IGBT (Insulated Gate Bipolar Translator) chip solder overflow drainage structure
By designing the first and second drainage grooves of the soldered copper-clad sheet surrounding the IGBT chip, the impact of solder overflow on chip performance is solved, effective drainage of solder and chip position stability are achieved, and the product thrust and reliability are ensured.
Patent Information
- Application Number
- CN202421963400.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-14
- Publication Date
- 2025-06-24
- Estimated Expiration
- 2034-08-14
AI Technical Summary
During the IGBT chip soldering process, solder is prone to overflow when heated in a vacuum environment, resulting in the inability to effectively combine the solder during subsequent aluminum wire soldering, resulting in product thrust failure or reliability failure. At the same time, solder overflow may also cause chip position deviation, affecting product performance.
An IGBT chip solder overflow drainage structure is designed, including a first drainage groove and a second drainage groove. The first drainage groove is arranged around the soldered copper sheet of the chip to accommodate the overflowing solder. The second drainage groove communicates with the first drainage groove and is used to accommodate the solder flowing out of the first drainage groove and is formed on the substrate around the chip by laser etching.
It effectively avoids the impact of solder overflow on chip performance, ensures that the solder will not leak during the solder, avoids product thrust and reliability problems caused by solder during subsequent soldering, and prevents chip position deviation.
Smart Images
Figure CN223023270U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of semiconductors, and particularly to a solder overflow drainage structure for an IGBT chip. Background Art
[0002] The welding process of an IGBT module chip is one of the key steps in IGBT module packaging, mainly including the following steps:
[0003] 1. Use a wafer mounter to mount the IGBT wafer and the tin sheet on a copper-clad ceramic substrate (DBC substrate). The IGBT chips on the wafer are automatically removed and placed on a fixed liner to form the circuit of the IGBT module.
[0004] 2. Vacuum reflow soldering (first time): Send the DBC substrate with the mounted wafer into a reflow furnace for heating and melting. Use electric heating, with a working temperature of approximately 245 °C and lasting for about 7 minutes. During the welding process, inject nitrogen into the furnace as a protective gas to ensure the welding quality.
[0005] 3. Non-destructive testing: Use an X-ray detection device to perform planar and three-dimensional imaging detection on the welded joint to check the internal welding effect, such as whether there are defects like voids.
[0006] 4. Wafer bonding and tinning on the one-piece pins: Use a bonder and bonding wires to connect the one-piece pins to the upper copper layer of the DBC substrate, and the DBC substrate to the bottom plate. This process uses a secondary soldering assembly machine to pre-tin the solder joints.
[0007] 5. Ultrasonic cleaning: Perform ultrasonic cleaning on the pins of the module, mainly to clean the residual rosin on the pins after welding.
[0008] 6. Vacuum reflow soldering (second time): After bonding, send the DBC substrate into the reflow furnace again for heating and melting to weld the DBC substrate to the copper substrate.
[0009] 7. Sealing: Assemble the semi-finished product and the housing using a dispensing and outer frame assembly machine, and use silicone sealant for dispensing.
[0010] 8. Ultrasonic welding: Use an ultrasonic welding device to weld the terminals to the semi-finished product. This is a friction welding method that does not use a soldering flux or welding materials.
[0011] 9. Potting and curing: Use a potting machine to pour silicone gel into the housing, and then use a curing machine for curing. The curing process is carried out under vacuum, and the silicone gel is cured by high temperature.
[0012] 10. Install the cover plate.
[0013] 11. Testing: Use testing instruments to ensure the performance and reliability of the IGBT module.
[0014] Wherein, when executing step 2, the chip is fixed on the copper clad sheet by vacuum heating. In this process, the solder is liquid and fluid during the heating process in a vacuum environment, and there is pressure from the chip above the solder, which may cause solder overflow. Solder overflow will cause solder under the aluminum wire during subsequent aluminum wire welding (bonding wire connection), resulting in the aluminum wire being unable to effectively combine with the copper clad sheet, causing product thrust failure or reliability failure. In addition, if the solder under the adjacent welded copper clad sheets overflows and circulates, the position of the chip itself will be offset during chip welding, causing product failure. Utility Model Content
[0015] A series of simplified concepts are introduced in the utility model content section, which are all simplifications of the prior art in the field, which will be further described in detail in the specific implementation section. The utility model content section of the utility model does not mean to attempt to define the key features and necessary technical features of the technical solution claimed for protection, nor does it mean to attempt to determine the scope of protection of the technical solution claimed for protection.
