Package structure for power-chip module

Packaging structure of power chip module

PACKAGE STRUCTURE FOR POWER-CHIP MODULE

This creation relates to a packaging structure of a power chip module, and in particular to a packaging structure of a power chip module with a metal heat sink.

In the field of power management integrated circuits, switching power supply circuits are often used. Common switching power supply circuits include Buck Converter and Boost Converter. In these switching power supply circuits, metal oxide half field effect transistors (MOSFETs, also known as power chips) are often used as power switches.

The above-mentioned power chips can be individually packaged in one package, or two or more power chips can be packaged in one package. There are even some packaging structures that encapsulate two power chips and a driver (Driver) together, such as an integrated driver metal oxide half field effect transistor (Driver MOS, DrMOS).

However, packaging the above-mentioned multiple semiconductor chips in the same package will face two main problems, one is the heat dissipation problem, and the other is that the area of the package may be too large or the height of the package may be too high.

For example, in the packaging structure of a traditional power chip module, each Wire-bonded is used to form electrical connections between chips. Since the wire bonding method requires a larger space, if two or three semiconductor chips are placed on the same plane of the same substrate, the area and volume of the package body will increase a lot. In addition, since the above-mentioned power chips continuously switch between switch on and switch off, and one of the power chips (for example: low-side MOS) will have current flow when it is on, causing the package structure to heat up , And even damage the power chip module.

This creation is to provide a power chip module packaging structure to solve the lack of the traditional power chip module packaging structure and improve the heat dissipation efficiency of the power chip module.

One aspect of this creation is to provide a package structure for a power chip module. The packaging structure includes a plurality of power chips, metal plates, and packaging glue. The power chips are electrically connected to each other to form a switch circuit, and the power chips have a plurality of heat dissipation surfaces. The metal plate has a first surface and a second surface opposite to the first surface, wherein the first surface of the metal plate covers the heat dissipation surfaces of the power chips. The packaging glue covers the power chips and at least partially covers the metal plate.

According to an embodiment of the present invention, the above-mentioned package structure further includes at least one substrate. Relative to the metal plate, the substrate is arranged under the power chips and is electrically connected to the power chips.

According to an embodiment of the present invention, the above-mentioned power chips include a high-side MOS and a low-side switch chip. MOS) or a combination thereof.

According to an embodiment of the present invention, it further includes a control chip located on the first or second surface of the metal plate.

According to an embodiment of the present invention, the above-mentioned encapsulant completely covers the power chips, control chips, and metal plates.

According to an embodiment of the present invention, the above-mentioned encapsulant completely covers the power chips and the control chips, and exposes at least a part of the second surface of the metal plate.

According to an embodiment of the present invention, the exposed second surface of the metal plate has a first part and a second part.

According to an embodiment of the present invention, the above-mentioned part of the encapsulating glue is arranged on the second surface of the metal plate and is located between the first part and the second part.

According to an embodiment of the present invention, the control chip and the encapsulant covering the control chip are arranged on the second surface of the metal plate and located between the first part and the second part.

According to an embodiment of the present creation, the above-mentioned first part is substantially parallel to the second part.

<p>100a, 100b, 100c, 200a, 200b, 300a, 300bPackaging structure</p><p>110,210,310First power chip</p><p>120, 220, 320Second power chip</p><p>122Second power chip contact</p><p>130, 230a, 230bcontrol chip</p><p>132Control chip contacts</p><p>140a, 140b, 240, 330a, 330bMetal plate</p><p>141, 241, 331First surface</p><p>142,242,332Second surface</p><p>150a, 150b, 250, 350Packaging glue</p><p>160,260Lead</p><p>170Wire frame contact</p><p>180, 280, 340pin</p><p>270Wire frame</p><p>A-A'Hatching</p>

Fig. 1A is a package structure 100a of a power chip module according to an embodiment of the invention; Fig. 1B is a package structure 100b of a power chip module according to an embodiment of the invention; Fig. 1C The figure is a cross-sectional view of the package structure 100a according to the section line AA' of FIG. 1A; FIG. 1D is a cross-sectional view of a package structure 100c of a power chip module according to an embodiment of the invention; FIG. 2A is a package structure 200a of a power chip module according to an embodiment of the invention 2B is a top view of the package structure 200a of the power chip module according to an embodiment of this creation, which includes leads and leadframes; Figure 2C is drawn according to an embodiment of this creation A cross-sectional view of the package structure 200b of the power chip module shown; Fig. 2D is a top view of the package structure 200b of the power chip module according to an embodiment of the invention; Fig. 3A is implemented according to one of the inventions A cross-sectional view of the package structure 300a of the power chip module shown in the example; and FIG. 3B is a cross-sectional view of the package structure 300b of the power chip module according to an embodiment of the present invention.

