Internal insulation metal frame

Abstract

The utility model relates to the field of electronic packaging, in particular to an internal insulation metal frame, which comprises radiating fins and a metal frame. By arranging the cooling fins made of the aluminum substrate, the heat conductivity coefficient of aluminum is high, the price is relatively low, the heat conduction efficiency can be remarkably improved, and the production cost is reduced. The grooves are formed in the bottoms of the cooling fins, and the protruding rods are inserted into the grooves, so that the connecting effect is achieved, assembling steps are reduced, the contact area is increased, thermal resistance is reduced, and the cooling effect is further improved. The copper foil layer is arranged on the outer side of the insulating layer, and the heat conductivity coefficient of copper is very high, so that heat can be quickly conducted from the interior of the metal frame to the external cooling fins. The problems of poor heat dissipation effect and relatively high cost due to the fact that electrical insulation between the existing lead frame and the heat dissipation sheet is realized through a built-in ceramic sheet are solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to electronic packaging technical field especially an inner insulation metal frame. BACKGROUND

[0002] In modern electronic devices, especially in high-power and high-performance application scenarios, such as power management ICs, power modules, and radio frequency devices, thermal management is a key factor to ensure device reliability and performance. In order to effectively dissipate heat, a design combining copper heat sinks and metal lead frames is usually used. However, the existing design often achieves electrical insulation between the lead frame and the copper heat sink through an embedded ceramic sheet. Although this method can provide some electrical isolation, it has the problems of general heat dissipation effect and high cost. Specifically, the thermal conductivity of ceramic materials (usually between 20-30 W / m·K) is relatively low, much lower than that of copper (about 400 W / m·K) or aluminum (about 200 W / m·K), which limits the overall system's heat dissipation capacity. In addition, the embedded ceramic sheet requires a copper frame to fix the ceramic sheet, increasing the number of components and requiring additional processing steps, increasing production difficulty and process complexity, resulting in a significant increase in manufacturing cost.

[0003] Therefore, there is an urgent need for an inner insulation metal frame with strong heat dissipation effect and low cost. SUMMARY

[0004] To solve the problem of poor heat dissipation effect and high cost of electrical insulation between the existing lead frame and the heat sink through an embedded ceramic sheet.

[0005] The utility model provides an inner insulation metal frame, which comprises a heat sink and a metal frame. The heat sink is made of an aluminum substrate. The bottom of the heat sink is provided with a groove. An insulating layer is arranged in the heat sink and the groove. A solder resist layer and a copper foil are arranged on the outer side of the insulating layer. The top of the metal frame is provided with a protruding rod and a support rod. The protruding rod is inserted into the groove, and the support rod is located on both sides of the protruding rod.

[0006] Preferably, the insulating layer is one of aluminum nitride or silicon nitride.

[0007] Preferably, the thickness of the insulating layer is 25μm~50μm.

[0008] Preferably, the solder resist layer is one of solder resist ink or liquid photosensitive solder resist.

[0009] Preferably, the thickness of the solder resist layer is 10μm~30μm.

[0010] Preferably, the metal frame has three pins. One pin is connected to the bottom end of the protruding rod, and the other two pins are connected to the bottom end of the support rod.

[0011] Preferably, the thickness of the copper foil is equal to the thickness of the solder resist layer.

[0012] The beneficial effects of this invention are as follows: by using a heat sink made of an aluminum substrate, which has a high thermal conductivity and is relatively inexpensive, heat transfer efficiency can be significantly improved, reducing production costs. The bottom of the heat sink has a groove into which a protruding rod is inserted, serving both as a connector and reducing assembly steps, while also increasing the contact area, reducing thermal resistance, and further improving heat dissipation. A copper foil layer is placed on the outside of the insulation layer; copper has a very high thermal conductivity, which helps to quickly conduct heat from the inside of the metal frame to the external heat sink. This solves the problem of poor heat dissipation and high cost associated with existing lead frames and heat sinks that rely on built-in ceramic sheets for electrical insulation. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of a combined structure of an internally insulated metal frame provided by this utility model.

[0014] Figure 2 This is a schematic diagram of the detachable structure of an internal insulating metal frame provided by this utility model.

[0015] Figure 3 This is a cross-sectional structural diagram of an internally insulating metal frame provided by this utility model.

[0016] Figure 4 for Figure 3 Enlarged view of point A in the middle.

[0017] Figure 5 This is a schematic diagram of the structure of the traditional metal wire frame and heat sink copper sheet provided by this utility model.

[0018] Figure 6 This is a cross-sectional view of the conventional metal wire frame and heat dissipation copper sheet provided by this utility model.

