Die for gold wire bonding and packaging equipment

Abstract

The utility model relates to the technical field of packaging, in particular to a mold for gold wire bonding and packaging equipment. The die comprises an upper die plate and a lower die plate, the upper die plate and the lower die plate are used for press fitting of a packaging structure with high pins, and a lead frame of the packaging structure comprises two pin sections and a concave section connected between the two pin sections; the accommodating groove of the lower die plate is used for accommodating the concave section of the lead frame, and the two bearing surfaces are used for bearing the pin section of the lead frame; the upper template comprises an air channel and a window, the window penetrates through the upper template so that the gold wire bonding operation head can penetrate through the window, the air channel is used for containing inert gas, and the air channel comprises a plurality of air outlets located in the surface, facing the lower template, of the upper template; and in the press fitting direction of the upper die plate and the lower die plate, the projections of air outlets of the windows and the air channels on the lower die plate are located in the containing groove. According to the die, a window for gold wire bonding operation head operation is small, loss of inert gas can be reduced, and the risk that a copper layer of a substrate and a copper bonding pad of a chip are oxidized is reduced.

Description

Technical Field

[0001] This application relates to the field of packaging technology, and in particular to a mold and packaging equipment for gold wire bonding. Background Technology

[0002] Gold wire bonding is a technique commonly used in the packaging of power electronic devices to establish an electrical connection between a chip (die) and a substrate or lead frame.

[0003] Thermo-ultrasonic bonding is a commonly used gold wire bonding process. This process adds a heat input to ultrasonic bonding, improving bonding reliability and efficiency. When the substrate includes a copper layer or the substrate to be soldered is copper, thermo-ultrasonic bonding requires the introduction of a protective gas to form a relatively closed heating track, preventing oxidation of the copper layer or substrate caused by the high temperatures during bonding. For package structures with high lead frame designs, existing pressure plates cannot provide adequate fixation and gas protection. Utility Model Content

[0004] This application provides a mold and packaging equipment for gold wire bonding. The mold is capable of performing thermo-ultrasonic gold wire bonding on package structures with high lead frame designs. The window for the gold wire bonding operation head is relatively small, which can reduce the loss of inert gas and reduce the risk of oxidation of the copper layer of the substrate and the copper pads of the chip during thermo-ultrasonic gold wire bonding.

[0005] In a first aspect, this application provides a mold for gold wire bonding. The mold includes an upper mold and a lower mold, which are used to press-fit a package structure with high pin counts. The lead frame of the package structure includes two pin segments and a recessed segment connecting the two pin segments. The surface of the lower mold facing the upper mold includes a receiving groove and two bearing surfaces located on both sides of the receiving groove. The receiving groove is used to receive the recessed segment of the lead frame, and the two bearing surfaces are used to support the pin segments of the lead frame. The upper mold includes an air passage and a window. The window penetrates the upper mold to allow the gold wire bonding operating head to pass through. The air passage is used to contain inert gas and includes a plurality of air outlets located on the surface of the upper mold facing the lower mold. Along the pressing direction of the upper and lower molds, the projection of the outlet gas from the window and the air passage onto the lower mold is located within the receiving groove.

[0006] When performing thermo-ultrasonic wire bonding on a package structure with high pin counts, the aforementioned mold creates a receiving space between the accommodating grooves of the upper and lower molds. This space can accommodate the recessed sections of the lead frame in the package structure, and the pins of the lead frame can be pressed and fixed by the upper and lower molds. The chip and substrate requiring thermo-ultrasonic wire bonding in the package structure are also housed within this space. Along the pressing direction of the upper and lower molds, the chip will not protrude from the pins of the lead frame, and the upper mold can structurally avoid the chip. When a window penetrating the upper mold is provided, the window can be used only to expose the wire bonding location of the package structure, allowing the wire bonding head to perform wire bonding through the window. Compared to traditional technologies, the window diameter can be smaller. This smaller diameter reduces the flow rate of inert gas lost through the window, keeping the inert gas in the receiving space relatively full, optimizing gas protection, and mitigating oxidation problems of the copper layer of the substrate and the copper pads of the chip during the thermo-ultrasonic wire bonding process.

[0007] In one embodiment, the window of the upper template is configured such that, during the press-fitting of the upper and lower templates into the packaging structure, the orthographic projection of the window onto the packaging structure overlaps with at least a portion of the chip and at least a portion of the substrate within the packaging structure. One window can correspond to a gold wire bonding position between a chip and the substrate, or it can correspond to the gold wire bonding positions between multiple chips or all chips and the substrate. The size and number of windows can be adjusted according to packaging requirements. The area of ​​the window is relatively small compared to the entire area of ​​the upper template, providing good inert gas protection and effectively preventing inert gas from escaping through the window.

[0008] In one embodiment, the upper template includes a pressure plate and a protruding structure. The pressure plate is used to press the lead segments of the lead frame against the bearing surface of the lower template. The protruding structure is disposed on the surface of the pressure plate facing the lower template. Along the pressing direction of the upper and lower templates, the projection of the protruding structure onto the lower template is located within a receiving groove. The protruding structure is used to press against the substrate of the encapsulation structure. The substrate is fixed by the protruding structure and the lower template, which can improve the structural stability of the encapsulation structure in thermo-ultrasonic wire bonding operations and improve the workability of wire bonding.

[0009] In one embodiment, the protruding structure includes a frame surrounding a window. The end face of the frame facing the lower template is used to press against the substrate of the packaging structure. The frame includes an outer wall extending through the frame and a cutout in the outer wall. The frame is used to enclose at least one chip, so as to accommodate the bonding area of ​​the chip connected to the substrate via gold wire bonding within the area enclosed by the frame. The end face of the frame facing away from the pressure plate is used to abut against the substrate, and the contact area between the two is larger, which can provide better support around the gold wire bonding location and improve workability.

[0010] In one embodiment, the protruding structure includes a partition, the two ends of which are connected to the inner wall of the frame. The end face of the partition facing away from the pressure plate is used to press against the substrate of the encapsulation structure. The partition divides the space enclosed by the frame into a first space and a second space, with a window located in the first space. The partition includes an auxiliary cutout that penetrates the partition to connect the first space and the second space, thereby allowing airflow between the first space and the second space. The partition can increase the contact area between the protruding structure and the substrate, improving workability. It should be understood that when the upper template includes multiple windows, depending on the position of the gold wire to be bonded, the windows can be located in the same space or in different spaces.

[0011] In one embodiment, the frame includes two openings, one connected to a first space and the other connected to a second space. Inert gas can be introduced into both the first and second spaces through the openings to achieve gas protection. When the concentration or pressure of the inert gas in the first and second spaces differs, the inert gas can be homogenized through airflow via the auxiliary openings.

[0012] In one embodiment, the multiple air outlets include a first type of air outlet and a second type of air outlet. The first type of air outlets are arranged on the side of the perforation facing away from the inner wall of the enclosure. The first type of air outlets includes multiple air outlets spaced apart, and the second type of air outlets also includes multiple air outlets spaced apart. The distribution density of the first type of air outlets is greater than that of the second type of air outlets. This ensures that a sufficient amount of inert gas can enter the enclosure 1 through the perforation, thereby achieving a good gas protection effect.

