Compact high-power half-bridge circuit device and PCB

Abstract

The utility model discloses a compact high-power half-bridge circuit device and a PCB, the compact high-power half-bridge circuit device comprises a device frame, a substrate, a substrate power tube core and a base island power tube core, and the device frame comprises a base island and a lead; the base island power tube core is arranged on one side, close to the lead, of the upper end face of the base island, and the substrate is arranged on one side, away from the lead, of the upper end face of the base island; the substrate power tube core is arranged on the substrate; the plastic package body is packaged on the upper layers of the device frame, the substrate, the substrate power tube core and the base island power tube core; a radiating fin is formed on one side of the device frame away from the substrate. According to the compact high-power half-bridge circuit device, a group of tube cores are integrated in a packaging appearance structure to form an independent half-bridge circuit device, so that the overcurrent capability and the creepage distance of the whole half-bridge circuit device are enhanced, mutual interference among multiple tube cores in the half-bridge circuit device is avoided, and the reliability of the device is improved. And the reliability and the performance of the device are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor packaging, in particular to a compact high-power half-bridge circuit device and a PCB board. Background Art

[0002] The bridge connection structure of power devices (such as IGBT devices or SiC MOSFET devices) is the most common structure in the current power conversion system, among which the half-bridge connection is the most basic unit of the bridge connection structure. Its characteristic is that the half-bridge structure includes two power devices connected in series, that is, the source end of the upper power device is connected to the drain end of the lower power device. The traditional half-bridge structure is connected on the system board through discrete power devices, but it has serious parasitics and is inconvenient to use. Therefore, it is often made into a half-bridge module.

[0003] Existing modules mostly use potting or plastic encapsulation to integrate multiple groups of power device dies into a larger packaging structure. Due to the large size, complex internal stress, heat transfer, stress, inductance, insulation, etc. between power tube dies affect or interfere with each other, high-performance packaging materials and higher-performance packaging equipment are required. In addition, the packaging qualification rate of traditional potting or plastic encapsulation modules is much lower than that of traditional power devices (if a die or a welding point fails, all dies and high-value materials in the entire module will be scrapped), which in turn causes unstable module packaging quality, increased packaging costs, unstable reliability, etc.

[0004] Traditional power device packaging can solve the above-mentioned shortcomings of potting or plastic encapsulation modules, but in device packaging, the base island carrying the power tube die is often directly connected to an external pin. Although the manufacture and packaging of the frame are relatively easy to achieve, the external pin connected to the base island is sometimes cut off after packaging. However, the lead connection frame connected to the base island after packaging is cut off in a design (such as Figure 1 As shown in FIG. 1 , in another design, it is used as an idle pin. For a half-bridge module, it usually includes at least five ports, so the packaging arrangement structures of the above two traditional power devices cannot be implemented in a half-bridge module. Therefore, the packaging structure for a half-bridge circuit module in the prior art method has the problem of poor packaging quality. Utility Model Content

[0005] The embodiment of the utility model provides a compact high-power half-bridge circuit device and a PCB board, aiming to solve the problem of poor packaging quality existing in the packaging structure used for the half-bridge circuit module in the prior art method.

[0006] In a first aspect, an embodiment of the utility model provides a compact high-power half-bridge circuit device, including a device frame, a substrate, a substrate power tube die, and a base island power tube die;

[0007] The device frame includes a base island and leads; a frame side rib semi-enclosing the base island is provided on the side of the base island not facing the leads, and the frame side rib is fixedly connected to an end of the base island away from the lead connection frame; a lead connection frame semi-enclosing the lead is provided on the side of the lead not facing the base island, and the end of the lead connection frame is connected to the end of the frame side rib through a connecting rib;

[0008] The base island power tube core is arranged on a side of the upper end surface of the base island close to the lead, and the substrate is arranged on a side of the upper end surface of the base island away from the lead; the substrate power tube core is arranged on the substrate;

[0009] Bonding wires for electrical connection are provided between the substrate and the substrate power tube core, between the substrate and the base island power tube core, between the substrate and the lead, between the base island power tube core and the lead, and between the substrate power tube core and the lead;

[0010] The plastic package is encapsulated on the device frame, the substrate, the substrate power tube core and the upper layer of the base island power tube core; a side of the device frame away from the substrate forms a heat sink.

[0011] In the compact high-power half-bridge circuit device, the width of the first pin and the second pin in the lead are not less than 2.0 mm, and the first pin is electrically connected to the substrate through a welding wire.

[0012] The compact high-power half-bridge circuit device, wherein the base island is tilted toward a side away from the substrate, and the distance between an end of the base island close to the lead and an initial plane is 0-100um; wherein the initial plane is a plane corresponding to the base island when it is not tilted.

