CN117855165A - Low-thermal-resistance double-sided metal heat dissipation TO247 structure and preparation method thereof - Google Patents

Abstract

The present invention provides a low thermal resistance double-sided metal heat dissipation TO247 structure and a preparation method, which relates to the field of chip packaging technology, including a metal frame, a chip, a heat-conducting component and a plastic package, the metal frame includes a wafer stage and a plurality of pins, the chip is arranged on the surface of the wafer stage, and the side of the wafer stage away from the chip is arranged as a first metal exposed surface, the heat-conducting component includes a metal block and a copper clip, the metal block is arranged on the side of the chip away from the metal frame, and the copper clip is arranged on the side of the metal block away from the chip, the plastic package wraps the chip, the wafer stage, the metal block and the copper clip, and the side of the copper clip away from the metal block is arranged as a second metal exposed surface. In the present invention, the heat generated by the chip can be transferred to the copper clip through the metal block, and the heat is extracted by the second metal exposed surface of the copper clip, and the second metal exposed surface of the copper clip and the first metal exposed surface jointly dissipate heat, thereby reducing the packaging thermal resistance of the TO247 structure and improving the heat transfer efficiency.

Description

Low thermal resistance double-sided metal heat dissipation TO247 structure and preparation method

Technical Field

The invention relates to the technical field of chip packaging, and in particular to a low thermal resistance double-sided metal heat dissipation TO247 structure and a preparation method thereof.

Background technique

TO247 package is a reliable, stable and efficient electronic component packaging form, which is widely used in various high-power electronic equipment.

For example, the application disclosed in the authorization announcement number "CN220041865U" discloses a TO247 package lead frame, including a lead frame composed of multiple lead frame units, the lead frame unit includes a base island and a frame body, the lower part of the base island is connected with a drain pin, the two sides of the drain pin are connected to the source pin and the gate pin respectively through connecting ribs, and the frame body is an integrated structure to fix the drain pin, source pin and gate pin, and the connection part between the drain pin and the base island is embedded with a magnetic bead. The magnetic bead provides a magnetic field through the grounding conduction of the drain pin, which can reduce the impact of electromagnetic interference when subjected to external electromagnetic interference, solving the problem that the TO247 package lead frame in the prior art cannot improve the anti-electromagnetic interference capability of the package structure.

However, with the rapid development of chips, the market has increasingly stringent requirements for power devices, and the conventional TO247 package thermal resistance has become a bottleneck for the development of high-performance operating temperature products on the market. For example, the TO247 package lead frame can only conduct heat through the exposed lead frame, which has a large thermal resistance and low heat transfer efficiency.

Summary of the invention

The present invention provides a low thermal resistance double-sided metal heat dissipation TO247 structure and a preparation method thereof, so as to solve the technical problem that the current TO247 structure can only conduct heat through an exposed lead frame, has a large thermal resistance and a low heat transfer efficiency.

In order to solve the above technical problems, the present invention discloses a low thermal resistance double-sided metal heat dissipation TO247 structure, comprising: a metal frame, a chip, a heat-conducting component and a plastic package body, the metal frame comprising a wafer carrier and a plurality of pins, the chip is arranged on the surface of the wafer carrier, and the side of the wafer carrier away from the chip is arranged as a first metal exposed surface, the heat-conducting component comprises a metal block and a copper clip, the metal block is arranged on the side of the chip away from the metal frame, and the copper clip is arranged on the side of the metal block away from the chip, the plastic package body wraps the chip, the wafer carrier, the metal block, the copper clip and one end of the pin close to the wafer carrier, the side of the copper clip away from the metal block is arranged as a second metal exposed surface, and the side of the copper clip away from the metal block and the side of the plastic package body away from the metal frame are in the same plane.

Preferably, the chip is electrically connected to the pin by at least one of a copper clip connection and a metal wire connection.

Preferably, the area ratio of the second metal exposed surface to the first metal exposed surface can be 1:1 at most.

Preferably, the metal block and the copper clip are both made of heat-conducting metal material.

Preferably, the metal block and the copper clip are made of the same metal material or different metal materials and are integrally formed.

Preferably, the chip and the wafer carrier are connected by a first adhesive, the chip and the metal block are connected by a second adhesive, and the metal block and the copper clip are connected by a third adhesive.

