CN203118939U - Square flat type power device capsule - Google Patents

Abstract

The utility model discloses a square flat power device package body, which comprises a conductive base plate and a conductive pad. The conductive base plate is composed of a heat dissipation area and a pin area of the base plate. One end of the negative pin is electrically connected to the end face of the heat dissipation area, the heat dissipation area is located directly below the rectifier chip and is electrically connected to the lower surface of the rectifier chip through a soft solder layer; the conductive pad is located on the rectifier chip On the other side, the conductive pad includes a welding area and at least two pins, and the connection between the welding area and the pins has a bent portion, so that the welding area is higher than the pins; an aluminum conductor strip is connected across the rectifier Between the positive electrode of the chip and the welding area of the conductive pad; there are at least two welding strips between the aluminum conductor strip and the rectifier chip and arranged alternately. The package body of the power device of the utility model is beneficial to reduce the ohmic contact resistance, improve the electric performance index, and reduce the generation of heat at the same time.

Description

Quad Flat Power Device Package

technical field

The utility model relates to the technical field of power devices, in particular to a square flat power device packaging body. the

Background technique

With the development of electronic products, consumer electronic products such as notebook computers, mobile phones, mini-CDs, palmtop computers, CPUs, and digital cameras are becoming more and more miniaturized. As products become smaller and thinner, how to dissipate the heat generated by millions of transistors in industrial ICs becomes a problem that has to be considered. In the prior art, although the calorific value can be reduced by improving the IC manufacturing process capability and reducing the voltage, the trend of increasing the calorific density cannot be avoided. If the heat dissipation problem is not solved, the reliability of the product will be affected due to overheating of the industrial device, which will seriously shorten the product life and even cause product damage. the

The prior art, as shown in FIG. 1 , is a schematic cross-sectional view of a typical DFN package structure, including a chip 900, a heat sink 920, a lead frame 930, a plurality of wires 940, and insulating glue 950 wrapping the above structure. The chip 900 is adhered to the heat sink 920 , the lead frame 930 has a plurality of mutually insulated pins, and the pads on the surface of the chip 900 are connected to the lead frame 930 through wires 940 . on the corresponding pins. The insulating glue 950 wraps all the above-mentioned structures to isolate them from the outside world, and only the pins of the lead frame 930 and the surface of the heat sink 920 opposite to the chip 900 are exposed to the air. The exposed pins of the lead frame 930 are used to realize the electrical connection between the packaged chip 900 and the outside world, and the exposed function of the heat sink 920 is to dissipate the heat generated by the chip 900 to the environment through the exposed surface; still There is a technical problem that the volume is large and is not conducive to heat dissipation. the

Contents of the invention

The purpose of the utility model is to provide a square flat power device package, which is beneficial to reduce the ohmic contact resistance, improve the electrical performance index, and reduce the generation of heat at the same time; The technical defect that the conductor strip is easy to break during use, thus prolonging the service life of the product and improving the reliability. the

In order to achieve the above purpose, the technical solution adopted by the utility model is: a square flat power device package, including a rectifier chip, an epoxy resin layer wrapped around the rectifier chip, and a conductive base plate, a conductive pad, The conductive base plate is composed of a heat dissipation area and a base plate pin area. The base plate pin area is composed of several negative pins arranged alternately. One end of the negative pin is electrically connected to the end face of the heat dissipation area. The heat dissipation area is located at The rectifier chip is directly below the rectifier chip and is electrically connected to the lower surface of the rectifier chip through a soft solder layer; the conductive pad is located on the other side of the rectifier chip, and the conductive pad includes a welding area and at least two pins, and the connection between the welding area and the pins The connection has a bent portion, so that the welding area is higher than the pin; an aluminum conductor strip spans between the positive electrode of the rectifier chip and the welding area of the conductive pad; the welding of the aluminum conductor strip and the rectifier chip There are at least 2 strips arranged alternately. the

