CN114038811A

CN114038811A - Semiconductor circuit and method for manufacturing semiconductor circuit

Info

Publication number: CN114038811A
Application number: CN202111245157.7A
Authority: CN
Inventors: 冯宇翔; 左安超; 谢荣才; 张土明
Original assignee: Guangdong Huixin Semiconductor Co Ltd
Current assignee: Guangdong Huixin Semiconductor Co Ltd
Priority date: 2021-10-26
Filing date: 2021-10-26
Publication date: 2022-02-11

Abstract

The invention relates to a semiconductor circuit and a method for manufacturing the same. The circuit substrate comprises a mounting surface and a heat dissipation surface, the insulating layer is arranged on the mounting surface, the circuit wiring layer is arranged on the surface of the insulating layer, the circuit wiring layer is provided with a plurality of element mounting positions and a bonding pad, a plurality of electronic elements are arranged on the element mounting positions of the circuit wiring layer, a plurality of pins are arranged on at least one side of the circuit substrate, provided with the electronic elements, is at least wrapped by the sealing layer, the other ends of the pins are exposed out of the sealing layer, mounting holes penetrating through the thickness of the sealing layer are formed in two ends of the sealing layer, grooves are formed around the mounting holes, and the sealing layer on the periphery of the mounting holes forms a protruding portion. Therefore, the thickness of the sealing layer at the position provided with the groove is smaller than that at other positions, the material consumption is obviously reduced, and the purpose of saving the material of the sealing layer is achieved.

Description

Semiconductor circuit and method for manufacturing semiconductor circuit

Technical Field

The invention relates to a semiconductor circuit and a manufacturing method of the semiconductor circuit, and belongs to the technical field of semiconductor circuit application.

Background

A semiconductor circuit is a power-driven type product that combines power electronics and integrated circuit technology. The outer surface of a semiconductor circuit is generally encapsulated with a resin material formed by injection molding to form a sealing layer, and the circuit board and the electronic components inside are sealed, and the leads protrude from one side or both sides of the sealing layer. The two ends of the sealing layer are generally provided with mounting holes for fixing, and the mounting holes and the peripheral sealing layer are in the same plane at present to form a whole, so that more materials are consumed, and the cost is higher.

Disclosure of Invention

The technical problem to be solved by the invention is to solve the problem that the cost is higher because the mounting hole and the peripheral sealing layer are on the same plane to form a whole without being processed in the design of the mounting hole of the sealing layer of the traditional semiconductor circuit, so that more materials are consumed.

Specifically, the present invention discloses a semiconductor circuit, including:

the circuit substrate comprises a mounting surface and a heat dissipation surface;

an insulating layer provided on the mounting surface;

a circuit wiring layer provided on a surface of the insulating layer, the circuit wiring layer being provided with a plurality of element mounting sites;

a plurality of electronic components arranged on the component mounting positions of the circuit wiring layer;

one ends of the pins are electrically connected with the circuit wiring layer respectively;

the sealing layer wraps up the one side that sets up electronic component's circuit substrate at least, and the other end of a plurality of pins exposes from the sealing layer, and the both ends of sealing layer are provided with the mounting hole that runs through its thickness, and the both ends on the surface of sealing layer still are provided with the recess around the mounting hole to make the sealing layer around the mounting hole form the bellying.

Optionally, the wall surface of the groove includes a first section surface and a second section surface, the first section surface is far away from the mounting hole, the second section surface is close to the mounting hole, the connection surface of the first section surface and the second section surface is a turning surface, and the turning surface is arc-shaped.

Optionally, the second segment surface is arc-shaped, and the bending direction of the second segment surface is opposite to the bending direction of the turning surface.

Optionally, the groove is disposed on both sides of the mounting hole.

Optionally, the wall surface of the groove is inclined inwardly from the groove bottom surface, the wall surface being inclined at an angle of 5 to 15 degrees to the vertical.

Optionally, the thickness of the hole wall of the mounting hole where the protruding portion is located is 1.2mm to 3.3mm, and the height of the hole wall is 3.5mm to 4.4 mm.

Optionally, the aperture wall is open towards the outside to form an indentation.

Optionally, the groove bottom surface of the groove is provided with a first opening reaching the surface of the circuit substrate, the surface of the circuit substrate being exposed from the groove bottom surface of the first opening.

Optionally, the surface of the sealing layer is further provided with a second opening on the inner side relative to the first opening, and the depth of the second opening is smaller than that of the first opening.

Optionally, the second opening has a larger aperture than the first opening.

The present invention also provides a method for manufacturing the semiconductor circuit, the method comprising:

providing a circuit substrate, and preparing an insulating layer on the surface of the circuit substrate;

preparing a circuit wiring layer on the surface of the insulating layer;

preparing pins, wherein one ends of the pins are connected with each other through connecting ribs;

configuring an electronic element and a pin on the circuit wiring layer;

electrically connecting the electronic element and the circuit wiring layer through a bonding wire;

performing injection molding on the circuit substrate provided with the electronic element and the pins through a packaging mold to form a sealing layer, wherein the sealing layer coats one surface, on which the electronic element is arranged, of the circuit substrate, mounting holes are formed in two ends of the sealing layer, grooves surrounding the mounting holes are further formed in two ends of the sealing layer, and therefore the sealing layer surrounding the mounting holes forms a protruding portion;

and cutting off the connecting ribs among the pins to form a semiconductor circuit to be tested, performing parameter test on the semiconductor circuit to be tested through test equipment, and bending and molding each pin of the semiconductor circuit to be tested which is qualified in test based on a preset pin shape according to the result of the parameter test if the test is qualified, so as to obtain the qualified semiconductor circuit.