[0013] The compact high-power half-bridge circuit device, wherein the substrate comprises a bottom metal layer, a top metal layer, and an insulating layer sandwiched between the bottom metal layer and the top metal layer;

[0014] An insulating dividing line is provided between the top metal layers, and the insulating dividing line divides the top metal layer into a mounting area and a connection area;

[0015] The substrate power tube core is arranged on the mounting area; the first connection end of the substrate power tube core is electrically connected to the connection area through a welding wire.

[0016] The compact high-power half-bridge circuit device is characterized in that the connection area is electrically connected to the first pin in the lead through a welding wire, and the first connection end of the base island power tube core is electrically connected to the mounting area and the second pin in the lead through a welding wire respectively.

[0017] The compact high-power half-bridge circuit device, wherein the second connection end of the substrate power tube core is electrically connected to the fourth pin in the lead through a welding wire, and the second connection end of the base island power tube core is electrically connected to the third pin in the lead through a welding wire.

[0018] The compact high-power half-bridge circuit device, wherein the first spacing between the substrate and the base island power tube core is greater than the assembly position distance value and greater than the package withstand voltage distance value;

[0019] The assembly position distance value is the position deviation distance corresponding to the assembly of the substrate and the base island power tube core; the package pressure resistance distance value is the distance value corresponding to the pressure resistance characteristic of the plastic package body.

[0020] In the compact high-power half-bridge circuit device, a U-shaped opening is provided at a position on the plastic package body corresponding to the pin gap, and the pin gap is the gap between the first pin and the second pin in the lead.

[0021] In a second aspect, an embodiment of the utility model provides a PCB board, wherein the PCB board is equipped with a compact high-power half-bridge circuit device as described in the first aspect above;

[0022] The PCB board is provided with a plurality of heat sink pads, and the heat sinks in the compact high-power half-bridge circuit device are welded on the corresponding heat sink pads; the inner pins in adjacent compact high-power half-bridge circuit devices are arranged in opposite directions.

[0023] In a third aspect, an embodiment of the present utility model provides a method for preparing a PCB board, wherein the method is used to prepare the PCB board as described in the second aspect, and the method comprises:

[0024] Design device framework structure;

[0025] Design substrate structure;

[0026] Printed stencils designed for substrate welding;

[0027] Positioning and assembling the device frame and the printing steel mesh and printing an alloy bonding material on the surface of the printing steel mesh;

[0028] Mounting a substrate on the surface of the printed alloy bonding material and reflow curing;

[0029] Coating an alloy bonding material on the surface layer of the substrate and the surface layer of the base island in the device frame and assembling power tube dies respectively;

[0030] Bonding wires to the power tube core to achieve electrical connection;

[0031] Encapsulating the half-bridge module to form a plastic package;

[0032] Performing rib cutting and forming on the packaged half-bridge module;

[0033] The molded half-bridge module is tested and mounted on the PCB board after the test is successful.

[0034] Through the above scheme, it can be known that the utility model provides a compact high-power half-bridge circuit device and PCB board, the compact high-power half-bridge circuit device includes a device frame, a substrate, a substrate power tube core and a base island power tube core, the device frame includes a base island and a lead; the base island power tube core is arranged on the side of the upper end surface of the base island close to the lead, and the substrate is arranged on the side of the upper end surface of the base island away from the lead; the substrate power tube core is arranged on the substrate; the plastic package is encapsulated in the upper layer of the device frame, the substrate, the substrate power tube core and the base island power tube core; the side of the device frame away from the substrate forms a heat sink. The above compact high-power half-bridge circuit device integrates a group of tube cores into a package shape structure to form an independent half-bridge circuit device, enhances the overcurrent capacity and creepage distance of the entire half-bridge circuit device, avoids the interference between multiple tube cores in the half-bridge circuit device; weakens the mutual influence or interference of heat transfer, stress, inductance, etc. generated between multiple half-bridge tube cores, enhances the insulation between each other, and improves the reliability and performance of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 A structural diagram of a conventional semiconductor power device provided by an embodiment of the utility model;

[0037] Figure 2 A cross-sectional structural diagram of a compact high-power half-bridge circuit device provided by an embodiment of the utility model;

[0038] Figure 3 Another cross-sectional structural diagram of a compact high-power half-bridge circuit device provided by an embodiment of the utility model;

[0039] Figure 4 A structural diagram of a single device frame in a compact high-power half-bridge circuit device provided by an embodiment of the utility model;

[0040] Figure 5 A combined structural diagram of multiple groups of device frames provided for an embodiment of the utility model;

[0041] Figure 6 A structural diagram of a substrate in a compact high-power half-bridge circuit device provided by an embodiment of the utility model;

