Packaging processing method of half-bridge structure and half-bridge packaging device

Abstract

The invention discloses a packaging processing method of a half-bridge structure and a half-bridge packaging device, and the packaging processing method comprises the steps: carrying out the bonding of a lead frame, a copper-clad ceramic substrate, a substrate power chip and a base island power chip through a bonding material, welding a metal wire, and carrying out the plastic packaging, thereby forming a plastic packaging body, a pin isolation groove is formed in the side edge, located between the first pin and the second pin, of the plastic package body, a cooling fin is arranged on the back face, located on the base island, of the lead frame, a long-strip-shaped groove is formed in the side, close to the first pin, of the cooling fin, the long-strip-shaped groove is further cut to form a cutting pit after the plastic package body is subjected to electrotinning, and the cutting pit is formed in the lead frame. And cleaning the cutting pit, fixing the cutting pit in a jig, filling liquid resin, baking to cure the liquid resin, and performing rib cutting and forming treatment. According to the packaging processing method, the base islands and the pins can achieve different electrical functions after packaging is completed, a half-bridge electrical structure can be achieved under the condition that the packaging appearance is not changed, and meanwhile the requirement for the high creepage distance of a circuit is met.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor packaging, and in particular to a packaging processing method for a half-bridge structure and a half-bridge packaging device. Background Art

[0002] In the field of semiconductor packaging, there are two types of traditional power device half-bridge modules. One type is that the base island is connected to the external pins to support the base island during processing. The ceramic substrate and chip can be placed without a fixture during the process, but this type of power device frame requires at least five independent output pins (such as Figure 1 The other is that the base island and the external pins are completely independent, and the base island and the external pins of the power frame are connected together through a small ceramic substrate through reflow using a chip assembly fixture during the manufacturing process (as shown in Figure 1). Figure 2 As shown). However, this packaging method will cause the space for placing the chip on the base island to be compressed. If it is a large IGBT chip, it cannot be packaged. In addition, the process flow during the packaging process is complicated, and the many types of fixtures lead to high packaging costs. In addition, for some products with high creepage distances, the creepage distance is generally required to be above 6.45mm. If this distance is to be met, the size of the plastic package needs to be increased. Increasing the size will change the appearance of the package. The packaging methods in the prior art have some difficult-to-overcome problems and defects. Summary of the invention

[0003] The embodiment of the present invention provides a packaging processing method of a half-bridge structure and a half-bridge packaging device, aiming to solve the problem in the prior art that the packaging of the half-bridge structure cannot be achieved while maintaining the appearance of the device.

[0004] In a first aspect, an embodiment of the present application provides a packaging and processing method for a half-bridge structure, wherein the packaging and processing method comprises:

[0005] Using adhesive material to bond and fix the copper-clad ceramic substrate to the base island of the lead frame, using adhesive material to bond and fix the substrate power chip to the copper-clad ceramic substrate, and bonding and fixing the base island power chip to the area on the base island located on one side of the copper-clad ceramic substrate;

[0006] Welding metal wires between the substrate power chip and the copper-clad ceramic substrate, the base island power chip and the pins of the lead frame, and between the base island power chip and the copper-clad ceramic substrate and the pins of the lead frame to achieve half-bridge electrical connection;

[0007] The initial assembly of the welded metal wires is encapsulated by a plastic encapsulation mold to form a plastic encapsulation body, the lead frame extends outside the plastic encapsulation body to form a plurality of parallel pins, and the side of the plastic encapsulation body between the first pin and the second pin forms a pin isolation groove; the back of the lead frame located on the base island is a heat sink; the side of the heat sink close to the first pin forms a long strip groove;

[0008] Electroplating tin on the plastic package;

[0009] The connecting piece of each pin in the long strip groove is further cut by a resin blade to cut off the connecting piece of the first pin and form a cutting pit to separate each pin from the lead frame;

[0010] After cleaning the debris in the cutting pit and washing it, the plastic package body is placed in a fixture for fixing; elastic protrusions are provided at both ends of the long strip groove in the fixture to seal the long strip groove;

[0011] Filling the cutting pit with liquid resin filling material, and placing the liquid resin filling material in an oven for baking and curing;

[0012] The pins of the baked plastic package body are cut and formed to obtain the final half-bridge package device.

