CN109935566A - Modified SOT223 frame - Google Patents

Abstract

Modified SOT223 frame, its binding force that base island pin and plastic packaging material can be improved, reduce the layering between frame and plastic packaging material, can avoid properties of product reduces, and guarantees product quality comprising Ji Dao, pin, the periphery setting of the Ji Dao is fluted, through-hole is provided on the pin, the Ji Dao, pin are encapsulated by plastic packaging material, and the plastic packaging material is filled in the groove, through-hole.

Description

Improved SOT223 framework

technical field

The invention relates to the technical field of integrated circuit packaging, in particular to an improved SOT223 frame.

Background technique

With the increasing demand for portable and small digital electronic products such as mobile phones and notebook computers and the continuous progress of chip processing technology, the production of integrated circuit chips has entered the stage of mass production, making integrated circuits develop in the direction of small size, high stability and high quality. It has become a problem that people in the field pay more and more attention to. The integrated circuit is mainly composed of a wire bonding frame, a chip and a plastic body. The wire bonding frame and the chip are packaged together through the plastic sealing body. At present, the commonly used wire bonding frame includes the SOT223 frame, but the existing SOT223 frame base island is relatively large, as shown in the figure As shown in 1, during bonding, the bonding strength between the pins on the base island and the plastic compound is poor, and due to the influence of the external environment, the frame and the plastic compound are easily delaminated, resulting in reduced product performance and poor quality. .

SUMMARY OF THE INVENTION

Aiming at the problems in the prior art that the bonding strength between the pins on the base island and the plastic sealing compound is poor, and the frame and the plastic sealing compound are easily delaminated, resulting in low product performance and poor quality, etc., the present invention provides an improved SOT223 The frame can improve the bonding force between the base island pins and the plastic sealing compound, reduce the delamination between the frame and the plastic sealing compound, avoid product performance degradation and ensure product quality.

An improved SOT223 frame, comprising a base island and pins, characterized in that: the periphery of the base island is provided with grooves, the pins are provided with through holes, and the base island and the pins are made of plastic sealing compound The package is integrated, and the groove and the through hole are filled with the plastic sealing compound.

It is further characterized in that, the pins include at least three, which are respectively a first pin, a second pin, and a third pin, and the first pin and the third pin are respectively arranged on the base island. On both sides, the sides of the first lead and the third lead are respectively arranged corresponding to the two sides of the base island, and there are provided between the first lead, the third lead and the base island. a gap, the second pin is arranged between the first pin and the third pin and is connected to one side of the base island to form an integral body;

The first pin, the second pin and the third pin are respectively provided with the through holes;

The grooves are respectively opened on both sides of the base island corresponding to the sides of the first pin and the third pin;

The groove is in the shape of an arc surface, and the through hole is in a circular shape;

The plastic sealing compound is respectively filled in the through holes and the grooves to form pillars;

A chip is installed on the base island, and the pads on the chip are connected to the pins through bonding wires;

The base islands and the pins are made of copper, and the surfaces of the base islands and the pins are silver-plated;

The material of the molding compound is epoxy resin;

The model of the chip is: BL1117-3.3, the bonding wires include six, which are the first bonding wire to the sixth bonding wire, the first bonding wire is connected to the first pin, the second bonding wire is The wire, the third bonding wire, and the fourth bonding wire are respectively connected to the base island, and the fifth bonding wire and the sixth bonding wire are respectively connected to the third pin.

With the above structure of the present invention, a groove is formed around the base island. When the base island is encapsulated by plastic sealing material, the plastic sealing material is filled in the groove to form a column, and the column can prevent the base island from shaking due to the influence of the external environment, thereby The bonding force between the plastic and the base island is enhanced. Similarly, holes are opened on the pins, and the plastic is filled in the through holes to form cylinders. The cylinders can prevent the pins from shaking due to the influence of the external environment, that is, through the through holes The inner plastic compound and the plastic body formed by the plastic compound are locked, thereby enhancing the bonding force between the plastic compound and the pins; and the columns formed after the grooves and through holes are filled also play a role in the vertical alignment of the base island and the pins. The support on the surface greatly reduces the delamination between the base island, the lead and the plastic packaging material, thereby avoiding the degradation of product performance and ensuring product quality and reliability.

Description of drawings

Fig. 1 is the top-view structural schematic diagram of the existing SOT223 frame;

Fig. 2 is the structural schematic diagram of the present invention top view;

3 is a schematic structural diagram of the present invention connecting a chip and a pin by a wire;

FIG. 4 is a schematic structural diagram of the present invention after being encapsulated by a plastic sealing compound.