The present application also provides a method for preparing a low thermal resistance double-sided metal heat dissipation TO247 structure, which is used to prepare the above-mentioned low thermal resistance double-sided metal heat dissipation TO247 structure, comprising the following steps:

Step 1: Prepare the metal frame;

Step 2: Apply a first adhesive on the wafer carrier of the metal frame, and mount the chip on the first adhesive;

Step 3: Electrically interconnect the chip and the metal frame pins;

Step 4: Apply a second adhesive on the chip, and install a thermal conductive component on the second adhesive, the thermal conductive component including a metal block and a copper clip;

Step 5: Using a plastic encapsulation process to obtain a plastic encapsulation body, the plastic encapsulation body wraps around the metal block chip, the wafer carrier, the metal block, the copper clip and a section of the lead close to the wafer carrier;

Step 6: Grind the side of the plastic package body away from the metal frame until the side of the copper clip away from the metal block and the side of the plastic package body away from the metal frame are in the same plane, thereby obtaining a TO247 structure semi-finished product;

Step 7: The TO247 structure is obtained by cutting and forming the semi-finished product of the TO247 structure.

Preferably, in step 3, the chip is electrically connected to the pins by using a bonding metal wire or a copper clip process.

Preferably, in step 4, the metal block is first mounted on the second adhesive, and then the third adhesive is applied to the side of the metal block away from the chip, and the copper clip is mounted on the third adhesive.

Preferably, in step 4, the metal block and the copper clip are first connected by an integrated molding process, and then the metal block with the copper clip is installed on the second adhesive.

The technical solution of the present invention has the following advantages: the present invention provides a low thermal resistance double-sided metal heat dissipation TO247 structure and a preparation method, which relates to the field of chip packaging technology, including a metal frame, a chip, a heat-conducting component and a plastic package, the metal frame includes a wafer stage and a plurality of pins, the chip is arranged on the surface of the wafer stage, the heat-conducting component includes a metal block and a copper clip, the metal block is arranged on the side of the chip away from the metal frame, the copper clip is arranged on the side of the metal block away from the chip, the plastic package wraps the chip, the wafer stage, the metal block and the copper clip, the side of the copper clip away from the metal block is arranged as a second metal exposed surface, and the side of the copper clip away from the metal block is in the same plane as the side of the plastic package away from the metal frame. In the present invention, the heat generated by the chip can be transferred to the copper clip through the metal block, and the heat is extracted by the second metal exposed surface of the copper clip, and the second metal exposed surface of the copper clip and the first metal exposed surface jointly dissipate heat, thereby reducing the packaging thermal resistance of the TO247 structure, improving the heat transfer efficiency of the TO247 structure, and enhancing the heat dissipation performance of the TO247 structure, which is conducive to the development of high-performance operating temperature products, and the TO247 structure provides a stronger and more powerful hardware guarantee for semiconductor circuit design.

Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the devices particularly pointed out in the written description and the drawings of the description.

The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

Figure 1 is a front view of the internal structure of a conventional TO247 structure;

Figure 2 is a side view of a conventional TO247 structure;

Figure 3 is a rear view of a conventional TO247 structure;

FIG4 is an enlarged view of the structure at point A in FIG2;

FIG5 is a front view of the internal structure of the double-sided metal heat dissipation TO247 structure with low thermal resistance of the present invention;

FIG6 is a side view of a double-sided metal heat dissipation TO247 structure with low thermal resistance according to the present invention;

FIG7 is a front view of the external structure of the double-sided metal heat dissipation TO247 structure with low thermal resistance of the present invention;

FIG8 is a rear view of a double-sided metal heat dissipation TO247 structure with low thermal resistance according to the present invention;

FIG9 is an enlarged view of the structure at B in FIG6 of the present invention;

FIG. 10 is a schematic diagram of the plastic package body after grinding in the present invention.

In the figure: 1. metal frame; 2. chip; 3. plastic package; 4. metal block; 5. copper clip; 6. second metal exposed surface; 7. first adhesive; 8. second adhesive; 9. third adhesive; 10. metal wire.

Detailed ways

The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

In addition, in the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes, and do not specifically refer to the order or sequence, nor are they used to limit the present invention. They are only used to distinguish components or operations described with the same technical terms, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions and technical features between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to 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 required by the present invention.