The semiconductor circuit of the present invention includes a circuit substrate, an insulating layer, a plurality of electronic components, a plurality of leads, and a sealing layer. The circuit substrate comprises a mounting surface and a heat dissipation surface, the insulating layer is arranged on the mounting surface, the circuit wiring layer is arranged on the surface of the insulating layer, the circuit wiring layer is provided with a plurality of element mounting positions and a bonding pad, a plurality of electronic elements are arranged on the element mounting positions of the circuit wiring layer, a plurality of pins are arranged on at least one side of the circuit substrate, provided with the electronic elements, is at least wrapped by the sealing layer, the other ends of the pins are exposed out of the sealing layer, mounting holes penetrating through the thickness of the sealing layer are formed in two ends of the sealing layer, grooves are formed around the mounting holes, and the sealing layer on the periphery of the mounting holes forms a protruding portion. The two ends of the sealing layer are provided with the grooves around the two sides of the mounting hole, so that the thickness of the sealing layer at the position provided with the grooves is smaller than that of other positions, compared with a structure with the same thickness of the sealing layer in the prior art, the material consumption of the sealing layer is obviously reduced, the purpose of saving the material of the sealing layer is achieved, and the manufacturing cost of the whole semiconductor circuit is reduced.

Drawings

FIG. 1 is a perspective view of a semiconductor circuit according to an embodiment of the present invention;

fig. 2 is a perspective view of a semiconductor circuit mounting heat sink according to an embodiment of the present invention;

FIG. 3 is a front view of a semiconductor circuit according to an embodiment of the present invention;

FIG. 4 is a cross-sectional view in the direction A-A of the semiconductor circuit of FIG. 3;

FIG. 5 is a cross-sectional view in the direction B-B of the semiconductor circuit of FIG. 3;

FIG. 6 is a flow chart of a method of fabricating a semiconductor circuit according to an embodiment of the present invention;

FIG. 7 is a schematic diagram of a method of forming an encapsulation layer during semiconductor circuit fabrication, in accordance with an embodiment of the present invention.

Reference numerals:

the package structure includes a sealing layer 10, a mounting hole 11, a first opening 12, a second opening 13, a groove 14, a first groove 141, a second groove 142, a turning surface 143, a first section surface 144, a second section surface 145, a groove bottom surface 146, a connecting wire 147, a protrusion 15, a heat sink 20, a circuit substrate 30, an insulating layer 40, a circuit wiring layer 50, a pad 51, an electronic component 60, a bonding wire 70, a lead 80, a fixing member 90, a gate 201, a thimble 202, an upper die 203, a lower die 204, a fixing device 205, and an exhaust port 206.

Detailed Description

It is to be noted that the embodiments and features of the embodiments may be combined with each other without conflict in structure or function. The present invention will be described in detail below with reference to examples.

The semiconductor circuit provided by the invention is a circuit module which integrates a power switch device, a high-voltage driving circuit and the like together and is sealed and packaged on the outer surface, and is widely applied to the field of power electronics, such as the fields of frequency converters of driving motors, various inversion voltages, variable frequency speed regulation, metallurgical machinery, electric traction, variable frequency household appliances and the like. The semiconductor circuit herein may be referred to by various other names, such as Modular Intelligent Power System (MIPS), Intelligent Power Module (IPM), or hybrid integrated circuit, Power semiconductor Module, Power Module, etc.

As shown in fig. 1 to 5, the semiconductor circuit according to the present invention includes a circuit substrate 30, a circuit wiring layer 50, an insulating layer 40, a plurality of electronic components 60, a plurality of leads 80, and a sealing layer 10. The circuit substrate 30 comprises a mounting surface and a heat dissipation surface, the insulating layer 40 is arranged on the mounting surface, the circuit wiring layer 50 is arranged on the surface of the insulating layer 40, the circuit wiring layer 50 is provided with a plurality of element mounting positions and a bonding pad 51, a plurality of electronic elements 60 are arranged on the element mounting positions of the circuit wiring layer 50, a plurality of pins 80 are arranged on at least one side of the circuit substrate 30, the sealing layer 10 at least wraps one surface of the circuit substrate 30 provided with the electronic elements 60, the other ends of the pins 80 are exposed out of the sealing layer 10, mounting holes 11 penetrating through the thickness of the sealing layer 10 are formed in two ends of the sealing layer 10, grooves 14 are formed around the mounting holes 11, and protruding portions 15 are formed in the sealing layer 10 around the mounting holes 11.