Detailed ways

Referring to Figures 2 to 4, an improved SOT223 frame includes a base island 1 and a pin 2. The materials of the base island 1 and the pin 2 are copper, and the surfaces of the base island 1 and the pin 2 are silver-plated; The pin 2 includes at least three pins, which are a first pin 21, a second pin 22, and a third pin 23. The first pin 21 and the third pin 23 are respectively arranged on both sides of the base island 1. The sides of the pin 21 and the third pin 23 are arranged corresponding to the two sides of the base island 1 respectively. A gap 25 is set between the first pin 21 , the third pin 23 and the base island 1 . 21. The third pin 23 is arranged symmetrically with the vertical center line of the base island 1 as the axis, and the second pin 22 is arranged between the first pin 21 and the third pin 23 to connect with one side of the base island 1. Integrated, the first pin 21, the second pin 22, and the third pin 23 are respectively provided with through holes 4, and the through holes 4 are circular;

The two sides of the base island 1 corresponding to the sides of the first pin 21 and the second pin 22 are respectively provided with four grooves 3, and the grooves 3 are arc-shaped;

The base island 1 , the first pin 21 , the second pin 22 and the third pin 23 are surrounded and fixed by a plastic sealing compound 6 . The material of the plastic sealing compound 6 is epoxy resin, and the grooves 3 and the through holes 4 are filled with plastic sealing compounds. Material 6, the plastic sealing compound 6 is filled in the through hole 4 to form a column, and the plastic sealing compound 6 is filled in the groove 3 to form a column; the base island 1 is dotted with adhesive film, and then the chip 7 is installed, and the chip 7 passes through the adhesive film. The glue is fixed to the base island 1, and the pads on the chip 7 are respectively connected to the first pin 21, the second pin 22, and the third pin 23 through the bonding wire 5;

The model of the chip in this embodiment is: BL1117-3.3, the bonding wires 5 include six, which are the first bonding wire 51 to the sixth bonding wire 56, the first bonding wire 51 is connected to the first pin 21, and the second bonding wire 52. The third bonding wire 53 and the fourth bonding wire 54 are respectively connected to the base island 1. Because the base island 1 and the second pin 22 are connected to form an integral body, the second bonding wire 52, the third bonding wire 53, and the fourth bonding wire The wires 54 are respectively connected with the second pins 22, and the fifth bonding wires 55 and the sixth bonding wires 56 are respectively connected with the third pins 23. The package structure of the SOT223 frame equipped with the chip can be used for precision power circuit devices in the field of industrial control. In the middle, it plays a role in stabilizing the voltage and ensuring that the voltage signal is more stable;

The present invention reduces the lateral distance of the base island 1, and the distance between the base island 1 and the pin 2 remains unchanged. In the prior art, the lateral distance of the base island 1 is L, and the shortened lateral distance of the base island 1 is l , in this embodiment, L is 3.7mm, l is 2.2mm, the distance between the first pin 21, the third pin 23 and the base island 1 is unchanged, thereby shortening the distance of the welding wire and solving the hidden danger of deformation of the welding wire , while reducing the amount of welding wire and improving processing efficiency.

Its working principle is as follows: in the process of encapsulating the improved SOT223 frame, point adhesive on the base island 1 of the SOT223 frame, and bond the chip 7 to the base island 1, and the chip 7 is provided with a solder joint. The chip 7 is connected to each pin 2 through the welding wire 5, and then the whole is put into the mold of the molding machine, and the plastic sealing compound 6 is injected into the high temperature to surround the base island 1, the chip 7 on the base island, and the pin 2. At the same time, the plastic sealing compound 6 is filled in the groove 3 and the through hole 4 to form a package, and then the whole package is cooled by blowing cold air. An effective anti-drag structure is formed between it and the plastic sealing compound 6, which greatly reduces the delamination of the package; put the plastic-sealed frame into an ultrasonic scanner (SONOSCAN, USA) to detect whether there are air holes during the plastic sealing process, so as to detect the packaging. Through testing, the package structure has good bonding force, which effectively avoids the delamination of the plastic package composed of the base island 1, the pin 2, the chip 7 and the plastic package 6.

Claims (8)

1. a kind of modified SOT223 frame comprising Ji Dao, pin, it is characterised in that: the periphery of the Ji Dao is provided with recessed Slot is provided with through-hole on the pin, and the Ji Dao, pin are packaged as a whole with plastic packaging material, are filled in the groove, through-hole State plastic packaging material.

2. a kind of modified SOT223 frame according to claim 1, which is characterized in that the pin includes at least three A, respectively the first pin, second pin, third pin, first pin, third pin are respectively arranged in the Ji Dao's Two sides, first pin, third pin side respectively it is corresponding with the two sides of the Ji Dao arrangement, first pin, Gap is provided between third pin and the base island, the second pin is arranged between first pin, third pin One is connected and composed with the side of the Ji Dao.

3. a kind of modified SOT223 frame according to claim 2, which is characterized in that first pin, second are drawn The through-hole is had on foot, third pin.

4. a kind of modified SOT223 frame according to claim 3, which is characterized in that with first pin, third The two sides of the corresponding Ji Dao in pin side have the groove.

5. according to claim 1 or a kind of 4 described in any item modified SOT223 frames, which is characterized in that the groove is Arc surface shape, the through-hole are circle.

6. a kind of modified SOT223 frame according to claim 5, which is characterized in that the plastic packaging material is filled in respectively Cylinder is formed in the through-hole, groove.

7. a kind of modified SOT223 frame according to claim 6, which is characterized in that be equipped with core on the Ji Dao Piece, the pad on the chip are connect by bonding wire with pin.

8. according to claim 1 or a kind of 7 described in any item modified SOT223 frames, which is characterized in that the plastic packaging material Material be epoxy resin.