Embodiment 1:

An embodiment of the present invention provides a double-sided metal heat dissipation TO247 structure with low thermal resistance, as shown in Figures 1 to 10, comprising: a metal frame 1, a chip 2, a thermally conductive component and a plastic package 3, the metal frame 1 comprising a wafer carrier and a plurality of pins, the chip 2 is arranged on the surface of the wafer carrier, and the side of the wafer carrier away from the chip 2 is arranged as a first metal exposed surface, the thermally conductive component comprises a metal block 4 and a copper clip 5, the metal block 4 is arranged on the side of the chip 2 away from the metal frame 1, and the copper clip 5 is arranged on the side of the metal block 4 away from the chip 2, the plastic package 3 wraps the chip 2, the wafer carrier, the metal block 4, the copper clip 5 and a section of the pins close to the wafer carrier, the side of the copper clip 5 away from the metal block 4 is arranged as a second metal exposed surface 6, and the side of the copper clip 5 away from the metal block 4 and the side of the plastic package 3 away from the metal frame 1 are in the same plane.

The working principle and beneficial effects of the above technical solution are as follows: as shown in Figures 1 to 4, the conventional TO247 structure is wrapped by a plastic packaging material, and a chip 2 is provided on the back of the second metal exposed surface 6 frame. The metal frame 1 and the chip 2 are connected with adhesive, so only single-sided metal heat dissipation can be achieved through the metal frame 1, and the heat transfer efficiency is low. In order to solve the above problem, as shown in Figures 5 to 10, the present invention arranges a metal block 4 on the chip 2, and the heat of the chip 2 can be transferred to the copper clip 5 through the metal block 4. The copper clip 5 further dissipates heat through the second metal exposed surface 6, thereby realizing double-sided metal heat dissipation of the second metal exposed surface 6 and the first metal exposed surface of the copper clip 5. The above-mentioned low thermal resistance double-sided metal heat dissipation TO247 structure can greatly reduce the packaging thermal resistance, improve the heat transfer efficiency of the TO247 structure, and enhance the heat dissipation performance of the TO247 structure, which is conducive to the development of high-performance operating temperature products. The TO247 structure provides a stronger and more powerful hardware guarantee for semiconductor circuit design.

Embodiment 2:

On the basis of the above-mentioned embodiment 1, as shown in FIG. 5 , FIG. 6 , FIG. 9 , and FIG. 10 , the chip 2 is electrically connected to the pins through at least one of the connection modes of the copper clip 5 or the metal wire 10 .

The working principle and beneficial effects of the above technical solution are as follows: the chip 2 can be electrically connected to the pin through the metal block 4 and the copper clip 5, or connected to the pin through the metal wire 10, or connected to the pin by a combination of the copper clip 5 and the metal wire 10. When the chip 2 is connected to the pin through the copper clip 5, one end of the sheet-like copper clip 5 extends to the pin and is provided with a protruding portion, which is respectively connected to different pins through the protruding portion. When the chip 2 is connected to the pin through the metal wire 10, one end of the metal wire 10 is connected to the chip 2, and the other end of the metal wire 10 is connected to the pin. When the chip 2 is connected to the metal wire 10 through the copper clip 5, the number of metal wires 10 can be selected at will, and the end of the copper clip 5 away from the metal block 4 can cover directly above the metal wire 10.

Embodiment 3:

Based on the embodiment 1 or 2, the area ratio of the second metal exposed surface 6 to the first metal exposed surface can be 1:1 at most.

The working principle and beneficial effects of the above technical solution are as follows: the area of the second metal exposed surface 6 and the area of the first metal exposed surface are set according to actual needs, and the maximum area ratio of the second metal exposed surface 6 to the first metal exposed surface is 1:1. When the areas of the second metal exposed surface 6 and the first metal exposed surface are the same, the heat dissipation speed on both sides of the TO247 structure is the same, which can achieve maximum heat dissipation and improve heat dissipation efficiency.

Embodiment 4:

On the basis of any one of the embodiments 1-3, as shown in FIG9 and FIG10 , the metal block 4 and the copper clip 5 are both made of heat-conducting metal material;

The metal block 4 and the copper clip 5 are made of the same metal material or different metal materials and are integrally formed;

The chip 2 is connected to the wafer stage by a first adhesive 7 , the chip 2 is connected to the metal block 4 by a second adhesive 8 , and the metal block 4 is connected to the copper clip 5 by a third adhesive 9 .