Next, embodiments and drawings are used to illustrate the creation in detail. In the drawings or descriptions, similar or identical parts use the same symbols or numbers. In the drawings, the shape or thickness of the embodiment may be enlarged to simplify or facilitate labeling, and the parts of the elements in the drawings will be described in words. It can be understood that the unillustrated or undescribed elements can be in various styles known to those skilled in the art.

FIG. 1A shows a package structure 100a of a power chip module according to an embodiment of the present invention. In Figure 1A, the package structure 100a package It includes a first power chip 110, a second power chip 120, a control chip 130, and a metal plate 140a.

In FIG. 1A, the control chip 130 is electrically connected to the second power chip 120 by wire bonding. In addition, the control chip 130 is also connected to the lead frame pins 170 by wire bonding, and then electrically connected to the first power chip 110 through the lead frame. The control chip 130 has a plurality of control chip contacts 132, which can be connected to the lead frame pins 170 by using the leads 160.

The first power chip 110, the second power chip 120, and the control chip 130 are electrically connected to each other to form a switch circuit. The first power chip 110, the second power chip 120, and the control chip 130 all have heat dissipation surfaces. When the above-mentioned chip is operated, heat is generated and the temperature of the chip is increased. When the temperature of the chip is too high, it will cause the chip's performance to drop or fail. Therefore, most of the current wafers have a heat dissipation surface to dissipate heat and reduce the temperature of the wafer itself.

In an embodiment of the present invention, the first power chip 110 is a low-side MOS, and the second power chip 120 is a high-side MOS. The above-mentioned first and second power chips 110 and 120 may be, for example, at least one upper bridge switch chip, at least a lower bridge switch chip, or a combination thereof. In addition, the control chip 130 is a driver circuit chip (Driver), which is used to drive the first power chip 110 and the second power chip 120.

The metal plate 140 a has a first surface 141 and a second surface 142 opposite to the first surface 141. The first surface 141 of the metal plate 140a completely covers and contacts one of the first power chip 110 and the second power chip 120; and one surface of the control chip 130 is in contact with the second surface of the metal plate 140a. surface142. Therefore, in this embodiment, the control chip 130 and the first power chip 110 and the second power chip 120 are located on opposite surfaces of the metal plate 140a. The metal plate 140a is easy to conduct heat to make the metal plate 140a contact the surfaces of the power chips 110, 120 and the control chip 130 to dissipate the heat generated by the chips and achieve the purpose of reducing the temperature of the package structure.

In an embodiment of this creation, the metal plate is a copper metal plate.

FIG. 1B shows a package structure 100b of a power chip module according to an embodiment of the present invention. In FIG. 1B, the package structure 100b includes a first power chip 110, a second power chip 120, a control chip 130, and a metal plate 140b.

Compared to the metal plate 140a in FIG. 1A, the heat dissipation surfaces of the first power chip 110 and the second power chip 120 are completely covered. The component composition of FIG. 1B is similar to that of FIG. 1A. The difference is that the first surface 141 of the metal plate 140b in FIG. 1B only covers part of the surface of the first power chip 110 and the second power chip 120.

The control chip 130 is disposed on the second surface 142 of the metal plate 140b, and a surface of the control chip 130 is in contact with the second surface 142 of the metal plate 140b.

In FIG. 1B, the control chip 130 has a plurality of control chip contacts 132, and the second power chip 120 has a plurality of second power chip contacts 122. The control chip 130 is connected to the lead frame pin 170 through the lead 160, and then is electrically connected to the first power chip 110, and the control chip contact 132 and the second power chip contact 122 are connected by the lead 160.

Figure 1C is the seal drawn according to the section line A-A' of Figure 1A A cross-sectional view of the mounting structure 100a. In Figure 1C, the heat dissipation surfaces of the first power chip 110 and the second power chip 120 are in contact with the first surface 141 of the metal plate 140a; and the heat dissipation surface of the control chip 130 is in contact with the second surface 142 of the metal plate 140a . The first power chip 110 and the second power chip 120 are respectively located on the two pins 180, and the pins 180 can be used to connect the lead frame pins 170 of FIG. 1A. In addition, the metal plate 140a is L-shaped and one end is connected to the other pin 180 to facilitate heat conduction. The encapsulant 150a completely covers the first power chip 110, the second power chip 120, the control chip 130, and the metal plate 140a.