[0013] In one embodiment, the protrusion structure is made of one or more combinations of steel, titanium and titanium alloys, aluminum and aluminum alloys, rubber, and resin. A protrusion structure made of a material with high rigidity can provide good pressure resistance and fixation. A protrusion structure made of a flexible material can reduce the stress generated by pressure on the substrate, protecting the substrate structure. The protrusion structure can be a combination of rigid and flexible materials, ensuring pressure resistance while protecting the substrate.

[0014] In one embodiment, the surface of the upper template facing away from the lower template includes a groove structure, and the orthographic projection of the window on the surface of the upper template facing away from the lower template lies within the groove structure. The groove structure can reduce the thickness of the upper template at that location, thus reducing the depth of the window along the direction. The smaller window depth means that the thickness of the upper template that the wire bonding operation head needs to pass through is smaller, and the movement distance of the wire bonding operation head along the direction is smaller, which helps to reduce process difficulty and improve efficiency.

[0015] In one embodiment, the air passage includes two air inlets, which are located on two sides of the upper template along a set direction, perpendicular to the pressing direction of the upper and lower templates. Inert gas is introduced into the air passage through these two air inlets, and the air intake volume and intake rate of the two air inlets are controlled to make the inert gas in the air passage nearly symmetrical, thereby improving the uniformity of the inert gas distribution in the air passage.

[0016] In one embodiment, the upper template is bent away from the lower template at both ends along a predetermined direction; along the pressing direction of the upper and lower templates, the distance between the two air inlets and the lower template is greater than the distance between the surface of the upper template used for pressing and sealing the structure and the lower template. This avoids other templates and ensures unobstructed air intake at the air inlets.

[0017] Secondly, this application provides a packaging device for performing thermo-ultrasonic gold wire bonding on a packaging structure. The packaging device includes two sets of auxiliary templates and any of the molds provided in the first aspect above; the two sets of auxiliary templates are respectively disposed on both sides of the mold along a set direction to assist in pressing and packaging the structure, the set direction being the direction of movement of the packaging structure.

[0018] The technical effects that can be achieved in the second aspect mentioned above can be referred to the corresponding effect descriptions in the first aspect mentioned above, and will not be repeated here. Attached Figure Description

[0019] Figure 1 A schematic diagram of a traditional packaging structure using gold wire bonding.

[0020] Figure 2 This application provides a schematic diagram of a mold for gold wire bonding of a packaging structure.

[0021] Figure 3 This application provides a schematic diagram of the structure of a mold for gold wire bonding;

[0022] Figure 4 This application provides a schematic diagram of the structure of the upper template of a mold for gold wire bonding;

[0023] Figure 5a This application provides a schematic diagram of the structure of the upper template of a mold for gold wire bonding;

[0024] Figure 5b This application provides a schematic diagram of the structure of the upper template of a mold for gold wire bonding;

[0025] Figure 6 This application provides a schematic diagram of a mold for gold wire bonding of a packaging structure.

[0026] Figure 7a This application provides a schematic diagram of the structure of the upper template of a mold for gold wire bonding;

[0027] Figure 7b This application provides a schematic diagram of the structure of the upper template of a mold for gold wire bonding;

[0028] Figure 8a This application provides a schematic diagram of the structure of the upper template of a mold for gold wire bonding;

[0029] Figure 8b This application provides a schematic diagram of a portion of the structure of a mold for gold wire bonding, in which the upper template mates with the packaging structure.

[0030] Figure 9 This application provides a schematic diagram of the structure of the upper template of a mold for gold wire bonding;

[0031] Figure 10a This application provides a schematic diagram of the structure of the upper template of a mold for gold wire bonding;

[0032] Figure 10b This application provides a schematic diagram of a partial structure of the upper template of a mold for gold wire bonding;

[0033] Figure 10c This application provides a schematic diagram of a portion of the structure of a mold for gold wire bonding, showing the cooperation between the protrusion structure and the packaging structure.

[0034] Figure 11a This application provides a schematic diagram of the structure of the upper template of a mold for gold wire bonding;

[0035] Figure 11b This application provides a schematic diagram of a mold for pressing a packaging structure into place for gold wire bonding.

[0036] Figure 12 This application provides a schematic diagram of the structure of a packaging device.

[0037] Figure label:

[0038] 01-Substrate; 02-Chip; 03-Lead frame; 031-Pin segment; 032-Recessed segment; 04-Bond wire; 05-Electronic component;

[0039] 1-Upper template; 11-Pressure plate; 12-Protruding structure; 121-Protruding strip; 122-Frame; 123-Partition; 2-Lower template; 21-Accommodating groove; 22-Bearing surface; 31-First auxiliary template; 32-Second auxiliary template;

[0040] a1 - First area; a2 - Second area; c - Vent; d1 - Air outlet; d2 - Air inlet; r - Auxiliary cutout; t - Stepped surface; A - Area; B - Boss; C - Window; D - Air passage; E - Air guide channel; J1 - First end; J2 - Second end; K - Groove structure; P1 - First space; P2 - Second space; Q - Accommodation space; R - Cutout; W - Encapsulation unit. Detailed Implementation

[0041] In the field of power electronics, thermo-ultrasonic gold wire bonding can be used to electrically connect chips to substrates. For example... Figure 1 The diagram illustrates the gold wire bonding principle of a lead frame. The package structure includes a substrate 01, electronic components disposed on the substrate 01, and a lead frame 03. The electronic components include multiple chips 02, at least one chip 02 being electrically connected to the lead frame 03 via bonding wires 04. The substrate 01 includes a copper layer, and each chip 02 and the lead frame 03 are connected to the copper layer of the substrate 01. This package structure is a semi-finished structure of a package module. The lead frame 03 is an uncut integral structure, planar in shape, surrounding the periphery of the chip 02. After cutting, the lead frame 03 is used to form various terminals for connecting the package structure to external circuits. In the thermo-ultrasonic gold wire bonding operation, the package structure is disposed between an upper template 1 and a lower template 2. The upper template 1 and the lower template 2 press-fit the lead frame 03 to fix the package structure. The upper template 1 includes a window C, within which the electronic components of the package structure are housed. The window C allows the electronic components of the package structure to avoid contact with the upper template 1. Taking one of the bonding wires, 04, as an example, its first end J1 is bonded to the chip 02 in a single welding process, and its second end J2 is bonded to the copper layer of the substrate 01 in a second welding process. When using thermo-ultrasonic bonding wires, the introduced high temperature may cause oxidation of the copper layer of the substrate 01 and the copper pads of the chip 02. Therefore, during thermo-ultrasonic bonding, an inert gas needs to be introduced into the bonding area to protect the copper layer of the substrate 01. Traditional gold wire bonding molds are not suitable for packaging structures with high lead frame designs and cannot achieve good press-fitting effects. Furthermore, to avoid electronic components, the traditional mold has a relatively large window for bonding operations, and the inert gas does not provide good protection for the copper layer of the substrate 01 and the copper pads of the chip 02, making the copper easily oxidized, resulting in poor workability of thermo-ultrasonic gold wire bonding.