[0013] In a second aspect, an embodiment of the present application further provides a half-bridge packaged device, wherein the half-bridge packaged device is processed by the packaging processing method described in the first aspect above, and the half-bridge packaged device includes a lead frame, a copper-clad ceramic substrate, a substrate power chip and a base island power chip;

[0014] Adhesive materials are provided between the lead frame and the copper-clad ceramic substrate, between the copper-clad ceramic substrate and the substrate power chip, and between the copper-clad ceramic substrate and the base island power chip;

[0015] Metal bonding wires for electrical connection are provided between the substrate power chip and the copper-clad ceramic substrate, the base island power chip and the pins of the lead frame, and between the base island power chip and the copper-clad ceramic substrate and the pins of the lead frame;

[0016] The side of the lead frame away from the copper-clad ceramic substrate is a heat sink, and the plastic encapsulation material is wrapped and arranged on the outside of the lead frame to form a plastic encapsulation body; the lead frame extends outside the plastic encapsulation body to form a plurality of parallel pins; the side of the plastic encapsulation body located between the first pin and the second pin is provided with a pin isolation groove; the back of the plastic encapsulation body is located on the side of the heat sink close to the pin and is provided with a long strip groove;

[0017] The bottom surface of the long strip groove is provided with an inwardly recessed cutting pit, and the cutting pit separates the first pin from the lead frame; and a curing material is provided in the cutting pit.

[0018] The embodiment of the present invention provides a packaging processing method for a half-bridge structure and a half-bridge packaging device. The packaging processing method includes using an adhesive material to bond a lead frame, a copper-clad ceramic substrate, a substrate power chip and a base island power chip, welding metal wires and then plastic-sealing to form a plastic package body, forming a pin isolation groove on the side of the plastic package body between a first pin and a second pin, the back of the lead frame located on the base island is a heat sink, and a long strip groove is formed on the side of the heat sink close to the first pin, the plastic package body is electroplated with tin and then the long strip groove is further cut to form a cutting pit, the cutting pit is cleaned and fixed in a jig, and then filled with liquid resin, and baked to solidify the liquid resin and perform rib cutting and forming processing. The above-mentioned packaging processing method, without changing the traditional power lead frame and packaging process, forms pin isolation grooves through plastic packaging and forms cutting pits through mechanical cutting, and uses liquid resin to fill the cutting pits and bake and cure them, so that the base island and each pin can respectively realize different electrical functions after the packaging is completed. The half-bridge electrical structure can be realized without changing the package shape, and the high creepage distance requirement of the circuit can be met at the same time; it can also maximize the chip space utilization and save packaging processing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0020] Figure 1 This is a structural diagram of a half-bridge package device obtained by processing using a conventional method;

[0021] Figure 2 Another structural diagram of a half-bridge package device obtained by processing using a prior art method;

[0022] Figure 3 A method flow chart of a packaging and processing method of a half-bridge structure provided by an embodiment of the present invention;

[0023] Figure 4 An internal structure diagram of a half-bridge package device provided by an embodiment of the present invention;

[0024] Figure 5 An equivalent circuit structure diagram of a half-bridge package device provided by an embodiment of the present invention;

[0025] Figure 6A front structural diagram of a half-bridge package device provided by an embodiment of the present invention;

[0026] Figure 7 A side structural diagram of a half-bridge package device provided by an embodiment of the present invention;

[0027] Figure 8 A back structural diagram of a half-bridge package device provided by an embodiment of the present invention;

[0028] Fig. 9 A cross-sectional structural diagram of a half-bridge package device provided by an embodiment of the present invention;

[0029] Fig.10 Another cross-sectional structural diagram of a half-bridge package device provided by an embodiment of the present invention;

[0030] Fig.11 Another cross-sectional structural diagram of a half-bridge package device provided by an embodiment of the present invention;

[0031] Fig.12 Another front structural diagram of a half-bridge package device provided by an embodiment of the present invention;

[0032] Fig.13 A structural diagram of a fixture provided by an embodiment of the present invention;

[0033] Fig.14 A structural diagram of the use state of a half-bridge package device provided by an embodiment of the present invention;

[0034] Fig.15 A schematic diagram of the processing process of a half-bridge package device provided in an embodiment of the present invention.