[0016] The technical problem to be solved by the utility model is to provide an IGBT chip solder overflow drainage structure which can prevent the solder overflow from affecting the device performance.
[0017] In order to solve the above technical problems, the utility model provides an IGBT chip solder overflow drainage structure, comprising:
[0018] A first drainage groove 1 is arranged around the soldering copper clad sheet 2 of the chip and is used to contain the solder overflowing during soldering;
[0019] One end of the second drainage groove 3 is connected to the first drainage groove 1 , and the groove depth gradually increases from the position connected to the first drainage groove 1 , and is used to accommodate the solder flowing out of the first drainage groove 1 .
[0020] Preferably, the IGBT chip solder overflow drainage structure is further improved, and the width of the first drainage groove 1 is greater than that of the second drainage groove 3. The first drainage groove 1 is arranged around the soldering copper clad sheet 2 of the chip with a large width, which is conducive to receiving the overflowed solder.
[0021] Preferably, the IGBT chip solder overflow drainage structure is further improved, and the second drainage groove 3 is connected to the first drainage groove 1 of the adjacent soldering copper clad sheet 2. The second drainage groove 3 serves as a redundant carrying space for the solder to prevent the first drainage groove 1 from overflowing.
[0022] Preferably, further improve the solder overflow drainage structure of the IGBT chip, and at least one second drainage groove 3 is formed on each side around the welded copper-clad sheet 2.
[0023] Preferably, further improve the solder overflow drainage structure of the IGBT chip. When there are at least two second drainage grooves 3 on the same side of the welded copper-clad sheet 2, at least one communication position is formed between the second drainage grooves 3 on the same side of the welded copper-clad sheet 2.
[0024] Preferably, further improve the solder overflow drainage structure of the IGBT chip, and at least one communication position is formed between the second drainage grooves 3 on different sides of the welded copper-clad sheet 2.
[0025] Preferably, further improve the solder overflow drainage structure of the IGBT chip, and the bottom wall of the second drainage groove 3 is formed as an arc surface, which is beneficial to the flow of solder.
[0026] Preferably, further improve the solder overflow drainage structure of the IGBT chip, and further include:
[0027] A third drainage groove 4, which is arranged around the first drainage groove 1 and forms a specified gap with the first drainage groove 1;
[0028] A second drainage groove 3, one end of which communicates with the second drainage groove 3 and the other end of which communicates with the third drainage groove 4;
[0029] Wherein, the depth of the second drainage groove 3 communicating with one side of the first drainage groove 1 is less than the depth of the side communicating with the third drainage groove 4, and the depth of the third drainage groove 4 is greater than that of the first drainage groove 1.
[0030] The first to third drainage grooves of the present invention can be formed on the substrate around the chip by laser ray etching.
[0031] In order to avoid the influence of the overflowing solder on the chip performance, the present invention designs a first drainage groove around the welded copper-clad sheet 2, and the first drainage groove is used to collect the overflowing solder. When arranged around the chip, there will be no solder leakage point.
[0032] The second drainage groove of the present invention is used to redundant the solder that may overflow from the first drainage groove, that is, to prevent the situation where the first drainage groove is filled with solder. The second drainage groove can be arranged according to actual needs to provide as much redundant solder accommodation space as possible.
[0033] The third drainage groove of the present utility model is arranged around the first drainage groove, providing a second line of defense against solder overflow in all directions. The second drainage groove is connected between the first drainage groove and the third drainage groove to communicate the first drainage groove and the third drainage groove. In order to avoid the functional area, the layout of the second drainage groove can be relatively flexible, and even arranged in a mesh shape. Such a design of the first to third drainage grooves provides a large amount of solder accommodation space, fundamentally solving the problem of the impact of solder overflow on the chip performance.