[0042] Based on this, embodiments of this application provide a mold and packaging equipment for gold wire bonding. When performing gold wire bonding on a high-lead frame structure, the mold has a relatively small window for the thermo-ultrasonic gold wire bonding operation head, which can reduce the loss of inert gas and improve the workability of thermo-ultrasonic gold wire bonding.

[0043] To make the objectives, technical solutions, and advantages of this application clearer, the application will now be described in further detail with reference to the accompanying drawings.

[0044] The terminology used in the following embodiments is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. As used in the specification and appended claims of this application, the singular expressions “a,” “an,” “the,” “the,” “the,” and “this” are intended to also include expressions such as “one or more” unless the context clearly indicates otherwise.

[0045] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0046] Figure 2 An example of a mold for gold wire bonding provided in an embodiment of this application is illustrated. This mold is used for thermo-ultrasonic gold wire bonding operations on package structures with high pin designs.

[0047] like Figure 2 As shown, the packaging structure is a semi-finished packaging module, specifically including a substrate 01, electronic components disposed on the substrate 01, and a lead frame 03. The electronic components are a combination of various power electronic devices. These power electronic devices include integrated circuit (IC) chips, insulated gate bipolar transistors (IGBTs), silicon carbide power transistors, silicon transistors, metal-oxide-semiconductor field-effect transistors (MOSFETs), and diodes, etc. Here, the electronic components exemplarily include multiple chips 02, each chip 02 and the lead frame 03 being connected to the copper layer of the substrate 01. At least one chip 02 is electrically connected to the copper layer of the substrate 01 via a bonding wire 04. The power electronic devices included in the final packaged module obtained from this packaging structure can be electrically connected to form a functional circuit, which is connected to an external circuit via the lead frame 03.

[0048] The lead frame 03 features a recessed design, comprising two pin segments 031 and a recessed segment 032 connecting the two pin segments 031. With reference to the plane containing the two pin segments 031, the recessed segment 032 is recessed relative to the two pin segments 031. The recessed segment 032 is groove-shaped and used to house electronic components. Specifically, each chip 02 is disposed in the recessed segment 032. Each chip 02 does not protrude beyond the pin segment 031 of the lead frame 03 and away from the surface of the substrate 01. Each chip 02 is electrically connected to the copper layer of the substrate 01 located between the recessed segment 032 and the chip 02 via a bonding wire 04. Along the thickness direction of the substrate 01, the bonding wire 04 does not protrude beyond the pin segment 031 of the lead frame 03 and away from the surface of the substrate 01. Figure 2 The high-pin frame design shown in the package structure allows the pin segment 031 of the lead frame 03 to form pins that protrude from the electronic components after cutting, facilitating the connection of the package structure to external circuits and providing better performance in terms of structural stability and reliability.

[0049] In some embodiments, the packaging structure of the mold for thermo-ultrasonic gold wire bonding provided in this application is an integrated circuit package (small out-line package, SOP), which can be applied to small and medium-scale integrated circuits such as memory, operational amplifiers, and power management chips.

[0050] Please continue to refer to Figure 2As shown, taking the package structure with a high pin design as an example, the mold provided in this embodiment for wire bonding of the package structure includes an upper mold plate 1 and a lower mold plate 2. The upper mold plate 1 and the lower mold plate 2 are used to interlock with each other along the height direction of the substrate 01 to press and fix the package structure. For ease of illustration, the Z direction is the thickness direction of the substrate 01, that is, the direction in which the upper mold plate 1 interlocks with the lower mold plate 2. For the recessed design of the lead frame 03 of the package structure, the surface of the lower mold plate 2 facing the upper mold plate 1 includes a receiving groove 21 and two bearing surfaces 22 located on both sides of the receiving groove 21. The receiving groove 21 is used to accommodate the recessed section 032 of the lead frame 03, and the two bearing surfaces 22 are used to support the pin sections 031 of the lead frame 03. The two pin sections 031 of the lead frame 03 can respectively overlap the two bearing surfaces 22 of the lower mold plate 2, and the recessed section 032 of the lead frame 03 is accommodated in the receiving groove 21 of the lower mold plate 2. The substrate 01 of the package structure and the electronic components are all accommodated in the receiving groove 21 of the lower mold plate 2. The upper template 1 covers the side of the packaging structure opposite to the lower template 2, forming a receiving space Q between the upper template 1 and the lower template 2. This space accommodates the recessed section 032 of the lead frame 03, the substrate 01, the chip 02, and the bonding wires 04. This receiving space Q is relatively closed between the upper template 1 and the lower template 2, and the thermo-ultrasonic wire bonding operation is performed within this space Q. The two lead segments 031 of the lead frame 03 are press-fitted between the upper template 1 and the lower template 2, achieving press-fitting and fixing of the packaging structure. The upper template 1 and the lower template 2 are engaged along the thickness direction of the substrate 01.

[0051] For thermo-ultrasonic wire bonding, the upper template 1 includes a window C and an air channel D. The window C penetrates the upper template 1 along the thickness direction of the substrate 01, allowing the wire bonding operation head to pass through the window C and enter the receiving space Q to perform wire bonding on the chip 02 and the substrate 01. The air channel D is used to introduce inert gas into the receiving groove 21 of the lower template 2, and the outlet d1 of the air channel D faces the receiving groove 21 of the lower template 2. Along the thickness direction of the substrate 01, the projections of the window C and the outlet d1 of the air channel D both fall within the receiving groove 21 of the lower template 2.

[0052] exist Figure 2In the structure shown, the lead segment 031 of the lead frame 03 is higher than the electronic component. Along the thickness direction of the substrate 01, the electronic component can avoid the upper template 1. The window C does not need to have the function of the upper template 1 avoiding the electronic component. Therefore, when setting the window C that penetrates the upper template 1, the window C can only be used to expose the gold wire bonding position of the packaging structure, so that the gold wire bonding operation head can pass through the window C to perform gold wire bonding. Compared with the traditional technology, the diameter of the window C can be made smaller. The reduction in the diameter of the window C can provide a certain shielding for the inert gas in the containment space Q, reduce the flow of inert gas lost through the window C, keep the inert gas in the containment space Q in a relatively full state, optimize the gas protection effect, and weaken the oxidation problem of the copper layer of the substrate 01 and the copper pads of the chip 02 in the thermo-ultrasonic gold wire bonding operation.

[0053] In the structural design of the upper template 1, the position of window C needs to be adapted to the position on the package structure where gold wire bonding is required. Specifically, it needs to be related to the positions of both ends of the bonding wire 04 between chip 02 and substrate 01. For the package structure, there may be multiple chips 02. When each chip 02 is connected to substrate 01 through bonding wire 04, one window C can correspond to the gold wire bonding positions of both ends of one bonding wire 04 with chip 02 and substrate 01. One window C can also correspond to the gold wire bonding positions of multiple chips 02 or all chips 02 with substrate 01.

