CN215644404U

CN215644404U - Power module's packaging mold and power module

Info

Publication number: CN215644404U
Application number: CN202121186584.8U
Authority: CN
Inventors: 丁锋; 赵斐; 刘谦
Original assignee: Shenzhen STS Microelectronics Co Ltd
Current assignee: Shenzhen STS Microelectronics Co Ltd
Priority date: 2021-05-28
Filing date: 2021-05-28
Publication date: 2022-01-25
Anticipated expiration: 2031-05-28

Abstract

The utility model discloses a packaging mold of a power module, which comprises a first template body and a second template body; the top surface of the first template body is downwards provided with a first forming groove; a second forming groove is formed in the bottom surface of the second template body upwards; the first forming groove and the second forming groove are closed to form a forming cavity for forming the packaging colloid; the first template body is also provided with a forming concave position for forming the insulating bulge; the parts of the first template body, which are positioned at the molding concave positions and are positioned at two opposite sides of the first molding groove in the circumferential direction, are also respectively provided with built-in concave positions; the built-in concave position extends downwards from the top surface of the first template body and penetrates through the inner side surface and the outer side surface of the first template body; the built-in concave position is used for the built-in of the pin of the semi-finished product and is matched with the pin of the semi-finished product; in the vertical direction, the depth of the forming concave position is greater than or equal to that of the built-in concave position. The utility model can simultaneously form the packaging colloid and the insulating bulge and simplify the process. The utility model also discloses a power module.

Description

Power module's packaging mold and power module

Technical Field

The utility model relates to the field of power module packaging equipment, in particular to a packaging mold of a power module and the power module.

Background

The conventional power module comprises a packaging colloid and at least two pins exposed out of the packaging colloid, and in the application process of the power module, because the distances between partial pins playing a conductive role in the power module are too close, static electricity in work easily climbs to another adjacent pin from one pin along the outer side surface of the packaging colloid, namely, the adjacent pins are easily conducted due to the creepage phenomenon between the adjacent pins, so that the power module is short-circuited and fails; in view of the above phenomenon, the conventional method adds an insulating bump on the shortest creepage path region between adjacent pins, that is, adds an insulating bump on the vertical path of the adjacent pins to increase creepage distance, thereby avoiding short circuit failure of the power module.

The conventional power module with the insulation bump is generally processed in the following manner: the power module adopts a packaging mold to form packaging colloid, specifically: fixedly connecting the lead frame, the ceramic substrate and the chip in sequence and electrically conducting to obtain a semi-finished product shown in figure 1, then placing a part to be packaged (including one end of the ceramic substrate, the chip, the pin and the like) of the semi-finished product in a mold cavity, injecting injection molding plastic, forming a packaging colloid, and cutting off other parts of the semi-finished product except the pin, which are positioned outside the packaging colloid through a rib cutting operation, thus obtaining a power module; and then the insulating bumps are fixed on the packaging colloid, so that the processing process is complicated.

SUMMERY OF THE UTILITY MODEL

In order to overcome the disadvantages of the prior art, an object of the present invention is to provide a power module package mold, which can simultaneously mold a package encapsulant and an insulating bump.

The second object of the present invention is to provide a power module packaged and molded by the packaging mold of the power module.

One of the purposes of the utility model is realized by adopting the following technical scheme:

the packaging mold of the power module comprises a first template body and a second template body; the top surface of the first template body is downwards provided with a first forming groove; the bottom surface of the second template body is upwards provided with a second forming groove and can be close to or far away from the first template body; when the second template body and the first template body are mutually abutted, the top surface of the first template body and the bottom surface of the second template body are mutually attached so as to close the first forming groove and the second forming groove to form a forming cavity for forming the packaging colloid; the first template body is also provided with a forming concave position which extends downwards from the top surface of the first template body and penetrates through the inner side surface of the first template body; the molding concave position is used for molding the insulating bulge; the parts of the first template body, which are positioned at the two opposite sides of the molding concave position in the circumferential direction of the first molding groove, are also respectively provided with built-in concave positions; the built-in concave position extends downwards from the top surface of the first template body and penetrates through the inner side surface and the outer side surface of the first template body; the built-in concave position is used for the built-in of the pin of the semi-finished product and is matched with the pin of the semi-finished product; in the vertical direction, the depth of the forming concave position is greater than or equal to that of the built-in concave position.