The scheme of further improvement in the above-mentioned technical scheme is as follows:

1. In the above solution, the welding areas of the conductive pads are located on the same level as the rectifier chip.

2. In the above solution, the number of the negative pins is four. the

3. In the above solution, the bandwidth-to-thickness ratio of the aluminum conductor is 1:9~14. the

Due to the application of the above-mentioned technical solutions, the utility model has the following advantages and effects compared with the prior art:

1. The square flat power device package body of the utility model has an aluminum conductor strip bridged between the positive pole of the rectifier chip and the welding area of the conductive pad, and the welding strip between the aluminum conductor strip and the positive pole of the rectifier chip is at least Two strips are arranged alternately. This structural design is beneficial to reduce the ohmic contact resistance, improve the electrical performance index, and reduce the generation of heat at the same time.

2. The quadrilateral flat power device package of the present invention has both the functions of the conductive pad, heat sink and base island in the prior art, which not only helps to further reduce the volume of the device, but also reduces the size of the components in the device. At the same time, because the heat dissipation area and the substrate pin area are integrated, the stability of electrical performance is improved. the

3. In the square flat power device package of the present invention, there is a bending part at the junction of the welding area and the lead area, so that the welding area is higher than the lead area, and ensures the connection between the welding area of the conductive pad and the rectifier chip. The positive poles are at the same level, which effectively avoids the technical defect that the aluminum conductor strip connected to the positive poles is easy to break during use, thereby prolonging the service life of the product and improving reliability. the

Description of drawings

Fig. 1 is the prior art structure schematic diagram;

Fig. 2 is a schematic diagram of the structure of the square flat power device package of the present invention;

Fig. 3 is a sectional view along line A-A in Fig. 3 . the

In the above drawings: 1. Rectifier chip; 2. Epoxy resin layer; 3. Conductive base plate; 31. Heat dissipation area; 32. Base plate pin area; 321. Drain pin; 4. Conductive pad; 5 1. Aluminum conductor strip; 6. Soft solder layer; 7. Welding area; 8. Pin area; 9. Bending part; 10. Welding strip.

Detailed ways

Below in conjunction with embodiment the utility model is further described:

Embodiment 1: A square flat power device package, including a rectifier chip 1, an epoxy resin layer 2 wrapped around the rectifier chip 1, and a conductive substrate 3, a conductive pad 4, the conductive substrate 3. It is composed of a heat dissipation area 31 and a base plate pin area 32. The base plate pin area 32 is composed of several negative pole pins 321 arranged alternately. One end of the negative pole pin 321 is electrically connected to the end surface of the heat dissipation area 31. The heat dissipation The region 31 is located directly below the rectifier chip 1 and is electrically connected to the lower surface of the rectifier chip 1 through a soft solder layer 6; the conductive pad 4 is located on the other side of the rectifier chip 1, and the conductive pad 4 includes a welding area 7 and at least two There is a pin 8, and the connection between the welding area 7 and the pin has a bent portion 9, so that the welding area 7 is higher than the pin 8; an aluminum conductor strip 5 is connected across the positive pole of the rectifier chip 1 and the conductive welding. Between the welding areas 7 of the disk 4; the aluminum conductor strips 5 and the welding strips 10 of the rectifier chip 1 are at least two and arranged alternately; the soft solder layer 6 is composed of the following components in mass percentage: lead 92.5 %, tin 5%, silver 2.5%; the width-thickness ratio of the aluminum conductor strip 5 is 1:10~15.