[0035] Figure numerals: 1. lead frame; 2. copper-clad ceramic substrate; 3. substrate power chip; 4. base island power chip; 5. adhesive material; 6. metal welding wire; 7. cutting pit; 8. fixture; 81. elastic bump; 9. curing material; 11. first pin; 12. second pin; 13. third pin; 14. fourth pin; 21. plastic package; 22. pin isolation groove; 23. long strip groove; 15. heat sink; 31. plastic package mold. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0038] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, the singular forms "a", "an" and "the" are intended to include the plural forms unless the context clearly indicates otherwise. It should also be further understood that the term "and / or" used in the present specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.

[0039] See also Figure 3 As shown in the figure, the embodiment of the present application discloses a packaging method for a half-bridge structure, wherein the packaging method includes steps S110 to S180. The packaging method below is described by taking the packaging of a power device TO247 as an example, and the packaging method can also be extended to other devices.

[0040] S110, using adhesive material to bond and fix the copper-clad ceramic substrate to the base island of the lead frame, using adhesive material to bond and fix the substrate power chip to the copper-clad ceramic substrate, and bonding and fixing the base island power chip to the area on the base island located on one side of the copper-clad ceramic substrate.

[0041] First, based on the half-bridge electrical principle, a high-insulation and high-thermal-conductivity copper-clad ceramic substrate 2 is designed for internal mounting. The front side of the copper-clad ceramic substrate 2 is electrically connected to components such as chips, and the back side is covered with a metal layer. The ceramic layer in the middle of the copper-clad ceramic substrate 2 must meet the application requirements of high insulation and high thermal conductivity.

[0042] The copper-clad ceramic substrate 2 is bonded and fixed to the base island of the lead frame 1 using adhesive material 5, and the area on the lead frame 1 for placing various components and welding wires is called the base island; the substrate power chip 3 is further bonded and fixed to the copper-clad ceramic substrate 2 using adhesive material 5; the base island power chip 4 is bonded and fixed to the area on the base island located on one side of the copper-clad ceramic substrate 2. Among them, the adhesive material 5 is a thermally conductive and electrically conductive alloy bonding material, that is, the adhesive material 5 has the characteristics of high electrical conductivity and high thermal conductivity; the adhesive residue is coated on the solder layer on the back of the power chip and bonded. The substrate power chip 3 can be an IGBT DIE or a Si CMOSFET DIE, etc., and the base island power chip 4 can be an IGBT DIE or a Si C MOSFET DIE, etc.

[0043] S120, welding metal wires between the substrate power chip and the copper-clad ceramic substrate, the base island power chip and the pins of the lead frame, and between the base island power chip and the copper-clad ceramic substrate and the pins of the lead frame to achieve half-bridge electrical connection.

[0044] According to the half-bridge electrical principle, wiring is performed, and corresponding metal bonding wires 6 are respectively welded between the substrate power chip 3 and the copper-clad ceramic substrate 2, between the substrate power chip 3 and the base island power chip 4, and between the copper-clad ceramic substrate 2 and the pins of the lead frame 1, so as to realize electrical connection of related components. Similarly, metal bonding wires 6 can be welded between the base island power chip 4 and the copper-clad ceramic substrate 2, and between the base island power chip 4 and the pins of the lead frame 1. After all the metal bonding wires 6 are welded, the half-bridge electrical connection can be realized. The specific connection structure is as follows: Figure 4 The equivalent circuit diagram obtained by the half-bridge electrical connection is shown in Figure 5 As shown, Figure 4 The first pin 11 corresponds to Figure 5 (1) port in; Figure 4 The second pin 12 corresponds to Figure 5 (2) port in; Figure 4 The third pin 13 corresponds to Figure 5 (3) port in; Figure 4 The fourth pin 14 corresponds to Figure 5 (4) port in; Figure 4 The metal layer of the copper-clad ceramic substrate is used as the floor, that is, Figure 5 This processing step corresponds to the (5) port in Fig.15 (a) process in .