Furthermore, the first template body comprises a bottom plate provided with a groove and a barrier strip which is fixed on the bottom plate and surrounds the notch of the groove; the area formed by surrounding the barrier strip and the groove together form the first forming groove; the built-in concave position and the forming concave position are both arranged on the barrier strip, and the built-in concave position extends to the bottom plate; the surface of the bottom plate, on which the barrier strip is fixed, is also provided with a bearing surface surrounding the barrier strip; the bearing surface is used for bearing the semi-finished product to remove the rest part of the part to be packaged.

Furthermore, one side of the bearing surface, which is far away from the barrier strip, also extends upwards to form a limit baffle plate surrounding the barrier strip; and the inner side surface of the limiting baffle is used for being attached to the outer side surface of the semi-finished lead frame.

Further, the outer side wall of the barrier strip is used for being attached to the inner side face of the semi-finished lead frame.

Furthermore, the molding concave position also penetrates through the outer side surface of the barrier strip.

Furthermore, two adjacent built-in concave positions on two sides of the insulating bulge form a group of built-in structures; at least two molding concave positions are arranged between two built-in concave positions of at least one group of built-in structures, and any two adjacent molding concave positions are spaced from each other.

Furthermore, each forming concave position is communicated with one adjacent built-in concave position, and no partition is formed between the forming concave position and the communicated built-in concave position; the depth of the molding concave position is the same as that of the built-in concave position.

Furthermore, a glue inlet is formed in the barrier strip.

The second purpose of the utility model is realized by adopting the following technical scheme:

a power module comprises a ceramic substrate, a chip, at least two pins arranged along the circumferential direction of the ceramic substrate, a packaging colloid and an insulating bulge; the chip is fixed on the ceramic substrate and is electrically communicated with the ceramic substrate; the pins are fixed on the ceramic substrate and are electrically communicated with the ceramic substrate; the packaging colloid wraps the ceramic substrate, the chip and the pins and exposes one side of the pins and the bottom surface of the ceramic substrate; the packaging colloid is fixed with an insulating bulge which is in contact with the outer side surface of the packaging colloid and is integrally injection-molded with the packaging colloid; at least two pins are respectively arranged on two opposite sides of the insulating bulge; two adjacent pins positioned on two sides of the insulating bulge form a group of pin components; two insulation bulges which are arranged at intervals are arranged between two pins of the pin assembly; the top surface of the insulating bulge is higher than the top surface of the pin or is flush with the top surface of the pin; the bottom surface of the insulating bulge is lower than the bottom surface of the pin or is flush with the bottom surface of the pin; the length of the insulating bulge is 0.2 mm.

Further, the top surface and the bottom surface of the insulation bulge are respectively flush with the top surface and the bottom surface of the pin.

Compared with the prior art, the utility model has the beneficial effects that:

the molding cavity for molding the packaging colloid is formed by matching the first molding groove and the second molding groove of the first template body and the second template body, the first template body is provided with a molding concave position for molding the insulating colloid and communicated with the molding cavity, and meanwhile, the two opposite sides of the molding concave position are provided with built-in concave positions for the built-in of pins of semi-finished products; the depth of the molding concave position is greater than or equal to that of the built-in concave position; therefore, when injection molding plastic is injected in the packaging process, the injection molding plastic can flow in the first forming groove and the forming concave position and enter the injection molding plastic forming packaging colloid in the forming cavity, and meanwhile, the injection molding plastic entering the forming concave position is formed into insulating bulges which protrude out of the packaging colloid and are positioned between the pins, so that the processing technology is simplified.

Drawings

Fig. 1 is a schematic structural diagram of a conventional semi-finished product.