The circuit substrate 30 is used for carrying the electronic component 60 in the semiconductor circuit, and includes a mounting surface on the surface and a heat dissipation surface on the back surface, the circuit substrate 30 may be made of a metal material, such as a rectangular plate made of aluminum of 1100, 5052, etc., the thickness of the rectangular plate is much thicker than other layers, generally 0.8mm to 2mm, and the common thickness is 1.5mm, so that the heat conduction and heat dissipation effects on electronic components such as power devices and the like are mainly realized. The heat dissipation surface of the circuit substrate 30 may be textured by laser etching or grinding (not shown) to enhance the bonding force with the middle sealing layer 10. The insulating layer 40 is disposed on the mounting surface of the circuit board 30, and the thickness of the insulating layer is thinner than that of the circuit board 30, generally 50um to 150um, and usually 110 um. The insulating layer 40 may be made of a resin material such as epoxy resin, and a filler such as alumina and aluminum carbide may be filled inside the resin material to improve thermal conductivity. In order to improve the thermal conductivity, the shape of these fillers may be angular, and in order to avoid the risk of the fillers damaging the contact surface of the electronic component 60 provided on the surface thereof, the fillers may be spherical, angular, or a mixture of angular and spherical.

The circuit wiring layer 50 may be formed by etching a copper foil provided on the surface of the insulating layer 40, or may be formed by printing a paste-like conductive medium, which may be a conductive material such as graphene, solder paste, or silver paste. The thickness of the circuit wiring layer 50 is substantially equivalent to that of the insulating layer 40, and is relatively thin, for example, about 70 um. The surface of the circuit wiring layer 50 is provided with a plurality of component mounting locations for mounting a plurality of electronic components 60, and the electronic components 60 include power devices and driving chips, wherein the power devices include switching devices such as IGBTs (Insulated Gate Bipolar transistors) or MOS (metal oxide semiconductor) devices, and freewheeling diodes, and the power consumed by the operation thereof is large and the amount of heat generated is large, so that the temperature during the operation of the whole semiconductor circuit is higher than the room temperature. The electronic component 60 also includes passive devices such as resistors, capacitors, and the like. The power device with very large heat generation quantity is fixedly arranged at the component mounting position through the metal radiating fin. The circuit wiring layer 50 and the plurality of electronic components 60 mounted on the circuit wiring layer 50 constitute the entire circuit of the semiconductor circuit.

The periphery of the surface of the circuit wiring layer 50 is also provided with a plurality of pads 51 to fix the pins 80, thereby transmitting signals to the internal circuit of the semiconductor circuit. The lead 80 is generally made of a metal such as copper, a nickel-tin alloy layer is formed on the surface of the copper by chemical plating and electroplating, the thickness of the alloy layer is generally 5 μm, and the copper can be protected from corrosion and oxidation by the plating layer and the solderability can be improved.

The lead 80 can be made of C194(-1/2H) plates (chemical components: Cu (97.0), Fe (2.4), P (0.03) and Zn (0.12)) or KFC (-1/2H) plates (chemical components: Cu (99.6), Fe (0.1-0.05) and P (0.03, 0.025-0.04)), the C194 or KFC plates with the thickness of 0.5mm are processed by a stamping or etching process, nickel plating thickness is 0.1-0.5um firstly, and tin plating thickness is 2-5um secondly; the excess connecting ribs of the pins 80 are cut and shaped into the desired shape by a special device.

Further, a thin layer of green oil (not shown) is provided on the surface of the circuit wiring layer 50 where the component mounting sites and the pads 51 are not provided, and serves to prevent short circuits between the traces of the circuit wiring layer 50 and also to prevent oxidation and contamination of the surface of the circuit wiring layer 50, thereby protecting the circuit wiring layer.

Compared with the sealing layer 10 in the prior art which is of an integral structure with the same plane and has a simpler structure but wastes sealing materials, the sealing layer 10 in the embodiment of the invention has the advantages that the grooves 14 are formed at two ends of the sealing layer 10 around two sides of the position of the mounting hole 11, so that the thickness of the sealing layer 10 at the position provided with the grooves 14 is smaller than that at other positions, compared with the structure in the prior art in which the thickness of the sealing layer 10 is not changed, the material consumption is obviously reduced, the purpose of saving the material of the sealing layer 10 is realized, and the manufacturing cost of the whole semiconductor circuit is reduced. Preferably, the position of the sealing layer 10 where the groove 14 is disposed is located outside the circuit substrate 30, that is, the region where the groove 14 is disposed does not cover the circuit substrate 30, so that the groove 14 occupies a larger volume, thereby saving more material of the sealing layer 10.