The working principle and beneficial effects of the above technical solution are as follows: the metal block 4 and the copper clip 5 are both made of high thermal conductivity materials. Preferably, the metal block 4 and the copper clip 5 are both made of metal copper. The metal block 4 and the copper clip 5 can be bonded or integrally formed by a third adhesive 9. Preferably, the metal block 4 and the copper clip 5 are formed by an integral forming process. The integral forming process includes but is not limited to bonding, forging, ultrasonic pressure welding, extrusion of two copper materials or thick copper plates, etc. The metal block 4 and the copper clip 5 are integrally formed, which can improve the stability of the metal block 4 and the copper clip 5, save adhesive and simplify the process.

Embodiment 5:

On the basis of any one of Examples 1-4, as shown in FIG. 5-FIG 10, the present application further provides a method for preparing a double-sided metal heat dissipation TO247 structure with low thermal resistance, which is used to prepare the above-mentioned double-sided metal heat dissipation TO247 structure with low thermal resistance, comprising the following steps:

Step 1: Prepare the metal frame 1;

Step 2: Apply the first adhesive 7 on the wafer carrier of the metal frame 1, and install the chip 2 on the first adhesive 7;

Step 3: Electrically interconnect the chip 2 and the pins of the metal frame 1;

Step 4: Apply a second adhesive 8 on the chip 2, and install a heat-conducting component on the second adhesive 8, wherein the heat-conducting component includes a metal block 4 and a copper clip 5;

Step 5: plastic encapsulation is performed by plastic encapsulation process to obtain a plastic encapsulation body 3, wherein the plastic encapsulation body 3 is wrapped around the metal block 4, the chip 2, the wafer carrier, the metal block 4, the copper clip 5 and the outside of a section of the lead close to the wafer carrier;

Step 6: Grind the side of the plastic package body 3 away from the metal frame 1 until the side of the copper clip 5 away from the metal block 4 and the side of the plastic package body 3 away from the metal frame 1 are in the same plane, thereby obtaining a TO247 structure semi-finished product;

Step 7: The TO247 structure is obtained by cutting and forming the semi-finished product of the TO247 structure.

The working principle and beneficial effects of the above technical solution are as follows: when preparing a conventional TO247 structure, as shown in Figures 1 to 4, first apply a first adhesive 7 to the metal frame 1, then mount the chip 2 on the first adhesive 7, then realize electrical interconnection between the chip 2 and the pins through a metal wire bonding process, then perform plastic sealing, and finally perform rib cutting and forming. The TO247 structure prepared by the above preparation method can only perform single-sided metal heat dissipation through the metal frame, and has poor heat dissipation performance. The conventional TO247 structure has a high thermal resistance. In order to solve the above problems, the present invention provides a double-sided metal heat dissipation TO247 structure with low thermal resistance. When preparing the double-sided metal heat dissipation TO247 structure, first prepare a metal frame 1; then apply a first adhesive 7 on the wafer carrier of the metal frame 1, and mount the chip 2 on the first adhesive 7; then electrically connect the chip 2 to the pins of the metal frame 1; then apply a second adhesive 8 on the chip 2, and mount a thermal conductive component on the second adhesive 8. The thermal conductive component includes a metal block 4 and a copper Clip 5; and use a plastic sealing process to obtain a plastic sealing body 3, the plastic sealing body 3 is wrapped around the metal block 4 chip 2, the wafer carrier, the metal block 4 and the copper clip 5; the side of the plastic sealing body 3 away from the metal frame 1 is ground until the side of the copper clip 5 away from the metal block 4 and the side of the plastic sealing body 3 away from the metal frame 1 are in the same plane, so as to obtain a TO247 structure semi-finished product; finally, the TO247 structure semi-finished product is cut and formed to obtain a TO247 structure, in which the heat generated by the chip 2 can be transferred to the copper clip 5 through the metal block 4, and the heat is conducted out by the second metal exposed surface 6 of the copper clip 5, and the second metal exposed surface 6 of the copper clip 5 and the first metal exposed surface jointly dissipate heat, thereby reducing the packaging thermal resistance of the TO247 structure, improving the heat transfer efficiency of the TO247 structure, and enhancing the heat dissipation performance of the TO247 structure, which is conducive to the development of high-performance operating temperature products. The TO247 structure provides a stronger and more powerful hardware guarantee for semiconductor circuit design.