FIG. 2 is a schematic structural diagram of a first template body according to the present invention;

FIG. 3 is an enlarged view of a portion A of FIG. 1 according to the present invention;

FIG. 4 is a view showing a state of the first die plate body in which the semi-finished product of the present invention is loaded;

FIG. 5 is an enlarged view of a portion B of FIG. 4 according to the present invention;

FIG. 6 is a schematic structural view of a second form body according to the present invention;

fig. 7 is a diagram illustrating a state of use of the packaging mold for the power module according to the present invention;

fig. 8 is a schematic structural diagram of a power module according to the present invention.

In the figure: 10. a first template body; 11. a base plate; 111. a bearing surface; 12. blocking strips; 121. the inner side surface of the barrier strip; 20. a molding cavity; 21. a first forming groove; 22. a second forming groove; 30. a concave position is arranged inside; 40. forming a concave position; 50. a limit baffle; 60. a glue inlet; 70. a second template body; 80. a ceramic substrate; 90. a chip; 100. a pin; 110. packaging the colloid; 120. an insulating protrusion; 131. an inner side surface of the lead frame; 132. an outer side surface of the lead frame; 140. the bottom surface of second template body.

Detailed Description

Referring to fig. 1 to 8, an embodiment of the present invention provides a power module package mold, including a first mold plate body 10 and a second mold plate body 70.

The top surface of the first template body 10 is downwards provided with a first forming groove 21; the first template body 10 is provided with a forming concave position 40 extending downwards from the top surface thereof, and it can be understood that the forming concave position 40 is provided with a first opening positioned on the top surface of the first template body 10; the molding concave 40 penetrates through the inner side surface of the first template body 10; here, the inner side surface of the first die plate body 10 refers to a surface facing the first forming groove 21, that is, the inner side surface of the first die plate body 10 is a groove wall of the first forming groove 21; thus, it will be appreciated that the forming recess 40 communicates with the first forming groove 21 and is located outside the first forming groove 21; the molding concave 40 is used for molding the insulating protrusion 120; the parts of the first template body 10, which are positioned at the forming concave positions 40 and are opposite to the two sides of the first forming groove 21 in the circumferential direction, are also respectively provided with built-in concave positions 30; the built-in concave position 30 is used for the built-in of the semi-finished pin 100 and is matched with the semi-finished pin 100; the built-in concave position 30 extends downwards from the top surface of the first template body 10 and penetrates through the inner side surface and the outer side surface of the first template body 10; it should be noted that the outer side surface of the first template body 10 refers to a surface thereof facing away from the first forming groove 21, so that the built-in concave position 30 communicates the outside with the first forming groove 21, so that the pins 100 extend out of the first forming groove 21; it is understood that the built-in recess 30 has a second opening on the top surface of the first template body 10 for the pins 100 to enter the built-in recess 30; in the vertical direction, the depth of the forming concave portion 40 is greater than or equal to the depth of the built-in concave portion 30, and it should be noted that the "vertical direction" is the moving direction of the first template body 10 and the second template body 70, so that the bottom surface of the insulating protrusion 120 is lower than the bottom surface of the pin 100 and is flush with the bottom surface of the pin 100, thereby ensuring that the insulating protrusion 120 completely passes through the area of the shortest path of the adjacent pins 100, and ensuring that the shortest creepage distance can be fully extended.

The bottom surface 140 of the second template body is provided with a second forming groove 22 upwards and can be abutted against or far away from the first template body 10; when the second mold plate body 70 and the first mold plate body 10 are abutted against each other, the top surface of the first mold plate body 10 and the bottom surface 140 of the second mold plate body are attached to each other so that the first forming groove 21 and the second forming groove 22 are closed to form the forming cavity 20 for forming the encapsulant 110.

On the basis of the structure, when the packaging mold of the power module is used, referring to fig. 2-7, the first forming groove 21 and the second forming groove 22 are closed to form the forming cavity 20, the part to be packaged of the semi-finished product is placed in the forming cavity 20, and the pin 100 extends out of the first forming groove 21 through the built-in concave position 30; then, when injecting the injection molding plastic into the package mold of the power module, the injection molding plastic flows in the molding cavity 20 and the molding concave 40, the molding cavity 20 molds the package colloid 110, and the molding concave 40 molds the insulating protrusion 120 protruding from the package colloid 110 and located between the pins 100, that is, the package colloid 110 and the insulating protrusion 120 are molded at the same time, which simplifies the process.