[0042] Figure 7 An internal top view of a compact high-power half-bridge circuit device provided by an embodiment of the utility model;

[0043] Figure 8 The overall structure diagram of the compact high-power half-bridge circuit device provided by the embodiment of the utility model;

[0044] Fig. 9 An overall side structural diagram of a compact high-power half-bridge circuit device provided by an embodiment of the utility model;

[0045] Fig.10 The overall structure diagram of the PCB board provided by the embodiment of the utility model;

[0046] Fig.11 An internal structure diagram of a PCB board provided in an embodiment of the utility model;

[0047] Fig.12 A flow chart of a method for preparing a PCB board provided in an embodiment of the utility model;

[0048] Fig.13 This is an application effect diagram of the method for preparing a PCB board provided in an embodiment of the utility model.

[0049] 1. Device frame; 2. Substrate; 3. Substrate power tube core; 4. Base island power tube core; 110. Base island; 120. Lead; 111. Frame side rib; 121. Lead connection frame; 13. Connecting rib; 5. Solder wire; 6. Plastic package; 7. Heat sink; 122. First pin; 123. Second pin; 124. Third pin; 125. Fourth pin; 21. Bottom metal layer; 22. Top metal layer; 23. Insulation layer; 24. Insulation dividing line; 221. Installation area; 222. Connection area; 61. U-shaped opening; 8. PCB board; 81. Heat sink pad; 9. Suction nozzle; 82. Pin pad; Printed steel mesh 301. Alloy bonding material under substrate 302. Alloy bonding material under substrate power tube core 303. Alloy bonding material under base island power tube core 304. Trapezoidal groove 305. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0051] In order to solve the problem of poor packaging quality in the packaging structure in the prior art, the embodiment of the utility model provides a compact high-power half-bridge circuit device. Figure 2 and Figure 3 The compact high-power half-bridge circuit device comprises a device frame 1, a substrate 2, a substrate power tube core 3 and a base island power tube core 4; the device frame 1 comprises a base island 110 and a lead 120; the side of the base island 110 not facing the lead connection frame 121 is provided with a frame side rib 111 for semi-enclosing the base island 110, and the frame side rib 111 is fixedly connected to an end of the base island 110 away from the lead connection frame 121; the side of the lead 120 not facing the base island 110 is provided with a lead connection frame 121 for semi-enclosing the lead 120, and the end of the lead connection frame 121 is connected to the end of the frame side rib 111 through a connecting rib 13; the base island power tube core 4 is arranged on the base island 1 The upper end surface of 10 is close to the side of the lead 120, and the substrate 2 is arranged on the side of the upper end surface of the base island 110 away from the lead 120; the substrate power tube core 3 is arranged on the substrate 2; welding wires 5 for electrical connection are provided between the substrate 2 and the substrate power tube core 3, between the substrate 2 and the base island power tube core 4, between the substrate 2 and the lead 120, between the base island power tube core 4 and the lead 120, and between the substrate power tube core 3 and the lead 120; the plastic package 6 is encapsulated in the upper layer of the device frame 1, the substrate 2, the substrate power tube core 3 and the base island power tube core 4; a heat sink 7 is formed on the side of the device frame 1 away from the substrate 2.

[0052] The specific structure of the device frame 1 is as follows Figure 4 and Figure 5As shown, the technical method of the present application designs a special structural frame of the power device according to the packaging requirements of the half-bridge circuit in the device. In this device frame 1, the base island 110 and the lead 120 are completely separated; adjacent device frames 1 are connected by the frame side ribs 111 around the base island 110. The end of the lead connection frame 121 is connected to the end of the frame side rib 111 through the connecting rib 13, and the end of the lead 120 away from the base island 110 is fixedly connected to the lead connection frame 121, so that the base island 110 and the lead 120 are combined to form an overall frame structure. Among them, the connecting rib 13 is an insulating material, such as silicon oxide. The substrate power tube core 3 and the base island power tube core 4 are both power tube cores.

[0053] Based on the packaging structure of traditional power devices, the device is redesigned to consist of a device frame 1, a substrate 2, a substrate power tube die 3 and a base island power tube die 4, so as to realize the packaging of a half-bridge of a group of power tube die based on the traditional packaging structure, that is, the high reliability, compactness and high yield of traditional power device packaging are retained, and the electrical influence between multiple groups of power tube die and the quality problem of packaging in the traditional potting or plastic packaging half-bridge module structure are solved. Finally, the performance and reliability of the module are improved.

[0054] In a more specific embodiment, the width of the first pin 122 and the second pin 123 in the lead 120 is not less than 2.0 mm, and the first pin 122 is electrically connected to the substrate 2 through the welding wire 5. Specifically, the base island 110 is tilted toward the side away from the substrate 2, and the distance between the end of the base island 110 close to the lead 120 and the initial plane is 0-100 um; wherein the initial plane is the plane corresponding to the base island 110 when it is not tilted.

