Packaging structure and preparation method of large QFN front film frame

Abstract

The present invention relates to the field of chip packaging technology, and specifically to a packaging structure and a preparation method of a large QFN front film frame, comprising: a base island is arranged on the surface of a lead frame body, a first pin and a second pin are arranged around the base island, and a collecting cavity is opened on both sides of each of the first pin and the second pin; an air outlet bin is arranged on both sides of the first pin and the second pin, and the air outlet bin comprises an upper cover plate, a lower cover plate and a vertical member, a limiting groove is opened on the surface of the lead frame body, the limiting groove surrounds the base island, an annular angle rib is installed in the limiting groove, the lead frame body is plastic-sealed by a plastic sealing body, the chip body is connected to the base island by a chip connecting glue, and a first wiring area and a second wiring area are arranged around the base island; the beneficial effect is: the patent of the present invention can ensure that during the packaging bonding process, large front film products no longer shake, the bonding is stable, the heat dissipation is improved, the product line is more comprehensive, and will not be limited to small sizes.

Description

Technical Field

[0001] The present invention relates to the technical field of chip packaging, in particular to a packaging structure of a large QFN front film frame and a preparation method thereof. Background Art

[0002] QFN (Quad Flat No-leads Package) is one of the surface mount packages. QFN is the name specified by the Japan Electronic Machinery Industry Association. There are electrode contacts on the four sides of the package. Since there are no leads, the mounting area is small and the height is low. There is a large exposed pad in the center of the bottom of the QFN package for heat conduction, and there are conductive pads around the package periphery surrounding the large pad to achieve electrical connection.

[0003] In the prior art, there are still many markets for front films in the industry because the front film does not require film-sticking equipment in the packaging factory, has low introduction costs, and has zero labor costs.

[0004] However, the traditional front film frame is prone to shaking during bonding, making it difficult to produce products with more lines and larger sizes. Therefore, the present invention proposes a packaging structure and a preparation method for a large QFN front film frame to solve the above problems. Summary of the invention

[0005] The object of the present invention is to provide a packaging structure and a preparation method of a large QFN front film frame to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solution: a packaging structure of a large QFN front film frame, the packaging structure of the large QFN front film frame comprising: a lead frame body, a base island is arranged on the surface of the lead frame body, a first pin and a second pin are arranged around the base island, and a collecting cavity is opened on both sides of each of the first pin and the second pin;

[0007] The air outlet bin is arranged on both sides of the first pin and the second pin, and comprises an upper cover plate, a lower cover plate and a vertical member.

[0008] Preferably, a limiting groove is provided on the surface of the lead frame body, the limiting groove surrounds the base island, an annular angle rib is installed in the limiting groove, and the lead frame body is plastic-sealed by a plastic sealing body.

[0009] Preferably, a chip body is provided in the base island, and the chip body is connected to the base island through chip connecting glue. A first wiring area and a second wiring area are provided around the base island. The first wiring area is located on the left and right sides of the base island, and the second wiring area is located on the upper and lower sides of the base island.

[0010] Preferably, the first pins are located at left and right sides of the base island, the second pins are located at upper and lower sides of the base island, the first pins are connected to the chip body through leads, and the second pins are connected to the chip body through leads.

[0011] Preferably, a first heat sink reinforcement rib, a second heat sink reinforcement rib, a third heat sink reinforcement rib, a fourth heat sink reinforcement rib, a fifth heat sink reinforcement rib and a sixth heat sink reinforcement rib are provided between the base island and the first pin, and a first heat sink reinforcement rib, a second heat sink reinforcement rib, a third heat sink reinforcement rib, a fourth heat sink reinforcement rib, a fifth heat sink reinforcement rib and a sixth heat sink reinforcement rib are provided between the base island and the second pin.

