A bonding aid tool for dual-in-line frame

Abstract

The application discloses a bonding auxiliary tool for a double-row lead frame, which comprises a receiving base, at least one upper pressing plate suitable for an upper base island of the lead frame, and at least one lower pressing plate suitable for a lower base island of the lead frame; the receiving base is provided with a placing groove for placing the lead frame; a gasket is arranged between the placing groove and the lead frame; for any one of the upper pressing plate or the lower pressing plate, the pressing plate is provided with a welding head movable area and a plurality of pressing fingers, the mounting end of the pressing finger is detachably mounted on the pressing plate, and the pressure bearing end of the pressing finger presses the lead frame through the welding head movable area. The application improves the efficiency of multi-column and multi-type bonding processes, reduces the risk of false welding, and improves the overall bonding quality.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor packaging technology, and in particular to a bonding auxiliary tool for a double-row lead frame. Background Technology

[0002] In semiconductor chip packaging, wire bonding is a crucial step in reliably connecting chip pads to leadframe pins, and its bonding quality directly affects the chip's electrical performance and reliability. To ensure the stability of the leadframe during bonding, bonding pressurization tools are typically used for fixation. Existing bonding pressurization tools generally consist of a pressing plate and a gasket, which can compress the leadframe during bonding, allowing the bonding head to smoothly complete the bonding operation.

[0003] However, the bonding aids in related technologies have relatively simple tool structures, and the hollow part of the laminating plate cannot flexibly match lead frames with different structures, especially double-row lead frames. Figure 1 This is a schematic diagram of a dual-row leadframe, which consists of two rows of multi-column frame units. Each frame unit has a base island for mounting the chip. Within the same column of the leadframe, different base island positions result in different bonding areas, making it difficult for existing bonding aids to match. Utility Model Content

[0004] The main objective of this application is to provide a bonding aid for a double-row lead frame, which aims to solve the problems of insufficient compatibility of bonding aids in related technologies, making it difficult to match double-row lead frames, and low bonding efficiency.

[0005] To achieve the above objectives, this application adopts the following technical solution: A bonding aid for a double-row lead frame includes a receiving base and at least one upper pressing plate for an upper base island of the lead frame and at least one lower pressing plate for a lower base island of the lead frame. The base is provided with a slot for placing the lead frame; a gasket is provided between the slot and the lead frame; For either the upper or lower pressing plate, the pressing plate has a welding head moving area and a number of pressure fingers. The mounting end of the pressure fingers is detachably mounted on the pressing plate, and the pressure-bearing end of the pressure fingers presses the lead frame through the welding head moving area. When the upper bonding plate is installed on the receiving base, the bonding portion corresponding to one of the upper base islands of the lead frame is located within the welding head movement area of ​​the upper bonding plate; when the lower bonding plate is installed on the receiving base, the bonding portion corresponding to one of the lower base islands of the lead frame is located within the welding head movement area of ​​the lower bonding plate.

[0006] In one embodiment, the bonding aid includes two upper bonding plates and two lower bonding plates, the two upper bonding plates being a coarse wire bonding plate and a coarse line bonding plate, and the two lower bonding plates being a fine wire bonding plate and a fine line bonding plate; Among them, the active area of ​​the welding head on the upper pressing plate and the active area of ​​the welding head on the lower pressing plate correspond to the upper base island and the lower base island in any column of the lead frame unit, respectively. Among them, the active area of ​​the welding head on the upper pressing plate and the active area of ​​the welding head on the lower pressing plate correspond to the upper base island and the lower base island in any column of the lead frame unit, respectively. The position of the pressing fingers on the pressing plate on the thick line is different from that on the pressing plate on the thin line; the position of the pressing fingers on the pressing plate on the thick line is different from that on the pressing plate on the thin line.

[0007] In one embodiment, each pressing plate is detachably disposed on top of the receiving base.

[0008] In one embodiment, quick-installation holes are provided on the upper and lower sides of each pressing plate. The quick-installation holes are composed of interconnected circular holes and narrow slots, and the width of the narrow slots is smaller than the width of the circular holes. The top of the base is provided with several mounting posts. Each mounting post consists of a limiting head and a connecting post set at the top and bottom. The width of the limiting head is smaller than the width of the round hole but larger than the width of the narrow groove, and the width of the connecting post is smaller than the width of the narrow groove.