[0055] In a more specific embodiment, in order to meet the use requirements of the device with excessive current, the pin width of the first pin 122 and the second pin 123 can be set to 2.0 mm or more, and this setting structure can make the current flow capacity of the first pin 122 and the second pin 123 reach 150A to 250A. Further, in order to improve the effect of packaging the half-bridge circuit device, that is, to improve the insulation performance between the base island 110 and the pin, the base island 110 can be set to be tilted as a whole, and the base island 110 can be rotated around the connection between the base island 110 and the frame side rib 111 to make the base island 110 tilted as a whole, that is, the end of the base island 110 close to the inner pin is tilted downward. Specifically, the spacing between the end of the base island 110 close to the lead 120 and the initial plane can be set to be 0-100um. Among them, the lead 120 can be composed of an inner lead on the side close to the base island 110 and an outer lead on the side away from the base island. The inner lead and the outer lead are connected to each other, and the lead connecting ribs connect the connection points between each inner lead and the outer lead in turn, and both ends of the lead connecting ribs are connected to the lead connection frame 121.

[0056] In a more specific embodiment, Figure 6 As shown, the substrate 2 includes a bottom metal layer 21, a top metal layer 22, and an insulating layer 23 sandwiched between the bottom metal layer 21 and the top metal layer 22; an insulating dividing line 24 is provided between the top metal layers 22, and the insulating dividing line 24 divides the top metal layer 22 into a mounting area 221 and a connection area 222; the substrate power tube core 3 is arranged on the mounting area 221; the first connection end of the substrate power tube core 3 is electrically connected to the connection area 222 through a welding wire 5. The connection area 222 is electrically connected to the first pin 122 in the lead 120 through a welding wire 5, and the first connection end of the base island power tube core 4 is electrically connected to the mounting area 221 and the second pin 123 in the lead 120 through a welding wire 5, respectively. Specifically, the second connection end of the substrate power tube core 3 is electrically connected to the fourth pin 125 in the lead 120 through the bonding wire 5, and the second connection end of the island power tube core 4 is electrically connected to the third pin 124 in the lead 120 through the bonding wire 5. The specific connection structure for electrical connection through the bonding wire 5 is as follows: Figure 7 shown.

[0057] Specifically, according to the packaging requirements of the half-bridge circuit in the device, the substrate power tube core 3 is arranged to be attached to the Figure 6The upper surface of the substrate 2 shown in the figure is mainly composed of a bottom metal layer 21, a top metal layer 22, and an insulating layer 23 sandwiched between the bottom metal layer 21 and the top metal layer 22, and the insulating layer 23 insulates the bottom metal layer 21 from the top metal layer 22. The top metal layer 22 needs to realize the layout of electrical connection, so an insulating dividing line 24 can be set on the top metal layer 22, and the insulating dividing line 24 can divide the top metal layer 22 into an installation area 221 and a connection area 222, so that the installation area 221 and the connection area 222 are insulated; in a more specific embodiment, the insulating dividing line 24 can also divide the installation area 221 into a first installation area 221 and a second installation area 221, so that the first installation area 221 and the second installation area 221 are insulated; the bottom metal layer 21 is set on the back of the substrate 2, and the bottom metal layer 21 completely covers the back of the substrate 2, and the insulating material corresponding to the insulating layer 23 meets the requirements of high insulation and high thermal conductivity.

[0058] In a more specific embodiment, the first spacing between the substrate 2 and the base island power tube core 4 is greater than the assembly position distance value and greater than the package pressure resistance distance value; the assembly position distance value is the corresponding position deviation distance when assembling the substrate 2 and the base island power tube core 4; the package pressure resistance distance value is the distance value corresponding to the pressure resistance characteristics of the plastic package 6.

[0059] The substrate 2, the substrate power tube core 3 (such as IGBT or SiC MOSFET tube core), and the base island power tube core 4 (such as IGBT or SiC MOSFET tube core) are sequentially mounted through the welding process. Each welding layer uses a highly conductive and thermally conductive alloy bonding material. The substrate power tube core 3 and the base island power tube core 4 need to be implemented according to the following packaging rules to meet the electrical and packaging requirements. Specifically, the first spacing C can be set to be greater than the assembly position distance value D and the package withstand voltage distance value E, such as Figure 3 As shown, the assembly position distance value is set to D, and the first spacing is C, wherein the assembly position distance value is the safety spacing between the substrate 2 and the base island power tube core 4; the package withstand voltage distance value is set to e, and the package withstand voltage distance value is also the withstand voltage spacing of the half-bridge package. The overflow size of the base island tube core bonding material is a1, the overflow size of the substrate bonding material is a2, the outer wall width of the suction nozzle 9 is b (the suction nozzle 9 is used to generate negative pressure and suck the base island power tube core 4 for assembly), the width of the base island power tube core 4 is w, the chip installation accuracy tolerance is t1, and the accuracy tolerance of the suction nozzle is t2. Then the assembly position distance value D can be calculated using the following formula: D = (bw) / 2+t1+t2+a1+a2.

