Chip packaging structure

Abstract

The embodiment of the utility model relates to the technical field of semiconductor packaging, in particular to a chip packaging structure. The packaging structure comprises a packaging frame, a pressure welding clamp and a plastic packaging mold. In the packaging structure, the positions of the frame connecting ribs are designed to be convex, so that the supporting strength of the positions of the base islands is enhanced; stress release grooves are designed at the tail ends of the connecting ribs on the other side to release internal stress generated when the frame connecting ribs are recessed, the layering risk of the base island position is reduced, and the product reliability is improved; through the matching design of the plastic package mold and the frame, the stress generated when the plastic package mold is matched with the frame is reduced, and the risk of frame base island layering caused by the plastic package process is reduced.

Description

TECHNICAL FIELD

[0001] The embodiment of the application relates to the technical field of semiconductor packaging, in particular to a chip packaging structure. BACKGROUND

[0002] The chip is one of the most key components in modern electronic technology, which plays a very important role in various electronic devices. The semiconductor packaging technology is a very important link in the chip manufacturing process, which can protect and reinforce the chip to improve the stability and reliability of the chip. However, in the actual semiconductor packaging process, the problem of chip back delamination often occurs, which will affect the quality and performance of the chip and cause great loss to the manufacturing enterprise. The existing frame structure design does not consider the stress release caused by the frame concave to cause the base island delamination problem. There is a stress release slot designed at the frame connecting rib position in the market, which solves part of the stress release problem, but does not completely improve it. Therefore, we need an effective solution to solve this problem. CONTENT OF THE UTILITY MODEL

[0003] The embodiment of the application provides a chip packaging structure, which can solve the problem of chip back delamination in the packaging process. The technical scheme is as follows:

[0004] The utility model provides a kind of chip packaging structure, and the packaging structure includes packaging frame, press welding fixture and plastic package mould;

[0005] The packaging frame is provided with base island 1, and the base island 1 is provided with protruding design 2 at the connecting rib position;

[0006] The packaging frame is further provided with frame connecting rib 3, the position of the frame connecting rib 3 is concave, the end position of the frame connecting rib 3 is designed with stress release slot 4, and the protruding design 2 is used to increase the supporting strength of the frame connecting rib 3 and improve the coplanarity of the base island 1;

[0007] The press welding fixture includes press welding fixture pressing plate window 7, press welding fixture pressing plate boss 8 and press welding fixture cushion block 9;

[0008] The press welding fixture pressing plate window 7 is located at the frame connecting rib 3, the press welding fixture pressing plate boss 8 is located at the frame connecting rib 3, and the press welding fixture cushion block 9 is designed with slot 10 at the position of the frame connecting rib 3;

[0009] The plastic package mould is provided with exhaust groove 14, and the exhaust groove 14 is arranged at the position of the frame connecting rib 3.

[0010] Optionally, the distance between the stress deformation point generated during the concave processing and the base island 1 satisfies a preset value.

[0011] Optionally, the press welding fixture pressing plate window 7 does not give way to the frame connecting rib 3, and the press welding fixture pressing plate boss 8 and the press welding fixture cushion block connecting rib giving way slot 10 give way to the frame connecting rib 3 under the condition that the design size space of the press welding fixture does not meet the condition.

[0012] Optionally, the position of the exhaust groove 14 and the position of the frame connecting rib 3 are provided with a preset gap, and the preset gap is used to prevent the force generated when the plastic sealing mold is matched with the packaging frame from being transmitted to the base island 1 from the connecting rib during mold clamping and mold opening.

[0013] Optionally, the preset gap is 20 to 30 microns.

[0014] Optionally, the center of the base island 1 is also provided with a press welding fixture vacuum hole 11, and the press welding fixture vacuum hole 11 is used to adsorb the packaging frame when the press welding fixture is wire bonding.

[0015] The application at least brings the following technical effects.

[0016] The utility model provides a kind of chip packaging structure, and packaging structure includes packaging frame, press welding fixture and plastic sealing mold.In packaging structure, frame connecting rib position is designed as protruding, and the support strength of base island position is enhanced;The other side connecting rib end is designed as stress release groove, and the internal stress generated when frame connecting rib is concave is released, the delamination risk of base island position is reduced, and product reliability is improved;The cooperation design of plastic sealing mold and frame reduces the stress generated when plastic sealing mold is matched with frame, and reduces the risk of frame base island delamination caused by plastic sealing process.