[0045] S130. The initial assembly of welded metal welding wires is encapsulated by a plastic encapsulation mold to form a plastic encapsulation body, wherein the lead frame extends outside the plastic encapsulation body to form a plurality of parallel pins, and the side of the plastic encapsulation body between the first pin and the second pin forms a pin isolation groove; the back side of the lead frame located on the base island is a heat sink; and a long strip groove is formed on the side of the heat sink close to the first pin.

[0046] After welding the metal welding wire 6, the initial assembly is obtained. The back of the lead frame 1 is a heat sink 15, which is exposed and arranged on the side of the plastic package body. The heat sink can be used for heat dissipation of the device. In other embodiments, in order to increase the area of ​​the heat sink and improve the heat dissipation effect of the device, a heat sink with a larger area can be additionally attached to the back of the lead frame. Then, it is placed in a plastic package mold 31 for plastic packaging to form a plastic package body 21. In the obtained plastic package body 21, the lead frame 1 extends outside the plastic package body 21 to form a plurality of parallel pins. The specific structure is as follows: Figure 6 and Figure 7 As shown. Among them, a first protruding block corresponding to the pin isolation groove 22 is provided in the plastic encapsulation mold 31, and a pin isolation groove 22 corresponding to the first protruding block can be formed during the plastic encapsulation process. The plastic encapsulation mold 31 is also provided with a second protruding block corresponding to the long strip groove 23, and a long strip groove 23 corresponding to the second protruding block can be formed during the plastic encapsulation process. Among them, the width of the pin isolation groove 22 is 1 / 2-2 / 3 of the distance between the first pin 11 and the second pin 12, and the depth of the pin isolation groove is 1-2mm. By setting the pin isolation groove 22, the creepage distance between the first pin 11 and the second pin 12 and between the pin end and the heat sink 15 on the back of the lead frame can be increased. The specific setting structure of the pin isolation groove 22 is as shown in the figure. Figure 6 and Figure 8 This processing step corresponds to Fig.15 In the preferred embodiment, the depth of the pin isolation groove 22 can generally be set to 1 mm-2 mm, and the specific depth can be set according to the creepage distance requirement.

[0047] A long strip groove 23 is provided on the back side of the plastic package 21, which is located on the side of the heat sink 15 close to the first pin 11, and the spacing a between the bottom surface of the long strip groove 23 and the connecting plate of the first pin 11 below is not less than 0.5mm. By providing the long strip groove 23 on the plastic package 21, combined with the pressure resistance characteristics of the plastic package material, this structural design enables the voltage that both sides of the long strip groove 23 can withstand to be at least 10,000 volts. At the same time, this structural design can increase the creepage distance between the root of the pin and the edge of the heat sink 15 on the back of the lead frame. Specifically, in order to achieve better application effects, the thickness of both side walls of the long strip groove 23 can be set to be not less than 0.2mm; that is, the thickness of the plastic package material between the inner side wall of the long strip groove 23 and the heat sink 15 is at least 0.2mm, and the thickness between the inner side wall of the long strip groove 23 and the outer side surface of the plastic package 21 is at least 0.2mm. The specific shape of the long strip groove 23 can be a trapezoidal groove or a wavy groove. The structure of the trapezoidal groove is as follows: Fig. 9 As shown, the groove contains a long strip of notch; the structure of the wavy groove is as shown Fig.10 As shown in FIG. 1 , the groove may include a plurality of long notches. This structural design for increasing creepage distance is applicable to a variety of package shapes.

[0048] Furthermore, the long strip groove 23 can be obtained by mechanically cutting the molded body 21 to form a cavity and then filling and curing it after the molded body 21 is molded; the long strip groove 23 can also be integrally formed by the second protruding block during the molded process.

[0049] S140, electroplating tin on the plastic package body.

[0050] Tin is electroplated on the outer side of the plastic package body 21 to form a protective layer on the metal outer surface.

[0051] S150, further cutting the connection piece of each pin in the long strip groove by using a resin blade to cut off the connection piece of the first pin and form a cutting pit to separate each pin from the lead frame.