[0054] Taking one of the chips, 02, as an example, Figure 2 As shown, when the chip 02 is connected to the substrate 01 via the bonding wire 04, a portion of the chip 02 and a portion of the substrate 01 can be exposed through the window C. Both ends of the bonding wire 04 are soldered to the chip 02 and the substrate 01 through the window C, achieving an electrical connection between the chip 02 and the substrate 01. Along the thickness direction of the substrate 01, the orthographic projection of the window C on the lower template 2 overlaps with the orthographic projection of the chip 02 on the lower template 2, and the orthographic projection of the window C on the lower template 2 overlaps with the orthographic projection of the substrate 01 on the lower template 2. The area of ​​the window C is relatively small compared to the entire area of ​​the upper template 1, providing good inert gas protection and effectively preventing the loss of inert gas through the window C.

[0055] It is understandable that the window C and airway D included in the upper template 1 are both structurally simplified designs, which reduces the strength and reliability of the upper template 1. In some embodiments, the window C and airway D are designed to avoid each other and are not connected to each other, so as to ensure that the upper template 1 has sufficient strength and reliability.

[0056] Figure 3 An example of an exploded structure of the mold press-fit packaging structure provided in the embodiments of this application is illustrated. For example... Figure 3As shown, the upper template 1 and lower template 2 are press-fitted encapsulation structures along the thickness direction of the substrate 01. The upper template 1 is rectangular in shape. Taking the structure of the upper template 1 as a reference, a three-dimensional coordinate system is established. This three-dimensional coordinate system includes mutually perpendicular X, Y, and Z directions. The Z direction is the thickness direction of the upper template 1, which is also the direction in which the upper template 1 and lower template 2 are press-fitted encapsulation structures. The X direction is the length direction of the upper template 1, and the Y direction is the width direction of the upper template 1.

[0057] like Figure 3 As shown, the upper template 1 and the lower template 2 are opposite each other along the Z-direction, and the packaging structure is placed between the upper template 1 and the lower template 2. The packaging structure is a semi-finished structure, which includes multiple packaging units W. Here, a packaging unit W is indicated by a dashed box. The multiple packaging units W are arranged adjacent to each other along the X-direction. After the packaging process is completed, the packaging structure is cut into multiple independent packaging units W. Each packaging unit W includes a substrate 01, electronic components, and a lead frame 03. The lead frames 03 of the multiple packaging units W are an integral structure. For the lead frame 03 of the packaging structure, the recessed section 032 is used to accommodate the receiving groove 21 of the lower template 2, and the two pin sections 031 are used to support the two bearing surfaces 22 of the lower template 2 respectively. The recessed section 032, the substrate 01 of the packaging structure, and the chip 02 included in the electronic components are all used to accommodate within the space formed by the receiving groove 21 of the upper template 1 and the lower template 2. The upper template 1 includes an air passage D through which inert gas is introduced through the air inlet d2, and the inert gas is sprayed out through the surface of the upper template 1 toward the accommodating groove 21. The air outlet d1 of the air passage D is not shown here.

[0058] Please continue to refer to Figure 3 As shown, the upper template 1 includes two windows C through which the thermo-ultrasonic wire bonding operation head passes. As an example, each window C can be used for welding operations at both ends of a single wire bond. Taking a chip 02 of a package unit W (shown by the dashed box) as an example, along the Z-direction, the orthographic projection of the window C corresponding to the chip 02 falls within the receiving groove 21 of the lower template 2. The orthographic projection of the window C on the package structure partially falls on the chip 02 and partially falls on the substrate 01. During the thermo-ultrasonic wire bonding operation, the wire bonding operation head can weld one end of the wire bond to the chip 02 and the other end to the substrate 01 through one window C. The lower template 2 is equipped with a heating device, which heats the package structure during the thermo-ultrasonic wire bonding operation to promote wire bonding.

[0059] During the thermo-ultrasonic wire bonding operation of a packaging unit W, the upper template 1 and lower template 2 press-fit and fix the packaging structure. After completing the thermo-ultrasonic wire bonding operation of a packaging unit W, the press-fit and fixation of the packaging structure by the upper template 1 and lower template 2 are released, and the packaging structure is moved along the X direction to move the previous or next packaging unit W to the operation position corresponding to the two windows C of the upper template 1. Then, the upper template 1 and lower template 2 are pressed-fit and fixed along the Z direction to perform the thermo-ultrasonic wire bonding operation on the next packaging unit W. As an example, the wire bonding sequence of the packaging structure is as follows: Figure 3 As shown by the black arrow in the diagram. After completing thermo-ultrasonic gold wire bonding for the packaging unit W within the dashed box, it is moved to the next packaging unit W in the manner indicated by the arrow. Specifically, along the X direction, the packaging unit W preceding the one within the dashed box has already completed thermo-ultrasonic gold wire bonding, and the chip 02 of each packaging unit W is connected to the substrate 01 via a bonding wire 04.

[0060] In some embodiments, inert gas can also be introduced into the lower template 2 and ejected into the encapsulation structure through the pores c on the surface of the upper template 1 via the lower template 2, thereby achieving gas protection in the thermo-ultrasonic gold wire bonding operation.

[0061] Figure 4 An example of a structure based on template 1 is provided. Figure 4 As shown, it has an internal cavity to form an air passage D, which avoids the window C. For ease of illustration, in one embodiment, the two side regions A of the upper template 1 along the Y direction are used to cooperate with the lower template 2 to clamp the pin segment 031 of the lead frame 03. It should be understood that, combined with manufacturing and assembly process errors, the perpendicularity of the X, Y, and Z directions can include approximately perpendicular or nearly perpendicular situations.

[0062] like Figure 4 As shown, the air passage D includes an inlet d2 and an outlet d1. The inlet d2 is used to introduce inert gas into the air passage D, and the outlet d1 is used to discharge the inert gas from the air passage D to the side of the upper template 1 facing the lower template 2. Along the Z-direction, the air passage D can have multiple outlets d1 on the surface of the upper template 1 facing the lower template 2, so that the inert gas can enter the receiving space Q more evenly, resulting in a uniform distribution of inert gas within the receiving space Q and providing good gas protection. To guide the inert gas to the receiving space Q between the upper template 1 and the lower template 2, along the Z-direction, the orthographic projection of each outlet d1 on the lower template 2 lies within the receiving space Q.

[0063] In one embodiment, multiple air outlets d1 of the air passage D are arranged in an array on the surface of the upper template 1 facing the lower template 2, and the inert gas in the air passage D can enter the accommodating space Q between the upper template 1 and the lower template 2 evenly through the multiple air outlets d1.

[0064] The location and number of air inlets d2 in airway D are not limited, as long as they can introduce inert gas into airway D. As a specific structural example, such as... Figure 4 As shown, two opposing air inlets d2 are provided in the air passage D of the upper template 1, and these two air inlets d2 are opposite each other along the X direction. In the thermo-ultrasonic wire bonding operation, inert gas is introduced into the air passage D through these two air inlets d2. By controlling the air intake volume and intake rate of the two air inlets d2, the inert gas in the air passage D is made nearly symmetrical along the X direction, improving the uniformity of the inert gas distribution in the air passage D. Of course, the two air inlets d2 can also be opposite each other about other directions perpendicular to the Z direction, which can be adjusted according to the mold design.

