Three-phase PFC module packaging structure

Abstract

The invention discloses a three-phase power factor correction (PFC) module packaging structure, the packaging structure is a dual in-line package (DIP), a plurality of layout areas are arranged on a substrate of the packaging structure, and a first single-phase PFC circuit, a second single-phase PFC circuit and a third single-phase PFC circuit are sequentially arranged on the plurality of layout areas from left to right; on a layout area corresponding to each single-phase PFC circuit, a voltage regulating circuit, a backflow diode and an upper diode in each single-phase PFC circuit are arranged according to the same layout position relation; the packaging structure further comprises an upper side pin and a lower side pin which are arranged in parallel, the low-voltage contact of each single-phase PFC circuit is connected with the upper side pin, and the high-voltage contact of each single-phase PFC circuit is connected with the lower side pin. According to the three-phase PFC module, DIP packaging is adopted, the three single-phase PFC circuits are arranged in a distributed mode, devices in the single-phase PFC circuits are arranged close to each other in a concentrated mode, the high-voltage pins and the low-voltage pins are arranged in two rows in parallel, the miniaturization design of the three-phase PFC circuits is achieved, and the three-phase PFC module is easy to install on a PCB.

Description

Technical Field

[0001] The present application relates to the field of integrated circuits, and in particular to a three-phase PFC module packaging structure. Background Art

[0002] The three-phase buck power factor correction (PFC) circuit can rectify the three-phase AC power supply into a lower voltage DC power supply to power the load. The structure of the three-phase Buck PFC circuit is as follows: Figure 1 shown.

[0003] The three-phase Buck PFC circuit includes three single-phase PFC circuits (also called bridge arms) and involves multiple switches and diodes. If discrete components are used to build the circuit, there will be problems such as difficult PCB board layout, large board area, and weak electromagnetic compatibility. Summary of the invention

[0004] In view of this, an embodiment of the present application provides a three-phase PFC module packaging structure, aiming to achieve a miniaturized design of a three-phase PFC circuit.

[0005] The technical solution of the embodiment of the present application is implemented as follows:

[0006] In a first aspect, an embodiment of the present application provides a three-phase power factor correction PFC module packaging structure, wherein the packaging structure is a dual in-line package (DIP), and a plurality of layout areas are provided on a substrate of the packaging structure, and a first single-phase PFC circuit, a second single-phase PFC circuit, and a third single-phase PFC circuit are sequentially arranged from left to right on the plurality of layout areas; on the layout areas corresponding to each single-phase PFC circuit, a voltage regulating circuit, a return diode, and an upper diode in each single-phase PFC circuit are arranged according to the same layout position relationship;

[0007] Wherein, the packaging structure further includes upper pins and lower pins arranged in parallel, the low-voltage contacts of each single-phase PFC circuit are connected to the upper pins, and the high-voltage contacts of each single-phase PFC circuit are connected to the lower pins.

[0008] In some embodiments, the plurality of layout areas include a plurality of first areas for arranging each of the voltage regulating circuits, a plurality of second areas for arranging each of the upper diodes, and a plurality of third areas for arranging each of the return diodes;

[0009] Among them, the voltage regulating circuit includes a switching tube, an input diode, and a lower diode. In each of the single-phase PFC circuits, the input end of the switching tube is respectively connected to the cathode of the input diode and the lower diode, and the output end of the switching tube is respectively connected to the anode of the upper switching tube and the return diode.

[0010] In some embodiments, the upper pins include a first upper pin, a second upper pin, a third upper pin, a fourth upper pin, a fifth upper pin, and a sixth upper pin arranged sequentially from left to right;

[0011] Among them, the low-voltage contact includes a driving end and an output end of each switching tube, and the driving end of each switching tube is connected to the first upper pin, the third upper pin and the fifth upper pin in sequence; the output end of each switching tube is correspondingly connected to the second upper pin, the fourth upper pin and the sixth upper pin in order from left to right.

[0012] In some embodiments, the lower pins include a first lower pin, a second lower pin, and a third lower pin arranged in sequence from left to right, and the first lower pin, the second lower pin, and the third lower pin are the AC power input terminals of the three-phase PFC module packaging structure; the high-voltage contact includes a cathode of each of the return diodes and an anode of the input diode, and the cathode of each of the return diodes is connected to the first lower pin, the second lower pin, and the third lower pin in sequence from left to right; the anode of each of the input diodes is connected to the first lower pin, the second lower pin, and the third lower pin in sequence from left to right;

[0013] Among them, the lower pin also includes a fourth lower pin and a fifth lower pin, the fourth lower pin is a ground terminal, and the fifth lower pin is an output terminal of the three-phase PFC module packaging structure; the high-voltage contact also includes an anode of each lower diode and a cathode of each upper diode; the anode of each lower diode is connected to the fourth lower pin, and the cathode of each upper diode is connected to the fifth lower pin.

[0014] In some embodiments, the package structure further includes a freewheeling diode and a temperature detection unit, and the plurality of layout areas further include a fourth area for arranging the freewheeling diode and a fifth area for arranging the temperature detection unit;

[0015] Among them, the upper pin also includes a seventh upper pin and an eighth upper pin, and the low-voltage contact also includes the two ends of the temperature detection unit; the first end of the temperature detection unit is connected to the seventh upper pin, and the second end of the temperature detection unit is connected to the eighth upper pin; the high-voltage contact also includes the anode and cathode of the freewheeling diode, the anode of the freewheeling diode is connected to the fourth lower pin, and the cathode of the freewheeling diode is connected to the fifth lower pin.

[0016] In some embodiments, the voltage regulating circuit in each of the single-phase PFC circuits is arranged on the upper side of the upper diode, and the return diode is arranged on the lower side of the upper diode; the freewheeling diode is arranged at the lower left corner of the substrate, and the temperature detection unit is arranged at the upper right corner of the substrate; the seventh upper pin and the eighth upper pin are arranged on the right side of the sixth upper pin; the fifth lower pin is arranged on the left side of the first lower pin, and the fourth lower pin is arranged on the left side of the fifth lower pin.