[0034] Correspondingly, the positions, depths, and shapes of the first to third drainage grooves can be well controlled by laser ray etching to achieve the expected effect. Description of the Drawings
[0035] The drawings of the present utility model are intended to show the general characteristics of the methods, structures, and / or materials used in specific exemplary embodiments according to the present utility model, supplementing the descriptions in the specification. However, the drawings of the present utility model are schematic diagrams not drawn to scale, and thus may not accurately reflect the precise structures or performance characteristics of any given embodiment. The drawings of the present utility model should not be construed as limiting or restricting the scope of the numerical values or properties covered by the exemplary embodiments according to the present utility model. The present utility model will be further described in detail below in conjunction with the drawings and specific embodiments:
[0036] Figure 1 It is a schematic structural diagram of the first embodiment of the present utility model.
[0037] Figure 2 It is a schematic structural diagram of the second embodiment of the present utility model.
[0038] Figure 3 It is a schematic structural diagram of the third embodiment of the present utility model.
[0039] Figure 4 It is a schematic structural diagram of the fourth embodiment of the present utility model.
[0040] Description of the Reference Numerals in the Drawings
[0041] The first drainage groove 1
[0042] The soldering copper clad 2
[0043] The second drainage groove 3
[0044] The third drainage groove 4. Detailed Description of the Embodiments
[0045] The following describes the implementation manners of the present utility model through specific embodiments. Those skilled in the art can fully understand other advantages and technical effects of the present utility model from the content disclosed in this specification. The present utility model can also be implemented or applied through different specific implementation manners. The details in this specification can also be applied based on different viewpoints, and various modifications or changes can be made without departing from the overall design concept of the utility model. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other. The following exemplary embodiments of the present utility model can be implemented in many different forms and should not be construed as being limited only to the specific embodiments described herein. It should be understood that these embodiments are provided to make the disclosure of the present utility model thorough and complete, and to fully convey the technical solutions of these exemplary specific embodiments to those skilled in the art. It should be understood that when an element is referred to as being "connected" or "coupled" to another element, the element can be directly connected or coupled to the other element, or there can be an intermediate element. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there is no intermediate element. In all the drawings, the same reference numerals always represent the same elements.
[0046] The first embodiment;
[0047] Referring to Figure 1 as shown, the present utility model provides an IGBT chip solder overflow drainage structure, including:
[0048] The first drainage groove 1, which is arranged around the welding copper clad 2 of the chip and is used to accommodate the solder that overflows and flows out during welding;
[0049] It should be noted that the shape and size of the welding copper clad 2 are determined by the chip to be welded. Therefore, the lengths of the first drainage grooves 1 may be different on the same substrate; if conditions permit, the first drainage groove 1 is preferably closer to the edge of the welding copper clad 2. Preferably, the distance between the first drainage groove 1 and the welding copper clad 2 is 0.5 mm to 2 mm;
[0050] The second drainage groove 3, one end of which is communicated with the first drainage groove 1, and the groove depth gradually increases from the position where it is connected to the first drainage groove 1, and is used to accommodate the solder flowing out of the first drainage groove 1.
[0051] It should be noted that since the drainage grooves are made by laser etching, the direction and depth of the drainage grooves are easy to control. The orientation of the second drainage groove 3 can be arranged according to the positions of other welding copper clads 2 adjacent to the welding copper clad 2 surrounded by the first drainage groove 1, and the length of the second drainage groove 3 is extended as much as possible, so as to be able to accommodate more overflowing solder.
[0052] Preferably, when there is only one second drainage groove 3 on one side of the first drainage groove 1, the position where the second drainage groove 3 connects with the first drainage groove 1 is at the center of the first drainage groove 1 on the connecting side.
[0053] Preferably, the first embodiment is further improved, and the width of the first drainage groove 1 is greater than that of the second drainage groove 3. The first drainage groove 1 is arranged around the soldering copper clad sheet 2 of the chip with a large width, which is conducive to receiving the overflowed solder.
[0054] Furthermore, the second drainage groove 3 may be curved or inclined, and is not limited to a straight groove.
[0055] In addition, it should be understood that, although the terms "first", "second", etc. can be used here to describe different elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the exemplary embodiments of the present utility model, the first element, component, region, layer or part discussed below may also be referred to as the second element, component, region, layer or part.