Embodiment 6:

On the basis of Embodiment 5, in step 3, the chip 2 is electrically connected to the pins by using a bonding metal wire 10 or a copper clip 5 process.

The working principle and beneficial effects of the above technical solution are as follows: the bonding metal wire 10 or the copper clip 5 process adopts the existing process, which can realize the electrical connection between the chip 2 and the pin.

Embodiment 7:

On the basis of Example 5 or 6, in step 4, as shown in Figures 9 and 10, the metal block 4 is first installed on the second adhesive 8, and then the third adhesive 9 is applied to the side of the metal block 4 away from the chip 2, and the copper clip 5 is installed on the third adhesive 9.

The working principle and beneficial effects of the above technical solution are as follows: the copper clip 5 can be installed on the metal block 4 through the third adhesive 9, and a second metal exposed surface 6 is provided on the side of the copper clip 5 away from the metal block 4. Heat can be dissipated through the second metal exposed surface 6, and double-sided metal heat dissipation is achieved in cooperation with the metal frame 1, thereby improving the heat dissipation efficiency.

Embodiment 8:

On the basis of Example 5 or 6, in step 4, the metal block 4 and the copper clip 5 are first connected by an integrated molding process, and then the metal block 4 with the copper clip 5 is installed on the second adhesive 8.

The working principle and beneficial effects of the above technical solution are as follows: the one-piece molding process can realize overall modularization of the metal block 4 and the copper clip 5, improve the stability of the connection between the metal block 4 and the copper clip 5, reduce the adhesive glue between the metal block 4 and the copper clip 5, further improve the thermal conductivity, and improve the heat transfer efficiency between the metal block 4 and the copper clip 5.

Embodiment 9:

On the basis of Example 8, in step 2 and step 4, an automatic gluing device is used for gluing, and the amount of glue applied by the automatic gluing device is calculated using the following formula (1):

(1);

in, is the glue application amount of the automatic glue application device, /> is the total mass of the metal frame 1, chip 2, metal block 4 and copper clip 5 after the second adhesive 8 is dried in step 4, is the total mass of the metal frame 1, chip 2, metal block 4 and copper clip 5, /> is the density of the first adhesive 7 and the second adhesive 8 after drying, /> is the preset coating area of the first adhesive 7, /> is the preset coating area of the second adhesive 8, /> For the first/> The preset coating area of the adhesive.

The working principle and beneficial effects of the above technical solution are as follows: when applying the first adhesive glue 7 on the wafer carrier of the metal frame 1 or applying the second adhesive glue 8 on the surface of the chip 2, applying too much glue or too little glue will affect the coating quality of the adhesive glue. If too much glue is applied, the adhesive glue is easy to overflow, causing waste and increasing thermal conductivity. If too little glue is applied, the bonding strength will be reduced. In order to improve the coating quality of the adhesive glue, the glue is applied by an automatic glue application device, which can automatically adjust the amount of glue applied according to the glue application position. Before applying the glue, the metal frame 1, the chip 2, the metal block 4 and the copper are weighed. The total mass of the clip 5 is then implemented in step 2-step 4, wherein the first preparation is a process for setting a standard glue coating amount, and both the first adhesive glue 7 and the second adhesive glue 8 are coated more, so that both the first adhesive glue 7 and the second adhesive glue 8 overflow. After step 4 is completed, the second adhesive glue 8 is dried, and then the overflowed first adhesive glue 7 and the second adhesive glue 8 are removed, and the total mass of the metal frame 1, the chip 2, the metal block 4 and the copper clip 5 after the second adhesive glue 8 is dried is weighed. The total mass of the first adhesive glue 7 and the second adhesive glue 8 can be calculated through the two weighing results, and then by The average thickness of the first adhesive 7 and the second adhesive 8 can be calculated, and the average thickness of the first adhesive 7 and the second adhesive 8 can be calculated based on the average thickness of the first adhesive 7 and the second adhesive 8. The preset coating area of the adhesive can be used to calculate the amount of adhesive applied by the automatic adhesive coating device. is 1 or 2, representing the preset coating area of the first adhesive 7 and the preset coating area of the second adhesive 8, respectively. The preset coating area of the first adhesive 7 is the maximum contact area between the chip 2 and the wafer stage, and the preset coating area of the second adhesive 8 is the maximum contact area between the chip 2 and the metal block 4. Based on the calculated coating amount of the automatic adhesive coating device, when coating the first adhesive 7, /> For/> , the automatic glue coating device can apply the glue amount corresponding to the first adhesive 7 on the carrier of the metal frame 1, and when applying the second adhesive 8, / For/> The automatic glue coating device can apply a coating amount corresponding to the second adhesive 8 on the carrier stage of the metal frame 1. The automatic glue coating device can select the corresponding coating amount for the first adhesive 7 or the second adhesive 8, and accurately control the thickness of the first adhesive 7 and the second adhesive 8, which not only reduces the influence of the adhesive on the thermal conductivity, but also saves the adhesive, avoids the overflow of the adhesive, does not affect the subsequent packaging, and can also ensure the bonding strength, thereby improving the preparation quality of the TO247 structure.