[0017] In some embodiments, the upper diode in each of the single-phase PFC circuits is arranged on the upper side of the voltage regulating circuit, and the return diode is arranged on the lower side of the voltage regulating circuit; the freewheeling diode is arranged at the lower left corner of the substrate, and the temperature detection unit is arranged at the upper right corner of the substrate; the seventh upper pin and the eighth upper pin are arranged on the right side of the sixth upper pin; the fifth lower pin is arranged on the left side of the first lower pin, and the fourth lower pin is arranged on the left side of the fifth lower pin.

[0018] In some embodiments, the upper diode in each of the single-phase PFC circuits is arranged at the upper left corner of the voltage regulating circuit, and the return diode is arranged at the lower right corner of the voltage regulating circuit; the freewheeling diode is arranged at the lower left corner of the substrate, and the temperature detection unit is arranged at the upper right corner of the substrate; the seventh upper pin and the eighth upper pin are arranged on the right side of the sixth upper pin; the fourth lower pin is arranged on the left side of the first lower pin, and the fifth lower pin is arranged on the left side of the fourth lower pin.

[0019] In some embodiments, the upper diode in each of the single-phase PFC circuits is arranged at the upper right corner of the voltage regulating circuit, and the return diode is arranged at the lower left corner of the voltage regulating circuit; the freewheeling diode is arranged at the lower right corner of the substrate, and the temperature detection unit is arranged at the upper left corner of the substrate; the seventh upper pin and the eighth upper pin are arranged on the left side of the first upper pin; the fifth lower pin is arranged on the right side of the third lower pin, and the fourth lower pin is arranged on the right side of the fifth lower pin.

[0020] In some embodiments, the switch tube, the input diode, the return diode, the upper diode, the lower diode and the freewheeling diode are packaged in the form of bare chips.

[0021] The three-phase PFC module packaging structure provided in the embodiment of the present application is a DIP package, and a plurality of layout areas are set on the substrate of the packaging structure, and the first single-phase PFC circuit, the second single-phase PFC circuit and the third single-phase PFC circuit are arranged in sequence from left to right on the plurality of layout areas; on the layout area corresponding to each single-phase PFC circuit, the voltage regulating circuit, the return diode and the upper diode in each single-phase PFC circuit are arranged according to the same layout position relationship; wherein, the packaging structure also includes upper pins and lower pins arranged in parallel, the low-voltage contact of each single-phase PFC circuit is connected to the upper pin, and the high-voltage contact of each single-phase PFC circuit is connected to the lower pin. In this way, the three-phase PFC module of the embodiment of the present application adopts a DIP package, and the three-way single-phase PFC circuits are distributed and arranged, and the devices in each single-phase PFC circuit are concentrated and arranged close to each other, and the high-voltage pins and the low-voltage pins are arranged in two columns in parallel, so as to realize the miniaturized design of the three-phase PFC circuit and make it easy to install on the PCB board. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the structure of a three-phase Buck PFC circuit according to an embodiment of the present application;

[0023] Figure 2 This is a schematic diagram of the circuit structure of a three-phase PFC module according to an embodiment of the present application;

[0024] Figure 3 This is a schematic diagram of a three-phase PFC module packaging structure according to an embodiment of the present application;

[0025] Figure 4 A schematic diagram of a three-phase PFC module packaging structure in an application example of the present application;

[0026] Figure 5 A schematic diagram of a three-phase PFC module packaging structure in an application example of the present application;

[0027] Figure 6 This is a schematic diagram of the device layout of a three-phase PFC module according to an embodiment of the present application;

[0028] Figure 7 This is a wiring diagram of a three-phase PFC module packaging structure according to an embodiment of the present application;

[0029] Figure 8 This is a schematic diagram of the device layout of a three-phase PFC module according to another embodiment of the present application;

[0030] Fig. 9 This is a wiring diagram of a three-phase PFC module packaging structure according to another embodiment of the present application;

[0031] Fig.10 This is a schematic diagram of the device layout of a three-phase PFC module in another embodiment of the present application;

[0032] Fig.11 This is a wiring diagram of a three-phase PFC module packaging structure according to another embodiment of the present application;

[0033] Fig.12 This is a schematic diagram of the device layout of a three-phase PFC module in yet another embodiment of the present application;

[0034] Fig.13 This is a wiring diagram of a three-phase PFC module packaging structure according to yet another embodiment of the present application.

[0035] Description of reference numerals:

[0036] 100. A first single-phase PFC circuit; 200. A second single-phase PFC circuit;

[0037] 300, a third single-phase PFC circuit; 400, a substrate; 401, a first region;

[0038] 402, second area; 403, third area; 404, fourth area; 405, fifth area. DETAILED DESCRIPTION

[0039] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0041] In the description of the present application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0042] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0043] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above", "above", "above" and "upper side" of a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below", "below" and "lower side" of a second feature includes the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0044] Here, the circuit structure of the three-phase Buck PFC circuit is as follows Figure 1 As shown, the three-phase AC power supply includes three phases A, B, and C. The three-phase AC power supply is connected to the three-phase PFC circuit after being filtered by a filtering circuit composed of a first inductor L1, a second inductor L2, a third inductor L3, a first capacitor C1, a second capacitor C2, and a third capacitor C3, wherein the A-phase power supply is connected to the first single-phase PFC circuit 100, the B-phase power supply is connected to the second single-phase PFC circuit 200, and the C-phase power supply is connected to the third single-phase PFC circuit 300. The circuit structures of the single-phase PFC circuits are the same. The first single-phase PFC circuit 100 includes a first diode D1, a second diode D2, a seventh diode D7, an eighth diode D8 and a first switch tube Q1. The second single-phase PFC circuit 200 includes a third diode D3, a fourth diode D4, a ninth diode D9, a tenth diode D10 and a second switch tube Q2. The third single-phase PFC circuit 300 includes a fifth diode D5, a sixth diode D6, an eleventh diode D11, a twelfth diode D12 and a third switch tube Q3. The first diode D1, the third diode D3 and the fifth diode D5 are upper diodes, the second diode D2, the fourth diode D4 and the sixth diode D6 are lower diodes, the seventh diode D7, the ninth diode D9 and the eleventh diode D11 are return diodes, and the eighth diode D8, the tenth diode D10 and the twelfth diode D12 are input diodes. The three-phase PFC circuit also includes a thirteenth diode D13, which is a freewheeling diode.

