and in particular relates to a pin, a power device, a manufacturing method of the power device, and a packaging mold of the power device.

Background technique

A typical power device is an IGBT module, a PIM module or an IPM module. The power device includes pins and a device body mainly composed of a DBC ceramic substrate, a chip and a bonding wire. In order to obtain better sealing performance, it is necessary to put the device body and pins into the packaging mold, and then inject the plastic packaging material into the packaging mold, so that it can be cured in the packaging mold and form a device that can hold the device body and pins together. Encapsulate the shell.

In order to expose a part of the cylindrical pin to the outside of the package shell, it is necessary to open a circular avoiding hole corresponding to the pin on the package mold. However, due to processing errors, the actual size of the existing circular avoidance holes is often larger than the design size, resulting in the radial size of the avoidance holes being larger than the radial size of the pins, so that the plastic packaging material can pass the avoidance during the packaging process of the power device. The hole overflows from the packaging mold. The above information disclosed in the background technology section is only used to strengthen the understanding of the background technology of the technology described in this article. Therefore, the background technology may contain certain information, which is not formed in the country for those skilled in the art. Known prior art.

Summary of the invention

In order to solve all or part of the above problems, the purpose of the present disclosure is to provide a pin, a power device, a method for manufacturing a power device, and a power device packaging mold, which solves the problem that the plastic packaging material is easy to pass through the avoiding hole during the packaging process of the power device. The problem of overflow in the mold.

According to a first aspect of the present disclosure, there is provided a stitch including a first section, a second section, and a third section arranged in sequence, wherein the second section is composed of a rotating body, and the rotation of the rotating body The distance from the point on the curved surface to the axis of rotation of the rotating body increases or decreases in the axial direction, the first section is composed of a first columnar body, and the bottom surface of the first columnar body is The small-area bottom surfaces are connected, and the cross-sectional area of the first columnar body is smaller than or equal to the area of the small-area bottom surface of the rotating body.

According to a second aspect of the present disclosure, there is provided a power device including the pins according to the first aspect of the present disclosure.

According to a third aspect of the present disclosure, there is provided a method for packaging a power device, which includes: loading the device body and pins of the power device into a packaging mold, and enabling the pins to escape from the packaging mold Partially penetrate the hole; inject the plastic molding material into the cavity of the packaging mold to solidify in the cavity and form a plastic housing that can fix the device body and the pins together; remove all The packaging mold; wherein the power device is the power device according to the second aspect of the present disclosure.

According to a fourth aspect of the present disclosure, there is provided a power device packaging mold, the packaging mold comprising: a mold cavity configured to accommodate a device main body and pins of the power device; and an escape hole communicating with the mold cavity , Allowing the pins to pass from the inside to the outside of the packaging mold; the injection hole communicates with the mold cavity. Wherein, the power device is the power device according to the second aspect of the present disclosure.

It can be known from the above technical scheme:

According to the first aspect of the present disclosure, the second section of the pin in the middle part is configured as a rotating body, so that the pin can make sealing contact with the hole wall of the avoiding hole of the packaging mold through the rotating body. In this case, even the avoiding hole If the existing circular avoiding hole is selected and its actual size is larger than the design size, the pin can also prevent the plastic material from overflowing from the packaging mold through the avoiding hole during the packaging process of the power device.

The power device described in the second and third aspects of the present disclosure and the manufacturing method thereof inherit the above-mentioned functions because of having or using the pin, that is, when the actual size of the existing circular avoiding hole is larger than the design size, the pin can prevent The plastic packaging material overflows from the packaging mold through the avoiding hole during the packaging process of the power device.

According to the packaging mold of the power device according to the fourth aspect of the present disclosure, the avoiding hole can cooperate with the pin of the power device, especially the rotating body of the pin, and prevent the plastic material from passing through the avoiding hole during the packaging process of the power device. Overflow in the encapsulation mold.

Description of the drawings

The preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. In the picture:

Fig. 1 is a schematic structural diagram of a power device in a packaging process according to an embodiment of the present disclosure;

Fig. 2 is an enlarged view of A in Fig. 1.

In the drawings, the same components use the same reference numerals. The drawings are not drawn to actual scale.

Detailed ways

The present disclosure will be further explained below in conjunction with the accompanying drawings.