[0065] like Figure 5a and Figure 5b The illustration shows an upper template 1 with a groove structure K formed on its surface opposite to the lower template 2 along the Z-direction, achieved through a recessed platform design. Each window C penetrates both surfaces of the upper template 1 containing the groove structure K along the Z-direction, and the orthographic projection of each window C onto the surface of the upper template 1 opposite to the lower template 2 falls within the area of ​​the groove structure K. This groove structure K design reduces the thickness of the upper template 1 at that location, thus reducing the depth of window C along the Z-direction. With a smaller depth of window C along the Z-direction, the thickness of the upper template 1 that the wire bonding operation head needs to pass through is smaller, and the operating distance of the wire bonding operation head along the Z-direction is shorter, which helps to reduce process difficulty and improve efficiency.

[0066] In one embodiment, the groove structure K is designed to be symmetrical about left and right along the X direction, which helps to improve the uniformity of stress distribution of the overall structure of the upper template 1 when it is used for press-fitting the packaging module, and also facilitates the formation of the groove structure K on the upper template 1.

[0067] In one embodiment, the groove structure K penetrates the upper template 1 along the Y direction, that is, the groove structure K connects the two sides of the upper template 1 along the Y direction. In the manufacturing process of the upper template 1, such a structural design can reduce the manufacturing difficulty.

[0068] In one embodiment, the groove structure K is stepped. Along the X direction, the groove structure K creates two steps on the surface of the upper template 1 facing away from the lower template 2. These two steps divide the surface of the upper template 1 facing away from the lower template 2 into three parts: a first area a1 and two second areas a2. The two second areas a2 are arranged adjacently on both sides of the first area a1, forming a step between the first area a1 and the second areas a2. Along the Z direction, the distance between the first area a1 and the surface of the upper template 1 facing the lower template 2 is greater than the distance between the second area a2 and the surface of the upper template 1 facing the lower template 2.

[0069] In one specific implementation, such as Figure 5a and Figure 5b As shown, the first section a1 and the second section a2 are connected by a step surface t. The step surface t can be a surface set at an angle to the Z direction, such that the step surface t forms angles with both the first section a1 and the second section a2. Along the surface perpendicular to the Y direction, the cross-section of the groove structure K is trapezoidal. The inclined step surface t connects the first section a1 and the second section a2 with a gradual gradient, which can weaken the internal stress changes caused by the structural changes of the upper template 1 at the step and enhance the structural strength.

[0070] In another specific implementation, the step surface t can be a surface parallel to the Z direction, such that the step surface t is perpendicular to the first region a1 and the second region a2. Along the surface perpendicular to the Y direction, the cross-section of the groove structure K is rectangular.

[0071] In some embodiments, such as Figure 6 The image shows a mold for gold wire bonding, and Figure 2 Compared to the mold shown, the upper mold plate 1 in this mold includes a pressure plate 11 and a protruding structure 12. The pressure plate 11 is used to press against the lead frame 03 of the packaging structure. The protruding structure 12 is disposed on the surface of the pressure plate 11 facing the lower mold plate 2. The protruding structure 12 protrudes towards the lower mold plate 2 to abut against the substrate 01 of the packaging structure, so that the surface of the substrate 01 facing away from the upper mold plate 1 can be relatively stably abutted against the inner wall of the receiving groove 21 of the lower mold plate 2. The substrate 01 is relatively fixed by the protruding structure 12. For the entire packaging structure, the lead segment 031 of the lead frame 03 is clamped between the pressure plate 11 of the upper mold plate 1 and the lower mold plate 2. The substrate 01 is abutted and fixed by the protruding structure 12 and the lower mold plate 2, which can improve the structural stability of the packaging structure in the thermo-ultrasonic wire bonding operation and improve the workability of thermo-ultrasonic wire bonding. When the upper mold plate 1 is pressed onto the packaging structure, the height of the protruding structure 12 protruding from the upper mold plate 1 is the height difference between the lead segment 031 and the recessed segment 032 of the lead frame 03. It should be understood that the raised structure 12 avoids the positions of electronic components and bonding wires in the package structure. The specific avoidance method can be achieved by edge chamfering, groove cutting, etc.

[0072] In one embodiment, the protruding structure can be made of a material with high rigidity to achieve a good pressure-resistant and fixing effect. Specifically, the material of the protruding structure 12 can be selected from one or more combinations of steel, titanium and titanium alloys, and aluminum and aluminum alloys.

[0073] During operation, the protruding structure 12 presses against the substrate 01, subjecting the substrate 01 to a certain pressure. If the substrate 01 experiences significant internal stress due to this pressure, it may cause structural damage. In some embodiments, to provide a certain degree of cushioning and fixation, the protruding structure can be made of a flexible material, such as at least one of rubber and resin, to reduce the stress on the substrate 01 caused by the pressure and protect its structure. Specifically, the rubber can be natural or synthetic rubber, and the resin can be one or a combination of polypropylene (PP), polyethylene (PE), polyvinyl chloride (PVC), polystyrene (PS), and acrylonitrile butadiene styrene (ABS).

[0074] In some embodiments, the protrusion structure 12 may be a combination of rigid and flexible materials to ensure compressive strength while protecting the substrate 01.

[0075] The shape of the protrusion structure 12 is not limited and can be selected according to the structure of the upper template 1 and various parameters of the encapsulation structure. For example, the shape of the protrusion structure 12 includes island-shaped, strip-shaped, dot-shaped, etc.

[0076] In one embodiment, such as Figure 7a The diagram shows the structure of an upper template 1, in which the protruding structure 12 serves to abut against the substrate 01 of the encapsulation structure. Simultaneously, the protruding structure 12 also functions as a gas guide. Specifically, the protruding structure 12 forms a gas guide channel E, which is used to more concentratedly guide the inert gas flowing out of the gas channel D to the window C, ensuring sufficient inert gas protection at the gold wire bonding operation location.

[0077] exist Figure 7a In the structure of the upper template 1 shown, the protruding structure 12 includes a plurality of protrusions 121, each of which is fixed to the pressure plate 11 and faces the surface of the lower template 2. Along the Z direction, each protrusion 121 protrudes from the surface of the pressure plate 11. When the upper template 1 and the lower template 2 are used to press-fit the encapsulation structure, each protrusion 121 faces away from the surface of the pressure plate 11 and is used to contact the substrate 01 of the encapsulation structure.

[0078] It should be understood that the height of each protrusion 121 relative to the pressure plate 11 can be adaptively selected according to the surface condition of the substrate 01 of the encapsulation structure to be pressed by the mold. When the surface of the substrate 01 facing the upper template 1 is flat, the height of each protrusion 121 relative to the pressure plate 11 can remain consistent. When the surface of the substrate 01 facing the upper template 1 is not coplanar at different positions, the height of the protrusion 121 corresponding to the surface of the substrate 01 at different positions relative to the pressure plate 11 can be adjusted accordingly, so that each protrusion 121 can abut against the substrate 01, achieving a pressing and fixing effect at different positions.