In the preparation process of the sealing layer 10 and the mounting holes 11, the circuit wiring layer 50 electrically connected with the plurality of pins 80 and the plurality of electronic components 60 can be plastically packaged in the sealing layer 10 by a plastic package mold through a plastic package process. The material of the sealing layer 10 may be thermosetting polymer such as epoxy resin, phenolic resin, silica gel, amino group, unsaturated resin; in order to improve heat dissipation, the sealing layer 10 may be a composite material containing powder or fiber of metal, ceramic, silicon oxide, graphene, or the like. In one example, the sealing layer 10 may be made of a molding compound prepared by mixing an epoxy resin as a matrix resin, a high-performance phenolic resin as a curing agent, silica powder and the like as fillers, and a plurality of additives. When the sealing layer 10 is formed, a liquid material formed by a molten injection molding material is injected into a package mold, the liquid material fills a cavity in the package mold, and the liquid material is cooled to form the solid sealing layer 10. As shown in fig. 1 to 3, the wall surface of the groove 14 surrounding the mounting hole 11 is two segments distributed in a zigzag manner, wherein a first segment surface 144 close to the mounting hole 11 is approximately perpendicular to a second segment surface 145 far from the mounting hole 11, and the junction of the first segment surface 144 and the second segment surface 145 is the zigzag surface 143. As the liquid material flows within the mold cavity past the turnaround surface 143, if the turnaround surface 143 is vertically connected, this may cause the flow of fluent material to be impeded at the vertical junction, for example as fluent material flows from first land 144 to second land 145, the flow blockage at the vertical junction causes the flow to gradually accumulate at the vertical junction, the liquid material flowing from the second section 145 is less relative to the first section 144, the liquid material at the first section 144 is too dense after the time is accumulated, the liquid material at the second section 145 is too dense, pores are generated due to the low liquid material density, so that the presence of the hollowness in the boss 15 decreases its strength, and when the fixing member 90 such as a screw is installed in the installation hole 11, when the screw cap presses the surface of the boss 15, the boss 15 is not strong enough to easily crack and damage, and the fixing strength of the fixing member 90 is affected. In order to solve the problem, the turning surface 143 is configured as an arc-shaped curved surface, as shown in fig. 1 to 3, so that the resistance of the liquid material at the position is greatly reduced, the liquid material can normally flow to reach the second section surface 145, the density of the sealing layer 10 at the second section surface 145 is kept consistent with the density of the first section surface 144, no air holes are generated, the strength of the protruding portion 15 is reduced, and the strength of the protruding portion 15 is effectively improved. Further, except that the turning surface 143 is an arc surface, the second section 145 connected with the turning surface may also be an arc surface, as shown in fig. 3, both the second section 145 and the turning surface 143 are arc surfaces, so as to further improve the fluidity of the liquid material, further effectively improve the density of the second section 145, and further better ensure the strength of the protruding portion 15. In fig. 3, the bending direction of the second section 145 is opposite to the bending direction of the turning surface 143, that is, the turning surface 143 is bent toward the outside of the sealing layer 10, and the second section 145 is bent toward the mounting hole 11, so that the overall surface formed by the turning surface 143 and the second section 145 connected thereto is more beautiful, and the bending of the second section 145 toward the mounting hole 11 also ensures that the thickness of the hole wall of the mounting surface is uniformly distributed, thereby further ensuring the strength of the protruding portion 15.

Specifically, in order to ensure the strength of the protruding portion 15 is good and the volume of the groove 14 is large, so as to simultaneously take into account the strength and the requirement of saving the material of the sealing layer 10, the thickness of the hole wall of the mounting hole 11 is 1.2mm to 3.3mm, the height of the hole wall is 3.5mm to 4.4mm, further, the thickness of the hole wall of the mounting hole 11 is preferably 1.5mm to 3mm, such as 1.7mm, and the height of the hole wall is 3.7 mm to 4.2mm, such as 4.0 mm.

The sealing layer 10 has two packaging structures, one is that the sealing layer 10 covers the surface and the back of the circuit substrate 30, namely covers one surface of the electronic element 60 arranged on the circuit substrate 30 and the back of the circuit substrate 30, and simultaneously the sealing layer 10 covers a part of the length of one end of the pin 80 connected to the circuit substrate 30, and the packaging is a full-covering mode of the sealing layer 10; in another packaging method, the sealing layer 10 covers the upper surface of the circuit substrate 30, i.e. the surface of the circuit substrate 30 and the electronic element 60, while the sealing layer 10 covers a part of the length of the pin 80 connected to one end of the circuit substrate 30, and the back surface of the circuit substrate 30, i.e. the heat dissipation surface, is exposed out of the sealing layer 10, thereby forming a half-covering method of the sealing layer 10. In the full-coating mode, when the back surface of the circuit substrate 30 is provided with the texture, the bonding strength between the circuit substrate and the sealing layer 10 can be effectively enhanced, so that the circuit substrate and the sealing layer are not easy to separate. In contrast, in the half-clad method, the back surface of the circuit board 30 may not be provided with a texture, and when the semiconductor circuit is mounted, as shown in fig. 2, the back surface of the circuit board 30 may be further provided with a heat sink 20, and the surface of the heat sink 20 is in close contact with the surface of the circuit board 30, so that heat generated by the circuit board 30 is radiated more efficiently by the heat sink 20.

In some embodiments of the present invention, as shown in fig. 1 to 4, the grooves 14 are provided on both sides of the mounting hole 11. Specifically, the grooves 14 are disposed on the outer side of the sealing layer 10 opposite to the circuit substrate 30 and located on two sides of the mounting hole 11, and are relatively symmetrically distributed on two sides of the mounting hole 11 to form a first groove 141 and a second groove 142 which are symmetrically distributed, so that the grooves 14 are formed in the other positions of the outer portion of the sealing layer 10 opposite to the circuit substrate 30 except the protruding portion 15, thereby further effectively reducing the volume of the sealing layer 10 and further saving the material of the sealing layer 10.

In some embodiments of the present invention, as shown in fig. 1 and 3, the wall of the mounting hole 11 is open toward the outside to form a notch, so as to facilitate the installation of a fixing member 90, such as a screw or a bolt, in the hole to fix the peripheral sealing layer 10 to the semiconductor circuit.

