A DFN packaged device

Abstract

The utility model discloses a kind of DFN encapsulation devices, including matrix metal frame;Matrix metal frame includes if packaging unit, the middle part of packaging unit is equipped with welding area;Welding area is provided with welding material, chip is welded on welding material;The top of welding area is provided with top metal pin, top metal pin is communicated with welding area;Three lower metal pins and a single pin are provided below welding area, and busbar is communicated between lower metal pins, and single pin is connected with metal sheet;Conductive material is connected between busbar and chip, and metal soldering wire is connected between metal sheet and chip;The side of pin is provided with bare copper metal contact point, and solderable plating layer is provided on bare copper metal contact point;Matrix metal frame is coated with plastic packaging material.The utility model realizes the function of tin climbing on the side of encapsulation device on the basis of using punching process to produce double-sided flat DFN encapsulation, has the advantages that welding state is conveniently observed, and welding performance is good.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor device manufacturing technology, and more specifically to a DFN packaged device. Background Technology

[0002] DFN (Dual Flat No-lead Package) is an advanced double-sided or square flat lead-free packaging technology. This package has pads only on the bottom and two sides, and features small size, high density, and good heat dissipation. It is widely used in semiconductor component packaging.

[0003] Currently, DFN packaged devices are manufactured using a punched pin method, exposing the metal pins on the side. However, the exposed metal pin contact points are not covered by an electroplating layer, making side soldering impossible. Furthermore, the exposed copper is prone to oxidation in the air, reducing the quality of the solder joint. When the product is soldered onto the PCB, the use of metal contact packaging instead of the previous pin-like leads makes it difficult to judge the solder joints from the product's appearance, especially the condition of the solder on the bottom. Therefore, this structure cannot perform AOI (Automated Optical Inspection) using an automatic camera system and image analysis configured for automatic solder joint defect identification. Instead, it requires perspective methods such as X-ray to judge the soldering effect, but this inspection cost is high, resulting in lower product reliability.

[0004] Therefore, there is an urgent need for a DFN packaged device. Summary of the Invention

[0005] The technical problem to be solved by this utility model is to provide a DFN packaged device to solve the problems in the background art.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows.

[0007] A DFN (Digital-Dependent Neck) packaged device includes a matrix metal frame; the matrix metal frame includes several package units arranged in a matrix, with a soldering area in the center of each package unit; soldering material is disposed on the soldering area, and a chip is soldered onto the soldering material; four vertically arranged upper metal pins are disposed above the soldering area, and the bottom of each upper metal pin is connected to the soldering area; three vertically arranged lower metal pins and one individual pin are disposed below the soldering area, with a busbar connecting the lower metal pins and the individual pin connected to a metal sheet; a conductive material is connected between the busbar and the chip, and a metal bonding wire is connected between the metal sheet and the chip; bare copper metal contacts are disposed on the sides of the upper metal pins, lower metal pins, and individual pin, and a solderable plating layer is disposed on the bare copper metal contacts, with each of the upper metal pins, lower metal pins, and individual pin extending 0.2 mm beyond the packaged device body; the matrix metal frame is covered with a molding compound, which wraps around the chip, conductive material, metal bonding wire, and the chip-side of the matrix metal frame.

[0008] To further optimize the technical solution, the matrix metal frame is provided with a number of circular positioning holes evenly distributed on its upper edge and a number of rectangular positioning holes evenly distributed on its lower edge.

[0009] To further optimize the technical solution, the chip has a first source, a second source, and a gate on the front side, and a drain on the back side, with the first and second sources arranged side by side.

[0010] The technical solution is further optimized in that the conductive material is sequentially connected to the first source electrode, the second source electrode, and the busbar. The conductive material is connected to the first source electrode to form a first bonding point, connected to the second source electrode to form a second bonding point, and connected to the busbar to form a third bonding point.

[0011] To further optimize the technical solution, the conductive material is a metal ribbon or metal wire, and the material is any one of aluminum, copper, or gold.

[0012] To further optimize the technical solution, one end of the metal bonding wire is connected to a metal sheet, and the other end is connected to a gate; the metal bonding wire is either a copper wire or a gold wire, and the diameter of the metal bonding wire is less than 2 mil.

[0013] To further optimize the technical solution, the metal sheet is covered with a silver plating layer, and the height of the busbar and the metal sheet is greater than the height of the welding area, the lower metal pin, and the individual pin.

[0014] To further optimize the technical solution, two horizontally arranged solder reservoirs are provided between the welding area and the upper metal pin.

[0015] Due to the adoption of the above technical solutions, the technical progress achieved by this utility model is as follows.