[0009] In one embodiment, a plurality of guide grooves are provided on both sides of the top length direction of the receiving base; A first threaded hole is provided on the side of the guide groove away from the placement groove so that one end of the limit screw enters the guide groove through the first threaded hole; the pressing plate is installed in one of the pair of guide grooves of the receiving base through guide pins provided on the upper and lower sides.

[0010] In one embodiment, the top surface of the receiving base is provided with a plurality of second threaded holes around the active area of ​​the welding head, and the mounting end of the pressure finger is fixed to the corresponding second threaded hole by screws.

[0011] In one embodiment, a pad is provided between the pressure finger and the second screw.

[0012] In one embodiment, nine pressure fingers are provided to press against the edge of the base island of the lead frame.

[0013] In one embodiment, the pad height at the lead frame bonding area is higher than the pad height in other areas.

[0014] One or more technical solutions proposed in this application have at least the following technical effects: This application addresses the upper and lower base islands within the same column of frame units in a dual-row leadframe. The provided bonding auxiliary tools include an upper bonding plate for chip bonding on the upper base island and a lower bonding plate for chip bonding on the lower base island. Based on the upper and lower bonding plates, considering scenarios where thick and thin wires are mixed during chip bonding at the same base island location, the tool is further refined into thick-wire bonding plates and thin-wire bonding plates for the upper base island, and thick-wire and thin-wire bonding plates for the lower base island. In various versions of this tool, by rationally distributing the pressure finger positions, stable fixation of the leadframe is achieved, enabling multiple bonding machines and multiple bonding heads to work simultaneously. This improves the efficiency of multi-column, multi-type bonding processes, reduces the risk of cold solder joints, and improves overall bonding quality. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of a double-row lead frame.

[0017] Figure 2 This is a diagram of the stitching process.

[0018] Figure 3 This is an isometric view of the bonding aid tool embodiment of the double-row lead frame of this application.

[0019] Figure 4 This is a top view of the bonding aid tool embodiment of the double-row lead frame of this application.

[0020] Figure 5 This is a schematic diagram of the thick-line version of the lamination plate corresponding to the upper and lower base islands of the lead frame in this application.

[0021] Figure 6 This is a schematic diagram of the thin-wire version of the lamination plate corresponding to the upper and lower base islands of the lead frame in this application.

[0022] Figure 7 This is a schematic diagram of the pad block structure.

[0023] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings.

[0024] Reference numerals: 001 Thick wire, 002 Thin wire, 100 Receiving base, 101 Placement slot, 102 Mounting post, 103 Guide slot, 104 First threaded hole, 105 Limiting screw, 200A Thick wire upper pressing plate, 200B Thin wire upper pressing plate, 200C Thick wire lower pressing plate, 200D Thin wire lower pressing plate, 201 Welding head moving area, 202 Pressing finger, 203 Quick-release hole, 204 Guide pin, 205 Second threaded hole, 206 Screw, 207 Spacer, 300 Lead frame, 301 Washer, 303 Chip, 304 Aluminum wire, 305 Base island. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] It should be noted that in this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an apparatus or system comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an apparatus or system. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the apparatus or system including that element. In this application, unless otherwise expressly specified and limited, the terms "connected," "fixed," etc., should be interpreted broadly. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal communication of two elements or the interaction between two elements. In this application, if descriptions refer to "first," "second," etc., such descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may expressly or implicitly include at least one of those features. For those skilled in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances. Furthermore, the technical solutions of the various embodiments can be combined with each other, but only on the basis that those skilled in the art can implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0027] Wire bonding machines include gold-copper wire bonding machines and aluminum wire bonding machines. Currently, most power devices and modules use aluminum wire as the primary connection material. Aluminum wire is cheaper than bonding materials such as gold and copper wire, significantly reducing packaging costs, especially in large-scale production. Aluminum wire bonding is the mainstream technology for high-power devices (such as IGBTs and MOSFETs).

[0028] In semiconductor chip packaging, wire bonding is a crucial step in reliably connecting chip pads to leadframe pins, and its bonding quality directly affects the chip's electrical performance and reliability. To ensure the stability of the leadframe during bonding, bonding pressurization tools are typically used for fixation. Existing bonding pressurization tools generally consist of a pressing plate and a gasket, which can compress the leadframe during bonding, allowing the bonding head to smoothly complete the bonding operation.