In some embodiments of the present invention, as shown in fig. 1-3, the groove bottom surface 146 of the groove 14 is provided with the first opening 12 that the groove bottom surface 146 reaches to the surface of the circuit substrate 30, and the surface of the circuit substrate 30 is exposed from the groove bottom surface 146 of the first opening 12. Wherein the first opening 12 is formed by positioning the thimble 202 mounted on the mold for packaging on the surface of the circuit substrate 30 during the formation of the sealing layer 10, for example, in the process of molding the sealing layer 10 by using thermosetting resin in a transfer molding manner, the free end of the thimble 202 of the mold abuts against the surface of the circuit substrate 30 to position the circuit substrate 30, after the resin heated to a liquid state is injected into the cavity of the mold, the mold is removed, the thimble 202 is pulled out, and then the resin is hardened, so that the first opening 12 is formed at the position where the thimble 202 is pulled out from the resin, and the bottom surface 146 of the first opening 12 is exposed from the circuit substrate 30 because the thimble 202 abuts against the surface of the circuit substrate 30. The surface of the circuit substrate 30 exposed here is also covered with the insulating layer 40, so that the surface of the metal layer of the circuit substrate 30 is not exposed, thereby ensuring the humidity insulating property of the circuit substrate 30.

Further, the first opening 12 is disposed in the outer periphery of the circuit substrate 30, and the circuit wiring layer 50 is not disposed at the position of the first opening 12. The circuit wiring layer 50 is not provided in a small area of the outer peripheral portion of the circuit substrate 30 to form a boundary, and when the circuit substrate 30 is manufactured, a plurality of circuit substrates 30 are provided on a single metal base material, and a boundary area is provided between each circuit substrate 30 to facilitate a mechanical device to cut at the boundary area to separate each individual circuit substrate 30. In the formation process of the sealing layer 10, the ejector pins 202 of the mold are abutted against these boundary regions, and if the ejector pins 202 are abutted against the circuit wiring layer 50 region, the tips of the ejector pins 202 contact the surface of the circuit wiring layer 50 or the surface of the electronic element 60, which may damage the circuit wiring layer 50 or damage the electronic element 60, so that the ejector pins 202 cannot abut against the circuit wiring layer 50. If the thimble 202 does not abut against the boundary area, it is necessary to reserve a blank area without wiring in a single pass in the area where the circuit wiring layer 50 is located, which occupies the area of the circuit wiring layer 50, and the thimble 202 abuts against the boundary area where the outer peripheral portion of the circuit substrate 30 is located, so that the area of the circuit wiring layer 50 is not occupied, thereby increasing the area of the circuit wiring layer 50. Further, by observing the state of the circuit substrate 30 on the bottom surface 146 of the first opening 12, it is possible to confirm whether the position of the circuit substrate 30 in the sealing layer 10 is reached, that is, whether the circuit substrate 30 moves while being set in the cavity of the mold during the formation of the sealing layer 10. If the circuit substrate 30 moves horizontally, the position where the ejector pin 202 abuts may enter the area where the circuit wiring layer 50 is located, such that part or all of the metal surface of the circuit wiring layer 50 is exposed from the bottom surface 146 of the first opening 12; or if the circuit substrate 30 moves vertically, the position of the thimble 202 may not be able to abut against the surface of the circuit substrate 30, so that the bottom surface 146 of the first opening 12 does not expose the circuit substrate 30. Therefore, only the groove bottom surface 146 of the first opening 12 exposes the surface of the circuit wiring layer 50, specifically, exposes the surface of the insulating layer 40 covered by the circuit wiring layer 50, and it can be determined that the position of the circuit substrate 30 in the sealing layer 10 is acceptable, so that the quality inspection efficiency of the entire semiconductor circuit can be improved.

Further, as shown in fig. 1 to 4, the first opening 12 is disposed on a connection line 147 connecting the slot bottom surface 146 and the first section surface 144 of the slot 14, in order to make the volume of the slot 14 as large as possible to save the material of the sealing layer 10, the slot 14 is close to the wall surface of the circuit substrate 30, that is, the first section surface 144 is close to the outermost pin 80 of the plurality of pins 80, as can be seen from fig. 4, the first section surface 144 is also close to both ends of the circuit substrate 30, and by disposing the first opening 12 on the connection line 147 connecting the slot bottom surface 146 and the first section surface 144 of the slot 14, the thimble 202 is abutted against the positions close to both ends of the circuit substrate 30, that is, the position where the circuit wiring layer 50 is not disposed on the insulating layer 40 on the circuit substrate 30, in the process of forming the sealing layer 10. Thereby achieving the above-described effects of the first opening 12.

In some embodiments of the present invention, as shown in fig. 1 to 3, the surface of the sealing layer 10 is further provided with a second opening 13 on the inner side of the first opening 12, and the depth of the second opening 13 is smaller than that of the first opening 12. The second opening 13 is formed by the sealing layer 10, for example, a protruded release column is further disposed in the cavity of the mold, and after the resin heated to liquid state is injected into the cavity of the mold and the mold is removed, the release column is pressed against the surface of the resin, so that the molded resin is released from the cavity of the mold, and the sealing layer 10 is formed after the resin is hardened. When the ejection pin abuts against the resin surface, the groove 14 is formed deep into the resin surface, and when the resin is ejected from the mold cavity, the groove 14 forms the second opening 13. Since the mold release column is only in contact with the surface of the resin and does not penetrate into the resin, the shallow groove is formed only on the surface thereof, and thus the depth thereof is much smaller than that of the first opening 12. Specifically, the diameter of the ejector pin 202 is much smaller than the diameter of the mold release column, so that the ejector pin 202 occupies as little area of the surface of the circuit substrate 30 as possible, and the boundary area is small, and a large contact force is formed when the mold release column with a larger thickness than the ejector pin 202 contacts the surface of the resin, thereby facilitating the resin to be released. Specifically, the depth of the second opening 13 is set to be generally 0.1mm to 0.7 mm, for example, 0.3 mm, the aperture of the second opening 13 is generally 2mm to 7mm, for example, 4mm, and the aperture of the first opening 12 is generally 0.2 mm to 2mm, for example, 1.2 mm.