Embodiment 10:

On the basis of Example 9, in step 4, when installing the metal block 4, in order to ensure the heat conduction effect of the metal block 4, the contact area between the metal block 4 and the chip 2 should be equal to the target heat transfer area, and the target heat transfer area is calculated by the following formula (2):

(2);

in, is the target heat transfer area, /> is the thermal impedance of the metal block 4, /> is the preset maximum operating temperature of chip 2, is the external working environment temperature of TO247 structure,/> is the heat generation power of chip 2, /> is the convective heat transfer coefficient of the exposed surface of the metal frame 1, /> is the exposed surface area of the metal frame 1, /> is the convection heat transfer coefficient of the second metal exposed surface 6 of the copper clip 5, /> is the area of the second metal exposed surface 6 of the copper clip 5, /> is the thermal resistance of chip 2, /> is the thermal resistance of the metal frame 1, /> is the coating amount of the first adhesive 7, /> is the preset coating area of the first adhesive 7, /> is the coating amount of the second adhesive 8, /> is the preset coating area of the second adhesive 8, /> is the thermal conductivity of the first adhesive 7 and the second adhesive 8.

The working principle and beneficial effects of the above technical solution are as follows: if the contact area between the metal block 4 and the chip 2 is small, the heat transfer efficiency of the metal block 4 will be reduced; if the contact area between the metal block 4 and the chip 2 is large, materials will be wasted, the weight of the TO247 structure will be increased, and the cost will be increased. Therefore, when selecting the metal block 4, not only the heat conduction effect of the metal block 4 should be ensured, but also the amount of the metal block 4 should be considered. The above solution can accurately calculate the target heat transfer area. In the calculation process, the formula The thermal resistance of the first adhesive 7 can be calculated by the formula The thermal resistance of the second adhesive 8 can be calculated, With/> The above formula (1) is used for calculation. When calculating, the thermal resistance of the first adhesive 7 and the second adhesive 8 is comprehensively considered according to the coating amount of the first adhesive 7 and the second adhesive 8, which can make the calculation of the target heat transfer area more accurate and achieve precise heat dissipation. According to the target heat transfer area, the metal block 4 can be selected. The metal block 4 is columnar. When the contact surface area between the metal block 4 and the chip 2 is equal to the target heat transfer area, the metal block 4 can not only quickly conduct the heat generated by the chip 2, but also ensure that the operating temperature of the chip 2 does not exceed the preset maximum operating temperature. The chip 2 operates within the normal operating temperature range, which can reduce the performance degradation, damage or failure caused by overheating, thereby improving The reliability and stability of the high system extend the service life of the chip 2, improve the working performance of the chip 2, reduce the energy consumption of the chip 2, and achieve energy-saving effects. Moreover, the volume of the metal block 4 is precisely controlled, and no waste of the metal block 4 is caused, thereby reducing the overall weight of the TO247 structure and further saving costs. Preferably, the area ratio of the second metal exposed surface 6 to the first metal exposed surface is 1:1, and the second metal exposed surface 6 of the copper clip 5 and the first metal exposed surface dissipate heat together, which can improve the heat dissipation effect, reduce the packaging thermal resistance of the TO247 structure, improve the heat transfer efficiency of the TO247 structure, and enhance the heat dissipation performance of the TO247 structure.