[0012] Preferably, a ventilation area is provided between the first heat sink reinforcement rib and the second heat sink reinforcement rib, a ventilation area is provided between the second heat sink reinforcement rib and the third heat sink reinforcement rib, a ventilation area is provided between the third heat sink reinforcement rib and the fourth heat sink reinforcement rib, a ventilation area is provided between the fourth heat sink reinforcement rib and the fifth heat sink reinforcement rib, and a ventilation area is provided between the fifth heat sink reinforcement rib and the sixth heat sink reinforcement rib.

[0013] Preferably, the ventilation area is provided with a first air outlet area, a second air outlet area, a third air outlet area and a fourth air outlet area, and the first air outlet area, the second air outlet area, the third air outlet area and the fourth air outlet area are equidistantly distributed from top to bottom in the ventilation area, and each air outlet area includes four circular through holes, and the four circular through holes are equidistantly linearly distributed in each air outlet area.

[0014] Preferably, the interior of the lead frame body is provided with a first connecting cavity, a second connecting cavity, a third connecting cavity and a fourth connecting cavity, the first connecting cavity is communicated with the first air outlet area, the second connecting cavity is communicated with the second air outlet area, the third connecting cavity is communicated with the third air outlet area, and the fourth connecting cavity is communicated with the fourth air outlet area.

[0015] Preferably, the first connecting chamber, the second connecting chamber, the third connecting chamber and the fourth connecting chamber are all connected to the collecting chamber, a lower cover plate is fixed at the outlet of the collecting chamber, a vertical piece is fixed on the lower cover plate, an upper cover plate is fixed on the upper end of the vertical piece, a plurality of air outlet channels are opened on the surface of the vertical piece, and the plurality of air outlet channels are evenly distributed on the surface of the vertical piece.

[0016] The invention discloses a method for preparing a packaging structure of a large QFN front film frame, comprising the packaging structure of the large QFN front film frame.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The packaging structure and preparation method of the large QFN front film frame proposed in the present invention can ensure that during the packaging bonding process, the large front film product will no longer shake, the bonding will be stable, the heat dissipation will be improved, the product line will be more comprehensive, and will not be limited to small sizes; multiple heat sink reinforcement ribs are added at the base conductor and the pin, and the reinforcement ribs can effectively stabilize the pin part, increase the connection strength between the pin and the base conductor, so that it will no longer shake during bonding, reduce the risk of pin deformation and the PPM of the two solder joint alarm, and improve the life of the bonding cutter. It can be suitable for products with a large number of complex lines, and the reinforcement ribs are made of heat dissipation material to achieve better heat dissipation. At the same time, the ventilation area, multiple connection cavities, collection cavity and other components provided can effectively dissipate the heat of the base island, thereby avoiding the problem that the traditional front film frame is prone to shaking during bonding and it is difficult to make products with more lines and larger sizes. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure of the present invention;

[0020] Figure 2 This is a schematic diagram of the first heat sink reinforcement rib structure of the present invention;

[0021] Figure 3 It is a schematic diagram of the ventilation area structure of the present invention;

[0022] Figure 4 It is a detailed diagram of the structure of the present invention;

[0023] Figure 5 It is a schematic diagram of the collecting chamber structure of the present invention.

[0024] In the figure: 1. lead frame body; 2. first pin; 3. annular angle rib; 4. base island; 5. chip connection glue; 6. chip body; 7. first wiring area; 8. second wiring area; 9. second pin; 10. limiting groove; 11. air outlet bin; 12. first heat sink reinforcement rib; 13. ventilation area; 14. second heat sink reinforcement rib; 15. third heat sink reinforcement rib; 16. fourth heat sink reinforcement rib; 17. fifth heat sink reinforcement rib; 18. sixth heat sink reinforcement rib; 19. upper cover; 20. air outlet channel; 21. lower cover; 22. first air outlet area; 23. second air outlet area; 24. third air outlet area; 25. fourth air outlet area; 26. collecting cavity; 27. first connecting cavity; 28. second connecting cavity; 29. ​​third connecting cavity; 30. fourth connecting cavity; 31. vertical member. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the technical solutions in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] Embodiment 1