[0045] Here, in addition to the filter circuit and the three-phase PFC circuit, the three-phase Buck PFC circuit also includes a fourth inductor L4, a fifth inductor L5 and a fourth capacitor C4. The fourth inductor L4, the fifth inductor L5 and the fourth capacitor C4 are arranged at the power supply end of the load. When the three-phase AC power supply supplies power to the load, the fourth inductor L4, the fifth inductor L5 and the fourth capacitor C4 store electric energy to achieve the effect of voltage reduction. Specifically, if each switch tube is in the on state, the three-phase AC power supply supplies power to the load through the filter circuit and the three-phase PFC circuit, and the fourth inductor L4, the fifth inductor L5 and the fourth capacitor C4 are in the charging state; if each switch tube is in the off state, the fourth inductor L4, the load, the fifth inductor L5 and the thirteenth diode D13 form a power-on loop, and the fourth inductor L4 and the fifth inductor L5 discharge the load and the fourth capacitor C4; after the fourth inductor L4 and the fifth inductor L5 are discharged, the fourth capacitor C4 discharges the load to maintain the voltage across the load.

[0046] It should be noted that since the three-phase Buck PFC circuit includes thirteen diodes, three switching tubes, five inductors and four capacitors, if discrete components are used to build the circuit, there will be problems such as difficult PCB board layout, large board area and weak electromagnetic compatibility.

[0047] Based on this, an embodiment of the present application provides a three-phase PFC module packaging structure to achieve a miniaturized design of a three-phase PFC circuit.

[0048] Here, since inductive components such as inductors and capacitors are large in size and are not convenient to package into modules, the three-phase PFC module packaging structure of the embodiment of the present application is suitable for a three-phase PFC module including a three-phase PFC circuit and a temperature detection unit, wherein the temperature detection unit is used to detect the temperature value inside the three-phase PFC module.

[0049] Specifically, the circuit structure of the three-phase PFC module is as follows: Figure 2 As shown, it includes a first single-phase PFC circuit 100, a second single-phase PFC circuit 200, a third single-phase PFC circuit 100, a thirteenth diode D13 and a temperature detection unit T. The three-phase PFC module includes eight low-voltage contacts and five high-voltage contacts, wherein the eight low-voltage nodes are respectively a driving terminal contact of the first switch tube Q1, an output terminal contact of the first switch tube Q1, a driving terminal contact of the second switch tube Q2, an output terminal contact of the second switch tube Q2, a driving terminal contact of the third switch tube Q3, an output terminal contact of the third switch tube Q3, a first temperature detection contact connected to the first end of the temperature detection unit T, and a second temperature detection contact connected to the second end of the temperature detection unit T; the five high-voltage contacts are respectively a contact connected to the A-phase power supply, a contact connected to the B-phase power supply, a contact connected to the C-phase power supply, a contact connected to the positive pole of the power supply end of the load, and a contact connected to the negative pole of the power supply end of the load.

[0050] In some embodiments, the first switch tube Q1, the second switch tube Q2 and the third switch tube Q3 may be triodes, the driving end of the switch tube is the base of the triode, and the output end of the switch tube is the emitter of the triode; the temperature detection unit T may be a thermistor.

[0051] like Figure 3 As shown, the three-phase PFC module packaging structure of the embodiment of the present application is a DIP package, and a plurality of layout areas are provided on a substrate 400 of the packaging structure, and a first single-phase PFC circuit 100, a second single-phase PFC circuit 200 and a third single-phase PFC circuit 300 are arranged in sequence from left to right on the plurality of layout areas; on the layout areas corresponding to the single-phase PFC circuits, the voltage regulating circuit, the return diode and the upper diode in the single-phase PFC circuits are arranged according to the same layout position relationship; wherein the packaging structure further includes upper pins and lower pins arranged in parallel, the low-voltage contact of each single-phase PFC circuit is connected to the upper pin, and the high-voltage contact of each single-phase PFC circuit is connected to the lower pin.

[0052] Specifically, the voltage regulating circuit includes a switching tube, an input diode and a lower diode. In each single-phase PFC circuit, the input end of the switching tube is respectively connected to the cathode of the input diode and the cathode of the lower diode, and the output end of the switching tube is respectively connected to the anode of the upper switching tube and the anode of the return diode.

[0053] Here, the first voltage regulating circuit includes a first switch tube Q1, a second diode D2 and an eighth diode D8, the second voltage regulating circuit includes a second switch tube Q2, a fourth diode D4 and a tenth diode D10, and the third voltage regulating circuit includes a third switch tube Q3, a sixth diode D6 and a twelfth diode D12.

[0054] Here, DIP package is a packaging method for integrated circuits. The shape of the integrated circuit in DIP package is rectangular, and two rows of parallel pins are set. The integrated circuit in DIP package can be directly installed on the DIP socket, or directly inserted into the printed circuit board with the same number of solder holes and geometric arrangement for soldering.

[0055] It can be understood that the components of each single-phase PFC circuit in the embodiment of the present application are arranged in a centralized manner, and the three single-phase PFC circuits are distributed from left to right, which facilitates the routing design of the three-phase PFC module packaging structure.

[0056] Exemplarily, the upper pins of the three-phase PFC module packaging structure include a first upper pin GA, a second upper pin EA, a third upper pin GB, a fourth upper pin EB, a fifth upper pin GC, and a sixth upper pin EC arranged in sequence from left to right. The low-voltage contact includes a driving end and an output end of each switch tube, and the driving end of each switch tube is sequentially connected to the first upper pin GA, the third upper pin GB, and the fifth upper pin GC; the output end of each switch tube is correspondingly connected to the second upper pin EA, the fourth upper pin EB, and the sixth upper pin EC in sequence from left to right.

[0057] Specifically, the driving end of the first switch tube Q1 is connected to the first upper pin GA, the output end of the first switch tube Q1 is connected to the second upper pin EA, the driving end of the second switch tube Q2 is connected to the third upper pin GB, the output end of the second switch tube Q2 is connected to the fourth upper pin EB, the driving end of the third switch tube Q3 is connected to the fifth upper pin GC, and the output end of the third switch tube Q3 is connected to the sixth upper pin EC.