[0017] Further, in the packaging structure, the press welding fixture window is designed in two schemes, giving way to the frame connecting rib or not, mainly considering the fixture design space, the press welding fixture pressing plate boss and the press welding fixture cushion block are designed to give way at the connecting rib position, to ensure the pressing of the press welding fixture and the frame, and at the same time, the frame deformation area caused by the interference fit of the fixture and the frame is transferred, so that the base island position is not affected by the deformation amount, thereby reducing the delamination of the die bonding area of the chip and improving the product reliability. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is the unit structure schematic view of lead frame of the utility model;

[0019] Figure 2 It is the cooperation schematic view of lead frame carrier and press welding fixture cushion block of the utility model;

[0020] Figure 3 It is the press welding fixture pressing plate structure schematic view of the utility model;

[0021] Figure 4 It is the press welding fixture cushion block structure schematic view of the utility model;

[0022] Figure 5 Figure 1 is a unit structure of the lead frame of the utility model and a pressing welding clamp cooperation schematic view;

[0023] Figure 6 Figure 2 is a unit structure of the lead frame of the utility model and a plastic encapsulation mold cooperation schematic view.

[0024] Reference signs:

[0025] 0 is a package line; 1 is a base island; 2 is a convex design at a frame web position; 3 is a frame web; 4 is a stress release groove; 5 is a concave line; 6 is a web concave area; 7 is a pressing welding clamp pressing plate window; 8 is a pressing welding clamp pressing plate boss; 9 is a pressing welding clamp cushion block, 10 is a web accommodation groove on the pressing welding clamp cushion block, 11 is a pressing welding clamp vacuum hole, 12 is a plastic encapsulation mold upper and lower mold joint surface, 13 is a pouring inlet; 14 is an exhaust groove. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the present application more clear, the following will make further detailed description to the embodiments of the present application in combination with the drawings.

[0027] In the present application, "a plurality of" refers to two or more. "And / or" describes the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can mean that A exists alone, A and B exist together, and B exists alone. The character " / " generally represents that the front and rear associated objects are in an "or" relationship.

[0028] For easy understanding, please refer to Figure 1 The frame structure design schematic view shown in Figure 1, the packaging structure includes a packaging frame, a pressing welding clamp and a plastic encapsulation mold, wherein 0 is a package line.

[0029] In the packaging frame, the packaging frame is provided with a base island 1, a convex design 2 is added at the web position of the base island 1, the convex design 2 is used to increase the support strength of the frame web 3 and improve the coplanarity of the base island 1, and then the stress deformation point generated during concave processing is far away from the base island, and the internal stress generated during concave processing is reduced to act on the base island.

[0030] In addition, in order to the effectiveness of the convex design, the convex design is further added under the following premise that the size space is satisfied. Condition one is that the distance between the concave line on the web and the edge of the package line is min 0.2mm, and condition two is that the distance between the edge of the base island and the concave line is mim 0.25mm.

[0031] The packaging frame is further provided with a frame web 3, the frame web 3 is processed at the position, and the frame web 3 is designed with a stress release groove 4 at the end position.

[0032] In the pressure welding fixture, the pressure welding fixture includes a pressure welding fixture pressing plate window 7, a pressure welding fixture pressing plate boss 8, and a pressure welding fixture cushion block 9.

[0033] The pressure welding fixture pressing plate window 7 is positioned with the frame connecting rib 3, the frame connecting rib position is not designed to be pressed during pressure welding, the pressure welding fixture pressing plate boss 8 is positioned with the frame connecting rib 3, and the pressure welding fixture cushion block 9 is designed to be slotted at the frame connecting rib 3 position 10. The purpose is that during pressure welding of the product, the frame pressure welding fixture cushion block 9 is in interference fit with the base island 1, and the resulting pressing force causes the deformation of the frame to be transferred to the connecting rib concave area 6, the connecting rib position 3, and the protruding design 2 position, preventing the resulting deformation from occurring at the base island position and reducing the risk of base island delamination.

[0034] The plastic packaging mold is provided with an exhaust groove 14, and the exhaust groove 14 is arranged at the frame connecting rib 3 position.

[0035] Optionally, the distance between the stress deformation point generated during the concave processing and the base island 1 satisfies a preset value, such as being away from the base island 1 and satisfying min0.25mm.