[0029] However, the bonding aids in the related technologies have a relatively simple structure. The hollow part of the laminating plate cannot flexibly match the double-row lead frame. On the other hand, the bonding wires are divided into thick wire 001 and thin wire 002. In the scenario of mixed bonding of thick wire 001 and thin wire 002, the bonding efficiency is low.

[0030] Based on the above problems and ideas, this application provides a bonding aid for dual-row lead frames to improve overall bonding quality and increase bonding efficiency. Specific embodiments and implementation methods are as follows: Reference Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 This embodiment proposes a bonding aid for a double-row lead frame, including a receiving base 100, at least one upper pressing plate suitable for the upper base island of the lead frame 300, and at least one lower pressing plate suitable for the lower base island of the lead frame 300. The receiving base 100 is provided with a placement groove 101 for placing the lead frame 300; a gasket 301 is provided between the placement groove 101 and the lead frame 300. For either the upper or lower pressing plate, the pressing plate has a welding head moving area 201 and a number of pressure fingers 202. The mounting ends of the pressure fingers 202 are detachably mounted on the pressing plate, and the pressure-bearing ends of the pressure fingers 202 press the lead frame 300 through the welding head moving area 201.

[0031] Among them, reference Figure 1The lead frame 300 is composed of double-row, multi-column frames, each of which is provided with a base island 305. After the upper pressing plate is installed on the receiving base 100, the bonding part corresponding to one of the upper base islands of the lead frame 300 is distributed in the welding head moving area 201 of the upper pressing plate; after the lower pressing plate is installed on the receiving base 100, the bonding part corresponding to one of the lower base islands of the lead frame 300 is distributed in the welding head moving area 201 of the lower pressing plate.

[0032] To further improve bonding efficiency, in one feasible implementation method, The bonding auxiliary tool includes two upper pressing plates and two lower pressing plates. The two upper pressing plates are a coarse line pressing plate 200A and a coarse line pressing plate 200C, and the two lower pressing plates are a fine line pressing plate 200B and a fine line pressing plate 200D. Among them, the active area of ​​the welding head on the thick upper pressing plate 200A and the active area of ​​the welding head on the thick lower pressing plate 200C correspond to the upper base island and lower base island in any column of the frame unit of the lead frame 300, respectively. Among them, the active area of ​​the welding head on the upper pressing plate 200B and the active area of ​​the welding head on the lower pressing plate 200D correspond to the upper base island and the lower base island in any column of the frame unit of the lead frame, respectively. The position of the pressing fingers on the pressing plate 200A on the thick line is different from the position of the pressing fingers on the pressing plate 200C on the thin line; the position of the pressing fingers on the pressing plate 200B on the thick line is different from the position of the pressing fingers on the pressing plate 200D on the thin line.

[0033] In one possible implementation, each pressing plate is detachably mounted on top of the receiving base.

[0034] Specifically, quick-installation holes 203 are provided on the upper and lower sides of the press plate. The quick-installation holes 203 are composed of interconnected round holes and narrow grooves, and the width of the narrow grooves is smaller than the width of the round holes. The top of the receiving base 100 is provided with several mounting posts 102. Each mounting post 102 consists of a limiting head and a connecting post arranged vertically. The width of the limiting head is smaller than the width of the circular hole but larger than the width of the narrow groove, and the width of the connecting post is smaller than the width of the narrow groove. Several guide grooves 103 are provided on both sides of the top of the receiving base 100 along its length. A first threaded hole 104 is provided on the side of the guide groove away from the placement groove 101, so that one end of the limiting screw 105 enters the guide groove 103 through the first threaded hole 104. The pressing plate is installed in one pair of guide grooves 103 of the receiving base 100 through guide pins 204 arranged on the upper and lower sides.

[0035] The top surface of the receiving base 100 is provided with several second threaded holes 205 around the welding head moving area 201, and the mounting end of the pressure finger 202 is fixed to the corresponding second threaded hole 205 by screws 206.

[0036] A pad 207 is provided between the pressure finger 202 and the second screw 206.

[0037] Nine pressure fingers 202 are provided to press against the edge of the base island 305 of the lead frame 300.

[0038] The height of the gasket 301 at the bonding area of ​​the lead frame 300 is higher than the height of the gaskets in other areas.