[0027] See also Figure 1-Figure 5 The present invention provides a technical solution: a packaging structure of a large QFN front film frame, the packaging structure of the large QFN front film frame comprising: a lead frame body 1, a base island 4 is arranged on the surface of the lead frame body 1, a first pin 2 and a second pin 9 are arranged around the base island 4, and a collecting cavity 26 is opened on both sides of each of the first pin 2 and the second pin 9;

[0028] The air outlet bin 11 is arranged on both sides of the first pin 2 and the second pin 9, and the air outlet bin 11 includes an upper cover plate 19, a lower cover plate 21 and a vertical member 31; a chip body 6 is arranged in the base island 4, and the chip body 6 is connected to the base island 4 through a chip connection glue 5, and a first wiring area 7 and a second wiring area 8 are arranged around the base island 4, the first wiring area 7 is located on the left and right sides of the base island 4, and the second wiring area 8 is located on the upper and lower sides of the base island 4. A method for preparing a packaging structure of a large QFN front film frame, including the packaging structure of the large QFN front film frame;

[0029] Since multiple heat sink reinforcement ribs are added between the base conductor and the pin, the reinforcement ribs can effectively stabilize the pin part, increase the connection strength between the pin and the base conductor, so that it will no longer shake during bonding, reduce the risk of pin deformation and the PPM of the second solder joint alarm, and improve the life of the bonding cutter. It can be suitable for products with many and complex lines, and the reinforcement ribs are made of heat dissipation material to achieve better heat dissipation, thereby ensuring that during the packaging bonding process, large front-film products will no longer shake, stabilize bonding, improve heat dissipation, and have a more comprehensive product line that is not limited to small sizes.

[0030] Embodiment 2

[0031] On the basis of the first embodiment, a base island 4 is provided, a chip body 6 is provided in the base island 4, the chip body 6 is connected to the base island 4 through a chip connection glue 5, a first wiring area 7 and a second wiring area 8 are provided around the base island 4, the first wiring area 7 is located on the left and right sides of the base island 4, and the second wiring area 8 is located on the upper and lower sides of the base island 4;

[0032] A limiting groove 10 is provided on the surface of the lead frame body 1 . The limiting groove 10 surrounds the base island 4 . An annular angle rib 3 is installed in the limiting groove 10 . The lead frame body 1 is plastic-sealed by a plastic sealing body.

[0033] The first pin 2 is located at the left and right sides of the base island 4, and the second pin 9 is located at the upper and lower sides of the base island 4. The first pin 2 is connected to the chip body 6 through a lead, and the second pin 9 is connected to the chip body 6 through a lead;

[0034] When in use, the chip body 6 is installed on the base island 4 through the chip connecting glue 5. Subsequently, in order to achieve electrical connection, the chip body 6 is connected to the first pin 2 and the second pin 9 through leads, and the side of the lead frame body 1 where the chip is set is completely plastic-sealed through a plastic sealing body. A heat dissipation surface is provided on the side where the chip is not set, and the heat dissipation surface is exposed to the plastic sealing body. Therefore, the heat dissipation surface should protrude from the lead frame body 1, so that it is convenient to expose the heat dissipation surface during plastic sealing; the exposure of the heat dissipation surface allows the heat generated by the chip body 6 during operation to be conducted to the base island 4, and then the heat dissipation is effectively dissipated through the heat dissipation surface of the base island 4, thereby further improving the heat dissipation performance, and the annular angle rib 3 installed in the limiting groove 10 is arranged on the surface of the lead frame body 1 in a ring shape as a whole, thereby improving the overall stability of the lead frame body 1.