In an embodiment of the present invention, the packaging glue is an insulating material.

FIG. 1D is a cross-sectional view of the package structure 100c of the power chip module according to an embodiment of the present invention. In Figure 1D, the packaging structure 100c is similar to the packaging structure 100a of Figure 1C, but the difference is that the packaging glue 150b of the packaging structure 100c only completely covers the first power chip 110, the second power chip 120, and the control The chip 130 is exposed and a part of the second surface 142 of the metal plate 140a is exposed. Since the metal plate has a partially exposed surface, the heat dissipation efficiency of the metal plate can be improved, thereby enhancing the performance of the chip in the package structure. In Figure 1D, the first power chip 110 and the second power chip 120 are respectively located on two pins 180, and the pins 180 can be used to respectively connect to the lead frame pins 170 of Figure 1A. In addition, the metal plate 140a is L-shaped and one end is connected to the other pin 180 to facilitate heat conduction.

FIG. 2A is a cross-sectional view of the package structure 200a of the power chip module according to an embodiment of the invention. In Figure 2A, the package structure 200a includes a first power chip 210, a second power chip 220, and a control The chip 230a, the metal plate 240, the packaging glue 250 and the pins 280.

The heat dissipation surfaces of the first power chip 210 and the second power chip 220 are in contact with the first surface 241 of the metal plate 240; and the heat dissipation surface of the control chip 230 a is in contact with the second surface 242 of the metal plate 240. The first power chip 210 and the second power chip 220 are respectively located on the two pins 280, and the pins 280 can be used to connect the lead frame pins 170 of FIG. 1A. In addition, the metal plate 240 is L-shaped and one end is connected to the other pin 280 to facilitate heat conduction. The encapsulant 250 completely covers the first power chip 210, the second power chip 220, and the control chip 230.

The difference between the package structure 200a and the package structure 100c in FIG. 1C is that the control chip 230a is located at the center of the second surface 242 of the metal plate 240, and the package structure 200a has the second surface 242 of the metal plate 240 exposed.

In an embodiment of the present creation, the control chip 230a located at the center of the second surface 242 of the metal plate 240 and the encapsulant 250 covering the control chip 230a also have an additional effect on the die bonding step in the subsequent manufacturing process. The calibration function.

It is worth noting that the control chip 130 in Figure 1A is located directly above the second power chip 120 (the upper bridge switch), and is only located on one side of the package structure 100a. As shown in FIG. 1A, the control chip 130 is located on the left side of the package structure 100a. Moreover, since the left side of the package structure 100a is completely covered by the encapsulant, the wiring connection direction of the control chip contact 132 is relatively unlimited, and it can be electrically connected to the second power chip 120 and the lead frame pins in four directions. 170. Connected to the control chip contact 132, the second power crystal The leads 160 between the chip contacts 122 and the lead frame pins 170 are covered by the encapsulant.

However, in Figure 2A, since the control chip 230a is located at the center of the packaging structure 200a and the distribution of the packaging glue 250, the metal plate 240 exposes two surfaces, the first part 251 and the second part 252, respectively. The control chip 230a and the packaging glue 250 covering it are located between the first part 251 and the second part 252. In an embodiment of the present creation, the first part 251 is substantially parallel to the second part 252.

FIG. 2B is a top view of the package structure 200a of the power chip module according to an embodiment of the present creation, which includes leads and lead frames. In Figure 2B, the first power chip 210 and the second power chip 220 are located on the same surface of the metal plate 240; and the control chip 230a and the first and second power chips 210 and 220 are located on different surfaces. The control chip 230a is electrically connected to the lead frame 270 by the lead 260, and the lead 260 is also covered by the encapsulant 250. According to an embodiment of the present invention, the control chip 230 can achieve the purpose of electrically connecting the first and second power chips through the lead frame.

The difference from FIG. 1A is that the control chip 230a in FIG. 2B is located at the center of the packaging structure 200a, and the packaging glue 250 is parallel to the direction of the control chip 230a. As can be seen from Figure 2B, because the first power chip 210 and the second power chip 220 are respectively located on the upper and lower sides of the control chip 230a, the leads 260 are not easily connected up and down to the lead frame 270, so the lead frame 270 is arranged on the control chip 230a. The left and right ends are perpendicular to the arrangement direction of the packaging glue 250. Therefore, the leads 260 can only be connected to the lead frame 270 from the left and right ends of the control chip 230a. However, Figure 2B only presents one of the creations The example is not to limit this creation.

