Integrally-formed glue pouring clamp

Abstract

The utility model relates to the field of semiconductor packaging, in particular to an integrally-formed glue pouring clamp. The clamp comprises an upper clamping plate, a sealing gasket and a lower clamping plate, a first groove structure is arranged in the upper clamping plate, and the sealing gasket and the upper clamping plate are matched to form a die cavity. An ejection hole is formed in the sealing gasket, and an ejection hole is also formed in the position corresponding to the lower clamping plate, so that the product is conveniently taken out. In addition, a hollow square sealing ring is arranged between the sealing gasket and the upper clamping plate, a secondary groove structure is formed, the sealing effect is further enhanced, the glue pouring clamp is of a combined structure, and a plurality of clamps can be spliced into a group for glue pouring. According to the utility model, the problems of glue overflow, glue permeation and difficulty in taking out products in the traditional glue pouring process without shell packaging are solved, and the glue pouring efficiency and the product quality are improved.

Description

Technical Field

[0001] The utility model relates to the field of semiconductor packaging, in particular to an integrated molding type glue potting fixture. Background Art

[0002] Traditional IGBT power modules and MOS modules use epoxy resin or sealant injected into the plastic housing to protect the internal components and isolate the chip, leads, and electrodes from the outside. However, this sealant has a low hardness, a certain degree of ductility and fluidity, and cannot be naturally molded, so a housing is required. Modules encapsulated in this way are suitable for most standalone applications, such as motor drives and electronic pumps. However, for some specialized applications, such as internal applications, the module must be combined with other components to form a unified component.

[0003] First, this module equipped with an outer frame and a base plate is not easy to install and use in a customized environment. Second, the existing technology requires an outer frame and a base plate, but the larger the outer shell is, the greater the weight and volume of the product. This affects the integration and makes it difficult to combine and assemble with other devices. On the other hand, it increases the cost of the product. Third, when injecting the colloid into the outer shell, vacuum degassing is difficult, time-consuming, and inefficient.

[0004] To achieve a caseless package, challenges such as silicone gel strength and hardness, as well as issues with the glue potting fixture, needed to be addressed. First, a silicone gel suitable for this package format needed to be found, with appropriate dosage and proportions, and a suitable glue potting process to meet the requirements. Second, implementing glue potting without a case also required addressing glue overflow and residual glue cleanup, necessitating the development and design of a dedicated fixture.

[0005] The original design of the glue potting fixture had only two clamping plates to contact and fix the product to be packaged, and the bottom was a sealed structure. Therefore, after the product was glued, it was difficult to remove the product, and a lot of glue overflowed from the heat dissipation surface of the product. Therefore, glue potting was achieved without a shell, and there were still problems such as glue overflow during the potting process and the problem of using a glue potting fixture to remove the product. Utility Model Content

[0006] The utility model provides an integrated molding glue potting fixture which uses only silicone gel to encapsulate components without using a plastic shell and a copper bottom plate, so as to realize naked sealing of the module and solve the problem that the encapsulated module is easy to overflow with glue and difficult to remove.

[0007] In order to achieve the purpose of this utility model, the present invention adopts the following scheme:

[0008] It includes a lower splint, a sealing gasket and an upper splint; the sealing gasket is arranged between the upper splint and the lower splint; a first groove structure is provided in the upper splint to form a mold cavity with the sealing gasket for placing the product to be glued; at least one sealing gasket ejection hole is provided in the area of ​​the sealing gasket corresponding to the first groove structure of the upper splint, and a lower splint ejection hole is provided at the position of the lower splint corresponding to the sealing gasket ejection hole.

[0009] Furthermore, it also includes a sealing ring, which is arranged between the sealing gasket and the upper clamping plate. The sealing ring includes a second groove structure to form a mold cavity with the sealing gasket and the first groove structure to accommodate the product to be glued.

[0010] Furthermore, the lower splint is provided with a groove, and the lower splint ejection hole is located in the groove.

[0011] Furthermore, sliding grooves are respectively provided on both sides of the first groove structure of the upper clamping plate, and a chip pin guide groove is provided on one side of the bottom of the sliding groove close to the first groove structure.

[0012] Furthermore, the upper clamping plate, the sealing gasket and the lower clamping plate are provided with through fixing holes for assembly and connection.

[0013] Preferably, the sealing gasket is a polyurethane plate or a Teflon plate.

[0014] Furthermore, the upper plate and the lower plate are both metal plates.

[0015] Preferably, the surface of the metal splint is covered with a polytetrafluoroethylene coating, a perfluoroalkoxy polymer coating or a silicone coating.

[0016] Furthermore, the glue pouring fixture is a combined structure, and multiple fixtures can be spliced ​​into a group for glue pouring.

