CN212659537U

CN212659537U - DFN or QFN lead frame

Info

Publication number: CN212659537U
Application number: CN202021729185.7U
Authority: CN
Inventors: 蔡择贤; 张怡; 程浪; 冯学贵; 卢茂聪
Original assignee: Guangdong Chippacking Technology Co ltd
Current assignee: Guangdong Chippacking Technology Co ltd
Priority date: 2020-08-18
Filing date: 2020-08-18
Publication date: 2021-03-05
Anticipated expiration: 2030-08-18

Abstract

The utility model relates to a DFN or QFN lead frame, including base island, pin and plastic-sealed material, the plastic-sealed material connects into a whole frame with base island, pin. The novel structure is adopted, the copper sheet stamping process idea is completely separated, the base island and the pins are connected into an integral frame by using the plastic packaging material, the positions and the fixing firmness of the base island and the pins are ensured by using the plastic packaging material, and the material utilization rate of the copper material is very high without arranging connecting ribs and peripheral frames in the traditional lead frame, so that a front film pasting process or a rear film pasting process is not needed; the lead frame has higher strength, is not easy to deform due to abnormal production, has stronger strength and supporting force of the pins, and can avoid the deformation of the base island or the pins caused by multiple bonding; after the chip is packaged into a single packaged product, the chip finished product is completely wrapped by the plastic package body due to no connecting ribs, so that the chip has extremely good sealing property, and water vapor is extremely difficult to invade into the plastic package body; and the phenomenon of glue overflow abnormity in the plastic packaging process is avoided.

Description

DFN or QFN lead frame

Technical Field

The utility model relates to a chip package technical field especially relates to a DFN or QFN lead frame.

Background

The lead frame in the prior art is formed by punching a copper sheet and comprises a plurality of lead frame units, the lead frame units are connected by connecting ribs to form an array, then a chip is adhered to the lead frame, a wire is bonded to the lead frame, then plastic Package is carried out, and finally cutting and separating are carried out to obtain a single packaged product. The lead frame has low material utilization rate and general pin strength, is easy to deform during bonding for multiple times, and needs to be improved.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a DFN or QFN lead frame that material utilization is high, intensity is high.

The utility model provides a technical scheme does: a DFN or QFN lead frame comprises a base island, pins and a plastic package material, wherein the base island and the pins are connected into an integral frame by the plastic package material.

Wherein, part of the pins are shared pins of adjacent lead frame units.

The utility model has the advantages that: the DFN or QFN lead frame adopts a brand-new structure, completely breaks away from the copper sheet stamping process thought, connects the base island and the pins into an integral frame by using a plastic package material (which is equivalent to embedding the base island and the pins on the plastic package material), and ensures the positions and the fixed firmness of the base island and the pins by using the plastic package material; the lead frame has higher strength, is not easy to deform due to abnormal production, has stronger strength and supporting force of the pins, and can avoid the deformation of the base island or the pins caused by multiple bonding; after the chip is packaged into a single packaged product, the chip finished product is completely wrapped by the plastic package body due to no connecting ribs, so that the chip has extremely good sealing property, and water vapor is extremely difficult to invade into the plastic package body; the phenomenon of glue overflow abnormity in the plastic packaging process is avoided; has good advantages in cost and performance, and is worth popularizing.

Drawings

Fig. 1 is a schematic perspective view of a DFN or QFN lead frame according to a first embodiment of the present invention;

FIG. 2 is a schematic perspective view of a lead frame unit in a first embodiment of a DFN or QFN lead frame of the present invention;

fig. 3 is a schematic diagram of arranging the strip-shaped base islands and the pins in the first step of the manufacturing method of the DFN or QFN lead frame according to the present invention;

FIG. 4 is a schematic diagram of a post-injection molding compound formed in step two of the manufacturing method of the DFN or QFN lead frame according to the present invention;

fig. 5 is a schematic diagram of the DFN or QFN lead frame manufacturing method according to the present invention after the pillar is cut into thin pieces in the third step;

fig. 6 is a top view of a first embodiment of a DFN or QFN leadframe according to the present invention;

fig. 7 is a top view of a second embodiment of a DFN or QFN leadframe of the present invention;

fig. 8 is a top view of a third embodiment of a DFN or QFN leadframe of the present invention;

fig. 9 is a top view of a fourth embodiment of a DFN or QFN leadframe of the present invention.