[0079] like Figure 7a As shown, in one embodiment, the protruding structure 12 includes multiple protrusions 121. The structural positions of these protrusions 121 are matched to form a gas guiding channel E that directs the airflow of inert gas towards the window C. Each gas guiding channel E is formed by two protrusions 121 arranged opposite each other. When the upper template 1 presses into the encapsulation structure, the two protrusions 121 corresponding to each gas guiding channel E can abut against the substrate 01 of the encapsulation structure, thereby confining the inert gas ejected from the multiple outlets d1 between the two protrusions 121 within the gas guiding channel E. Since the inlet d2 is located on both sides of the upper template 1 along the X direction, the airflow of inert gas tends to flow from both sides of the upper template 1 along the X direction towards the center. By setting the gas guiding direction of the gas guiding channel E to be approximately parallel to the X direction, the inert gas ejected from the outlet d1 can be guided towards the window C in accordance with the airflow direction of the inert gas.

[0080] Specifically, for each window C, a funnel-shaped air guide channel E is formed by two opposing protrusions 121. The end of the air guide channel E facing window C has a smaller diameter, and the end away from window C has a larger diameter. The distance between the two protrusions 121 forming one air guide channel E is smaller than the distance between their ends facing window C. When the density of multiple air outlets d1 distributed on the surface of the upper template 1 facing the lower template 2 is uniform per unit area, the number of air outlets d1 at the larger diameter end of the air guide channel E is greater than the number of air outlets d1 at the smaller diameter end. When the inert gas tends to flow from one end of the upper template 1 towards the center along the X direction, the funnel shape of the air guide channel E can converge the inert gas, thereby guiding more inert gas towards window C. When thermal ultrasonic wire bonding is performed on the package structure through window C, the temperature at window C is higher. The gas channel E concentrates more inert gas at window C, which can provide better protection for the copper layer of substrate 01 and the copper of chip 02.

[0081] based on Figure 7a The embodiment of the protrusion structure 12 shown in this application also provides a method such as... Figure 7bThe upper template 1 is shown. (As shown) Figure 7b As shown, for each window C, a funnel-shaped air channel E is formed by two protrusions 121 facing each other. In order to achieve a better inert gas gathering effect, the distribution density of multiple air outlets d1 is adjusted so that the distribution density of air outlet d1 between the two protrusions 121 corresponding to each air channel E is greater than the distribution density of air outlet d1 in other areas.

[0082] It should be understood that the protruding structure 12 can also form the air guiding channel E through other structural forms. The formed air guiding channel E may also have other shapes, which need to be adjusted according to the specific form of the packaging structure pressed by the mold, so as to guide the air to the window C while avoiding the electronic components and bonding positions of the packaging structure. This application embodiment will not provide further examples.

[0083] In one embodiment, such as Figure 8a The diagram illustrates the structure of an upper template 1, which includes a protruding structure 12 that functions to abut against the substrate 01 of the encapsulation structure. Specifically, the protruding structure 12 includes a frame 122 that protrudes from the surface of the upper template 1 facing the lower template 2. When the upper template 1 and the lower template 2 are used to press-fit the encapsulation structure, the end face of the frame 122 facing away from the pressure plate 11 is used to contact the substrate 01 of the encapsulation structure. The frame 122 is used to enclose at least one chip 02, so that the bonding area of ​​the chip 02 connected to the substrate 01 by the bonding wire 04 is contained within the area enclosed by the frame 122. The end face of the frame 122 facing away from the pressure plate 11 abuts against the substrate 01, resulting in a larger contact area. In thermo-ultrasonic wire bonding operations, the frame 122 can provide support around the wire bonding position, enhancing the stability of the mold pressing and improving workability.

[0084] To introduce inert gas into the enclosure 122 and provide inert gas protection for the gold wire bonding sites, such as... Figure 8a As shown, the frame 122 includes a cutout R that penetrates the outer wall of the inner wall of the frame 122, allowing the inert gas ejected from the air outlet d1 outside the frame 122 to be introduced into the frame 122, providing inert gas protection for the thermo-ultrasonic gold wire bonding operation performed at window C.

[0085] The frame 122 encloses two windows C, each window C corresponding to a bonding position of a gold wire 04. The gold wire bonding operation head can pass through one of the windows C to weld the two ends of a gold wire 04 to the chip 02 and the substrate 01 respectively, realizing the gold wire bonding between the chip 02 and the substrate 01. The area enclosed by the frame 122 is larger than the area of ​​the two windows C, and the frame 122 can abut against the substrate 01 to support the bonding positions corresponding to the two windows C.

[0086] like Figure 8bAs shown, taking the enclosure 122 enclosing two chips 02 as an example, each chip 02 is connected to the substrate 01 via a bonding wire 04. The first end J1 of each bonding wire 04 is soldered to one chip 02, and the second end J2 of the bonding wire 04 is soldered to the substrate 01. For ease of illustration, the pressure plate 11 of the upper template 1 is separated from the enclosure 122 of the protruding structure 12, so that the enclosure 122 abuts against the substrate 01 and surrounds the chip 02. The pressure plate 11 of the upper template 1 includes two windows C, located within the area enclosed by the enclosure 122. Along the Z direction, i.e., perpendicular to the substrate 01, the orthographic projection of one window C onto the substrate 01 overlaps the orthographic projection of one bonding wire 04 onto the substrate 01, and the orthographic projection of the other window C onto the substrate 01 overlaps the orthographic projection of the other bonding wire 04 onto the substrate 01.

[0087] Please continue to refer to Figure 8b As shown, the frame 122 surrounds the two chips 02, and the area enclosed by the frame 122 is larger than the area of ​​the substrate 01 occupied by the two chips 02. The cutouts R of the frame 122 allow inert gas to enter the frame 122. During thermo-ultrasonic gold wire bonding, the inert gas inside the frame 122 can provide gas protection for the copper layer of the substrate 01 and the copper pads of the chips 02, preventing copper oxidation caused by the high temperature of welding.

[0088] Refer to together Figure 8a and Figure 8b As shown, with the air inlets d2 located on both sides of the upper template 1 along the X direction, the inert gas flow tends to flow from both sides of the upper template 1 along the X direction towards the center. The perforations R penetrate the inner and outer walls of the frame 122 approximately parallel to the X direction, guiding the inert gas ejected from the outlets d1 outside the frame 122 towards the window C inside the frame 122, following the direction of the inert gas flow. In one embodiment, perforations R are provided on both sides of the frame 122 along the X direction, thereby simultaneously guiding the inert gas ejected from the outlets d1 outside the frame 122 along the X direction towards the window C inside the frame 122.