In the above description, the bottom surface of the second die plate body 70 is a surface facing the first die plate body 10; the top surface of the first template body 10 refers to its surface facing the second template body 70.

It is worth mentioning that, during demolding, the insulating protrusion 120 can be separated from the first template body 10 from the first opening; when the first and second

die plate bodies

10 and 70 are abutted, the bottom surface 140 of the second die plate body is also used to close the first and second openings.

At this time, the bottom surface 140 of the second template body is also attached to the top surface of the pin 100, and the pin 100 fills the built-in recessed portion 30, so as to block the built-in recessed portion 30 and prevent the injection molding compound from overflowing from the built-in recessed portion 30.

Specifically, the first template body 10 comprises a bottom plate 11 provided with a groove and a barrier strip 12 fixed on the bottom plate 11 and surrounding the notch of the groove; the area formed by the surrounding of the barrier strip 12 and the groove together form a first forming groove 21, and it can be understood that the area formed by the surrounding of the barrier strip 12 is communicated with the groove; the built-in concave position 30 and the forming concave position 40 are both arranged on the barrier strip 12, and the built-in concave position 30 extends to the bottom plate 11; it should be understood that the built-in concave portion 30 extends through the inner side surface and the outer side surface of the barrier bar 12, and it should be noted here that the outer side surface of the barrier bar 12 refers to a surface thereof facing away from the first forming groove 21, and the inner side surface 121 of the barrier bar refers to a surface thereof facing toward the first forming groove 21; it will be appreciated that when the first template body 10 and the second template body 70 are abutted, the bottom surface 140 of the second template body abuts the top surface of the stop bar 12; the surface of the bottom plate 11 to which the barrier strips 12 are fixed is also formed with a supporting surface 111 surrounding the barrier strips 12, so that during the injection molding process, the supporting surface 111 supports the semi-finished product to remove the rest of the part to be packaged, such as the pins 100, and the pins 100 can be prevented from being broken by mistake.

Accordingly, the bottom surface of the second template body 70 further has a sealing region corresponding to the supporting surface 111 to seal the remaining portion of the semi-finished product except the portion to be sealed.

More specifically, the side of the bearing surface 111 away from the barrier strip 12 also extends upwards to form a limit baffle 50 surrounding the barrier strip 12; the inner side surface of the limiting baffle 50 is used for being attached to the outer side surface 132 of the semi-finished lead frame so as to position the semi-finished product and improve the packaging precision; here, the outer side surface 132 of the lead frame refers to a surface of the lead frame facing away from the center thereof; the inner side surface of the limit stop 50 refers to the surface facing the barrier strip 12.

Of course, the outer side wall of the barrier strip 12 may also be used to attach to the inner side 131 of the lead frame of the semi-finished product, so as to position the semi-finished product; the inner side surface 131 of the lead frame refers to a surface of the lead frame facing the center thereof; the outer side wall of the barrier rib 12 refers to a surface of the barrier rib 12 facing away from the first forming groove 21.

In order to avoid the injection molding plastic from overflowing from the molding concave 40, the molding concave 40 may be processed into a structure that does not penetrate through the outer side surface of the barrier rib 12, that is, the side of the molding concave 40 away from the first molding groove 21 has a solid inner wall, however, in this structure, the processing position of the molding concave 40 needs to be controlled to avoid penetrating through the outer side surface of the barrier rib 12 during processing, which has a high requirement on the processing precision; in this embodiment, since the outer side wall of the barrier rib 12 is attached to the inner side surface 131 of the semi-finished lead frame, the molding concave portion 40 can be configured to penetrate through the outer side surface of the barrier rib 12, and the inner side surface 131 of the lead frame can block the notch of the molding concave portion 40 on the outer side surface of the barrier rib 12, so as to prevent the injection molding plastic from overflowing from the molding concave portion 40.