[0016] This invention provides a DFN packaged device with leads protruding from the package body, providing a larger solderable area and increasing the bonding area between the solder and the leads. During PCB soldering, the solder can climb along the vertical sides of the leads to a greater height, enhancing both soldering performance and reliability. Furthermore, the solder climbing status is clearly visible and can be assessed through automated optical inspection. This invention, based on the punching process for producing double-sided flat DFN packages, achieves side solder climbing functionality, offering advantages such as convenient observation of the soldering status and superior soldering performance. Attached Figure Description

[0017] Figure 1 This is an appearance drawing of the present utility model; Figure 2 This is a schematic diagram of the front structure of the chip in this utility model; Figure 3 This is a schematic diagram of the internal welding structure of the packaging unit in this utility model; Figure 4 This is a side view of the encapsulation unit after it has been covered by the encapsulation material in this utility model; Figure 5 This is a perspective view of the present invention; Figure 6 This is a front view of the bare copper metal contact point of this utility model when no solderable coating has been obtained; Figure 7 This is a back view of the bare copper metal contact point of this utility model when no solderable coating has been obtained; Figure 8 This is a schematic diagram of the packaging unit structure in this utility model; Figure 9 This is a partial structural schematic diagram of the matrix metal frame in this utility model; Wherein: 101. Chip, 102. First source, 103. Second source, 104. Gate; 105. First bonding point, 106. Second bonding point, 107. Third bonding point; 2. Matrix-type metal frame, 201. Circular positioning hole, 202. Rectangular positioning hole, 203. Lower metal pin, 204. Individual pin, 205. Solder reservoir, 206. Soldering area, 207. Pin busbar, 208. Metal sheet, 209. Upper metal pin; 300. Bare copper metal contact point; 301. Solderable plating; 302. Welding material; 303. Metal welding wire; 304. Conductive material; 4. Plastic sealing material. Detailed Implementation

[0018] The present invention will now be described in further detail with reference to the accompanying drawings.

[0019] A DFN packaged device, combined with Figures 1 to 9 As shown, the assembly includes a chip, a matrix metal frame, soldering materials, and molding compound. The chip has a first source, a second source, and a gate. The matrix metal frame includes circular positioning holes, rectangular positioning holes, lower metal leads, individual leads, a solder reservoir, a soldering area, lead busbars, metal sheets, and upper metal leads. Metal bonding wires and conductive materials connect the chip and the matrix metal frame.

[0020] Chip 101 can be a MOS chip. Chip 101 has a first source 102, a second source 103 and a gate 104 on the front side. The first source 102 and the second source 103 are both rectangular and are arranged side by side. The gate 104 is located at the midpoint of the right side of chip 101. The back side of chip 101 is the drain.

[0021] The array metal frame 2 includes several packaging units arranged in a matrix, with a distance between the packaging units. The middle part of the packaging unit is a welding area 206, which is used to place welding material 302, and the chip 101 is welded to the array metal frame 2 by welding material 302.

[0022] The upper part of the packaging unit has four vertically arranged upper metal pins 209, which are located above the soldering area 206, and the bottom of each upper metal pin 209 is connected to the soldering area 206. Two horizontally arranged solder reservoirs 205 are provided between the soldering area 206 and the upper metal pins 209. The length of the solder reservoirs 205 is less than the length of the soldering area 206 to prevent excessive solder material 302 from overflowing from the soldering area 206 onto the upper metal pins 209.

[0023] The lower part of the packaging unit consists of three vertically arranged lower metal pins 203 and a single pin 204 located below the soldering area 206. A busbar 207 connects the lower metal pins 203. The single pin 204 is connected to a metal sheet 208, which is covered with a silver plating layer.

[0024] The height of busbar 207 and metal plate 208 is greater than the height of solder area 206, lower metal pin 203 and individual pin 204.

[0025] The matrix metal frame 2 has several circular positioning holes 201 evenly arranged on its upper edge and several rectangular positioning holes 202 evenly arranged on its lower edge. The upper and lower edges of the matrix metal frame 2 use positioning holes of different shapes, which makes it easier to distinguish the direction of the metal frame.

[0026] Conductive material 304 connects the first source 102 and the second source 103 of chip 101 to the busbar 207 of the matrix metal frame 2 using a double wedge bonding method. Conductive material 304 connects to the first source 102 to form a first bonding point 105, and connects to the second source 103 to form a second bonding point 106. Conductive material 304 connects to the busbar 207 to form a third bonding point 107.

[0027] The conductive material 304 can be in the shape of a metal ribbon or a metal wire, and its material can be any one of aluminum, copper, or gold. The conductive material 304 is preferably aluminum ribbon because aluminum ribbon has excellent electrical, thermal, and mechanical properties. The double wedge bonding connection method provides a larger contact area, resulting in lower contact resistance and better thermal conductivity; at the same time, the two solder joints more firmly lock the aluminum ribbon onto the first source 102 and the second source 103 of the chip 101, ensuring better mechanical strength.

[0028] Metal bonding wire 303 connects the gate 104 of chip 101 to the metal sheet 208 of the matrix metal frame 2. The metal bonding wire 303 can be made of conductive materials 304 such as copper wire or gold wire. Since the diameter of the metal bonding wire 303 is less than 2 mil and there is a pre-plated silver layer on the metal sheet 208, a clean, stable and chemically compatible interface can be provided for the bonding of the metal bonding wire 303, which can form a strong intermetallic compound, thereby ensuring high and consistent bond pull strength and ball shear strength.