[0058] Exemplarily, the three-phase PFC module packaging structure also includes a temperature detection unit T, the upper pins also include a seventh upper pin T1 and an eighth upper pin T2, and the low-voltage contact also includes two ends of the temperature detection unit T; the first end of the temperature detection unit T is connected to the seventh upper pin T1, and the second end of the temperature detection unit T is connected to the eighth upper pin T2.

[0059] It can be understood that the upper pins of the three-phase PFC module packaging structure of the embodiment of the present application are arranged close to the correspondingly connected single-phase PFC circuits or temperature detection units T, which facilitates the wiring between each upper pin and the corresponding device.

[0060] It should be noted that the seventh upper pin T1 and the eighth upper pin T2 are not limited to the arrangement positions of the upper pins. Figure 3 As shown in the arrangement position, the arrangement position of the seventh upper pin T1 and the eighth upper pin T2 in the upper pins is not specifically limited in the embodiment of the present application. The seventh upper pin T1 and the eighth upper pin T2 can be arranged on the left side of the first upper pin GA, or on the right side of the sixth upper pin EC. The arrangement position of the seventh upper pin T1 and the eighth upper pin T2 is specifically determined based on the layout position of the temperature detection unit T.

[0061] Exemplarily, the lower pins of the three-phase PFC module packaging structure include a first lower pin a, a second lower pin b and a third lower pin c arranged in sequence from left to right, and the first lower pin a, the second lower pin b and the third lower pin c are the AC power input end of the three-phase PFC module packaging structure; the high-voltage contact includes the cathode of each return diode and the anode of the input diode, and the cathode of each return diode is correspondingly connected to the first lower pin a, the second lower pin b, and the third lower pin c in order from left to right; the anode of each input diode is correspondingly connected to the first lower pin a, the second lower pin b, and the third lower pin c in order from left to right.

[0062] Specifically, the first lower pin a is used to connect the A phase power supply, the second lower pin b is used to connect the B phase power supply, the third lower pin c is used to connect the C phase power supply, the cathode of the seventh diode D7 and the anode of the eighth diode D8 are connected to the first lower pin a, the cathode of the ninth diode D9 and the anode of the tenth diode D10 are connected to the second lower pin b, and the cathode of the eleventh diode D11 and the anode of the twelfth diode D12 are connected to the third lower pin c.

[0063] Exemplarily, the lower pins also include a fourth lower pin n and a fifth lower pin p, the fourth lower pin n is the ground terminal, and the fifth lower pin p is the output terminal of the three-phase PFC module packaging structure; the high-voltage contact also includes an anode of each lower diode and a cathode of each upper diode; the anode of each lower diode is connected to the fourth lower pin n, and the cathode of each upper diode is connected to the fifth lower pin p.

[0064] Specifically, the fourth lower pin n is used to connect the negative pole of the power supply end of the load, the fifth lower pin p is used to connect the positive pole of the power supply end of the load, the anode of the second diode D2, the anode of the fourth diode D4 and the anode of the sixth diode D6 are all connected to the fourth lower pin n, and the cathode of the first diode D1, the cathode of the third diode D3 and the cathode of the fifth diode D5 are all connected to the fifth lower pin p.

[0065] Exemplarily, the three-phase PFC packaging structure also includes a freewheeling diode, and the high-voltage contact also includes an anode and a cathode of the freewheeling diode, the anode of the freewheeling diode is connected to the fourth lower pin n, and the cathode of the freewheeling diode is connected to the fifth lower pin p.

[0066] Here, the freewheeling diode is the thirteenth diode D13.

[0067] It can be understood that the lower pins of the three-phase PFC module packaging structure of the embodiment of the present application are arranged close to the correspondingly connected single-phase PFC circuits or the thirteenth diode D13, which facilitates the connection between the lower pins and the corresponding devices.

[0068] It should be noted that the arrangement positions of the fourth lower pin n and the fifth lower pin p on the lower pins are not limited to Figure 3 As shown in the arrangement position, the arrangement position of the fourth lower pin n and the fifth lower pin p in the lower pins is not specifically limited in the embodiment of the present application. The fourth lower pin n and the fifth lower pin p can be arranged on the left side of the first lower pin a, or on the right side of the third lower pin c. The arrangement position of the fourth lower pin n and the fifth lower pin p is specifically determined based on the layout position of the thirteenth diode D13.

[0069] It can be understood that the upper pins of the three-phase PFC module packaging structure in the embodiment of the present application are all low-voltage pins, and the lower pins are all high-voltage pins.

[0070] It can be understood that the three-phase PFC module of the embodiment of the present application adopts DIP packaging, and the high-voltage pins and the low-voltage pins are arranged in two parallel rows, which realizes the miniaturized design of the three-phase PFC circuit and is easy to install on the substrate.

[0071] Exemplarily, the first switch tube Q1, the second switch tube Q2, the third switch tube Q3, the first diode D1, the second diode D2, the third diode D3, the fourth diode D4, the fifth diode D5, the sixth diode D6, the seventh diode D7, the eighth diode D8, the ninth diode D9, the tenth diode D10, the eleventh diode D11, the twelfth diode D12 and the thirteenth diode D13 are all packaged in the form of bare chips.

[0072] Specifically, the above-mentioned device is packaged in the form of a bare chip and covered on the top layer of the corresponding wafer, and is connected to the devices or copper foil in other layout areas by setting bonding wires.

[0073] Exemplarily, the multiple layout areas include multiple first areas for arranging each voltage regulating circuit, multiple second areas for arranging each upper diode, multiple third areas for arranging each return diode, a fourth area for arranging a freewheeling diode, and a fifth area for arranging a temperature detection unit T.

[0074] Specifically, the multiple first regions include three first regions, which are respectively used to arrange the first voltage regulating circuit, the second voltage regulating circuit and the third voltage regulating circuit; the multiple second regions include three second regions, which are respectively used to arrange the first diode D1, the third diode D3 and the fifth diode D5; the multiple third regions include three third regions, which are respectively used to arrange the seventh diode D7, the ninth diode D9 and the eleventh diode D11.