[0089] To better protect the copper layer of substrate 01 during thermo-ultrasonic gold wire bonding, more inert gas needs to be directed into the enclosure 122. Based on Figure 8a The embodiment of the protrusion structure 12 shown in this application also provides a method such as... Figure 9 The upper template 1 is shown. (As shown) Figure 9As shown, for each opening R of the frame 122, multiple air outlets d1 are provided outside the frame 122 as shown in the dashed frame. These multiple air outlets d1 are located on the side of the opening R away from the inner wall of the frame 122. The airflow of inert gas tends to flow from both sides of the upper template 1 along the X direction towards the center. Therefore, the multiple air outlets d1 in the dashed frame corresponding to each opening R will pass through the opening R and enter the frame 122. For ease of understanding, the multiple air outlets d1 corresponding to the opening R are referred to as the first type of air outlets, and the other air outlets are referred to as the second type of air outlets. The distribution density of the multiple air outlets d1 included in the first type of air outlets is greater than the distribution density of the air outlets d1 included in the second type of air outlets in other areas, to ensure that a sufficient amount of inert gas can enter the frame 122 through the opening R, thereby achieving a good gas protection effect.

[0090] Figure 10a This application provides a structure for an upper template 1. For example... Figure 10a As shown, the protruding structure 12 includes a frame 122 and a partition 123. The two ends of the partition 123 are respectively connected to the inner wall of the frame 122. The end face of the partition 123 facing away from the pressure plate 11 is used to press against the substrate 01, further increasing the contact area of ​​the protruding structure 12 against the substrate 01 and improving the support and stability effect.

[0091] In some embodiments, the partition 123 divides the space enclosed by the frame 122 into two spaces. When the upper template 1 includes multiple windows C, depending on the position of the gold wire to be bonded, the windows C can be set in the same space or in different spaces. Figure 10a In the example template 1, the two windows C enclosed by the frame 122 are located in one of the spaces, which facilitates the thermal ultrasonic gold wire bonding operation.

[0092] Understandably, depending on the requirements of wire bonding and the layout of chip 02 in the packaging structure, the frame 122 and the partition 123 may have other structural forms to increase the contact area with the substrate 01 and optimize the support effect. For example, the frame 122 can be trapezoidal, hexagonal, or irregular polygonal, and the partition 123 can be "L" shaped, "Y" shaped, etc.

[0093] Combination Figure 10b The upper template 1 shown has a partial structure where a partition 123 divides the internal space of the frame 122 into a first space P1 and a second space P2. Two windows C are located within the first space P1. The first space P1 and the second space P2 are arranged along the X direction. An auxiliary perforation r connects the first space P1 and the second space P2, allowing airflow to pass between the two perforations R. This allows inert gas in one space to enter the other space through the auxiliary perforation r, achieving airflow exchange.

[0094] The frame 122 includes two openings R, which are connected to the first space P1 and the second space P2 respectively. The auxiliary opening r of the partition 123 allows airflow to be conducted between the two openings R.

[0095] In some embodiments, the frame 122 is used to enclose some chips 02 that require wire bonding, specifically housing these chips 02 within a first space P1, so as to accommodate the bonding area of ​​the chip 02 connected to the substrate 01 by the wire bonding 04 within the first space P1. The second space P2 can be used to accommodate other electronic components of the package structure, and the partition 123 can spatially isolate the at least one chip 02 from other electronic components, which is beneficial to improving the workability of thermo-ultrasonic wire bonding.

[0096] Based on the upper template 1, the two air inlets d2 of the air passage D are located on both sides of the pressure plate 11 along the X direction. The inert gas ejected from the multiple air outlets d1 can enter the enclosure 122 through the two perforations R. The inert gas in the first space P1 and the inert gas in the second space P2 can be interconnected through the auxiliary perforation r of the partition 123. When the concentration or pressure of the inert gas in the first space P1 and the inert gas in the second space P2 are different, the inert gas can be homogenized through airflow interconnection.

[0097] like Figure 10c As shown, taking the enclosure 122 enclosing two chips 02 as an example, the two chips 02 are located in the first space P1 formed by the partition 123 and the enclosure 122. Other electronic devices 05 are also disposed on the substrate 01, adjacent to the two chips 02, and located in the second space P2 formed by the partition 123 and the enclosure 122. Each chip 02 is connected to the substrate 01 via a bonding wire 04, with both ends of the bonding wire 04 soldered to the chip 02 and the substrate 01, respectively. The two openings R of the enclosure 122 are connected to the first space P1 and the second space P2, respectively. In the thermo-ultrasonic wire bonding operation, the inert gas entering the first space P1 through the right opening R can provide gas protection for the copper layer of the substrate 01 in the first space P1, and the inert gas entering the second space P2 through the left opening R can provide gas protection for the copper layer of the substrate 01 in the second space P2. The inert gas in the first space P1 and the inert gas in the second space P2 can be interconnected through the auxiliary perforation of the partition 123, ensuring the flow of inert gas in the thermo-ultrasonic gold wire bonding working space.

[0098] In the thermo-ultrasonic gold wire bonding operation of the encapsulation structure provided in this application embodiment, other templates may also be provided on both sides of the upper template 1 along the X direction. When the air inlet d2 of the air passage D of the upper template 1 is located at both ends of the upper template 1 along the X direction, the air inlet d2 may be structurally blocked or interfered with by other templates, affecting the smooth air intake of the air inlet d2. In order to avoid other templates and ensure the smooth air intake of the air inlet d2 of the air passage D, this application embodiment provides a method such as... Figure 11a The upper template 1 is shown. (As shown) Figure 11a As shown, the upper template 1 has protrusions B at both ends along the X direction. Along the Z direction, the protrusions B protrude from the surface of the upper template 1 away from the lower template 2. The air inlet d2 of the air passage D is located on the protrusions B.

[0099] As a structural example, each boss B is folded, specifically a folded edge protruding from the surface of the upper template 1 away from the lower template 2. In the fabrication of the upper template 1, both ends of the upper template 1 along the X direction can be bent towards the side away from the lower template 2 along the Z direction, and then bent outwards along the X direction to form the boss B. Along the Z direction, the plane position of the air inlet d2 of the air passage D is different from the plane position of the upper template 1 used for press-fitting the encapsulation structure. When the upper template 1 and lower template 2 press-fit the encapsulation structure, the distance between the air inlet d2 and the lower template 2 is greater than the distance between the surface of the upper template 1 used for press-fitting the encapsulation structure and the lower template 2. The air intake direction of the air inlet d2 is parallel to the X direction.

[0100] Figure 11b The example includes Figure 11a The state of the mold press-fitting and packaging structure of the upper template 1 is shown. For example... Figure 11b As shown, along the X direction, both ends of the encapsulation structure extend from the ends of the upper template 1 and the lower template 2. The two ends of the encapsulation structure can be press-fitted by other templates. When inert gas is introduced into the air passage D of the upper template 1 through the air inlet d2, the plane where the air inlet is located is at a different layer from the plane where the press-fitting is located. When other templates are used to press-fit the encapsulation structure, the air intake of the air inlet d2 will not be blocked by other templates, thus not affecting the air intake effect.