[0017] Furthermore, the combined structure includes a connection gasket clamped between the upper and lower clamping plates when the upper and lower clamping plates are bolted together, or a frame for bolting the fixing holes.

[0018] The utility model can realize the packaging of the module without the outer frame and base plate through the design of the glue pouring fixture, simplify the structure of the device and reduce the product cost; the design of the sealing gasket solves the problem of glue overflow in the traditional module; the design of the glue pouring fixture solves the problem that the product is difficult to remove after packaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a front assembly diagram of the glue pouring fixture according to an embodiment of the present utility model;

[0020] Figure 2 Rear assembly diagram of the glue pouring fixture according to the embodiment of the utility model;

[0021] Figure 3This is a diagram of a glue-filling fixture assembly according to an embodiment of the present utility model;

[0022] Figure 4 This is a schematic diagram of the combined structure of the glue pouring fixture according to an embodiment of the present utility model.

[0023] In the above drawings:

[0024] 1. Upper splint; 2. Lower splint; 3. Sealing gasket; 4. First groove structure; 5. Mold cavity; 6. Sealing gasket ejection hole; 7. Lower splint ejection hole; 8. Sealing ring; 9. Second groove structure; 10. Groove; 11. Slide groove; 12. Chip pin guide groove; 13. Fixing hole; 14. Fixing bolt; 15. Nut. DETAILED DESCRIPTION

[0025] The following describes in detail embodiments of the present invention, examples of which are shown in the accompanying drawings. The exemplary embodiments can be implemented in various forms and should not be construed as limited to the examples set forth herein. On the contrary, these embodiments are provided to make the present invention more comprehensive and complete and to fully convey the concepts of the exemplary embodiments to those skilled in the art. The same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0026] In the description of the present invention, it should be noted that, unless otherwise clearly stipulated and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it 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, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] The front assembly diagram of the glue potting fixture provided in this embodiment is as follows Figure 1 As shown, it includes a lower splint 2, a sealing gasket 3 and an upper splint 1; the sealing gasket 3 is arranged between the upper splint 1 and the lower splint 2; a first groove structure 4 is provided in the upper splint 1 to form a mold cavity 5 for placing the product to be glued together with the sealing gasket 3; at least one sealing gasket ejection hole 6 is provided in the area of ​​the sealing gasket 3 corresponding to the first groove structure 4 of the upper splint 1, and a lower splint ejection hole 7 is provided at the position of the lower splint 2 corresponding to the sealing gasket ejection hole 6.

[0028] This embodiment also includes a sealing ring 8, which is arranged between the sealing gasket 3 and the upper splint 1. The sealing ring 8 includes a second groove structure 9 to form a mold cavity 5 with the sealing gasket 3 and the first groove structure 4 to accommodate the product to be glued. The design of the sealing ring 8 takes into account the height of the glue pouring, and uses the height of the clamp to limit the height of the glue, so that glue will not climb onto the product pins, ensuring that the pins are clean and easy to solder. Through the design of the sealing gasket 3, the utility model ensures that the heat dissipation surface of the product is in close contact with the bottom of the clamp, thereby preventing glue seepage and leakage, and solving the problem of glue overflow in traditional modules. The design of the sealing ring 8 takes into account the height of the glue pouring, and uses the height of the clamp to limit the height of the glue, so that glue will not climb onto the product pins, ensuring that the pins are clean and easy to solder.

[0029] In this embodiment, the lower clamping plate 2 is provided with a groove 10, and the ejection hole 6 of the lower clamping plate 2 is located in the groove 10. The first groove structure 4 of the upper clamping plate 1 is provided with a slide groove 11 on both sides, and the bottom of the slide groove 11 is provided with a chip pin guide groove 12 on the side close to the first groove structure 4. The upper clamping plate 1, sealing gasket 3 and lower clamping plate 2 are provided with a through-hole 13 for assembly connection.

[0030] In this embodiment, the sealing gasket 3 and the sealing ring 8 are made of polyurethane sheets, which can also be replaced with Teflon sheets. The metal plates used for the upper and lower clamping plates 1 and 2 are both P20 mold steel plates. The surfaces of the metal plates are covered with a polytetrafluoroethylene coating to prevent the silicone gel from adhering to the fixture surface during the injection and curing process, facilitating cleaning and reuse of the fixture. In other embodiments, the polytetrafluoroethylene coating can be replaced with a perfluoroalkoxy polymer coating or a silicone coating.

[0031] In this embodiment, the glue pouring fixture is a combined structure, and multiple fixtures can be spliced ​​into a group for glue pouring. The glue pouring fixture is a combined structure such as Figure 4 shown.

[0032] The combined structure includes a connection gasket clamped between the upper and lower clamping plates when the upper clamping plate 1 and the lower clamping plate 2 are connected by the fixing bolts 14. In another embodiment, the frame with the fixing holes 13 is connected by the fixing bolts 14 to splice and perform combined glue filling.