The welding areas 7 of the conductive pads 4 are located on the same level as the rectifier chip 1 ; the width-thickness ratio of the aluminum conductor strips 5 is 1:12. the

Embodiment 2: A square flat power device package, including a rectifier chip 1, an epoxy resin layer 2 wrapped around the rectifier chip 1, characterized in that: it also includes a conductive substrate 3, a conductive pad 4, the The conductive base plate 3 is composed of a heat dissipation area 31 and a base plate pin area 32. The base plate pin area 32 is composed of a number of negative pins 321 arranged alternately. One end of the negative pin 321 is electrically connected to the end face of the heat dissipation area 31. , the heat dissipation area 31 is located directly below the rectifier chip 1 and is electrically connected to the lower surface of the rectifier chip 1 through a soft solder layer 6; the conductive pad 4 is located on the other side of the rectifier chip 1, and the conductive pad 4 includes a welding area 7 and at least two pins 8, the connection between the welding area 7 and the pins has a bent portion 9, so that the welding area 7 is higher than the pins 8; an aluminum conductor strip 5 is connected across the rectifier chip 1 Between the positive electrode and the welding area 7 of the conductive pad 4; the aluminum conductor strip 5 and the welding strip 10 of the rectifier chip 1 are at least two and arranged alternately. the

The welding areas 7 of the conductive pads 4 are located on the same level as the rectifier chip 1; the number of the negative pins 321 is four; the width-thickness ratio of the aluminum conductor strip 5 is 1:10. the

When the above-mentioned square flat power device package is used, an aluminum conductor strip is connected between the positive pole of the rectifier chip and the welding area of the conductive pad, and there are at least two welding strips between the aluminum conductor strip and the positive pole of the rectifier chip And arranged alternately, this structural design is beneficial to reduce ohmic contact resistance, improve electrical performance indicators, and reduce heat generation; secondly, it also has the three functions of conductive pads, heat sinks and base islands in the prior art. The functions of the components are not only beneficial to further reduce the volume of the device, but also reduce the number of components in the device. At the same time, because the heat dissipation area and the pin area of the substrate are integrated, the stability of the electrical performance is improved; again, the power rectification chip package There is a bending part at the connection between the welding area and the pin area, so that the welding area is higher than the pin area, and ensures that the welding area of the conductive pad is at the same level as the positive electrode of the rectifier chip, thereby effectively avoiding the problem of being connected to the positive electrode. The technical defect that the aluminum conductor strip is easy to break during use, thus prolonging the service life of the product and improving the reliability. the

The above-mentioned embodiments are only to illustrate the technical concept and characteristics of the present utility model, and its purpose is to enable those familiar with this technology to understand the content of the present utility model and implement it accordingly, and not to limit the protection scope of the present utility model. All equivalent changes or modifications made according to the spirit of the utility model shall fall within the protection scope of the utility model. the

Claims (4)

1. A square flat power device package, comprising a rectifier chip (1), an epoxy resin layer (2) wrapped around the rectifier chip (1), characterized in that it also includes a conductive substrate (3), The conductive pad (4), the conductive substrate (3) is composed of a heat dissipation area (31) and a substrate pin area (32), and the substrate pin area (32) is composed of several negative pins arranged alternately (321), one end of the negative pin (321) is electrically connected to the end surface of the heat dissipation area (31), and the heat dissipation area (31) is located directly below the rectifier chip (1) and passes through the lower surface of the rectifier chip (1) The soft solder layer (6) is electrically connected; the conductive pad (4) is located on the other side of the rectifier chip (1), the conductive pad (4) includes a welding area (7) and at least two pins (8), soldering There is a bending part (9) at the connection between the area (7) and the pin, so that the welding area (7) is higher than the pin (8); an aluminum conductor strip (5) is connected across the rectifier chip (1 ) and the welding area (7) of the conductive pad (4); at least two welding strips (10) of the aluminum conductor strip (5) and the rectifier chip (1) are arranged alternately. 2. The power device package according to claim 1, characterized in that: the respective welding areas (7) of the conductive pads (4) are located on the same level as the rectifier chip (1). 3. The power device package according to claim 1, characterized in that: the number of said negative pins (321) is four. 4. The power device package according to claim 1, characterized in that: the width-thickness ratio of the aluminum conductor strip (5) is 1:9~14.

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