[0052] Use a resin blade of appropriate width to cut in the long strip groove 23, that is, cut the plastic package 21 and the connecting piece of the pin below the long strip groove 23. The connecting piece of the pin is also the metal connecting piece connecting the pin to the base island. Cutting pits 7 are formed by cutting to completely separate each pin (here mainly the first pin 11) from the lead frame 1, and finally form a cutting pit 7 with a depth of b. This processing step corresponds to Fig.15 (c) process in .

[0053] In the specific processing process, a cutting pit 7 with a width smaller than the long strip groove 23 can be obtained by cutting, that is, the width of the obtained long strip groove 23 is larger than the width of the cutting pit 7. Further, the depth b is the specific depth of cutting above the front of the pin, and cutting is stopped when cutting to the depth b; specifically, the spacing between the bottom surface of the cutting pit 7 and the connecting piece of the first pin 11 is 0.15-0.3mm, that is, the cutting depth b is 0.15-0.3mm. The cutting depth b can be set to 0.15-0.3mm accordingly, so that after cutting through the thickness of the pin, continue to cut 0.15-0.30mm to ensure that the base island and the pin can be completely disconnected.

[0054] c is the width of the cutting pit 7 formed by cutting. Further, the width c of the cutting pit 7 can be set to 0.3-0.5 mm. The cutting width c can be set according to the width of the resin blade and the size of the special plastic encapsulation material particles. Setting the cutting width c to 0.3-0.5 mm can ensure that the width of the cutting pit 7 can be filled with resin filler, and the resin filler does not affect the strength and reliability of the product after curing, while ensuring that the withstand voltage value between the connecting piece inside the first pin 11 and the base island meets the actual working requirements.

[0055] d is the distance between the central axis of the cutting and the bottom pin. The specific value of d can be set according to the distance between the base island and the pin. A unified starting point can be selected to ensure that the base island and the pin will not be lost during the cutting process, and the distance between the inner wall of the cutting pit 7 formed by the cutting and the adjacent inner wall of the long strip groove 23 is not less than 0.2mm, that is, to ensure that there is at least 0.20mm between the two sides of the cutting pit 7 and the inner wall of the long strip groove 23 during the cutting process. The specific structure is as follows Fig.11 and Fig.12 shown.

[0056] S160, after cleaning the debris in the cutting pit and washing it, the plastic package body is placed in a fixture for fixing; elastic protrusions are provided at both ends of the long strip groove in the fixture to seal the long strip groove.

[0057] The plastic encapsulation powder and metal debris in the cutting pit 7 can be cleaned and further cleaned with deionized water. The appearance of the cutting pit 7 is checked under a microscope. After confirming that it is qualified, the obtained initial product is placed in a specific jig 8 for fixing. The jig 8 is a special jig 8 for liquid resin filling; the jig 8 is made of an integral high-temperature resistant material, and a plurality of elastic protrusions 81 are provided on the bottom surface of the jig 8. The elastic protrusions 81 are used to seal the two ends of the long strip groove 23, and the elastic protrusions 81 are made of a high-temperature resistant and highly elastic material. The specific structure of the jig 8 is as follows: Fig.13 As shown, the structure after the initial product is placed on the fixture 8 is as follows Fig.14 This processing step corresponds to Fig.15 (d) process in .

[0058] S170, filling the cutting pit with liquid resin filler, and placing the liquid resin filler in an oven for baking and curing.

[0059] A special liquid resin filler is injected into the cutting pit 7, and the jig 8 and the initial product are placed in an oven for baking and curing, and finally a solidified material 9 is formed in the cutting pit 7, wherein the top surface of the solidified material 9 is an arc surface with a certain height difference, and the depth value of the arc surface in the solidified material 9 in the cutting pit 7 is to further increase the creepage distance between the edge of the heat sink 15 and the root of the pin. Specifically, the top surface of the solidified material 9 in the elongated groove 23 in the baked plastic package 21 is not less than 0.5 mm from the connecting piece of the first pin 11 below (that is, the distance a between the bottom surface of the elongated groove 23 and the connecting piece of the first pin 11 below). Specifically, the cross-section of the elongated groove 23 in the baked plastic package 21 is an inverted trapezoid or a wavy shape (that is, corresponding to the above-mentioned trapezoidal groove or wavy groove). This processing step corresponds to Fig.15 (e) process in .

