CN212209466U - A high-density QFN package structure - Google Patents

Abstract

The utility model provides a high-density QFN package structure, including a package body, a central pad is provided at the center of the bottom surface of the package body, an L-shaped first pad is provided at each of the four corners of the bottom surface of the package body, and n rectangular second pads are evenly spaced between two adjacent first pads; the two ends of the first pad are respectively connected to the adjacent two sides of the package body, the first pad is bent close to the central pad, and a locking glue gap is surrounded between the first pad and the adjacent two sides of the bottom surface of the package body. The conductive pads in the utility model have a high integration density, and the L-shaped first pad can not only effectively reduce the length of the unidirectional dimension, thereby avoiding short circuits between the conductive pads, but also effectively ensure the overcurrent capacity of the first pad. In addition, the locking glue gap formed between the first pad and the package body can effectively improve the stability of the structure between the first pad and the package body.

Description

A high-density QFN package structure

technical field

The utility model relates to a packaging structure of electronic components, and specifically discloses a high-density QFN packaging structure.

Background technique

QFN (Quad Flat No-lead Package) is one of the surface mount packages. Surface mount technology is a circuit assembly technology that mounts a leadless or short lead surface mount device on the surface of a circuit board or the surface of other substrates, and is soldered and assembled by reflow soldering or dip soldering.

The QFN package structure is square or rectangular, a large-area exposed pad is arranged on the bottom surface of the package body for heat conduction, and there are conductive pads for electrical connection around the periphery of the package around the large pad. In the prior art, a number of conductive pads are arranged around the periphery of the bottom surface of the package body. In order to avoid problems such as short circuits, the conductive pads are set away from the four corners of the bottom surface of the package body. The QFN package structure has low space utilization and integrated low degree.

Utility model content

Based on this, it is necessary to provide a high-density QFN package structure in view of the problems of the prior art, the integration density of the conductive pads is high, and the short circuit between the conductive pads can be effectively avoided.

In order to solve the problems of the prior art, the utility model discloses a high-density QFN package structure, which includes a package body, a center pad is arranged on the center of the bottom surface of the package body, and an L-shaped first surface is arranged at four corners of the bottom surface of the package body. Pads, n rectangular second pads are equally spaced between two adjacent first pads, where n is an integer greater than 1;

Two ends of the first pad are respectively connected with adjacent two sides of the package body, the first pad is bent close to the central pad, and a glue gap is surrounded between the first pad and the adjacent two sides of the bottom surface of the package body.

Further, a corner of the glue-locking gap portion close to the center pad is provided with a conductive reinforcement portion, and the conductive reinforcement portion and the first pad are integrally formed.

Further, the area of the glue-locking gap portion is S, the area of the conductive strengthening portion is P, and 0.2S≤P≤0.5S.

Further, the conductive strengthening portion is in the shape of a right-angle fan.

Further, one end of the second pad close to the central pad is provided with a reinforcement notch.

Further, the distance between the first pad and the adjacent second pad is D, and the distance between the two adjacent second pads is also d, where D=d.

Further, 0.2mm≤D≤0.5mm.

Further, n=3, D=0.4mm.

The beneficial effects of the utility model are as follows: the utility model discloses a high-density QFN package structure, four first pads are added at the four corners of the bottom surface of the package body, and the integration density of the conductive pads in the overall structure is high, and the shape is L The glyph-shaped first pad can not only effectively reduce the length of the unidirectional dimension, thereby avoiding short circuit between the conductive pads, but also effectively ensure the overcurrent capability of the first pad. The formed glue-locking gap can effectively improve the stability of the structure between the first pad and the package body, thereby effectively preventing the first pad from falling off.

Description of drawings

Figure 1 is a schematic structural diagram of the utility model.

FIG. 2 is a schematic structural diagram of another embodiment of the present invention.

Reference numerals are: the package body 10 , the center pad 11 , the first pad 12 , the glue gap portion 121 , the conductive reinforcement portion 122 , the second pad 13 , and the reinforcement gap 131 .

Detailed ways

In order to further understand the features, technical means, and specific goals and functions achieved by the present invention, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

Refer to Figure 1 and Figure 2.

The embodiment of the present utility model discloses a high-density QFN package structure, as shown in FIG. 1 , including a package body 10 , a center pad 11 is provided in the center of the bottom surface of the package body 10 , and the center pad 11 is generally a ground pad. The four corners of the bottom surface of the 10 are provided with an L-shaped first pad 12. The L-shaped first pad 12 can ensure sufficient space between the conductive pads while ensuring a sufficient area, so as to avoid conductive soldering. A short circuit occurs between the pads, and n rectangular second pads 13 are equally spaced between two adjacent first pads 12 , and the center pad 11 , the first pad 12 and the second pad 13 No contact, n is an integer greater than 1, and both the first pad 12 and the second pad 13 are used as I/O ports;

Both ends of the first pad 12 are respectively connected to the adjacent two sides of the package body 10 , and the first pad 12 is bent close to the center pad 11 , that is, the tip of the first pad 12 points to the center pad 11 , and the first pad 12 A glue gap portion 121 is surrounded between two adjacent sides of the bottom surface of the package body 10 .