As shown in fig. 1 to 4, the groove 14 is disposed on the surface of the sealing layer 10, since the sealing layer 10 is separated from the mold cavity from the surface thereof during demolding, in order to further facilitate the separation of the sealing layer 10 from the mold cavity, the wall surface of the groove 14 is inclined upward and inward from the groove bottom surface 146, specifically, the first section surface 144, the second section surface 145 and the turning surface 143 are all inclined inward along the upward direction of the groove bottom surface 146 of the groove 14, which facilitates the separation of the wall surface of the groove 14 of the sealing layer 10 from the inner wall surface of the mold cavity. Specifically, the wall surface is inclined at an angle of 5 to 15 degrees, for example, 8 degrees, with respect to the vertical direction, thereby ensuring the speed of stripping.

In some embodiments of the present invention, as shown in fig. 4, the semiconductor circuit further includes a plurality of bonding wires 70, the bonding wires 70 being connected between the plurality of electronic components 60, the circuit wiring layer 50, and the plurality of leads 80. For example, the bonding wire 70 may connect the electronic component 60 and the electronic component 60, may also connect the electronic component 60 and the circuit wiring layer 50, may also connect the electronic component 60 and the lead 80, and may also connect the circuit wiring layer 50 and the lead 80. The electronic components 60 are power devices such as IGBTs, freewheeling diodes, and driver chips mentioned in the above embodiments, and others such as resistors, capacitors, and the like. The bond wires 70 are typically gold wires, copper wires, hybrid gold and copper wires, 38um or thinner aluminum wires below 38um, 100um or thicker aluminum wires above 100 um.

The present invention also proposes a manufacturing method of the semiconductor circuit mentioned based on the above embodiment, as shown in fig. 6, the manufacturing method including the steps of:

step S100, providing a circuit substrate 30, and preparing an insulating layer 40 on the surface of the circuit substrate 30;

step S200, preparing a circuit wiring layer 50 on the surface of the insulating layer 40;

step S300, preparing pins 80, wherein one ends of a plurality of pins 80 are connected with each other through connecting ribs;

step S400, disposing the electronic component 60 and the pin 80 in the circuit wiring layer 50;

step S500, electrically connecting the electronic component 60 and the circuit wiring layer 50 by a bonding wire 70;

step S600, performing injection molding on the circuit substrate 30 provided with the electronic element 60 and the pins 80 through a packaging mold to form a sealing layer 10, wherein the sealing layer 10 covers one surface of the circuit substrate 30, on which the electronic element 60 is mounted, mounting holes 11 are formed at two ends of the sealing layer 10, and grooves 14 surrounding the mounting holes 11 are further formed at two ends of the sealing layer 10, so that the sealing layer 10 surrounding the mounting holes 11 form protrusions 15;

step S700, cutting off connecting ribs among the pins 80 to form a semiconductor circuit to be tested, performing parameter test on the semiconductor circuit to be tested through test equipment, and bending and molding each pin 80 of the semiconductor circuit to be tested which is qualified according to the result of the parameter test and the preset shape of the pin 80 if the test is qualified, so as to obtain the qualified semiconductor circuit.

In step S100, the circuit substrate 30 with a suitable size can be designed according to the required circuit layout, for example, for a general semiconductor circuit, the size of the circuit substrate 30 can be selected to be 64mm × 30 mm. Taking the circuit substrate 30 as an aluminum substrate as an example, the aluminum substrate is formed by directly routing 1m × 1m aluminum, the routing knife uses high-speed steel as a material, the motor uses a rotating speed of 5000 rpm, and the routing knife is set at a right angle with the plane of the aluminum; or may be formed by stamping. And uneven textures can be formed on the back surface of the circuit substrate 30 by laser etching and polishing. Next, an insulating layer 40 is prepared on the surface of the circuit substrate 30, and the insulating layer 40 is used to put the circuit wiring layer 50 and the circuit substrate 30 in communication to cause a short circuit.

In step S200, a metal substrate such as copper foil may be laminated on the surface of the insulating layer 40, and then the surface of the metal substrate is processed, such as by etching the copper foil, and the copper foil is partially removed to form the circuit wiring layer 50. A plurality of element mounting sites are formed on the circuit wiring layer 50, and pads 51 are formed at portions of the circuit wiring layer 50 located on the first circuit substrate 30.

Further, a thin layer of green oil (not shown) may be disposed on the surface of the circuit wiring layer 50, and the green oil layer coats the surface of the circuit wiring layer 50 except for the component mounting locations and the pads 51, so as to prevent damage caused by transmission short circuit between the traces of the circuit wiring layer 50, and prevent oxidation and contamination of the surface of the circuit wiring layer 50, thereby protecting the circuit wiring layer.