[0060] S180, cutting and molding the pins of the baked plastic package body to obtain a final half-bridge package device.

[0061] The baked plastic package body 21 is cut and shaped, and the packaging process is completed to obtain a half-bridge packaged device with a half-bridge electrical circuit function.

[0062] The embodiment of the present invention further provides a half-bridge packaged device, which is manufactured by the packaging method described in the above embodiment. Figure 4As shown, the half-bridge package device includes a lead frame 1, a copper-clad ceramic substrate 2, a substrate power chip 3 and a base island power chip 4; bonding materials are provided between the lead frame 1 and the copper-clad ceramic substrate 2, between the copper-clad ceramic substrate 2 and the substrate power chip 3, and between the copper-clad ceramic substrate 2 and the base island power chip 4; metal bonding wires 6 for electrical connection are provided between the substrate power chip 3 and the copper-clad ceramic substrate 2, the base island power chip 4 and the pins of the lead frame 1, and between the base island power chip 4 and the copper-clad ceramic substrate 2 and the pins of the lead frame 1; the lead frame 1 is away from the One side of the copper-clad ceramic substrate 2 is a heat sink 15, and the plastic encapsulation material is wrapped and arranged on the outside of the lead frame 1 to form a plastic encapsulation body 21; the lead frame 1 extends outside the plastic encapsulation body 21 to form a plurality of parallel pins; the side of the plastic encapsulation body 21 located between the first pin 11 and the second pin 12 is provided with a pin isolation groove 22; the back of the plastic encapsulation body 21 is located on the side of the heat sink 15 close to the pin and is provided with a long strip groove 23; the bottom surface of the long strip groove 23 is provided with an inwardly recessed cutting pit 7, and the cutting pit 7 separates the first pin 11 from the lead frame 1; and the cutting pit 7 is provided with a curing material 9.

[0063] Compared with the prior art, the present invention claims protection for a packaging processing method and a half-bridge packaging device of a half-bridge structure. The structure and method, without changing the traditional power lead frame and packaging process, cut off the base island inside the plastic package body and the connecting piece of the pin connected thereto by mechanical cutting through a customized plastic packaging mold and after plastic packaging, so that the base island and the pin can respectively realize two different electrical signals after the packaging is completed, which can satisfy the half-bridge electrical circuit and will not change the packaging appearance. At the same time, it also has the following advantages: a standard integral lead frame is adopted, and the packaging process is simple; the whole process does not require customized chip assembly equipment and fixtures, which reduces the hardware investment and packaging cost, and reduces the complexity of the process. The size of the inner insulating substrate is small, and the price of the substrate is relatively low. There is no space loss on the base island, and the chip space utilization is maximized. The trapezoidal groove structure pre-set on the back of the plastic package body below the heat sink can also reduce the amount of plastic package cutting; the groove after cutting and filling can increase the creepage distance between the edge of the heat sink and the root of the external pin, which can meet the requirements of higher creepage distance of the device.

[0064] The packaging processing method and half-bridge packaging device of the half-bridge structure provided in the embodiment of the present invention include using adhesive materials to bond the lead frame, copper-clad ceramic substrate, substrate power chip and base island power chip, welding metal wires and then plastic-sealing to form a plastic package body, forming a pin isolation groove on the side of the plastic package body between the first pin and the second pin, the back of the lead frame located on the base island is a heat sink, and a long strip groove is formed on the side of the heat sink close to the first pin, the plastic package body is electroplated with tin and then the long strip groove is further cut to form a cutting pit, the cutting pit is cleaned and fixed in a fixture, and then filled with liquid resin, baked to solidify the liquid resin and perform rib cutting and forming processing. The above-mentioned packaging processing method, without changing the traditional power lead frame and packaging process, forms pin isolation grooves through plastic packaging and forms cutting pits through mechanical cutting, and uses liquid resin to fill the cutting pits and bake and cure them, so that the base island and each pin can respectively realize different electrical functions after the packaging is completed. The half-bridge electrical structure can be realized without changing the package shape, and the high creepage distance requirement of the circuit can be met at the same time; it can also maximize the chip space utilization and save packaging processing costs.