FIG. 2C is a cross-sectional view of the package structure 200b of the power chip module according to an embodiment of the present invention. In FIG. 2C, the packaging structure 200b includes a first power chip 210, a second power chip 220, a control chip 230b, a metal plate 240, a packaging glue 250, and pins 280.

The heat dissipation surfaces of the first power chip 210, the second power chip 220, and the control chip 230b are in contact with the first surface 241 of the metal plate 240. The first power chip 210, the second power chip 220, and the control chip 230b are respectively located on the three pins 280, and the pins 280 can be used to connect the lead frame pins 170 of FIG. 1A. In addition, the metal plate 240 is L-shaped and one end is connected to the other pin 280 to facilitate heat conduction. The encapsulant 250 completely covers the first power chip 210, the second power chip 220, and the control chip 230.

The difference between the package structure 200b and the package structure 200a in FIG. 2A is that the control chip 230b is located at the center of the first surface 241 of the metal plate 240. The encapsulant 250 does not completely cover the second surface 241 of the metal plate 240, and the exposed part of the second surface 241 has the effect of increasing heat dissipation.

In FIG. 2C, the encapsulant 250 has a bump at the center of the second surface 242 of the metal plate 240. In an embodiment of the present invention, the bumps formed by the encapsulant 250 have a better alignment effect for the die bonding step in the subsequent manufacturing process.

FIG. 2D is a top view of the package structure 200b of the power chip module according to an embodiment of the present invention. In FIG. 2D, the first power chip 210, the second power chip 220, and the control chip 230b are all located on the first surface of the metal plate 240. In addition, the encapsulant 250 partially covers the metal plate A cross-shaped pattern is formed on the second surface of the metal plate 240 and at the center of the second surface of the metal plate 240.

Since it is convenient for the machine to hold the electronic chip module during testing or the process of placing the package on the motherboard, there is a packaging glue 250 in the middle. In an embodiment of the present invention, compared with the one-shaped packaging adhesive, the packaging adhesive with a cross-shaped pattern is easier to be sucked by the machine and be aligned and installed. In an embodiment of this creation, the edge of the encapsulant with a cross-shaped pattern is arc-shaped.

FIG. 3A is a cross-sectional view of the package structure 300a of the power chip module according to an embodiment of the present invention. In FIG. 3A, the packaging structure 300a includes a first power chip 310, a second power chip 320, a metal plate 330a, pins 340, and a packaging glue 350.

The first power chip 310 and the second power chip 320 are respectively disposed and electrically connected to the two pins 340. The first surface 331 of the metal plate 330a is in contact with the heat dissipation surfaces of the first power chip 310 and the second power chip 320, and the metal plate 330a is U-shaped and its two ends are respectively connected to the two pins 340 to facilitate heat conduction . The encapsulant 350 wraps around the metal plate 330a and has the same height as the second surface 332 of the metal plate 330a.

FIG. 3B is a cross-sectional view of the package structure 300b of the power chip module according to an embodiment of the present invention. In FIG. 3B, the packaging structure 300b includes the first power chip 310, the second power chip 320, the metal plate 330b, the pins 340, and the packaging glue 350.

The packaging structure 300b is similar to the packaging structure 300a of FIG. 3A, and the difference lies in that the packaging glue 350 in the packaging structure 300b and the second surface 332 of the metal plate 330b are not equal in height. In Figure 3B, the metal plate 330b The second surface 332 protrudes from the encapsulant 350 to form a convex surface. In an embodiment of the present invention, the convex surface formed by the metal plate 330b facilitates the calibration of the die bonding step in the subsequent manufacturing process. It is worth noting that the pins 340 in FIGS. 3A and 3B both have exposed surfaces and have the function of heat dissipation.

In the embodiment of the present invention, the thermal conductivity of the metal plate is used to directly cover the heat dissipation surface of the chip, which not only increases the heat dissipation efficiency of the package structure itself, but also improves the performance of the chip in the package structure. In addition, in some embodiments, the chips in the package structure are in a stacked structure, so the bottom area of the package structure can be greatly reduced to achieve the purpose of reducing the volume of the package structure.

Although the embodiment of this creation has been disclosed as above, it is not used to limit this creation. Anyone who is familiar with this technique can make some changes and modifications without departing from the spirit and scope of this creation. Therefore, this creation is protected. The scope shall be subject to the definition of the scope of patent application attached hereafter.