[0075] It should be noted that copper foil is laid on the top plate of the substrate 400 , and the copper foil is divided into a plurality of layout areas so that the devices arranged in the same area are connected.

[0076] In one application example, Figure 4 As shown, the substrate 400 is a ceramic substrate, a copper sheet is directly laid on the ceramic substrate, and various components are arranged on the copper sheet.

[0077] In one application example, Figure 5 As shown, the substrate 400 is a metal substrate, on which a copper sheet is laid after being isolated by a polymer insulating layer, and various devices are arranged on the copper sheet.

[0078] In one embodiment, the device layout scheme of the three-phase PFC module is as follows: Figure 6 The layout area of ​​each single-phase PFC circuit includes a first area 401, a second area 402 and a third area 403, wherein the first area 401 is arranged on the upper side of the corresponding second area 402, and the third area 403 is arranged on the lower side of the corresponding second area 402; the fourth area 404 is arranged at the lower left corner of the substrate 400, and the fifth area 405 is arranged at the upper right corner of the substrate 400.

[0079] based on Figure 6 In the layout area shown, the voltage regulating circuit in each single-phase PFC circuit is arranged on the upper side of the upper diode, and the return diode is arranged on the lower side of the upper diode; the freewheeling diode is arranged at the lower left corner of the substrate 400, and the temperature detection unit T is arranged at the upper right corner of the substrate 400.

[0080] based on Figure 6 In the layout area shown, the seventh upper pin T1 and the eighth upper pin T2 are arranged close to the fifth area 405, and the arrangement positions of the upper pins are, from left to right, the first upper pin GA, the second upper pin EA, the third upper pin GB, the fourth upper pin EB, the fifth upper pin GC, the sixth upper pin EC, the seventh upper pin T1 and the eighth upper pin T2; the fourth lower pin n and the fifth lower pin p are arranged close to the fourth area 404, and the arrangement positions of the lower pins are, from left to right, the fourth lower pin n, the fifth lower pin p, the first lower pin a, the second lower pin b and the third lower pin c.

[0081] Here, the positional relationship between the switch tube, input diode and lower switch tube arranged on each first area 401 is determined based on the arrangement position of the upper pin corresponding to the switch tube. The switch tube is arranged close to the corresponding upper pin to facilitate wiring at the driving end and input end of the switch tube.

[0082] based on Figure 6 The specific structural diagram of the three-phase PFC module packaging structure is shown in the layout area shown in FIG. Figure 7As shown. The devices arranged in the same layout area are connected to the same potential through copper wiring, and the devices are connected to the devices or copper in other layout areas by setting binding wires on the top layer. Specifically, a grounding copper sheet is set on the substrate 400 (shown in the shaded area), and the three-phase PFC module is provided with two fourth lower pins n, and the two fourth lower pins n are connected to the grounding copper sheet through binding wires, and the second diode D2, the fourth diode D4, the sixth diode D6 and the thirteenth diode D13 are connected to the grounding copper sheet through binding wires; multiple second areas are connected to the fourth area, and the fifth lower pin p is connected to the copper sheets of multiple second areas and the fourth area; the first lower pin a, the second lower pin b and the third lower pin c are connected to the copper sheets of the corresponding third area, and the eighth diode D8, the tenth diode D10 and the twelfth diode D12 are connected to the copper sheets of the corresponding third area through binding wires to achieve connection with the corresponding The first switch tube Q1 is arranged on the right side of the second diode D2 and the eighth diode D8, and is connected to the first upper pin GA and the second upper pin EA through a binding wire; the second switch tube Q2 is arranged on the upper side of the fourth diode D4 and the tenth diode D10, and is connected to the third upper pin GB and the fourth upper pin EB through a binding wire; the third switch tube Q3 is arranged on the right side of the sixth diode D6 and the twelfth diode D12, and is connected to the fifth upper pin GC and the sixth upper pin EC through a binding wire; the switch tubes and the return diodes of each single-phase PFC circuit are connected to the upper switch tubes through a binding wire; the temperature detection unit T is connected to the seventh upper pin T1 and the eighth upper pin T2 through a binding wire.

[0083] It can be understood that in the present embodiment, there are no cross-binding wires between the single-phase PFC circuits, the third region 403 is arranged on the lower side of the substrate 400 to be close to the lower pins, and the binding wires of the upper diode are short; the first switch tube Q1, the second switch tube Q2 and the third switch tube Q3 are arranged close to the corresponding upper pins, and the binding wires of the switch tubes are short; the fourth lower pin n is connected to an independent grounding copper foil, the anode of the thirteenth diode D13 is connected to the grounding copper foil through a binding wire, the binding wires of the freewheeling diode and the lower diode are short, and the two groups of binding wires of the thirteenth diode D13 are welded to the two fourth lower pins n, thereby enhancing the overcurrent capacity of the three-phase PFC module.

[0084] In one embodiment, the device layout scheme of the three-phase PFC module is as follows: Figure 8 The layout area of ​​each single-phase PFC circuit includes a first area 401, a second area 402 and a third area 403, wherein the second area 402 is arranged on the upper side of the corresponding first area 401, and the third area 403 is arranged on the lower side of the corresponding first area 401; the fourth area 404 is arranged at the lower left corner of the substrate 400, and the fifth area 405 is arranged at the upper right corner of the substrate 400.

[0085] based on Figure 8 In the layout area shown, the upper diode in each single-phase PFC circuit is arranged on the upper side of the voltage regulating circuit, and the return diode is arranged on the lower side of the voltage regulating circuit; the freewheeling diode is arranged at the lower left corner of the substrate 400, and the temperature detection unit T is arranged at the upper right corner of the substrate 400.

[0086] based on Figure 8 In the layout area shown, the seventh upper pin T1 and the eighth upper pin T2 are arranged close to the fifth area 405, and the arrangement positions of the upper pins are, from left to right, the first upper pin GA, the second upper pin EA, the third upper pin GB, the fourth upper pin EB, the fifth upper pin GC, the sixth upper pin EC, the seventh upper pin T1 and the eighth upper pin T2; the fourth lower pin n and the fifth lower pin p are arranged close to the fourth area 404, and the arrangement positions of the lower pins are, from left to right, the fourth lower pin n, the fifth lower pin p, the first lower pin a, the second lower pin b and the third lower pin c.