[0060] The package withstand voltage distance value is related to the withstand voltage characteristics of the plastic packaging material. For example, the withstand voltage characteristic value of a certain plastic packaging material is 20KV / mm. Assuming that the withstand voltage requirement of the half-bridge package is 40KV, the corresponding package withstand voltage distance value e=40KV / 20KV=2mm can be calculated.

[0061] Furthermore, the size of the assembly position distance value D and the package voltage resistance distance value e is judged. If D≥e, then C≥D; if D≤e, then C≥e; that is, the corresponding minimum distance value of the first spacing C is determined according to the assembly position distance value and the package voltage resistance distance value, and the minimum distance value of the first spacing C is a maximum value between the assembly position distance value and the package voltage resistance distance value.

[0062] like Figure 2 As shown, wiring is performed according to the half-bridge circuit design principle, and the substrate power tube core 3 and the base island power tube core 4 are electrically connected in sequence through the welding wire 5 to realize the half-bridge electrical connection between the tube cores and between the tube core and the inner pin. A plastic sealing safety spacing needs to be set between the top of the welding wire 5 of the substrate power tube core 3 and the top of the plastic sealing body 6 to ensure that the welding wire 5 does not expose the outside of the plastic sealing body 6 and the welding wire 5 is not close to the front of the plastic sealing body 6. The design rules are as follows. The plastic sealing safety spacing is set to X, the thickness of the base island 110 is H1, the thickness of the substrate 2 is H2, the maximum arc height of the welding wire 5 on the substrate 2 is h, the tube core thickness is S, the solder thickness is d1, the mounting glue thickness is d2, and the total thickness of the plastic sealing body 6 is A. Then the overall package thickness A≥X+H1+H2+S+d1+d2+h can be determined; among them, the plastic package safety distance X is determined according to the device process capability and the withstand voltage requirements; the base island 110 thickness H1 is determined according to the module overcurrent, withstand voltage, heat dissipation and other requirements; the substrate 2 thickness H2 is determined according to the module overcurrent, withstand voltage, heat dissipation and other requirements. When designing the substrate, the size in the X direction can be slightly larger, which is not only conducive to substrate wiring, but also increases the heat transfer area between the power tube core and the substrate, and between the substrate and the base island, and improves the speed of heat dissipation. A plastic package safety distance needs to be set between the top of the tube core welding wire on the substrate and the top of the plastic package to ensure that the welding wire does not expose the plastic package or approach the front of the plastic package.

[0063] In a more specific embodiment, a U-shaped opening 61 is provided on the plastic package body 6 at a position corresponding to the pin gap, and the pin gap is the gap between the first pin 122 and the second pin 123 in the lead 120. Specifically, the width of the pin gap is 1.2-2.8 times the width of the second pin 123; the width of the U-shaped opening 61 is 1 / 2-4 / 5 of the width of the pin gap.

[0064] Further, in the process of performing the plastic encapsulation operation to obtain the plastic encapsulation body 6, the corresponding plastic encapsulation body 6 can be formed by the plastic encapsulation processing mold, and the plastic encapsulation processing mold is provided with a push rod on the left and right sides below the plastic encapsulation body 6, respectively, to ensure that the push rod presses the two sides of the base island 110 during plastic encapsulation, so that the base island 110 maintains a stable tilted state, at this time, due to the pressing force of the push rod, the back of the base island 110 can be completely attached to the bottom surface of the plastic encapsulation cavity in the plastic encapsulation processing mold, thereby ensuring that no plastic encapsulation material flows into the back of the base island 110, and the edge of the base island 110 will be exposed at the push rod. Further, in order to meet the high-voltage resistance requirements of the device product, the plastic encapsulation body 6 is provided with a U-shaped opening 61 (U-shaped groove) at the gap between the first pin 122 and the second pin 123, and the gap between the first pin 122 and the second pin 123 also corresponds to the pin gap. By providing the U-shaped opening 61, the creepage distance between the first pin 122 and the second pin 123 can be increased, thereby further improving the performance of the half-bridge circuit device. Therefore, the appearance structure of the plastic package body 6 after the half-bridge package is plastic-sealed is as follows Figure 8 shown.