In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and implementation modes. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims (10)

1. A low thermal resistance double-sided metal heat dissipation TO247 structure, characterized in that it comprises: a metal frame (1), a chip (2), a heat conducting component and a plastic package (3), the metal frame (1) comprising a wafer carrier and a plurality of pins, the wafer carrier surface is provided with a chip (2), a side of the wafer carrier away from the chip (2) is provided as a first metal exposed surface, the heat conducting component comprises a metal block (4) and a copper clip (5), the metal block (4) is provided on a side of the chip (2) away from the metal frame (1), a copper clip (5) is provided on a side of the metal block (4) away from the chip (2), the plastic package (3) wraps the chip (2), the wafer carrier, the metal block (4), the copper clip (5) and a section of pins close to the wafer carrier, a side of the copper clip (5) away from the metal block (4) is provided as a second metal exposed surface (6), and a side of the copper clip (5) away from the metal block (4) and a side of the plastic package (3) away from the metal frame (1) are in the same plane. 2. The low thermal resistance double-sided metal heat dissipation TO247 structure according to claim 1, characterized in that the chip (2) is electrically connected to the pin by at least one of a copper clip (5) connection and a metal wire (10) connection. 3. The low thermal resistance double-sided metal heat dissipation TO247 structure according to claim 1, characterized in that the area ratio of the second metal exposed surface (6) to the first metal exposed surface can be at most 1:1. 4. The low thermal resistance double-sided metal heat dissipation TO247 structure according to claim 1, characterized in that the metal block (4) and the copper clip (5) are both made of heat-conducting metal material. 5. The low thermal resistance double-sided metal heat dissipation TO247 structure according to claim 1, characterized in that the metal block (4) and the copper clip (5) are made of the same metal material or different metal materials and are integrally formed. 6. The low thermal resistance double-sided metal heat dissipation TO247 structure according to claim 1 is characterized in that the chip (2) and the carrier are connected by a first adhesive (7), the chip (2) and the metal block (4) are connected by a second adhesive (8), and the metal block (4) and the copper clip (5) are connected by a third adhesive (9). 7. A method for preparing a low thermal resistance double-sided metal heat dissipation TO247 structure, for preparing a low thermal resistance double-sided metal heat dissipation TO247 structure as described in any one of claims 1 to 6, characterized in that it comprises the following steps: Step 1: Prepare the metal frame (1); Step 2: applying a first adhesive (7) on the wafer carrier of the metal frame (1), and mounting the chip (2) on the first adhesive (7); Step 3: Electrically interconnecting the chip (2) and the pins of the metal frame (1); Step 4: applying a second adhesive (8) on the chip (2), and installing a heat-conducting component on the second adhesive (8), wherein the heat-conducting component includes a metal block (4) and a copper clip (5); Step 5: Using a plastic encapsulation process to obtain a plastic encapsulation body (3), wherein the plastic encapsulation body (3) is wrapped around the metal block (4), the chip (2), the wafer carrier, the metal block (4), the copper clip (5) and the outside of a section of the lead close to the wafer carrier; Step 6: Grind the side of the plastic package body (3) away from the metal frame (1) until the side of the copper clip (5) away from the metal block (4) and the side of the plastic package body (3) away from the metal frame (1) are in the same plane, thereby obtaining a TO247 structure semi-finished product; Step 7: The TO247 structure is obtained by cutting and forming the semi-finished product of the TO247 structure. 8. The method for preparing a double-sided metal heat dissipation TO247 structure with low thermal resistance according to claim 7, characterized in that in step 3, a bonding metal wire (10) or a copper clip (5) process is used to electrically connect the chip (2) to the pin. 9. The method for preparing a double-sided metal heat dissipation TO247 structure with low thermal resistance according to claim 7, characterized in that, in step 4, the metal block (4) is first mounted on the second adhesive (8), and then the third adhesive (9) is applied to the side of the metal block (4) away from the chip (2), and the copper clip (5) is mounted on the third adhesive (9). 10. The method for preparing a double-sided metal heat dissipation TO247 structure with low thermal resistance according to claim 7, characterized in that, in step 4, the metal block (4) and the copper clip (5) are first connected by an integrated molding process, and then the metal block (4) with the copper clip (5) is installed on the second adhesive (8).