[0039] Specifically, in this embodiment, the receiving base 100 is used to support and carry the lead frame 300, which can be a TO263 double-row lead frame. The receiving base 100 has a placement groove 101 for placing the lead frame, and a gasket 301 provides cushioning. Pressing plates 200A-200D are detachably installed on the top of the receiving base 100 to press the lead frames at different positions. Specifically, for the double-row lead frame, this embodiment uses four types of pressing plates: pressing plate 200A for thick lead, pressing plate 200C for thick lead, pressing plate 200B for thin lead, and pressing plate 200D for thin lead. Each pressing plate has a welding head movement area 201 corresponding to the base island setting position of the lead frame, ensuring that the welding head can enter and operate during the bonding process.

[0040] The pressure fingers 202 on each bonding plate are fixed at the second threaded hole 205 by screws 206 with the assistance of pads 207, providing stable clamping to the edge of the base island 305 and preventing displacement during bonding. Quick-release holes 203 mate with mounting posts 102 on the receiving base, enabling quick installation and removal of the bonding plates. The mounting posts consist of limit heads and connecting posts, and their narrow slot and round hole structure allows for limiting and positioning. The guide grooves 103 and limit screws 105 on the receiving base, along with guide pins 204, ensure the stability and precise alignment of the bonding plate installation by having the limit screws 105 at both ends press against the guide pins 204. The base island 305 is the chip mounting area of ​​the lead frame, its edges are fixed by the pressure fingers, and its interior is the area to be bonded.

[0041] In use, first, place the lead frame 300 into the placement slot 101 of the receiving base 100, and place a shim 301 below it to achieve height adaptation. Then, install the pressing plates 200A-200D onto the base, quickly fixing them to the mounting post 102 via the quick-release hole 203, and then precisely guide and position them using the guide groove 103 and guide pin 204. Next, fix the pressure finger 202 to the second threaded hole 205 with screws 206, so that the pressure-bearing end of the pressure finger presses against the edge of the base island 305 of the lead frame 300, thereby stabilizing its position. At this time, the soldering head can enter the soldering head movement area 201 to perform bonding operations on the solder pads on the base island 305 and the pins of the lead frame, ensuring stable soldering of both thick and thin wires. It is worth mentioning that, referring to... Figure 7 The height of the gasket 301 in the lead frame bonding area is higher than that of other gasket areas to form a boss for supporting the bonding point.

[0042] Understandably, this embodiment unifies the design of base islands of various sizes by adopting a double-row frame design. For each row of base islands, a specific type of pressing plate is used. For example, the first row uses a coarse-line pressing plate 200A and a fine-line pressing plate 200B, while the second row uses a coarse-line pressing plate 200C and a fine-line pressing plate 200D. This is because each base island has both coarse and fine lines during bonding. Using existing bonding pressing tools would be very inefficient for bonding such a frame. Therefore, a pressing plate is provided for each row of frames. For the coarse-line version, a coarse-line pressing plate 200A and a coarse-line pressing plate 200C are used when bonding coarse lines; for the fine-line version, a fine-line pressing plate 200B and a fine-line pressing plate 200D are used when bonding fine lines. (Refer to...) Figure 5 and Figure 6 The difference between the thick-line version and the thin-line version of the same row of pressed plates is the position of the pressing fingers.

[0043] Understandably, two bonding machines with four welding heads can be used in combination to bond one column of thick wire and the other column of thin wire, effectively reducing the movement trajectory of mechanical parts and improving bonding efficiency. In one example, a thick wire bonding plate is used to press the upper base island of the first column of the lead frame, and then a thin wire bonding plate is used to press the upper base island of the second column of the lead frame. The two heads of the two bonding machines work simultaneously, greatly improving bonding efficiency. After the upper base islands of the first and second columns are bonded, thick and thin wire bonding plates suitable for the lower base islands can be installed. Then, the two bonding machines work simultaneously to complete the thick wire bonding of the first column of the lead frame and the thin wire bonding of the second column. Next, the thin wire bonding plate can be used to press the upper base island of the first column of the lead frame, and the thick wire bonding plate can be used to press the upper base island of the second column of the lead frame. This process is repeated until all bonding is complete.

[0044] In another example, a thick wire bonding plate is used to press the upper base island of the first column of the lead frame, a thick lower wire bonding plate is used to press the lower base island of the second column of the lead frame, a thin wire bonding plate is used to press the upper base island of the third column of the lead frame, and a thin lower wire bonding plate is used to press the lower base island of the fourth column of the lead frame. Then, the four heads of the two bonding machines work simultaneously, which greatly improves the wire bonding efficiency.