[0029] A molding compound is applied to the matrix-type metal frame. The molding compound is preferably an epoxy resin material with insulating properties. The molding compound forms a package that encapsulates the chip 101, the conductive material 304, the metal bonding wires 303, and the chip-side of the matrix-type metal frame 2.

[0030] The exposed portions of the matrix metal frame are all plated with a tin layer, and a solderable plating layer 301 is also provided on the back of the matrix metal frame 2. The tin layer on the matrix metal frame is obtained through a rack plating process after molding. The specific process is as follows: the circular positioning hole 201 on the upper edge of the matrix metal frame 2 is clamped with a rack plating clamp, and then the molded matrix metal frame 2 is immersed in an electroplating solution, so that a solderable plating layer 301 is obtained on the back of the matrix metal frame 2.

[0031] The upper metal pin 209, the lower metal pin 203, and the individual pin 204 all extend 0.2 mm beyond the packaged device body, and the sides of the upper metal pin 209, the lower metal pin 203, and the individual pin 204 are all bare copper metal contacts 300. The bare copper metal contacts 300 are formed by punching after molding. A punching die is used to punch the matrix metal frame 2 along the edge of the molded body to obtain a single packaged device with bare copper metal contacts 300 on the side.

[0032] The surfaces of the upper metal pin 209, the lower metal pin 203, and the individual pin 204 are all covered with a solderable plating layer 301. This solderable plating layer 301 is formed through a barrel plating process. Specifically, an electroplating solution and a metal agitator are added to the electroplating barrel. The metal agitator can be conductive materials such as iron needles or steel balls, and its size is determined by the area of ​​the bare copper metal contact point 300 on the side of the pin. The packaged devices are then placed into the electroplating barrel in batches. As the barrel rolls, the collision between the metal agitator and the packaged devices in the solution creates the solderable plating layer 301 on the bare copper metal contact point 300 on the side of the pin. When the packaged devices are soldered onto the circuit board, because the upper metal pin 209, the lower metal pin 203, and the individual pin 204 all extend beyond the packaged device body, and the bare copper metal contact point 300 has the solderable plating layer 301, the pins can achieve solder creep, thereby enhancing the soldering strength.

Claims

1. A DFN packaged device, characterized by: The system includes a matrix metal frame (2); the matrix metal frame (2) includes several packaging units arranged in a matrix, and a welding area (206) is provided in the middle of the packaging unit; welding material (302) is provided on the welding area (206), and a chip (101) is welded on the welding material (302); four vertically arranged upper metal pins (209) are provided above the welding area (206), and the bottom of each upper metal pin (209) is connected to the welding area (206); three vertically arranged lower metal pins (203) and one individual pin (204) are provided below the welding area (206), a busbar (207) is connected between the lower metal pins (203), and the individual pin (204) is connected to a metal sheet (208); the busbar A conductive material (304) is connected between (207) and the chip (101), and a metal bonding wire (303) is connected between the metal sheet (208) and the chip (101); bare copper metal contact points (300) are provided on the sides of the upper metal pin (209), the lower metal pin (203) and the individual pin (204), and a solderable plating layer (301) is provided on the bare copper metal contact points (300), and the upper metal pin (209), the lower metal pin (203) and the individual pin (204) all extend 0.2mm beyond the packaged device body; the matrix metal frame (2) is covered with a molding compound (4), and the molding compound (4) wraps around the chip (101), the conductive material (304), the metal bonding wire (303), and the side of the matrix metal frame (2) with the chip.

2. The DFN packaged device of claim 1, wherein: The matrix metal frame (2) has several circular positioning holes (201) evenly arranged on its upper edge and several rectangular positioning holes (202) evenly arranged on its lower edge.

3. The DFN packaged device of claim 2, wherein: The chip (101) has a first source (102), a second source (103) and a gate (104) on the front side, and a drain on the back side of the chip (101), with the first source (102) and the second source (103) arranged side by side.

4. The DFN packaged device of claim 3, wherein: The conductive material (304) is sequentially connected to the first source (102), the second source (103), and the busbar (207). The conductive material (304) is connected to the first source (102) to form a first bonding point (105), connected to the second source (103) to form a second bonding point (106), and connected to the busbar (207) to form a third bonding point (107).

5. The DFN packaged device of claim 4, wherein: The conductive material (304) is a metal ribbon or metal wire, and the material is any one of aluminum, copper, or gold.

6. The DFN packaged device of claim 3, wherein: One end of the metal bonding wire is connected to a metal sheet (208), and the other end is connected to a gate (104); the metal bonding wire (303) is either a copper wire or a gold wire, and the diameter of the metal bonding wire (303) is less than 2 mil.

7. The DFN packaged device of claim 1, wherein: The metal sheet (208) is covered with a silver plating layer, and the height of the busbar (207) and the metal sheet (208) is greater than the height of the welding area (206), the lower metal pin (203), and the individual pin (204).

8. A DFN packaged device according to claim 1, characterized in that: Two horizontally arranged tin storage grooves (205) are arranged between the soldering area (206) and the upper metal pin (209).

Images