[0065] Furthermore, in order to improve the isolation between the first pin 122 and the second pin 123 (increase the creepage distance between the two pins), the width of the pin gap can be set to 1.2-2.8 times the width of the second pin; further, the width of the U-shaped opening is set to 1 / 2-4 / 5 of the width of the pin gap, and the depth of the U-shaped opening is set to 2 / 3-4 / 5 of the width of the U-shaped opening.

[0066] Furthermore, after the half-bridge circuit device is plastic-sealed and the electroplating and printing processes are completed, rib cutting and forming are performed, and the end of the inner pin extending from the plastic package body 6 is bent into a seagull wing shape (L shape), and the outer end of the inner pin is bent toward the side close to the heat sink 7; a mounting distance E is formed between the back side of the outer end of the inner pin and the heat sink 7 on the back side of the plastic package body 6, and the mounting distance E can be set to 0 to 50um.

[0067] The present application also discloses a PCB board 8, such as Fig.10 As shown, the PCB board 8 is equipped with a compact high-power half-bridge circuit device as described in the above embodiment; a plurality of heat sink pads 81 are provided on the PCB board 8, and the heat sink 7 in the compact high-power half-bridge circuit device is welded to the corresponding heat sink pads 81; the inner pins in adjacent compact high-power half-bridge circuit devices are arranged in opposite directions.

[0068] Specifically, the packaged half-bridge circuit device can be mounted on the PCB board 8 after passing the electrical parameter test. When mounting, the heat sink 7 and the outer ends of the inner pins of the half-bridge circuit device are simultaneously welded to the corresponding pads of the PCB board 8. According to the performance requirements of the traditional high-power electrical module, a corresponding number of single half-bridge circuit devices are matched and mounted to achieve the purpose of replacing the traditional high-power electrical module. Among them, multiple heat sink pads 81 can be set on the PCB board 8, and the heat sink 7 of the half-bridge circuit device can be welded to a corresponding heat sink pad 81; the PCB board 8 formed by the above scheme integrates a group of power tube cores into a power device, and forms a half-bridge circuit device separately. Combining multiple half-bridge circuit devices together can realize the function of a single high-power potting or plastic-sealed module. In order to improve the overall heat dissipation performance of the PCB board 8 on which the half-bridge circuit devices are arranged and avoid interference between adjacent half-bridge circuit devices, the inner pins in adjacent compact high-power half-bridge circuit devices can be arranged in relative directions, that is, the inner pins in one half-bridge circuit device are arranged upward, and the inner pins in the other adjacent half-bridge circuit device are arranged downward, thereby realizing the staggered arrangement of multiple half-bridge circuit devices.

[0069] like Fig.10 The PCB board in the half-bridge module (half-bridge circuit device) can be directly mounted on the PCB board for use after passing the electrical parameter test. During mounting, the 1 heat sink and 4 pins of the half-bridge module, a total of 5 ports, are simultaneously soldered to the 5 pad areas of the PCB. According to the performance requirements of the traditional module, a corresponding number of single half-bridge modules are mounted, and the adjacent half-bridge devices are rotated 180° and staggered for mounting; not only does it achieve the purpose of replacing the traditional high-power module, but also the heat impact between the half-bridge modules is relatively small. PCB boards without half-bridge circuit devices such as Fig.11 As shown, a heat sink pad 81 and a pin pad 82 are provided on the PCB board.

[0070] Compared with the prior art, the utility model claims protection for a specific application of a compact high-power half-bridge packaging technology in a half-bridge circuit device, thereby designing a new type of half-bridge circuit device. The above-mentioned half-bridge circuit device integrates a group of tube cores in a package shape to form an independent half-bridge circuit device. By adjusting the pin width and newly setting a U-shaped opening 61 on the plastic package body 6, the overcurrent capability and creepage distance of the entire half-bridge circuit device are enhanced, which can not only improve the packaging quality, qualified rate, and reliability, but also greatly reduce the use of high-value packaging equipment and materials, greatly reduce the heat transfer, stress, inductance, etc. generated between the power tube cores in the traditional module. The mutual influence or interference is greatly reduced, and the insulation between each other is enhanced. At the same time, multiple half-bridge circuit devices are combined and mounted on the PCB board 8, which also reduces the overall space of the area where the PCB board 8 is located relative to the high-power potting or plastic-sealed large-volume half-bridge module.

[0071] The present utility model embodiment also provides a method for preparing a PCB board, the method is used to prepare the PCB board described in the above embodiment, such as Fig.12 As shown, the method includes steps S1 to S10. Fig.13 As shown, the packaging technology and implementation method involved in the method further include jigs and components in the packaging process: a printed steel mesh 301, an alloy bonding material 302 under the substrate, an alloy bonding material 303 under the substrate power tube core 3, an alloy bonding material 304 under the base island power tube core 4, and a trapezoidal groove 305 formed by the trapezoidal top rod after plastic sealing.