[0056] Second embodiment;
[0057] refer to Figure 2 As shown, the utility model provides an IGBT chip solder overflow drainage structure, comprising:
[0058] A first drainage groove 1 is arranged around the soldering copper clad sheet 2 of the chip and is used to contain the solder overflowing during soldering;
[0059] It should be noted that the shape and size of the soldering copper clad sheet 2 are determined according to the soldering chip, so the lengths of the first drainage grooves 1 may be different on the same substrate; if conditions permit, the closer the first drainage grooves 1 are to the edge of the soldering copper clad sheet 2, the better. Preferably, the distance between the first drainage grooves 1 and the soldering copper clad sheet 2 is 0.5 mm to 2 mm;
[0060] One end of the second drainage groove 3 is connected to the first drainage groove 1 , and the groove depth gradually increases from the position connected to the first drainage groove 1 , and is used to accommodate the solder flowing out of the first drainage groove 1 .
[0061] The second drainage groove 3 is connected to the first drainage groove 1 of the adjacent welded copper clad sheet 2 .
[0062] Preferably, the second embodiment is further improved, and at least one second drainage groove 3 is formed on each side around the welding copper cladding sheet 2 .
[0063] Third embodiment;
[0064] Reference Figure 3 As shown, the present utility model provides a solder overflow drainage structure for an IGBT chip, including:
[0065] The first drainage groove 1, which is arranged around the welding copper cladding 2 of the chip, and is used to accommodate the solder that overflows and flows out during welding;
[0066] It should be noted that the shape and size of the welding copper cladding 2 are determined according to the chip to be welded, so the lengths of the first drainage grooves 1 may be different on the same substrate; if conditions permit, the first drainage groove 1 is preferably closer to the edge of the welding copper cladding 2. Preferably, the distance between the first drainage groove 1 and the welding copper cladding 2 is 0.5 mm to 2 mm;
[0067] The second drainage groove 3, one end of which is connected to the first drainage groove 1, and the groove depth gradually increases from the position where it is connected to the first drainage groove 1, and is used to accommodate the solder flowing out of the first drainage groove 1.
[0068] The second drainage groove 3 is connected to the first drainage groove 1 of the adjacent welding copper claddings 2. When there are at least two second drainage grooves 3 on the same side of the welding copper cladding 2, there is at least one communication position formed between the second drainage grooves 3 on the same side of the welding copper cladding 2.
[0069] Exemplarily, the second drainage groove 3 can form an interlaced network shape between adjacent welding copper claddings 2.
[0070] Preferably, further improving the third embodiment, there is at least one communication position formed between the second drainage grooves 3 on different sides of the welding copper cladding 2.
[0071] Exemplarily, the second drainage groove 3 can form an interlaced network shape between different sides of the same welding copper cladding 2.
[0072] Fourth embodiment;
[0073] Reference Figure 4 As shown, the present utility model provides a solder overflow drainage structure for an IGBT chip, including:
[0074] The first drainage groove 1, which is arranged around the welding copper cladding 2 of the chip, and is used to accommodate the solder that overflows and flows out during welding;
[0075] It should be noted that the shape and size of the welding copper cladding 2 are determined according to the chip to be welded, so the lengths of the first drainage grooves 1 may be different on the same substrate; if conditions permit, the first drainage groove 1 is preferably closer to the edge of the welding copper cladding 2. Preferably, the distance between the first drainage groove 1 and the welding copper cladding 2 is 0.5 mm to 2 mm;
[0076] The second drainage groove 3, one end of which is connected to the first drainage groove 1, has a gradually increasing groove depth starting from the position where it is connected to the first drainage groove 1, and is used to accommodate the solder flowing out of the first drainage groove 1.
[0077] The second drainage groove 3 is connected to the first drainage groove 1 of the adjacent soldering copper clad 2. When there are at least two second drainage grooves 3 on the same side of the soldering copper clad 2, there is at least one communication position formed between the second drainage grooves 3 on the same side of the soldering copper clad 2.
[0078] Exemplarily, the second drainage groove 3 can form a staggered network shape between adjacent soldering copper clads 2.
[0079] Preferably, further improving the third embodiment, there is at least one communication position formed between the second drainage grooves 3 on different sides of the soldering copper clad 2.