[0087] Here, the positional relationship between the switch tube, input diode and lower switch tube arranged on each first area 401 is determined based on the arrangement position of the upper pin corresponding to the switch tube. The switch tube is arranged close to the corresponding upper pin to facilitate wiring at the driving end and input end of the switch tube.

[0088] based on Figure 8 The specific structural diagram of the three-phase PFC module packaging structure is shown in the layout area shown in FIG. Fig. 9As shown. The devices arranged in the same layout area are connected to the same potential through copper routing, and the devices are connected to the devices or copper in other layout areas by setting binding wires on the top layer. Specifically, a grounding copper sheet is set on the substrate 400 (shown in the shaded area). The second diode D2, the fourth diode D4, the sixth diode D6 and the thirteenth diode D13 are connected to the grounding copper sheet through binding wires, and the fourth lower pin n is connected to the thirteenth diode D13 through a binding wire to achieve connection with the second diode D2, the fourth diode D4 and the sixth diode D6; multiple second areas are connected to the fourth area, and the fifth lower pin p is connected to the copper sheets of multiple second areas and the fourth area; the first lower pin a, the second lower pin b and the third lower pin c are connected to the copper sheets of the corresponding third areas, and the eighth diode D8, the tenth diode D10 and the twelfth diode D12 are connected to the copper sheets of the corresponding third areas through binding wires. , to achieve connection with the corresponding lower pin; the first switch tube Q1 is arranged on the upper side of the second diode D2 and the eighth diode D8, and is connected to the first upper pin GA and the second upper pin EA through the binding wire; the second switch tube Q2 is arranged on the upper side of the fourth diode D4 and the tenth diode D10, and is connected to the third upper pin GB and the fourth upper pin EB through the binding wire; the third switch tube Q3 is arranged on the upper side of the sixth diode D6 and the twelfth diode D12, and is connected to the fifth upper pin GC and the sixth upper pin EC through the binding wire; the upper switch tubes and the return diodes of each single-phase PFC circuit are connected to the switch tubes through the binding wire; the temperature detection unit T is connected to the seventh upper pin T1 and the eighth upper pin T2 through the binding wire.

[0089] It can be understood that in this embodiment, there are no cross-binding wires between the single-phase PFC circuits, the third area 403 is arranged on the lower side of the substrate 400 to be close to the lower pin, and the binding wires of the upper diode are short; the first switch tube Q1, the second switch tube Q2 and the third switch tube Q3 are arranged close to the corresponding upper pins, and the binding wires of the switch tubes are short; an independent grounding copper foil is arranged on the substrate 400, and the anode of the thirteenth diode D13 is respectively connected to the grounding copper foil and the fourth lower pin n through binding wires, and the binding wires of the freewheeling diode and the lower diode are short.

[0090] In one embodiment, the device layout scheme of the three-phase PFC module is as follows: Fig.10 The layout area of ​​each single-phase PFC circuit includes a first area 401, a second area 402 and a third area 403, wherein the second area 402 is arranged at the upper left corner of the corresponding first area 401, and the third area 403 is arranged at the lower right corner of the corresponding first area 401; the fourth area 404 is arranged at the lower left corner of the substrate 400, and the fifth area 405 is arranged at the upper right corner of the substrate 400.

[0091] based on Fig.10 In the layout area shown, the upper diode in each single-phase PFC circuit is arranged at the upper left corner of the voltage regulating circuit, and the return diode is arranged at the lower right corner of the voltage regulating circuit; the opening tube, input diode and lower diode of the voltage regulating circuit are arranged in sequence from top to bottom; the freewheeling diode is arranged at the lower left corner of the substrate 400, and the temperature detection unit T is arranged at the upper right corner of the substrate 400.

[0092] based on Fig.10 In the layout area shown, the seventh upper pin T1 and the eighth upper pin T2 are arranged close to the fifth area 405, and the arrangement positions of the upper pins are, from left to right, the first upper pin GA, the second upper pin EA, the third upper pin GB, the fourth upper pin EB, the fifth upper pin GC, the sixth upper pin EC, the seventh upper pin T1 and the eighth upper pin T2; the fourth lower pin n and the fifth lower pin p are arranged close to the fourth area 404, and the arrangement positions of the lower pins are, from left to right, the fourth lower pin n, the fifth lower pin p, the first lower pin a, the second lower pin b and the third lower pin c.

[0093] based on Fig.10 The specific structural diagram of the three-phase PFC module packaging structure is shown in the layout area shown in FIG. Fig.11As shown. The devices arranged in the same layout area are connected to the same potential through copper routing, and the devices are connected to the devices or copper in other layout areas by setting binding wires on the top layer. Specifically, the fourth lower pin n is connected to the thirteenth diode D13 through the binding wire, the second diode D2, the fourth diode D4 and the sixth diode D6 are arranged on the lower side of each first area, the thirteenth diode D13 is connected to the second diode D2 through the binding wire, the second diode D2 is connected to the fourth diode D4 through the binding wire, and the fourth diode D4 is connected to the sixth diode D6 through the binding wire, so that the second diode D2, the fourth diode D4, the sixth diode D6 and the thirteenth diode D13 are connected to the fourth lower pin n; multiple second areas are connected to the fourth area, the fifth lower pin p is connected to the copper of multiple second areas and the fourth area; the first lower pin a, the second lower pin b and the third lower pin c are connected to the copper of the corresponding third area, the eighth diode D8 , the tenth diode D10 and the twelfth diode D12 are connected to the copper foil of the corresponding third area through the binding wire to achieve connection with the corresponding lower pin; the first switch tube Q1 is arranged on the upper side of the corresponding first area, and is connected to the first upper pin GA and the second upper pin EA through the binding wire; the second switch tube Q2 is arranged on the upper side of the corresponding first area, and is connected to the third upper pin GB and the fourth upper pin EB through the binding wire; the third switch tube Q3 is arranged on the upper side of the corresponding first area, and is connected to the fifth upper pin GC and the sixth upper pin EC through the binding wire; the return diode is arranged in the middle of the corresponding first area, and is respectively connected to the corresponding switch tube and the upper switch tube through the binding wire; the temperature detection unit T is connected to the seventh upper pin T1 and the eighth upper pin T2 through the binding wire.