[0072] S1. Design the device framework structure.

[0073] According to the packaging requirements of the half-bridge module (half-bridge circuit device), based on the packaging structure of traditional power semiconductor discrete devices, a device frame matching the half-bridge module is designed.

[0074] S2. Design the substrate structure.

[0075] The insulating thermally conductive substrate on which the power tube die is mounted is designed according to the packaging requirements of the half-bridge module. This type of substrate needs to be able to achieve both electrical connection and meet the heat dissipation requirements of the power tube die.

[0076] S3. Printed steel mesh designed for substrate welding.

[0077] According to the welding characteristic requirements corresponding to the substrate for packaging the half-bridge module, the printed steel mesh 301 of the substrate structure is designed. The material suitable for welding the substrate can be sintered silver, solder paste, or other alloy bonding materials.

[0078] S4, positioning and assembling the device frame and the printing steel mesh and printing an alloy bonding material on the surface of the printing steel mesh.

[0079] The device frame is loaded from the track and matched and positioned with the printing steel mesh 301 using positioning holes, and then the alloy bonding material 302 is printed on the surface of the printing steel mesh.

[0080] S5. Mounting a substrate on the surface of the printed alloy bonding material and reflow curing.

[0081] The substrate is mounted and baked to solidify the alloy bonding material 302. If the volatiles generated when the alloy bonding material 302 is solidified have an adverse effect on subsequent processes, a specific temperature and environment are required to clean the volatiles of the alloy bonding material 302.

[0082] S6, coating the surface layer of the substrate and the surface layer of the base island in the device frame with alloy bonding material and assembling power tube cores respectively.

[0083] The alloy bonding material 303 and the alloy bonding material 304 are applied respectively, and then the substrate power tube die 3 and the base island power tube die 4 are respectively assembled at the corresponding positions. According to the withstand voltage requirement for packaging the half-bridge circuit device, the first spacing between the substrate and the power tube die on the base island needs to meet the corresponding withstand voltage requirement, and the specific process of setting the first spacing is shown in the above embodiment.

[0084] S7, bonding wires to the power tube core to achieve electrical connection.

[0085] The power tube core is wire bonded to make electrical connection between the power tube core and other components. According to the wiring requirements corresponding to the packaging of the half-bridge module, the substrate power tube core 3 and the base island power tube core 4 are wire bonded in sequence to achieve the half-bridge electrical connection between the substrate power tube core 3 and the base island power tube core 4, and between the power tube core and the corresponding pins in the lead 120.

[0086] S8. Encapsulate the half-bridge module to form a plastic package.

[0087] When designing the plastic encapsulation mold, a U-shaped opening 61 is designed on the plastic encapsulation body between the first pin and the second pin to increase the creepage distance. On the base island near one end of the pin, a trapezoidal push rod is set on each side, and a trapezoidal groove 305 is formed on both sides of the plastic encapsulation body after plastic encapsulation to ensure that the trapezoidal push rod presses the two sides of the base island during plastic encapsulation, and the back of the base island is completely attached to the surface of the plastic encapsulation cavity, and no plastic encapsulation material flows into the back of the base island, and a local area of ​​the base island at the push rod is exposed to the outside. Plastic encapsulation material is injected into the plastic encapsulation mold to complete the plastic encapsulation.

[0088] S9, cutting and forming the packaged half-bridge module.

[0089] After the plastic encapsulation, the half-bridge module is packaged and the external pins and heat sink are electroplated. After printing is completed, the ribs are cut and formed. The external pins are bent into a seagull wing shape (L shape). A mounting distance is formed between the back of the external pins and the heat sink on the back of the plastic encapsulation body, and the distance is controlled between 0 and 50um.

[0090] S10, testing the formed half-bridge module, and mounting it on a PCB board after the test is successful.

[0091] The half-bridge module is mounted on the PCB board after passing the electrical parameter test. The pins contained in the heat sink and the leads, a total of 5 ports, are soldered to the corresponding pads on the PCB board 18 (including the heat sink pad 81 and the pin pad 81, the pin pad 81 includes the first pin pad 811, the second pin pad 812, the third pin pad 813 and the fourth pin pad 814). At the same time, adjacent half-bridge modules are rotated 180° and staggered to form a staggered arrangement structure.