[0035] Embodiment 3

[0036] On the basis of the second embodiment, a first heat sink reinforcement rib 12, a second heat sink reinforcement rib 14, a third heat sink reinforcement rib 15, a fourth heat sink reinforcement rib 16, a fifth heat sink reinforcement rib 17 and a sixth heat sink reinforcement rib 18 are provided between the base island 4 and the first pin 2, and a first heat sink reinforcement rib 12, a second heat sink reinforcement rib 14, a third heat sink reinforcement rib 15, a fourth heat sink reinforcement rib 16, a fifth heat sink reinforcement rib 17 and a sixth heat sink reinforcement rib 18 are provided between the base island 4 and the second pin 9;

[0037] A ventilation area 13 is provided between the first heat sink reinforcement rib 12 and the second heat sink reinforcement rib 14, a ventilation area 13 is provided between the second heat sink reinforcement rib 14 and the third heat sink reinforcement rib 15, a ventilation area 13 is provided between the third heat sink reinforcement rib 15 and the fourth heat sink reinforcement rib 16, a ventilation area 13 is provided between the fourth heat sink reinforcement rib 16 and the fifth heat sink reinforcement rib 17, and a ventilation area 13 is provided between the fifth heat sink reinforcement rib 17 and the sixth heat sink reinforcement rib 18;

[0038] The ventilation area 13 is provided with a first air outlet area 22, a second air outlet area 23, a third air outlet area 24 and a fourth air outlet area 25, which are evenly spaced from top to bottom in the ventilation area 13, and each air outlet area includes four circular through holes, which are evenly spaced and linearly distributed in each air outlet area; the lead frame body 1 is provided with a first connecting cavity 27, a second connecting cavity 28, a third connecting cavity 29 and a fourth connecting cavity 30, the first connecting cavity 27, the first connecting cavity 27 and the first air outlet area 22 are communicated, the second connecting cavity 28 and the second air outlet area 23 are communicated, the third connecting cavity 29 and the third air outlet area 24 are communicated, and the fourth connecting cavity 30 and the fourth air outlet area 25 are communicated;

[0039] The first connecting chamber 27, the second connecting chamber 28, the third connecting chamber 29 and the fourth connecting chamber 30 are all connected to the collecting chamber 26. A lower cover plate 21 is fixed at the outlet of the collecting chamber 26. A vertical member 31 is fixed on the lower cover plate 21. An upper cover plate 19 is fixed on the upper end of the vertical member 31. A plurality of air outlet channels 20 are opened on the surface of the vertical member 31. The plurality of air outlet channels 20 are evenly distributed on the surface of the vertical member 31.

[0040] By setting multiple groups of heat sinks between the pins and the base island 4 to strengthen the connecting ribs, the connection strength between the pins and the base conductors is improved. When the chip body 6 is working, the heat generated will be transported to the corresponding connecting cavity through four groups of air outlet areas. Each air outlet area corresponds to a corresponding connecting cavity. Multiple air outlet areas complement each other, and multiple connecting cavities do not interfere with each other, thereby improving the intensity of heat dissipation. Finally, the heat will flow together into the collecting cavity 26. The lower cover plate 21, upper cover plate 19 and vertical member 31 will allow the heat to flow out through the opened air outlet channel 20, thereby improving the heat dissipation performance.

[0041] In actual use, due to the addition of multiple heat sink reinforcement ribs between the base conductor and the pin, the reinforcement ribs can effectively stabilize the pin part, increase the connection strength between the pin and the base conductor, so that it no longer shakes during bonding, reduces the risk of pin deformation and the PPM of the second solder joint alarm, and improves the life of the bonding cutter. It can be suitable for products with a large number of complex lines, and the reinforcement ribs are made of heat dissipation material to achieve better heat dissipation, thereby ensuring that during the packaging bonding process, large front-film products will no longer shake, stable bonding, and improved heat dissipation. The product line is more comprehensive and will not be limited to small sizes. This avoids the problem that the traditional front-film frame is prone to shaking during bonding, making it difficult to produce products with more lines and larger sizes.