[0019] In the diagram: 1-Heat sink; 11-Groove; 12-Insulation layer; 13-Solder resist layer; 14-Copper foil; 2-Metal frame; 21-Protruding rod; 22-Support rod; 3-Copper heat sink; 4-Ceramic plate; 5-Copper frame; 6-Metal wire frame. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] Reference Figures 1-4An internally insulated metal frame 2 includes a heat sink 1 and a metal frame 2; the heat sink 1 is made of an aluminum substrate, and a groove 11 is provided at the bottom of the heat sink 1. An insulating layer 12 is provided inside the heat sink 1 and the groove 11. A solder resist layer 13 and a copper foil 14 are provided on the outside of the insulating layer 12; a protruding rod 21 and a support rod 22 are provided at the top of the metal frame 2. The protruding rod 21 is inserted into the groove 11, and the support rod 22 is located on both sides of the protruding rod 21.

[0022] and Figures 5-6 Compared to traditional metal wire frames 6 and heat sink copper fins 3, the inner insulating metal frame 2 incorporates a heat sink 1 made of an aluminum substrate. Aluminum has a high thermal conductivity and is relatively inexpensive, significantly improving heat transfer efficiency and reducing production costs. The bottom of the heat sink 1 has a groove 11 into which a protruding rod 21 is inserted, serving both as a connector and reducing assembly steps. This also increases the contact area, reduces thermal resistance, and further improves heat dissipation. A copper foil layer 14 is placed on the outside of the insulation layer 12. Copper has a very high thermal conductivity, facilitating rapid heat transfer from the inside of the metal frame 2 to the external heat sink 1. This solves the problem of poor heat dissipation and high cost associated with existing lead frames and heat sinks that rely on internal ceramic plates 4 for electrical insulation.

[0023] In some embodiments, the insulating layer 12 is either aluminum nitride or silicon nitride.

[0024] Aluminum nitride and silicon nitride have high thermal conductivity, which significantly improves heat dissipation and ensures that devices operate within a safe temperature range. Furthermore, they possess excellent electrical insulation properties, ensuring electrical isolation and safety. In addition, both aluminum nitride and silicon nitride can be coated using various processes, and the thickness can be flexibly adjusted according to actual needs, facilitating processing.

[0025] Preferably, the thickness of the insulating layer 12 is 25μm to 50μm.

[0026] Reference Figure 4 The insulation layer 12 is selected with a thickness range of 25μm to 50μm to provide high thermal conductivity and good electrical insulation properties.

[0027] In some embodiments, the solder resist layer 13 is one of solder resist ink or liquid photosensitive solder resist.

[0028] Both solder resist inks and liquid photoresist can effectively prevent short circuits during the soldering process and provide basic electrical insulation and physical protection. Solder resist inks are less expensive and can be applied via screen printing or spraying, making the process simple and easy to control. Liquid photoresist is suitable for more complex patterning and can be achieved through multiple coatings and photolithography processes, ensuring the uniformity and consistency of the coating.

[0029] Preferably, the thickness of the solder resist layer 13 is 10μm to 30μm.

[0030] Reference Figure 4 The solder resist layer 13 is selected with a thickness range of 10μm to 30μm, which reduces thermal resistance and facilitates heat conduction while providing sufficient electrical insulation performance.

[0031] In some embodiments, the metal frame 2 has three pins, one of which is connected to the bottom end of the protrusion 21, and the other two pins are connected to the bottom end of the support rod 22.

[0032] Reference Figure 2 The protruding rod 21 and the support rod 22 ensure that the metal frame 2 will not shift or loosen during installation or use; the three pins evenly distribute stress, reduce local stress concentration, and extend the service life of the metal frame 2.

[0033] In some embodiments, the thickness of the copper foil 14 is equal to the thickness of the solder resist layer 13.

[0034] Reference Figure 4 The equal thickness of the copper foil 14 and solder resist layer 13 ensures the flatness and consistency of the circuit board surface, reducing stress concentration problems caused by thickness differences. It also makes the manufacturing process easier to control, reducing process complexity and variables, and improving yield and quality stability.

[0035] In the description of the embodiments of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "assembly" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0036] In the description of the embodiments of this utility model, specific features, structures, materials or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0037] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An internally insulated metal frame, characterized in that: include: The heat sink is made of an aluminum substrate and has a groove at the bottom. The interior of the heat sink and the interior of the groove are both lined with an insulating layer. The outside of the insulating layer is lined with a solder resist layer and copper foil. The metal frame has a protruding rod and a support rod at the top. The protruding rod is inserted into a groove, and the support rod is located on both sides of the protruding rod.

2. The internally insulated metal frame according to claim 1, characterized in that: The insulating layer is either aluminum nitride or silicon nitride.

3. The internally insulated metal frame according to claim 2, characterized in that: The thickness of the insulating layer is 25μm~50μm.

4. The internally insulated metal frame according to claim 1, characterized in that: The solder resist layer is one of solder resist ink or liquid photosensitive solder resist agent.

5. The internally insulated metal frame according to claim 4, characterized in that: The thickness of the solder resist layer is 10μm~30μm.

6. The internally insulated metal frame according to claim 1, characterized in that: The metal frame has three pins, one of which is connected to the bottom of the protruding rod, and the other two pins are connected to the bottom of the support rod.

7. The internally insulated metal frame according to claim 1, characterized in that: The thickness of the copper foil is equal to the thickness of the solder resist layer.

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