Since the molding concave portion 40 penetrates through the outer side surface of the barrier rib 12, the insulation bump 120 molded by injection molding plastic is in contact with the inner side surface 131 of the lead frame, and thus, when a rib cutting operation is performed after the packaging is completed to remove the portion of the semi-finished product except for the pin 100, which is located outside the packaging colloid 110, a pulling force is generated between the insulation bump 120 and the inner side surface 131 of the lead frame, and the pulling force may cause the insulation bump 120 to be broken; at this time, in order to reduce the tensile force between each insulating protrusion 120 and the inner side 131 of the lead frame, in the present embodiment, it is preferable that two adjacent recessed portions 30 located at both sides of the insulating protrusion 120 constitute a set of built-in structures; at least two molding concave positions 40 are arranged between two built-in concave positions 30 of at least one group of built-in structures, and any two adjacent molding concave positions 40 are spaced from each other, so that the length of each insulating protrusion 120 in the extending direction of the barrier strip 12 can be reduced by increasing the number of the insulating protrusions 120 on the basis of ensuring that the same creepage distance is increased, and further the tensile force is reduced.

Furthermore, each forming concave position 40 is communicated with one adjacent built-in concave position 30, and no partition is formed between the forming concave positions and the communicated built-in concave positions 30; the depth of the molding concave position 40 is the same as that of the built-in concave position 30, and at this time, the thicknesses of the insulating protrusion 120 and the pin 100 are the same; therefore, a notch is processed on the barrier strip 12, and the length of the notch in the extending direction of the barrier strip 12 is the sum of the lengths of the built-in concave position 30 and the forming concave position 40, so that the built-in concave position 30 and the forming concave position 40 can be obtained at the same time, only one-time processing is needed, and the processing steps are further simplified; here, the insulation bump 120 after molding is directly attached on the pin 100.

Specifically, the barrier strip 12 is provided with a glue inlet 60 for the injection molding plastic to enter the first forming groove 21.

It is worth mentioning that other necessary components of the encapsulation mold constituting the present power module are directly known from the prior art, such as: the molding compound 110 is pushed out from the molding cavity 20, and other necessary parts of the molding die of the power module will not be described herein.

Referring to fig. 1 and 8, an embodiment of the utility model further discloses a power module, which includes a ceramic substrate 80, a chip 90, at least two pins 100 arranged along the circumference of the ceramic substrate 80, a packaging adhesive 110, and an insulating bump 120; the chip 90 is fixed on the ceramic substrate 80 and electrically connected with the ceramic substrate 80; the pins 100 are fixed on the ceramic substrate 80 and electrically connected with the ceramic substrate 80; the packaging colloid 110 wraps the ceramic substrate 80, the chip 90 and the pin 100 and exposes one side of the pin 100 and the bottom surface of the ceramic substrate 80; the encapsulant 110 is fixed with an insulating protrusion 120 which is in contact with the outer side surface and is integrally injection-molded with the encapsulant; at least two pins 100 are respectively arranged on two opposite sides of the insulating protrusion 120; two adjacent pins 100 on two sides of the insulating protrusion 120 form a group of pin assemblies; two insulating bulges 120 which are arranged at intervals are arranged between two pins 100 of the pin assembly so as to prolong the shortest creepage distance; the top surface of the insulating bump 120 is higher than the top surface of the pin 100 or flush with the top surface of the pin 100; the bottom surface of the insulating bump 120 is lower than the bottom surface of the pin 100 or flush with the bottom surface of the pin 100; the length of the insulating protrusion 120 is 0.2mm, that is, the length of the insulating protrusion 120 in the arrangement direction of the pins 100 is 0.2 mm; at this time, the two insulating protrusions 120 extend by a creepage distance H of 0.4mm in total, and the increased creepage distance H is a minimum length which can be achieved on the basis of avoiding the current from climbing from one of the pins 100 to the adjacent other pin 100 through a plurality of tests.

Specifically, two insulating protrusions 120 are in contact with two pins 100 of a group pin assembly of the pins 100, respectively.

Further, the top and bottom surfaces of the insulation bump 120 are flush with the top and bottom surfaces of the pin 100, respectively, so that the insulation bump 120 can completely pass through the area of the shortest path between the adjacent pins 100.

The above embodiments are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited thereby, and any insubstantial changes and substitutions made by those skilled in the art based on the present invention are within the protection scope of the present invention.