[0042] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. The packaging structure of the large QFN front film frame is characterized by: The packaging structure of the large QFN front film frame comprises: a lead frame body (1), a base island (4) is arranged on the surface of the lead frame body (1), a first pin (2) and a second pin (9) are arranged around the base island (4), and a collecting cavity (26) is opened in the lead frame body (1) below and on both sides of each first pin (2) and second pin (9); A first heat sink reinforcement rib (12), a second heat sink reinforcement rib (14), a third heat sink reinforcement rib (15), a fourth heat sink reinforcement rib (16), a fifth heat sink reinforcement rib (17) and a sixth heat sink reinforcement rib (18) are provided between the base island (4) and the first pin (2); and a first heat sink reinforcement rib (12), a second heat sink reinforcement rib (14), a third heat sink reinforcement rib (15), a fourth heat sink reinforcement rib (16), a fifth heat sink reinforcement rib (17) and a sixth heat sink reinforcement rib (18) are provided between the base island (4) and the second pin (9); A ventilation area (13) is provided between the first heat sink reinforcement rib (12) and the second heat sink reinforcement rib (14), a ventilation area (13) is provided between the second heat sink reinforcement rib (14) and the third heat sink reinforcement rib (15), a ventilation area (13) is provided between the third heat sink reinforcement rib (15) and the fourth heat sink reinforcement rib (16), a ventilation area (13) is provided between the fourth heat sink reinforcement rib (16) and the fifth heat sink reinforcement rib (17), and a ventilation area (13) is provided between the fifth heat sink reinforcement rib (17) and the sixth heat sink reinforcement rib (18); The lead frame body (1) is provided with a first connecting cavity (27), a second connecting cavity (28), a third connecting cavity (29) and a fourth connecting cavity (30) inside, the first connecting cavity (27) being in communication with the first gas outlet area (22), the second connecting cavity (28) being in communication with the second gas outlet area (23), the third connecting cavity (29) being in communication with the third gas outlet area (24), and the fourth connecting cavity (30) being in communication with the fourth gas outlet area (25); The first connecting cavity (27), the second connecting cavity (28), the third connecting cavity (29) and the fourth connecting cavity (30) are all in communication with the collecting cavity (26); the outlet of the collecting cavity (26) is located on both sides of the first pin (2) and the second pin (9); a lower cover plate (21) is fixed at the outlet of the collecting cavity (26); a vertical member (31) is fixed on the lower cover plate (21); an upper cover plate (19) is fixed at the upper end of the vertical member (31); a plurality of air outlet channels (20) are provided on the surface of the vertical member (31); and the plurality of air outlet channels (20) are evenly distributed on the surface of the vertical member (31); An air outlet bin (11) is arranged on both sides of the first pin (2) and the second pin (9), and the air outlet bin (11) comprises an upper cover plate (19), a lower cover plate (21) and a vertical member (31).

2. The packaging structure of the large QFN front film frame according to claim 1, characterized in that: A limiting groove (10) is provided on the surface of the lead frame body (1), the limiting groove (10) surrounds the base island (4), an annular corner rib (3) is installed in the limiting groove (10), and the lead frame body (1) is plastic-sealed by a plastic sealing body.

3. The packaging structure of the large QFN front film frame according to claim 1, characterized in that: A chip body (6) is arranged inside the base island (4), and the chip body (6) is connected to the base island (4) via a chip connection adhesive (5). A first wiring area (7) and a second wiring area (8) are arranged around the base island (4), and the first wiring area (7) is located on the left and right sides of the base island (4), and the second wiring area (8) is located on the upper and lower sides of the base island (4).

4. The packaging structure of the large QFN front film frame according to claim 1, characterized in that: The first pin (2) is located on the left and right sides of the base island (4), and the second pin (9) is located on the upper and lower sides of the base island (4). The first pin (2) is connected to the chip body (6) through a lead wire, and the second pin (9) is connected to the chip body (6) through a lead wire.

5. The packaging structure of the large QFN front film frame according to claim 1, characterized in that: The ventilation area (13) is provided with a first air outlet area (22), a second air outlet area (23), a third air outlet area (24) and a fourth air outlet area (25); the first air outlet area (22), the second air outlet area (23), the third air outlet area (24) and the fourth air outlet area (25) are equidistantly distributed from top to bottom in the ventilation area (13); each air outlet area comprises four circular through holes; and the four circular through holes are equidistantly and linearly distributed on each air outlet area.

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