In step S300, the lead 80 may be prepared from a copper substrate, for example, a strip with a length C of 25mm, a width K of 1.5mm and a thickness H of 1mm is prepared, and then a nickel layer is formed on the surface of the lead 80 by electroless plating: the nickel layer is formed on the surface of the copper material with a special shape by the mixed solution of nickel salt and sodium hypophosphite and adding a proper complexing agent, the metal nickel has strong passivation capability, a layer of extremely thin passivation film can be rapidly generated, and the corrosion of atmosphere, alkali and certain acid can be resisted. The nickel plating crystal is extremely fine, and the thickness of the nickel layer is generally 0.1 mu m; then, by an acid sulfate process, the copper material with the formed shape and the nickel layer is soaked in a plating solution with positive tin ions for electrifying at room temperature, a nickel-tin alloy layer is formed on the surface of the nickel layer, the thickness of the nickel layer is generally controlled to be 5 mu m, and the protection and the weldability are greatly improved by the formation of the nickel layer. In order to limit the spacing between the pins 80, the second ends of the pins 80 are pressed by a specific mold to form connecting ribs, so that the pins 80 can be rapidly mounted on the circuit substrate 30, and the preparation of the pins 80 is completed.

In step S400, the component mounting sites and the pads 51 of the circuit wiring of the circuit substrate 30 are first solder-paste-coated with a steel mesh, which can be used to a thickness of 0.13mm, by a solder-paste printer using the steel mesh, which is where solder-paste soldering is required, such as subsequent soldering of the electronic components 60 and the like at the component mounting sites. Or a silver paste dispenser, which applies a specific pattern with silver paste to the component mounting sites and the lands 51, by which soldering of the electronic components 60 at these sites can also be achieved.

Then, the electronic element 60 and the pin 80 are mounted, the electronic element 60 can be directly placed at an element mounting position, one end of the pin 80 is placed on the bonding pad 51, the other end of the pin 80 needs to be fixed by a carrier, the carrier is made of materials such as synthetic stone and stainless steel, and due to the connection effect of the reinforcing ribs, the pin 80 is conveniently fixed at the position of the bonding pad 51. Then, the circuit board 30 placed on the carrier is cured by reflow soldering, solder paste or silver paste, and the electronic component 60 and the lead 80 are solder-fixed to the component mounting site and the pad 51, respectively.

In step S500, the step is to connect the bonding wires 70 to route wires. One of the driving bonding pads 51 of the driving chip traces in the electronic component 60 may be directly connected to the gate bonding region of the power device, such as an IGBT, through bonding wires 70, such as gold wires, copper wires, gold-copper hybrid wires, and thin aluminum wires below 38um or 38um, and the other driving bonding pads 51 of the driving chip traces may be directly connected to the pads 51 of the circuit wiring layer 50 through bonding wires 70, such as gold wires, copper wires, gold-copper hybrid wires, and thin aluminum wires below 38um or 38 um. The emitter bonding region of the IGBT is directly connected to the pad 51 of the circuit wiring layer 50 through a thick aluminum line of 100um or more.

In step S600, this step is a step of forming the sealing layer 10. Firstly, the circuit substrate 30 with the electronic element 60 and the pin 80 installed in the above steps can be baked in an oxygen-free environment, the baking time is not less than 2 hours, and the baking temperature can be selected to be 5 ℃. The circuit board 30 with the pins 80 arranged thereon is carried to a package mold, which includes an upper mold 203 and a lower mold 204, as shown in fig. 7, and the pins 80 are fixedly disposed between the upper mold 203 and the lower mold 204, and the pins 80 fixed by soldering to the circuit board 30 are brought into contact with a fixing device 205 provided on the lower mold 204 to position the circuit board 30. The top mold 203 is provided with a thimble 202, the free end of the thimble 202 abuts against the insulating layer 40 on the surface of the outer periphery of the circuit substrate 30, and the thimble 202 can be used for controlling the distance between the circuit substrate 30 and the lower mold 204 so as to realize the purpose that the circuit substrate 30 and the groove bottom surface 146 of the lower mold 204 are parallel, the distance cannot be too far, otherwise, the heat dissipation performance is affected, the distance cannot be too close, otherwise, the situation of insufficient glue injection and the like can be caused. The diameter of the thimble 202 is preferably designed to be larger than the diameter of the contact point of the metal connector by 0.1 mm.

Then, the package mold on which the circuit board 30 is placed is clamped, and the sealing resin is injected through the gate 201. The sealing method may employ transfer mold molding using thermosetting resin or injection mold molding using thermosetting resin. Also, the gas corresponding to the inside of the sealing resin cavity injected from the gate 201 is discharged to the outside through the exhaust port 206.

Specifically, for the packaging mold shown in fig. 7, the widths of the injection molding runners of the upper surface and the lower surface are different, and generally, the width of the runner of the upper surface is much larger than that of the runner of the lower surface.

Finally, demoulding is carried out, specifically, the demoulding column arranged on the upper mould 203 abuts against the surface of the dense resin to enable the sealing resin to be separated from the inner surface of the upper mould 203, after demoulding, when the demoulding column abuts against the surface of the dense resin, the demoulding column can penetrate into the surface of the sealing resin to form a shallow groove 14, and the groove 14 forms the second opening 13. When the upper mold 203 is removed, mounting holes 11 are formed at both ends of the sealing resin, and recesses 14 are formed at both sides of the mounting holes 11 with respect to the width direction of the sealing resin, so that the sealing resin in the mounting holes 11 forms the protrusions 15. Further, the inner wall surface of the upper mold 203 corresponding to the mounting hole 11 is inclined inward from bottom to top, so that the wall surface of the groove 14 is inclined inward from the groove bottom surface 146 of the groove 14, which is more favorable for separating the sealing resin from the inner surface of the upper mold 203 when the stripping column abuts against the surface of the sealing resin.