Claims

1. A packaging mold for a power module is characterized in that: comprises a first template body and a second template body; the top surface of the first template body is downwards provided with a first forming groove; the bottom surface of the second template body is upwards provided with a second forming groove and can be close to or far away from the first template body; when the second template body and the first template body are mutually abutted, the top surface of the first template body and the bottom surface of the second template body are mutually attached so as to close the first forming groove and the second forming groove to form a forming cavity for forming the packaging colloid; the first template body is also provided with a forming concave position which extends downwards from the top surface of the first template body and penetrates through the inner side surface of the first template body; the molding concave position is used for molding the insulating bulge; the parts of the first template body, which are positioned at the two opposite sides of the molding concave position in the circumferential direction of the first molding groove, are also respectively provided with built-in concave positions; the built-in concave position extends downwards from the top surface of the first template body and penetrates through the inner side surface and the outer side surface of the first template body; the built-in concave position is used for the built-in of the pin of the semi-finished product and is matched with the pin of the semi-finished product; in the vertical direction, the depth of the forming concave position is greater than or equal to that of the built-in concave position.

2. The package mold for a power module according to claim 1, wherein: the first template body comprises a bottom plate provided with a groove and a barrier strip which is fixed on the bottom plate and surrounds the outside of the notch of the groove; the area formed by surrounding the barrier strip and the groove together form the first forming groove; the built-in concave position and the forming concave position are both arranged on the barrier strip, and the built-in concave position extends to the bottom plate; the surface of the bottom plate, on which the barrier strip is fixed, is also provided with a bearing surface surrounding the barrier strip; the bearing surface is used for bearing the semi-finished product to remove the rest part of the part to be packaged.

3. The package mold for a power module according to claim 2, wherein: one side of the bearing surface, which is far away from the barrier strip, also extends upwards to form a limit baffle plate which surrounds the barrier strip; and the inner side surface of the limiting baffle is used for being attached to the outer side surface of the semi-finished lead frame.

4. The package mold for a power module according to claim 2, wherein: the outer side wall of the barrier strip is used for being attached to the inner side face of the semi-finished lead frame.

5. The package mold for a power module according to claim 4, wherein: the molding concave position also penetrates through the outer side surface of the barrier strip.

6. The package mold for a power module according to claim 5, wherein: two adjacent built-in concave positions on two sides of the insulating bulge form a group of built-in structures; at least two molding concave positions are arranged between two built-in concave positions of at least one group of built-in structures, and any two adjacent molding concave positions are spaced from each other.

7. The packaging mold for power modules according to any one of claims 5 to 6, wherein: each forming concave position is communicated with one adjacent built-in concave position, and no partition is formed between the forming concave positions and the communicated built-in concave positions; the depth of the molding concave position is the same as that of the built-in concave position.

8. The package mold for a power module according to claim 2, wherein: and the barrier strip is provided with a glue inlet.

9. A power module, characterized by: the packaging structure comprises a ceramic substrate, a chip, at least two pins arranged along the circumferential direction of the ceramic substrate, a packaging colloid and an insulating bulge; the chip is fixed on the ceramic substrate and is electrically communicated with the ceramic substrate; the pins are fixed on the ceramic substrate and are electrically communicated with the ceramic substrate; the packaging colloid wraps the ceramic substrate, the chip and the pins and exposes one side of the pins and the bottom surface of the ceramic substrate; the packaging colloid is fixed with an insulating bulge which is in contact with the outer side surface of the packaging colloid and is integrally injection-molded with the packaging colloid; at least two pins are respectively arranged on two opposite sides of the insulating bulge; two adjacent pins positioned on two sides of the insulating bulge form a group of pin components; two insulation bulges which are arranged at intervals are arranged between two pins of the pin assembly; the top surface of the insulating bulge is higher than the top surface of the pin or is flush with the top surface of the pin; the bottom surface of the insulating bulge is lower than the bottom surface of the pin or is flush with the bottom surface of the pin; the length of the insulating bulge is 0.2 mm.

10. The power module of claim 9, wherein: the top surface and the bottom surface of the insulating bulge are respectively flush with the top surface and the bottom surface of the pin correspondingly.