The dashed lines in fig. 1, 6, 7, 8, 9 are only used to show the distinction of the lead frame elements, non-structural lines.

Wherein, 1, a base island; 2. a pin; 3. plastic packaging material; 4. a lead frame unit.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

As an embodiment one of the DFN or QFN lead frame of the present invention, as shown in fig. 1 to fig. 6, includes a base island 1, pins 2 and a molding compound 3, the molding compound 3 connects the base island 1 and the pins 2 into an integral frame.

The utility model discloses a manufacturing method of DFN or QFN lead frame, including following step:

s1: arranging the strip-shaped base island and the pins in an injection mold according to the position requirement;

s2, injecting plastic package material into the injection mould, wherein the plastic package material wraps the base island and the pins to form a columnar body;

s3: and cutting the columnar body into slices to form the DFN or QFN lead frame.

The DFN or QFN lead frame adopts a brand-new structure, completely breaks away from the copper sheet stamping process thought, the base island 1 and the pins 2 are connected into an integral frame by the plastic package material 3 (equivalent to embedding the base island 1 and the pins 2 on the plastic package material 3), the positions and the fixed firmness of the base island 1 and the pins 2 are ensured by the plastic package material 3, and the material utilization rate of a copper material is very high without a front film pasting or a back film pasting process because connecting ribs and peripheral frames in the traditional lead frame are not required to be arranged; the lead frame has higher strength, is not easy to deform due to abnormal production, has stronger strength and supporting force of the pin 2, and can avoid the deformation of the base island or the pin caused by multiple bonding; after the chip is packaged into a single packaged product, the chip finished product is completely wrapped by the plastic package body due to no connecting ribs, so that the chip has extremely good sealing property, and water vapor is extremely difficult to invade into the plastic package body; the phenomenon of glue overflow abnormity in the plastic packaging process is avoided; has good advantages in cost and performance, and is worth popularizing.

In the present embodiment, some of the leads are shared by adjacent lead frame units. In the cutting process, the plastic encapsulated lead frame needs to be cut and separated into single packaged products, and the common pin needs to be cut into two parts. If the metal is not cut, the technical scheme (embodiment three) as shown in fig. 8 can be adopted, and when the chip unit is cut, only the plastic package material is cut, so that the cutting is easier.

Before the step S1, the utility model also includes a step S0.5 of pouring the copper juice into the casting mold to make the strip-shaped base island and the pins. Of course, the strip-shaped base island and the pins can be manufactured in other manners.

As an embodiment two of the DFN or QFN lead frame of the present invention, as shown in fig. 7, the difference from the embodiment one lies in that four sides of the lead frame unit 4 are all provided with the pins 2 (only two sides are provided with the pins in the embodiment one), and other structures and beneficial effects are all consistent with the embodiment one by one.

As the fourth embodiment of the DFN or QFN lead frame of the present invention, as shown in fig. 9, the difference from the second embodiment is that there is no common pin, and when cutting into chip units, only the molding compound is cut, and the cutting is easier.

In the present application, the first to fourth embodiments are all 3 × 4 arrays, and there are 12 lead frame units 4, which are only examples, and in the actual production process, there may be m × n arrays and m × m arrays, where m and n are both natural numbers.

The above description is only exemplary of the present invention and should not be taken as limiting the scope of the present invention, as any modifications, equivalents, improvements and the like made within the spirit and principles of the present invention are intended to be included within the scope of the present invention.

Claims

1. The DFN or QFN lead frame is characterized by comprising a base island, pins and a plastic package material, wherein the base island and the pins are connected into an integral frame by the plastic package material.

2. The DFN or QFN leadframe according to claim 1, wherein some of the leads are common leads for adjacent leadframe units.