[0033] In this embodiment, the steps of using the glue potting fixture to perform glue potting on the module package are as follows:

[0034] The glue pouring fixture assembly diagram of the utility model embodiment is as follows Figure 3 As shown, the groove 10 of the lower splint 2 faces downward and is placed at the bottom to play a supporting role. Then, the sealing gasket 3 is placed on the lower splint 2. According to the fixing holes 13 (also screw holes) on the lower splint 2 and the sealing gasket 3, the sealing gasket 3 and the lower splint 2 are aligned.

[0035] Place the sealing ring 8 on the sealing gasket 3 and align the bottom sealing gasket 3 and the sealing ring 8 according to their corresponding fixing holes 13. The thickness of the sealing ring 8 used in this embodiment is generally the thickness of the sealant.

[0036] Place the product to be packaged after completing the previous processes (chip welding, wire bonding and electrode welding) into the half-assembled fixture above, with the ceramic substrate of the product facing down and the pins facing up; when the product is placed flat and its position matches the mold cavity 5, the back of the product will be attached to the sealing ring 8 at the bottom of the fixture. After tightening the fixing bolts 14, the two surfaces will fit tightly together, thus preventing glue leakage and seepage, and ensuring that the back of the product is clean and glue-free.

[0037] Put the upper clamp 1 on the fixture with the product on it, with the side of the chip pin guide groove 12 in the slide groove 11 of the upper clamp 1 facing downward, press the product pins with the pressure plate, and check whether the four corner positioning holes coincide with the positions of the sealing ring 8 below and the lower clamp 2; insert the four fixing bolts 14 into the fixing holes 13, and after the fixing bolts 14 pass through the clamp, screw on the nuts 15 at the bottom of the clamp to tighten it.

[0038] After the entire assembly process is completed, the glue filling, degassing and curing operations are carried out in sequence. After curing is completed, the fixing bolts 14 are removed first, and then the upper splint 1 is removed and the product can be taken out. If the product is inconvenient to take out, you can use a push rod or your fingers (gloves must be worn) to push from the bottom of the lower splint 2 to smoothly take out the product. If the product is stuck to the sealing gasket 3 at this time, you can directly use a push rod or your fingers (gloves must be worn) to push the product out of the sealing gasket 3 through the ejection hole 6 to separate the product and the sealing gasket 3.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. An integrated molding glue-filling fixture, characterized in that: It includes a lower splint, a sealing gasket and an upper splint; The sealing gasket is arranged between the upper splint and the lower splint; a first groove structure is provided in the upper splint to form a mold cavity with the sealing gasket for placing the product to be poured with glue; the sealing gasket is provided with at least one sealing gasket ejection hole in the area corresponding to the first groove structure of the upper splint, and a lower splint ejection hole is provided in the position of the lower splint corresponding to the sealing gasket ejection hole.

2. The one-piece molding glue-potting fixture according to claim 1, characterized in that: It also includes a sealing ring, which is arranged between the sealing gasket and the upper clamping plate. The sealing ring includes a second groove structure to form a mold cavity with the sealing gasket and the first groove structure to accommodate the product to be glued.

3. The one-piece molding glue-potting fixture according to claim 1, characterized in that: The lower clamping plate is provided with a groove, and the lower clamping plate ejection hole is located in the groove.

4. The one-piece molding glue-potting fixture according to claim 1, characterized in that: Slide grooves are respectively provided on both sides of the first groove structure of the upper clamping plate, and a chip pin guide groove is provided on the side of the bottom of the slide groove close to the first groove structure.

5. The one-piece molding glue-potting fixture according to claim 1, characterized in that: The upper clamping plate, the sealing gasket and the lower clamping plate are provided with through fixing holes for assembly and connection.

6. The one-piece molding glue-potting fixture according to claim 2, characterized in that: The sealing gasket is a polyurethane plate or a Teflon plate.

7. The one-piece molding glue-potting fixture according to claim 1, characterized in that: The upper clamping plate and the lower clamping plate are both metal clamping plates.

8. The one-piece molding glue-potting fixture according to claim 7, characterized in that: The surface of the metal splint is covered with a polytetrafluoroethylene coating, a perfluoroalkoxy polymer coating or a silicone coating.

9. The one-piece molding glue-potting fixture according to claim 1, characterized in that: The glue pouring fixture is a combined structure, and multiple fixtures can be spliced ​​into a group for glue pouring.

10. The one-piece molding glue-potting fixture according to claim 9, characterized in that: The combined structure includes a connection gasket clamped between the upper and lower clamping plates when the upper and lower clamping plates are connected by bolts, or a frame for bolting the fixing holes.

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