[0094] It can be understood that in this embodiment, there are no cross-binding wires between the single-phase PFC circuits, the third area 403 is arranged on the lower side of the substrate 400 to be close to the lower pins, and the binding wires of the upper diode are short; the single-phase PFC circuits are symmetrically distributed, the strong power loop is excellent, and the electromagnetic compatibility of the three-phase PFC module is strong.

[0095] In one embodiment, the device layout scheme of the three-phase PFC module is as follows: Fig.12 The layout area of ​​each single-phase PFC circuit includes a first area 401, a second area 402 and a third area 403, wherein the second area 402 is arranged at the upper right corner of the corresponding first area 401, and the third area 403 is arranged at the lower left corner of the corresponding first area 401; the fourth area 404 is arranged at the lower right corner of the substrate 400, and the fifth area 405 is arranged at the upper left corner of the substrate 400.

[0096] based on Fig.10In the layout area shown, the upper diode in each single-phase PFC circuit is arranged at the upper right corner of the voltage regulating circuit, and the return diode is arranged at the lower left corner of the voltage regulating circuit; the opening tube, input diode and lower diode of the voltage regulating circuit are arranged in sequence from top to bottom; the freewheeling diode is arranged at the upper left corner of the substrate 400, and the temperature detection unit T is arranged at the lower right corner of the substrate 400.

[0097] based on Fig.10 In the layout area shown, the seventh upper pin T1 and the eighth upper pin T2 are arranged close to the fifth area 405, and the arrangement positions of the upper pins are, from left to right, the seventh upper pin T1, the eighth upper pin T2, the first upper pin GA, the second upper pin EA, the third upper pin GB, the fourth upper pin EB, the fifth upper pin GC and the sixth upper pin EC; the fourth lower pin n and the fifth lower pin p are arranged close to the fourth area 404, and the arrangement positions of the lower pins are, from left to right, the first lower pin a, the second lower pin b, the third lower pin c, the fifth lower pin p and the fourth lower pin n.

[0098] based on Fig.10 The specific structural diagram of the three-phase PFC module packaging structure is shown in the layout area shown in FIG. Fig.11As shown. The devices arranged in the same layout area are connected to the same potential through copper routing, and the devices are connected to the devices or copper in other layout areas by setting binding wires on the top layer. Specifically, the fourth lower pin n is connected to the thirteenth diode D13 through the binding wire, the second diode D2, the fourth diode D4 and the sixth diode D6 are arranged on the lower side of each first area, the thirteenth diode D13 is connected to the second diode D2 through the binding wire, the second diode D2 is connected to the fourth diode D4 through the binding wire, and the fourth diode D4 is connected to the sixth diode D6 through the binding wire, so that the second diode D2, the fourth diode D4, the sixth diode D6 and the thirteenth diode D13 are connected to the fourth lower pin n; multiple second areas are connected to the fourth area, the fifth lower pin p is connected to the copper of multiple second areas and the fourth area; the first lower pin a, the second lower pin b and the third lower pin c are connected to the copper of the corresponding third area, the eighth diode D8 , the tenth diode D10 and the twelfth diode D12 are connected to the copper foil of the corresponding third area through the binding wire to achieve connection with the corresponding lower pin; the first switch tube Q1 is arranged on the upper side of the corresponding first area, and is connected to the first upper pin GA and the second upper pin EA through the binding wire; the second switch tube Q2 is arranged on the upper side of the corresponding first area, and is connected to the third upper pin GB and the fourth upper pin EB through the binding wire; the third switch tube Q3 is arranged on the upper side of the corresponding first area, and is connected to the fifth upper pin GC and the sixth upper pin EC through the binding wire; the return diode is arranged in the middle of the corresponding first area, and is respectively connected to the corresponding switch tube and the upper switch tube through the binding wire; the temperature detection unit T is connected to the seventh upper pin T1 and the eighth upper pin T2 through the binding wire.

[0099] It can be understood that in this embodiment, there are no cross-binding wires between the single-phase PFC circuits, the third area 403 is arranged on the lower side of the substrate 400 to be close to the lower pins, and the binding wires of the upper diode are short; the single-phase PFC circuits are symmetrically distributed, the strong power loop is excellent, and the electromagnetic compatibility of the three-phase PFC module is strong.

[0100] It should be noted that, since the components and connection relationships of each single-phase PFC circuit are the same, in some application examples, the layout position relationship of each single-phase PFC circuit is not limited to the following: Figure 3 The relationship shown in the figure, based on other arrangement methods, the single-phase PFC circuits are arranged in sequence from left to right on multiple layout areas, and based on the layout position relationship of each single-phase PFC circuit, the arrangement positions of the upper pins and the lower pins corresponding to each single-phase PFC circuit are adjusted accordingly, which also belongs to the protection scope of the present application.

[0101] For example, in one application example, the third single-phase PFC circuit 300, the second single-phase PFC circuit 200 and the first single-phase PFC circuit 100 are arranged in sequence from left to right on multiple layout areas, and the arrangement positions of the upper pins are the fifth upper pin GC, the sixth upper pin EC, the third upper pin GB, the fourth upper pin EB, the first upper pin GA and the second upper pin EA from left to right; the arrangement positions of the lower pins are the third lower pin c, the second lower pin b and the first lower pin a from left to right. In some application examples, the arrangement positions of the upper pins connecting the output end and the driving end of the same switch tube are interchanged, which also belongs to the same technical concept as the aforementioned embodiment of the present application.

[0102] In some embodiments of the present application, a three-phase PFC module packaged based on the aforementioned three-phase PFC module packaging structure can be applied to an air conditioner. After the three-phase AC power supply is connected to the three-phase Buck PFC circuit in which the aforementioned three-phase PFC module is set, it is used to power loads such as the compressor and fan of the air conditioner.