FIG. 1 is a schematic diagram of the structure of a power device according to an embodiment of the present disclosure during the packaging process; FIG. 2 is an enlarged view of A in FIG. 1. As shown in Figures 1 and 2, the plastic packaging material in this embodiment relates to a new type of pin 102, a power device 100 including the pin 102, a manufacturing method of the power device 100, and a packaging mold 200 of the power device 100 .

In the embodiment of the present disclosure, the power device 100 may be specifically an IGBT module, a PIM module or an IPM module, which mainly includes a device body 101 and pins 102 connected to it. Among them, the device main body 101 is usually composed of a DBC ceramic substrate, a plurality of chips arranged on the DBC ceramic substrate, and bonding wires configured to connect the chips.

As shown in FIG. 2, the stitch 102 includes a first section 102a, a second section 102b, and a third section 102c arranged in sequence. The second section 102b is composed of a rotating body, and the distance from a point on the rotating surface of the rotating body to the rotating shaft of the rotating body increases or decreases in the axial direction. The first section 102a is composed of a first columnar body, the bottom surface of the first columnar body is connected to the bottom surface of the second section 102b with a small area, and the cross-sectional area of the first columnar body is less than or equal to the area of the bottom surface of the rotating body with a small area , So that the first section 102a can be partially penetrated from the packaging mold 200. That is to say, the pin 102 configures the second section 102b in the middle part as a rotating body, so that it can make sealing contact with the hole wall of the avoiding hole 204 of the packaging mold 200 through the rotating body (see Figures 1 and 2 for details). ). In this case, even if the avoiding hole 204 is selected as an existing circular avoiding hole and its actual size is larger than the designed size, the pin 102 can prevent the plastic material from passing through the avoiding hole 204 from the packaging mold during the packaging process of the power device 100 Overflow in 200.

In some embodiments, the third section 102c of the stitch 102 is composed of a second columnar body, the bottom surface of the second columnar body is connected to the large-area bottom surface of the second section 102b, and the cross-sectional area of the second columnar body is smaller than that of the rotating body. The area of the bottom surface is large, so as to reduce the occupation of the internal space of the power device 100 by the third section 102c.

In these embodiments, the packaging mold 200 includes a cavity 203 and an injection hole (not shown) in addition to the escape hole 204. The mold cavity 203 is configured to accommodate the device main body 101 of the power device 100 and the pins 102 connected to the device main body 101, and can receive a molding material (such as epoxy resin) to form a molded case (not shown) in the mold cavity 203 show). The injection hole communicates with the mold cavity 203, and can receive the molding material and guide it into the mold cavity 203. The escape hole 204 communicates with the mold cavity 203, and allows the pins 102 to pass out of the packaging mold 200. The so-called injection holes and plastic-encapsulated shells are conventional technologies in the field, so they will not be repeated here.

In some embodiments of the present disclosure, the packaging mold 200 includes a first mold body 201 and a second mold body 202 that can be spliced with each other to form a mold cavity 203, so as to prevent the mold body from being opened and closed as much as possible while ensuring that they can be opened and closed. Excessive quantity increases the cost of design and processing. Preferably, the escape hole 204 and the injection hole are separately provided on the first mold body 201 and the second mold body 202.

In some embodiments of the present disclosure, the first section 102a of the stitch 102 can at least partially pass through the escape hole 204, and the side wall of the second section 102b of the stitch 102 contacts with the hole wall of the escape hole 204 to prevent the molding material During the packaging process of the power device 100, it overflows from the packaging mold 200 through the escape hole 204.

In some embodiments of the present disclosure, the avoiding hole 204 of the packaging mold 200 can be selected as an existing circular avoiding hole, and can also be a new avoiding hole shown in FIG. 1 or FIG. 2. In the embodiment shown in FIGS. 1 and 2, the avoidance hole 204 is a new avoidance hole, which includes a first section 204a and a second section 204b that are close to the mold cavity 203 in turn, wherein the first section 204a is cylindrical and can interact with The first section 102a of the pin 102 performs clearance fit, thereby reducing the risk of jamming and deformation of the pin 102 when passing through the avoiding hole 204, and ensuring that the pin 102 can be more easily pierced during the packaging process of the power device 100 Enter the escape hole 204. The second section 204b is in the shape of a rotating body and can make sealing contact with the second section 102b of the pins, thereby preventing the plastic molding material from overflowing from the packaging mold 200 through the escape hole 204 during the packaging process of the power device 100.