[0045] This embodiment achieves compatible fixation of double-row, multi-column lead frames through multiple detachable pressing plates and independently designed welding head movable areas, improving fixture flexibility. The mating structure of quick-release holes and mounting posts allows for rapid installation and removal of the pressing plates, reducing fixture replacement time. Numerous pressing points precisely clamp the base island edges, ensuring the stability of the bonding process and solder joint quality. Overall, this solution improves bonding efficiency, reduces downtime due to fixture replacement, and enhances adaptability to different structures and wire diameter combinations, significantly improving the reliability and versatility of chip packaging processes.

[0046] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A bonding aid for a double-row lead frame, characterized in that, It includes a receiving base and at least one upper pressing plate for the upper base island of the lead frame and at least one lower pressing plate for the lower base island of the lead frame. The receiving base is provided with a placement groove for placing the lead frame; a gasket is provided between the placement groove and the lead frame; For either the upper pressing plate or the lower pressing plate, the pressing plate has a welding head moving area and a plurality of pressure fingers. The mounting end of the pressure fingers is detachably mounted on the pressing plate, and the pressure-bearing end of the pressure fingers presses the lead frame through the welding head moving area. Wherein, after the upper pressing plate is installed on the receiving base, the bonding part corresponding to one of the upper base islands of the lead frame is distributed in the welding head moving area of ​​the upper pressing plate; after the lower pressing plate is installed on the receiving base, the bonding part corresponding to one of the lower base islands of the lead frame is distributed in the welding head moving area of ​​the lower pressing plate.

2. The bonding aid tool for the double-row lead frame according to claim 1, characterized in that, The bonding aid includes two upper bonding plates and two lower bonding plates, wherein the two upper bonding plates are respectively a coarse wire bonding plate and a coarse line bonding plate, and the two lower bonding plates are respectively a fine wire bonding plate and a fine line bonding plate; The active area of ​​the welding head on the thick upper pressing plate and the active area of ​​the welding head on the thick lower pressing plate correspond to the upper base island and the lower base island in any column of the lead frame unit, respectively. The active area of ​​the welding head on the pressing plate on the thin line and the active area of ​​the welding head on the pressing plate on the thin line correspond to the upper base island and the lower base island in any column of the frame unit of the lead frame, respectively. The pressing finger positions on the pressing plate on the thicker line are different from those on the pressing plate on the thinner line; the pressing finger positions on the pressing plate on the thicker line are different from those on the pressing plate on the thinner line.

3. The bonding aid tool for the double-row lead frame according to claim 1, characterized in that, Each of the pressing plates is detachably mounted on top of the receiving base.

4. The bonding aid tool for the double-row lead frame according to claim 3, characterized in that, Each of the pressing plates has quick-installation holes on its upper and lower sides. The quick-installation holes are composed of interconnected circular holes and narrow slots, and the width of the narrow slots is smaller than the width of the circular holes. The top of the receiving base is provided with several mounting posts. Each mounting post consists of a limiting head and a connecting post arranged vertically. The width of the limiting head is smaller than the width of the circular hole but larger than the width of the narrow groove. The width of the connecting post is smaller than the width of the narrow groove.

5. The bonding auxiliary tool for the double-row lead frame according to claim 3, characterized in that, Several guide grooves are provided on both sides of the top length direction of the receiving base; The guide groove is provided with a first threaded hole on the side away from the placement groove, so that one end of the limiting screw enters the guide groove through the first threaded hole; the pressing plate is installed in one of the pair of guide grooves of the receiving base by guide pins provided on the upper and lower sides.

6. The bonding aid tool for the double-row lead frame according to claim 1, characterized in that, The top surface of the receiving base is provided with a plurality of second threaded holes around the movable area of ​​the welding head, and the mounting end of the pressure finger is fixed to the corresponding second threaded hole by screws.

7. The bonding aid tool for a double-row lead frame according to claim 6, characterized in that, A pad is provided between the pressure finger and the second screw.

8. The bonding aid tool for the double-row lead frame according to claim 1, characterized in that, Nine pressure fingers are provided to press down on the edge of the base island of the lead frame.

9. The bonding aid tool for the double-row lead frame according to claim 1, characterized in that, The height of the spacer in the bonding area of ​​the lead frame is higher than the height of the spacers in other areas.

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