[0092] The utility model provides a compact high-power half-bridge circuit device and a PCB board. The compact high-power half-bridge circuit device comprises a device frame 1, a substrate 2, a substrate power tube core 3 and a base island power tube core 4. The device frame 1 comprises a base island 110 and a lead 120; the base island power tube core 4 is arranged on a side of the upper end surface of the base island 110 close to the lead 120, and the substrate 2 is arranged on a side of the upper end surface of the base island 110 away from the lead 120; the substrate power tube core 3 is arranged on the substrate 2; a plastic package 6 is encapsulated in the upper layer of the device frame 1, the substrate 2, the substrate power tube core 3 and the base island power tube core 4; a side of the device frame 1 away from the substrate 2 forms a heat sink 7. The above-mentioned compact high-power half-bridge circuit device integrates a group of tube cores into a packaging shape structure to form an independent half-bridge circuit device, thereby enhancing the overcurrent capability and creepage distance of the entire half-bridge circuit device, avoiding interference between multiple tube cores in the half-bridge circuit device; weakening the mutual influence or interference of heat transfer, stress, inductance, etc. generated between multiple half-bridge tube cores, enhancing the insulation between each other, and improving the reliability and performance of the device.

[0093] The above description is only a specific embodiment of the present invention, so that those skilled in the art can understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but should conform to the widest scope consistent with the principles and novel features applied herein.

Claims

1. A compact high-power half-bridge circuit device, characterized in that: It includes a device frame, a substrate, a substrate power tube die and a base island power tube die; The device frame includes a base island and leads; a frame side rib semi-enclosing the base island is provided on the side of the base island not facing the leads, and the frame side rib is fixedly connected to an end of the base island away from the lead connection frame; a lead connection frame semi-enclosing the lead is provided on the side of the lead not facing the base island, and the end of the lead connection frame is connected to the end of the frame side rib through a connecting rib; The base island power tube core is arranged on a side of the upper end surface of the base island close to the lead, and the substrate is arranged on a side of the upper end surface of the base island away from the lead; the substrate power tube core is arranged on the substrate; Bonding wires for electrical connection are provided between the substrate and the substrate power tube core, between the substrate and the base island power tube core, between the substrate and the lead, between the base island power tube core and the lead, and between the substrate power tube core and the lead; The plastic package is encapsulated on the device frame, the substrate, the substrate power tube core and the upper layer of the base island power tube core; a side of the device frame away from the substrate forms a heat sink.

2. The compact high-power half-bridge circuit device according to claim 1, characterized in that: The width of the first pin and the second pin in the lead is not less than 2.0 mm, and the first pin is electrically connected to the substrate through a welding wire.

3. The compact high-power half-bridge circuit device according to claim 2, characterized in that: The base island is tilted toward a side away from the substrate, and a distance between an end of the base island close to the lead and an initial plane is 0-100 um; wherein the initial plane is a plane corresponding to the base island when it is not tilted.

4. The compact high-power half-bridge circuit device according to any one of claims 1 to 3, characterized in that: The substrate comprises a bottom metal layer, a top metal layer, and an insulating layer sandwiched between the bottom metal layer and the top metal layer; An insulating dividing line is provided between the top metal layers, and the insulating dividing line divides the top metal layer into a mounting area and a connection area; The substrate power tube core is arranged on the mounting area; the first connection end of the substrate power tube core is electrically connected to the connection area through a welding wire.

5. The compact high-power half-bridge circuit device according to claim 4, characterized in that: The connection area is electrically connected to the first pin in the lead through a welding wire, and the first connection end of the base island power tube core is electrically connected to the installation area and the second pin in the lead through a welding wire respectively.

6. The compact high-power half-bridge circuit device according to claim 5, characterized in that: The second connection end of the substrate power tube core is electrically connected to the fourth pin in the lead through a welding wire, and the second connection end of the base island power tube core is electrically connected to the third pin in the lead through a welding wire.

7. The compact high-power half-bridge circuit device according to any one of claims 1 to 3, characterized in that: The first distance between the substrate and the base island power tube core is greater than the assembly position distance value and greater than the package withstand voltage distance value; The assembly position distance value is the position deviation distance corresponding to the assembly of the substrate and the base island power tube core; the package pressure resistance distance value is the distance value corresponding to the pressure resistance characteristic of the plastic package body.

8. The compact high-power half-bridge circuit device according to claim 7, characterized in that: A U-shaped opening is provided at a position on the plastic package body corresponding to the pin gap, and the pin gap is the gap between the first pin and the second pin in the lead.

9. A PCB board, characterized in that: The PCB board is provided with a compact high-power half-bridge circuit device as described in any one of claims 1 to 8; The PCB board is provided with a plurality of heat sink pads, and the heat sinks in the compact high-power half-bridge circuit device are welded on the corresponding heat sink pads; the inner pins in adjacent compact high-power half-bridge circuit devices are arranged in opposite directions.

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