[0103] It should be noted that: "first", "second", etc. are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0104] In addition, the technical solutions described in the embodiments of the present application can be combined arbitrarily without conflict.

[0105] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A three-phase power factor correction PFC module packaging structure, characterized in that: The packaging structure is a dual in-line package DIP, and a plurality of layout areas are provided on a substrate of the packaging structure, and a first single-phase PFC circuit, a second single-phase PFC circuit and a third single-phase PFC circuit are arranged in sequence from left to right on the plurality of layout areas; on the layout areas corresponding to the single-phase PFC circuits, the voltage regulating circuit, the return diode and the upper diode in the single-phase PFC circuits are arranged according to the same layout position relationship; Wherein, the packaging structure further includes upper pins and lower pins arranged in parallel, the low-voltage contacts of each single-phase PFC circuit are connected to the upper pins, and the high-voltage contacts of each single-phase PFC circuit are connected to the lower pins.

2. The packaging structure according to claim 1, characterized in that: The plurality of layout areas include a plurality of first areas for arranging the voltage regulating circuits, a plurality of second areas for arranging the upper diodes, and a plurality of third areas for arranging the return diodes; Among them, the voltage regulating circuit includes a switching tube, an input diode, and a lower diode. In each of the single-phase PFC circuits, the input end of the switching tube is respectively connected to the cathode of the input diode and the lower diode, and the output end of the switching tube is respectively connected to the anode of the upper switching tube and the return diode.

3. The packaging structure according to claim 2, characterized in that: The upper pins include a first upper pin, a second upper pin, a third upper pin, a fourth upper pin, a fifth upper pin and a sixth upper pin arranged in sequence from left to right; Among them, the low-voltage contact includes a driving end and an output end of each switching tube, and the driving end of each switching tube is connected to the first upper pin, the third upper pin and the fifth upper pin in sequence; the output end of each switching tube is correspondingly connected to the second upper pin, the fourth upper pin and the sixth upper pin in order from left to right.

4. The packaging structure according to claim 3, characterized in that: The lower pins include a first lower pin, a second lower pin and a third lower pin arranged in sequence from left to right, and the first lower pin, the second lower pin and the third lower pin are the AC power input terminals of the three-phase PFC module packaging structure; the high-voltage contact includes a cathode of each of the return diodes and an anode of the input diode, and the cathode of each of the return diodes is connected to the first lower pin, the second lower pin and the third lower pin in sequence from left to right; the anode of each of the input diodes is connected to the first lower pin, the second lower pin and the third lower pin in sequence from left to right; Among them, the lower pin also includes a fourth lower pin and a fifth lower pin, the fourth lower pin is a ground terminal, and the fifth lower pin is an output terminal of the three-phase PFC module packaging structure; the high-voltage contact also includes an anode of each lower diode and a cathode of each upper diode; the anode of each lower diode is connected to the fourth lower pin, and the cathode of each upper diode is connected to the fifth lower pin.

5. The packaging structure according to claim 4, characterized in that: The packaging structure further includes a freewheeling diode and a temperature detection unit, and the plurality of layout areas further include a fourth area for arranging the freewheeling diode and a fifth area for arranging the temperature detection unit; Among them, the upper pin also includes a seventh upper pin and an eighth upper pin, and the low-voltage contact also includes the two ends of the temperature detection unit; the first end of the temperature detection unit is connected to the seventh upper pin, and the second end of the temperature detection unit is connected to the eighth upper pin; the high-voltage contact also includes the anode and cathode of the freewheeling diode, the anode of the freewheeling diode is connected to the fourth lower pin, and the cathode of the freewheeling diode is connected to the fifth lower pin.

6. The packaging structure according to claim 5, characterized in that: The voltage regulating circuit in each of the single-phase PFC circuits is arranged on the upper side of the upper diode, and the reflux diode is arranged on the lower side of the upper diode; the freewheeling diode is arranged at the lower left corner of the substrate, and the temperature detection unit is arranged at the upper right corner of the substrate; the seventh upper pin and the eighth upper pin are arranged on the right side of the sixth upper pin; the fifth lower pin is arranged on the left side of the first lower pin, and the fourth lower pin is arranged on the left side of the fifth lower pin.

7. The packaging structure according to claim 5, characterized in that: The upper diode in each of the single-phase PFC circuits is arranged on the upper side of the voltage regulating circuit, and the return diode is arranged on the lower side of the voltage regulating circuit; the freewheeling diode is arranged at the lower left corner of the substrate, and the temperature detection unit is arranged at the upper right corner of the substrate; the seventh upper pin and the eighth upper pin are arranged on the right side of the sixth upper pin; the fifth lower pin is arranged on the left side of the first lower pin, and the fourth lower pin is arranged on the left side of the fifth lower pin.

8. The packaging structure according to claim 5, characterized in that: The upper diode in each of the single-phase PFC circuits is arranged at the upper left corner of the voltage regulating circuit, and the return diode is arranged at the lower right corner of the voltage regulating circuit; the freewheeling diode is arranged at the lower left corner of the substrate, and the temperature detection unit is arranged at the upper right corner of the substrate; the seventh upper pin and the eighth upper pin are arranged on the right side of the sixth upper pin; the fourth lower pin is arranged on the left side of the first lower pin, and the fifth lower pin is arranged on the left side of the fourth lower pin.

9. The packaging structure according to claim 5, characterized in that: The upper diode in each of the single-phase PFC circuits is arranged at the upper right corner of the voltage regulating circuit, and the reflux diode is arranged at the lower left corner of the voltage regulating circuit; the freewheeling diode is arranged at the lower right corner of the substrate, and the temperature detection unit is arranged at the upper left corner of the substrate; the seventh upper pin and the eighth upper pin are arranged on the left side of the first upper pin; the fifth lower pin is arranged on the right side of the third lower pin, and the fourth lower pin is arranged on the right side of the fifth lower pin.

10. The packaging structure according to any one of claims 5 to 9, characterized in that: The switch tube, the input diode, the return diode, the upper diode, the lower diode and the freewheeling diode are packaged in the form of bare chips.

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