The present invention can effectively expand the I/O port of the semiconductor device to form a high-density structure by adding the first pad 12 structure at the four corners of the bottom surface of the package body 10, and can effectively meet the functional requirements of high-density integration; The first pad 12 can not only effectively shorten the length of a single dimension, ensure that the package body 10 does not need to increase the extra volume, and can also avoid short circuits, and the area of the first pad 12 is also large enough to effectively ensure the first pad 12 . In addition, the first pad 12 can effectively hook the glue gap portion 121, thereby effectively improving the stability of the structure between the first pad 12 and the package body 10, and preventing the first pad 12 from falling off.

In this embodiment, as shown in FIG. 2 , each glue gap portion 121 is provided with a conductive reinforcement portion 122 at the corner of each glue gap portion 121 close to the center pad 11 , and the conductive reinforcement portion 122 and the first pad 12 are integrally formed. By increasing the area of the first pad 12 , not only can the pad have good electrical properties, but also the diameter of the inscribed circle of the conductive structure formed by the first pad 12 and the conductive strengthening portion 122 can be effectively increased, which can ensure During soldering, a circular soldering space with a large enough diameter is provided for the solder paste, which not only improves soldering stability, but also simplifies soldering operations. There is no need to write an L-shape along the first pad 12 during soldering.

Based on the above embodiment, the area of the glue gap portion 121 is S, and the area of the conductive reinforcement portion 122 is P, 0.2S≤P≤0.5S, so as to ensure that there is enough space left in the glue gap portion 121, thereby ensuring the first pad 12 The effect of securing the hook position with the package body 10 .

Based on the above-mentioned embodiment, the conductive reinforcement portion 122 is in the shape of a right-angle fan, which can maximize the diameter of the inscribed circle of the conductive structure formed by the first pad 12 and the conductive reinforcement portion 122 , and can effectively ensure the remaining glue gap portion 121 remains. The space is large enough to ensure the stable effect of the hook position of the first pad 12 .

In this embodiment, the end of the second pad 13 close to the center pad 11 is provided with a reinforcement gap 131 , and the reinforcement gap 131 can effectively improve the stability of the connection structure between the second pad 13 and the package body 10 .

In this embodiment, the distance between the first pad 12 and the adjacent second pad 13 is D, and the distance between two adjacent second pads 13 is also d, D=d, preferably, The width of the second pad 13 is also D.

Based on the above embodiment, 0.2mm≤D≤0.5mm.

Based on the above embodiment, n=3, D=0.4mm, which is used for the package structure of QFN2020, that is, the bottom surface of the package body 10 is provided with four first pads 12 and twelve second pads 13 .

The above-mentioned embodiments only represent several embodiments of the present invention, and the descriptions thereof are specific and detailed, but should not be construed as limiting the scope of the present invention. It should be pointed out that for those of ordinary skill in the art, some modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for this utility model shall be subject to the appended claims.

Claims (8)

1. A high-density QFN package structure, comprising a package body (10), the center of the bottom surface of the package body (10) is provided with a center pad (11), wherein the bottom surface of the package body (10) is four Each corner is provided with an L-shaped first pad (12), and n rectangular second pads (13) are equally spaced between two adjacent first pads (12), where n is an integer greater than 1; Both ends of the first pad (12) are respectively connected to adjacent two sides of the package body (10), the first pad (12) is bent close to the central pad (11), and the first pad (12) is bent close to the central pad (11). A glue gap portion (121) is surrounded between a bonding pad (12) and two adjacent sides of the bottom surface of the package body (10). 2. A high-density QFN package structure according to claim 1, characterized in that, a conductive strengthening portion (122) is provided at a corner of the glue-locking gap portion (121) close to the center pad (11) , the conductive strengthening portion (122) and the first pad (12) are integrally formed. 3. A high-density QFN package structure according to claim 2, wherein the area of the glue-locking gap portion (121) is S, and the area of the conductive reinforcement portion (122) is P, 0.2S ≤P≤0.5S. 4 . The high-density QFN package structure according to claim 3 , wherein the conductive strengthening portion ( 122 ) is in the shape of a right-angle sector. 5 . 5. A high-density QFN package structure according to claim 1, characterized in that, a reinforcement notch (131) is provided at one end of the second pad (13) close to the central pad (11). 6. A high-density QFN package structure according to claim 1, wherein the distance between the first pad (12) and the adjacent second pad (13) is D, The distance between two adjacent second pads (13) is also d, D=d. 7 . The high-density QFN package structure according to claim 6 , wherein 0.2mm≦D≦0.5mm. 8 . 8 . The high-density QFN package structure according to claim 6 , wherein n=3 and D=0.4mm. 9 .

Images