Next, the packaging method of the power device 100 will be described. The packaging method includes the steps: a. Load the device body 101 and pins 102 of the power device 100 into the packaging mold 200, and enable the pins to partially pass through the escape holes 204 of the packaging mold 200; b. Inject the plastic packaging material Encapsulate the mold cavity 203 of the packaging mold 200 to solidify in the mold cavity 203 and form a plastic housing that can fix the device body 101 and the pins 102 together; c. Remove the packaging mold 200. This packaging method inherits its effect due to the use of the above-mentioned pin 102, that is, when the packaging method is implemented, even if the avoiding hole 204 is selected as the existing circular avoiding hole 204 and its actual size is larger than the designed size, the pin 102 can also be used. The plastic packaging material is prevented from overflowing from the packaging mold 200 through the avoiding hole 204 during the packaging process of the power device 100.

In the implementation of the packaging method, if the avoidance hole 204 is selected as a new avoidance hole, it includes a first section 204a and a second section 204b that are close to the mold cavity 203 in turn, and the first section 204a is cylindrical and can be connected to the pin 102. The first section 102a performs clearance fit, and the second section 204b is in the shape of a rotating body and can make sealing contact with the second section 102b of the stitch. Then, the packaging method can not only prevent the power device 100 from overflowing from the packaging mold 200 through the avoiding hole 204 during the packaging process of the power device 100, but also reduce the risk of jamming and deformation of the pins 102 during the process of passing through the avoiding hole 204. It is precisely because of the use of the avoidance holes 204 and the pins 102 shown in FIG. 1 and FIG. 2 that this packaging method can have the advantages of more convenience and efficiency in the implementation process, which can reduce the packaging cost of the power device 100 At the same time, the qualification rate of the power device 100 is improved.

The terms "first", second", and "third" in the embodiments of the present disclosure are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. , The features defined with “first”, “second”, and “third” may explicitly or implicitly include at least one of the features. In the description of the present disclosure, “plurality” means at least two, such as two One, three, etc., unless specifically defined otherwise.

The above are only the preferred embodiments of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person skilled in the art can easily make changes or changes within the technical scope disclosed in the present disclosure, and such changes Or changes should be covered within the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the protection scope of the claims. As long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any manner. The present disclosure is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims (10)

A stitch, characterized in that the stitch includes a first section, a second section and a third section arranged in sequence, wherein the second section is composed of a rotating body, and a point on the rotating surface of the rotating body is The distance of the axis of rotation of the rotating body increases or decreases in the axial direction, the first section is composed of a first columnar body, and the bottom surface of the first columnar body is connected to the bottom surface of the second section with a small area, And the cross-sectional area of the first columnar body is smaller than or equal to the area of the bottom surface of the rotating body with a small area. The stitch according to claim 1, wherein the third section is composed of a second columnar body, and the bottom surface of the second columnar body is connected to the bottom surface of the second section with a large area. The stitch according to claim 2, wherein the cross-sectional area of the second columnar body is smaller than the area of the bottom surface of the rotating body with a large area. A power device, characterized by comprising the pin according to any one of claims 1 to 3. A method for packaging a power device, which is characterized in that it comprises: Put the device main body and pins of the power device into the packaging mold, and enable the pins to partially pass through the escape holes of the packaging mold; Injecting the plastic packaging material into the cavity of the packaging mold to solidify in the cavity and form a plastic housing that can fix the device body and the pins together; Remove the packaging mold; Wherein, the power device is the power device according to claim 4. The packaging method of claim 5, wherein the first section of the stitch can at least partially pass through the escape hole, and the side wall of the second section of the stitch and the hole wall of the escape hole To contact. A power device packaging mold, characterized in that the packaging mold includes: The mold cavity is configured to accommodate the device body and pins of the power device; An escape hole communicates with the mold cavity and allows the pins to pass out of the encapsulation mold; The injection hole communicates with the mold cavity; Wherein, the power device is the power device according to claim 4. The packaging mold according to claim 7, wherein the first section of the stitch can at least partially pass through the escape hole, and the side wall of the second section of the stitch and the hole wall of the escape hole To contact. The packaging mold of claim 7, wherein the escape hole includes a first section and a second section that are sequentially close to the mold cavity, wherein the first section is cylindrical and can be connected to the pins. The first section performs clearance fit, and the second section presents a rotating body shape and can make sealing contact with the second section of the stitch. 8. The packaging mold according to claim 7, wherein the packaging mold comprises a first mold body and a second mold body that can be spliced with each other to form the mold cavity.

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