[0080] Exemplarily, the second drainage groove 3 can form a staggered network shape between different sides of the same soldering copper clad 2.
[0081] Further included:
[0082] The third drainage groove 4 is arranged around the first drainage groove 1, and a specified gap is formed between it and the first drainage groove 1;
[0083] The second drainage groove 3, one end of which is connected to the second drainage groove 3, and the other end is connected to the third drainage groove 4;
[0084] Wherein, the depth of the side of the second drainage groove 3 connected to the first drainage groove 1 is less than the depth of the side connected to the third drainage groove 4, and the depth of the third drainage groove 4 is greater than that of the first drainage groove 1.
[0085] It should be noted that the third drainage groove 4 is for redundant overflow and is connected to the first drainage groove 1 through the second drainage groove 3. Therefore, the position requirement of the third drainage groove 4 is not strictly restricted, the width and depth requirements of the third drainage groove 4 are not strictly restricted, and the distance between the third drainage groove 4 and the first drainage groove 1 is not strictly restricted but the closer the better, as long as it is arranged at a reasonable position in the non-functional area around the soldering copper clad 2 it surrounds.
[0086] Correspondingly, the third drainage groove 4 may not be provided around the soldering copper clad 2 with a smaller area. Since the solder of the soldering copper clad 2 with a smaller area is less, the third drainage groove 4 may not be provided.
[0087] Preferably, further improving the above first to fourth embodiments, the bottom wall of the second drainage groove 3 is formed as an arc surface, and the arc surface is beneficial to the flow of solder.
[0088] Unless otherwise defined, all terms used herein, including technical and scientific terms, shall have the same meaning as commonly understood by one of ordinary skill in the art to which this utility model pertains. It will also be understood that terms such as those defined in a general dictionary shall be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and shall not be interpreted in an idealized or overly formal sense, unless expressly defined herein.
[0089] The above has described this utility model in detail through specific implementation manners and examples, but these do not constitute a limitation to this utility model. Without departing from the principle of this utility model, those skilled in the art can also make many variations and improvements, which should also be regarded as the protection scope of this utility model.
Claims
1. An IGBT chip solder overflow drainage structure, characterized in that: include: A first drainage groove (1) is arranged around the soldering copper clad sheet (2) of the chip and is used to contain solder that overflows and flows out during soldering; The second drainage groove (3) has one end connected to the first drainage groove (1), and its groove depth gradually increases from the position connected to the first drainage groove (1), and is used to accommodate solder flowing out of the first drainage groove (1).
2. The IGBT chip solder overflow drainage structure according to claim 1, characterized in that: The width of the first drainage groove (1) is greater than that of the second drainage groove (3).
3. The IGBT chip solder overflow drainage structure according to claim 1, characterized in that: The second drainage groove (3) is connected to the first drainage groove (1) of the adjacent welded copper clad sheet (2).
4. The IGBT chip solder overflow drainage structure according to claim 1, characterized in that: At least one second drainage groove (3) is formed on each side around the welding copper clad sheet (2).
5. The IGBT chip solder overflow drainage structure according to claim 4, characterized in that: When at least two second drainage grooves (3) are present on the same side of the welded copper-clad sheet (2), at least one connecting position is formed between the second drainage grooves (3) on the same side of the welded copper-clad sheet (2).
6. The IGBT chip solder overflow drainage structure according to claim 4, characterized in that: The second drainage grooves (3) on different sides of the welded copper-clad sheet (2) form at least one connecting position with each other.
7. The IGBT chip solder overflow drainage structure according to claim 1, characterized in that: The bottom wall of the second drainage groove (3) is formed as an arc surface.
8. The IGBT chip solder overflow drainage structure according to claim 1, characterized in that: Also includes: a third drainage groove (4), which is arranged around the first drainage groove (1) and forms a specified gap between the third drainage groove (4) and the first drainage groove (1); A second drainage groove (3), one end of which is connected to the second drainage groove (3), and the other end of which is connected to the third drainage groove (4); The depth of the second drainage groove (3) connected to the first drainage groove (1) is less than the depth of the second drainage groove (3) connected to the third drainage groove (4), and the depth of the third drainage groove (4) is greater than the first drainage groove (1).