When the thimble 202 is pulled out, the first opening 12 is formed in the sealing resin, and the thimble 202 abuts against the surface of the circuit board 30, so that the bottom surface 146 of the first opening 12 is exposed from the circuit board 30. The sealing resin is thereafter cured to form the sealing layer 10, and the free ends of the leads 80 are exposed from the sealing layer 10.

In step S700, a connecting rib (not shown) connecting the other ends of the plurality of pins 80 is cut off to form a semiconductor circuit to be tested, wherein the connecting rib is a residue generated in the process of manufacturing the pins 80, and the connecting rib may cause a short circuit between the pins 80 and the pins 80, and therefore the connecting rib needs to be cut off in the process of manufacturing the semiconductor circuit. In one example, the connecting rib connecting the second ends of the plurality of pins 80 may be cut off by a specific device so that the other ends of the pins 80 are not connected to each other, so as to obtain the semiconductor circuit to be tested, so as to perform the parameter test on the semiconductor circuit to be tested in the next step.

The test equipment can be used for performing parameter test on the semiconductor circuit to be tested, for example, the test equipment can send a test signal to the semiconductor circuit to be tested and receive a feedback signal fed back by the semiconductor circuit to be tested; the test equipment processes the feedback signal to obtain corresponding feedback data, compares the feedback data with a preset threshold range, judges that the semiconductor circuit to be tested is qualified when the feedback data meet the preset threshold range, and then bends and molds each pin 80 of the semiconductor circuit to be tested which is qualified based on the shape of the preset pin 80, thereby obtaining the qualified semiconductor circuit.

Further, before the testing equipment can be used for carrying out parameter testing on the semiconductor circuit to be tested, laser marking can be carried out through the laser equipment so as to mark the surface of the sealing layer 10 of the semiconductor circuit, and therefore identification and management of the semiconductor circuit product are facilitated.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims

1. A semiconductor circuit, comprising:

an insulating layer provided on the mounting surface;

a plurality of electronic components arranged on the component mounting sites of the circuit wiring layer;

the sealing layer wraps at least one surface, provided with the electronic element, of the circuit substrate, the other ends of the pins are exposed out of the sealing layer, mounting holes penetrating the thickness of the sealing layer are formed in the two ends of the sealing layer, grooves surrounding the mounting holes are further formed in the two ends of the surface of the sealing layer, and therefore protruding portions are formed in the sealing layer surrounding the mounting holes.

2. The semiconductor circuit of claim 1, wherein the wall surface of the recess comprises a first segment surface and a second segment surface arranged in a zigzag manner, wherein the first segment surface is away from the mounting hole, the second segment surface is close to the mounting hole, a connection surface of the first segment surface and the second segment surface is a zigzag surface, and the zigzag surface is arc-shaped.

3. The semiconductor circuit of claim 2, wherein the second segment surface is curved in a direction opposite to a direction of curvature of the turning surface.

4. The semiconductor circuit according to claim 1, wherein the recess is provided on both sides of the mounting hole.

5. The semiconductor circuit of claim 1, wherein the wall surface of said recess is inclined inwardly from the bottom surface of the groove, said wall surface being inclined at an angle of 5 degrees to 15 degrees with respect to the vertical.

6. The semiconductor circuit according to claim 1, wherein a thickness of a hole wall of the mounting hole in which the protruding portion is located is 1.2mm to 3.3mm, and a height of the hole wall is 3.5mm to 4.4 mm.

7. The semiconductor circuit according to claim 1, wherein a groove bottom surface of the recess is provided with a first opening reaching a surface of the circuit substrate, the surface of the circuit substrate being exposed from the groove bottom surface of the first opening.

8. The semiconductor circuit according to claim 7, wherein a second opening is further provided on the surface of the sealing layer on the inner side of the first opening, and the depth of the second opening is smaller than the depth of the first opening.

9. The semiconductor circuit according to claim 8, wherein an aperture of the second opening is larger than an aperture of the first opening.

10. A method for manufacturing a semiconductor circuit according to any one of claims 1 to 9, characterized in that the manufacturing method comprises:

preparing a circuit wiring layer on the surface of the insulating layer;

configuring electronic elements and pins on the circuit wiring layer;

performing injection molding on the circuit substrate provided with the electronic element and the pins through a packaging mold to form a sealing layer, wherein the sealing layer coats one surface, on which the electronic element is mounted, of the circuit substrate, mounting holes are formed in two ends of the sealing layer, and grooves surrounding the mounting holes are formed in two ends of the sealing layer, so that a protruding portion is formed in the sealing layer surrounding the mounting holes;

and cutting off the connecting ribs among the pins to form a semiconductor circuit to be tested, performing parameter test on the semiconductor circuit to be tested through test equipment, and bending and molding each pin of the semiconductor circuit to be tested which is qualified in test based on a preset pin shape if the test is qualified according to the result of the parameter test to obtain the qualified semiconductor circuit.