[0065] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A packaging method for a half-bridge structure, characterized in that: The packaging processing method comprises: Using adhesive material to bond and fix the copper-clad ceramic substrate to the base island of the lead frame, using adhesive material to bond and fix the substrate power chip to the copper-clad ceramic substrate, and bonding and fixing the base island power chip to the area on the base island located on one side of the copper-clad ceramic substrate; Welding metal wires between the substrate power chip and the copper-clad ceramic substrate, the base island power chip and the pins of the lead frame, and between the base island power chip and the copper-clad ceramic substrate and the pins of the lead frame to achieve half-bridge electrical connection; The initial assembly of the welded metal wires is encapsulated by a plastic encapsulation mold to form a plastic encapsulation body, the lead frame extends outside the plastic encapsulation body to form a plurality of parallel pins, and the side of the plastic encapsulation body between the first pin and the second pin forms a pin isolation groove; the back of the lead frame located on the base island is a heat sink; the side of the heat sink close to the first pin forms a long strip groove; Electroplating tin on the plastic package; The connecting piece of each pin in the long strip groove is further cut by a resin blade to cut off the connecting piece of the first pin and form a cutting pit to separate each pin from the lead frame; After cleaning the debris in the cutting pit and washing it, the plastic package body is placed in a fixture for fixing; elastic protrusions are provided at both ends of the long strip groove in the fixture to seal the long strip groove; Filling the cutting pit with liquid resin filling material, and placing the liquid resin filling material in an oven for baking and curing; The pins of the baked plastic package body are cut and formed to obtain the final half-bridge package device.

2. The packaging method of the half-bridge structure according to claim 1, characterized in that: The top surface of the solidified material in the long strip groove in the baked plastic package body is spaced at a distance of not less than 0.5 mm from the connecting piece of the first pin below.

3. The packaging method of the half-bridge structure according to claim 1 or 2, characterized in that: The cross section of the long strip groove in the baked plastic package body is in an inverted trapezoidal or wavy shape.

4. The packaging method of the half-bridge structure according to claim 3, characterized in that: The width of the long strip groove is greater than the width of the cutting pit.

5. The packaging method of the half-bridge structure according to claim 4, characterized in that: The distance between the bottom surface of the cutting pit and the connecting piece of the first pin is 0.15-0.3 mm.

6. The packaging method of the half-bridge structure according to claim 5, characterized in that: The width of the cutting pit is 0.3-0.5 mm.

7. The packaging method of the half-bridge structure according to claim 6, characterized in that: The thickness of the two side walls of the long strip groove is not less than 0.2 mm.

8. The packaging method of the half-bridge structure according to claim 3, characterized in that: The bonding material is a thermally and electrically conductive alloy bonding material.

9. The packaging method of the half-bridge structure according to claim 3, characterized in that: The width of the pin isolation groove is 1 / 2-2 / 3 of the distance between the first pin and the second pin, and the depth of the pin isolation groove is 1-2 mm.

10. A half-bridge packaged device, characterized in that: The half-bridge packaged device is obtained by using the packaging method according to any one of claims 1 to 9, and the half-bridge packaged device comprises a lead frame, a copper-clad ceramic substrate, a substrate power chip and a base island power chip; Adhesive materials are provided between the lead frame and the copper-clad ceramic substrate, between the copper-clad ceramic substrate and the substrate power chip, and between the copper-clad ceramic substrate and the base island power chip; Metal bonding wires for electrical connection are provided between the substrate power chip and the copper-clad ceramic substrate, the base island power chip and the pins of the lead frame, and between the base island power chip and the copper-clad ceramic substrate and the pins of the lead frame; The side of the lead frame away from the copper-clad ceramic substrate is a heat sink, and the plastic encapsulation material is wrapped and arranged on the outside of the lead frame to form a plastic encapsulation body; the lead frame extends outside the plastic encapsulation body to form a plurality of parallel pins; the side of the plastic encapsulation body located between the first pin and the second pin is provided with a pin isolation groove; the back of the plastic encapsulation body is located on the side of the heat sink close to the pin and is provided with a long strip groove; The bottom surface of the long strip groove is provided with an inwardly recessed cutting pit, and the cutting pit separates the first pin from the lead frame; and a curing material is provided in the cutting pit.

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