[0101] Based on the aforementioned mold, this application embodiment also provides a packaging device, which includes the aforementioned mold for gold wire bonding. Figure 12As shown, the packaging device includes an upper template 1 and a lower template 2. The upper template 1 and lower template 2 are used to press-fit the packaging structure in the thermo-ultrasonic gold wire bonding process, forming a relatively closed gold wire bonding track space between the upper template 1 and the lower template 2. The packaging device also includes two first auxiliary templates 31 and two second auxiliary templates 32. One first auxiliary template 31 is used to form a set of auxiliary templates opposite to one second auxiliary template 32 along the Z direction. Taking one first auxiliary template 31 and one second auxiliary template 32 as a combination, a set of first auxiliary templates 31 and one second auxiliary template 32 are respectively arranged on both sides of the upper template 1 and the lower template 2 along the X direction. Along the X direction, the two first auxiliary templates 31 are arranged on both sides of the upper template 1, and the two second auxiliary templates 32 are arranged on both sides of the lower template 2. The air inlet d2 of the upper template 1 avoids the two first auxiliary templates 31 through the boss B. When the upper template 1 and the lower template 2 form a space for gold wire bonding, the two second auxiliary templates 32 can cooperate with the lower template 2 to provide support for the encapsulation structure, while the two first auxiliary templates 31 can seal the space for gold wire bonding along the X direction. This helps inert gas to accumulate between the upper template 1 and the lower template 2 and also reduces the heat transfer to other areas of the encapsulation structure during thermo-ultrasonic gold wire bonding. The gold wire bonding in different areas of the encapsulation structure requires movement of the encapsulation structure along the X direction, which can also be considered the direction of movement of the encapsulation structure.

[0102] This packaging device features a high-pin frame design, creating a relatively enclosed thermo-ultrasonic wire bonding working space between the upper template 1 and the lower template 2. This allows the upper template 1 to avoid obstructing the chip 02 within the packaging structure. During thermo-ultrasonic wire bonding, the chip 02 and substrate 01 are bonded through window C of the upper template 1. This prevents the loss of inert gas, provides excellent gas protection for the copper layer of the substrate 01, and improves the operability of the thermo-ultrasonic wire bonding.

[0103] In one embodiment, the packaging structure provided in this application can specifically be a power module, the electronic components of which can be connected to form a power conversion circuit. This power conversion circuit can be used to achieve one of the following circuit conversions: DC to AC, AC to DC, or DC to DC.

[0104] Power modules are widely used in electric vehicles, new energy, photovoltaics, wind power, and other fields for managing and regulating power transmission and conversion. They achieve excellent performance, including high voltage, high current, stable temperature, and low electromagnetic radiation. The main functions of a power module include voltage conversion, current control, and reversible conversion. Voltage conversion transforms the voltage of a power source from one level to another, meeting the needs of different devices or systems. Current control regulates the current to ensure it remains within acceptable limits, preventing overcurrent damage to equipment or circuits. Reversible conversion converts direct current (DC) to alternating current (AC) or vice versa.

[0105] In consumer electronics, power modules are primarily used in power adapters, inverters, and frequency converters. In the power energy sector, they are mainly used in solar inverters and wind power converters. In energy storage, they are primarily used in energy storage converters or DC-DC converters. In automotive electronics, power modules are mainly used in electric vehicle motor controllers, on-board chargers (OBCs), microcontroller units (MCUs), and generator control units (GCUs).

[0106] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A mold for gold wire bonding, characterized by, The mold includes an upper mold plate and a lower mold plate, which are used to press-fit a package structure with high pins. The lead frame of the package structure includes two pin segments and a recessed segment connecting the two pin segments. The surface of the lower template facing the upper template includes a receiving groove and two bearing surfaces located on both sides of the receiving groove. The receiving groove is used to accommodate the recessed section of the lead frame, and the two bearing surfaces are used to support the pin section of the lead frame. The upper template includes an air passage and a window, the window penetrating the upper template for the passage of a gold wire bonding operation head, the air passage for containing inert gas, and the air passage including a plurality of air outlets located on the surface of the upper template facing the lower template; Along the pressing direction of the upper and lower templates, the projection of the outlet air of the window and the air passage onto the lower template is located within the receiving groove.

2. The mold of claim 1, wherein, The window is configured as follows: When the upper template and the lower template press-fit the packaging structure, the orthographic projection of the window on the packaging structure overlaps with a part of the chip and a part of the substrate in the packaging structure.

3. The mold of claim 1, wherein, The upper template includes a pressure plate and a raised structure; The pressure plate is used to press the lead frame pin segment onto the bearing surface of the lower template; The protruding structure is disposed on the surface of the pressure plate facing the lower template. Along the pressing direction of the upper template and the lower template, the projection of the protruding structure on the lower template is located in the receiving groove. The protruding structure is used to press against the substrate of the encapsulation structure.

4. The mold of claim 3, wherein The protruding structure includes a frame surrounding the outer periphery of the window, and the end face of the frame facing the lower template is used to press against the substrate of the encapsulation structure. The frame includes an outer wall that extends through the frame and a perforation in the outer wall.

5. The mold of claim 4, wherein The protruding structure includes a partition, the two ends of which are connected to the inner wall of the frame, and the end face of the partition facing away from the pressure plate is used to press against the substrate of the encapsulation structure. The partition divides the space enclosed by the frame into a first space and a second space, and the window is located in the first space; The partition includes an auxiliary perforation that extends through the partition to connect the first space and the second space.

6. The mold of claim 5, wherein The frame includes two openings, one of which is connected to the first space and the other of which is connected to the second space.

7. The mold of claim 4, wherein The plurality of air outlets include a first type of air outlet and a second type of air outlet, wherein the first type of air outlet is arranged on the inner wall side of the hollowed-out structure opposite to the frame. The first type of air outlet includes a plurality of air outlets spaced apart, and the second type of air outlet includes a plurality of air outlets spaced apart. The distribution density of the first type of air outlet is greater than the distribution density of the second type of air outlet.

8. The mold of claim 3, wherein The material of the protruding structure includes one or more combinations of steel, titanium and titanium alloys, aluminum and aluminum alloys, rubber, and resin.

9. The mold of claim 1, wherein, The surface of the upper template facing away from the lower template includes a groove structure, and the orthographic projection of the window onto the surface of the upper template facing away from the lower template is located within the groove structure.

10. The mold of any one of claims 1-9, wherein, The air passage comprises two air inlets, which are respectively located at two sides of the upper mold plate along a set direction, and the set direction is perpendicular to the pressing direction of the upper mold plate and the lower mold plate.

11. The mold of claim 10, wherein, Two ends of the upper mold plate along a set direction are bent away from the lower mold plate. Along the pressing direction of the upper mold plate and the lower mold plate, the distance between the two air inlets and the lower mold plate is greater than the distance between the surface of the upper mold plate for pressing the packaging structure and the lower mold plate.

12. A packaging apparatus, characterized by The mold comprises two groups of auxiliary mold plates and the mold as claimed in any one of claims 1-11. Along a set direction, the two groups of auxiliary mold plates are respectively arranged at two sides of the mold for assisting in pressing the packaging structure, and the set direction is the moving direction of the packaging structure.

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