[0036] When the pressure welding fixture design size space does not meet the condition, the pressure welding fixture pressing plate window 7 does not position the frame connecting rib 3, the pressure welding fixture pressing plate boss 8 and the pressure welding fixture cushion block connecting rib position slot 10 position the frame connecting rib 3. Among them, not positioning is one of the two scheme designs of the pressure welding fixture window 7, and the object of positioning and not positioning is the base island connecting rib. Providing two scheme designs mainly considers the fixture design space. The person skilled in the art will face different frame structure designs in actual operation, and the size will be different under different designs. Therefore, it can be considered according to the structure to define the design size of the pressure welding fixture pressing plate window to meet the condition, and then consider the design of positioning and not positioning.

[0037] Optionally, the position of the exhaust groove 14 and the position of the frame connecting rib 3 are provided with a preset gap. During mold closing and mold opening of plastic packaging, the preset gap is used to prevent the force generated when the plastic packaging mold cooperates with the packaging frame from being transmitted from the connecting rib to the base island 1.

[0038] Optionally, the preset gap is 20 to 30 microns.

[0039] In addition, the center of the base island 1 is also provided with a pressure welding fixture vacuum hole 11, which is used to adsorb the packaging frame during pressure welding of the pressure welding fixture, so as to achieve the effect of closer cooperation between the packaging frame and the pressure welding fixture.

[0040] In addition, in order to more intuitively represent the pressing of the upper and lower molds, the plastic packaging mold upper and lower mold closing surface 12 is marked for illustration.

[0041] In summary, the chip packaging structure provided by the utility model has the frame connecting rib position designed as a protrusion, which enhances the support strength of the base island position; the other side of the frame connecting rib end is designed as a stress release groove, which releases the internal stress generated when the frame connecting rib is concave, reduces the risk of base island delamination at the position, and improves product reliability; the cooperation of the plastic packaging mold and the frame reduces the stress generated when the plastic packaging mold cooperates with the frame, and reduces the risk of frame base island delamination caused by the plastic packaging process.

[0042] In another aspect, a chip packaging method is provided, which is suitable for the chip packaging structure described above, and the packaging method comprises:

[0043] A protrusion design 2 is added at the base island 1 connecting rib position of the packaging frame;

[0044] Concave processing is performed at the position of the frame connecting rib 3 of the packaging frame;

[0045] A stress release groove 4 is designed at the end position of the frame connecting rib 3, and the protrusion design 2 is used to increase the support strength of the frame connecting rib 3 and improve the coplanarity of the base island 1;

[0046] The pressing plate window 7 of the pressure welding clamp is positioned away from the frame connecting rib 3;

[0047] The pressing plate boss 8 of the pressure welding clamp is positioned away from the frame connecting rib 3;

[0048] The pressure welding clamp pad block 9 is designed as a slot 10 at the position of the frame connecting rib 3;

[0049] Optionally, the method further comprises:

[0050] In response to the pressure welding clamp design size space not satisfying the preset condition, the pressing plate window 7 of the pressure welding clamp is not positioned away from the frame connecting rib 3, and the pressing plate boss 8 of the pressure welding clamp and the pressure welding clamp pad block connecting rib positioning groove 10 are positioned away from the frame connecting rib 3.

[0051] Optionally, the method further comprises:

[0052] The position of the exhaust groove 14 and the position of the frame connecting rib 3 have a preset gap, and the preset gap is used to prevent the force generated when the plastic packaging mold cooperates with the packaging frame from being transmitted to the base island 1 during the mold closing and opening.

[0053] Further, in the packaging structure, the pressure welding clamp window is designed in two schemes, i.e., positioned away from the frame connecting rib or not, mainly considering the clamp design space, the pressure welding clamp pressing plate boss and the pressure welding clamp pad block are designed as positioning away from the connecting rib at the connecting rib position, which ensures the pressure combination of the pressure welding clamp and the frame, and at the same time, shifts the frame deformation area caused by the interference fit of the clamp and the frame, so that the base island position is not affected by the deformation amount, thereby reducing the delamination of the chip bonding area and improving the product reliability.

[0054] The above-mentioned sequence numbers of the embodiments of the present application are only for description, and do not represent advantages or disadvantages of the embodiments. The above-mentioned is only optional embodiments of the present application, and does not limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A chip packaging structure, characterized in that: The packaging structure includes a packaging frame, a pressure welding fixture and a plastic packaging mold; The packaging frame is provided with a base island (1), and a protrusion design (2) is added at the rib connection position of the base island (1); The packaging frame is further provided with a frame connecting rib (3), the position of the frame connecting rib (3) is concavely processed, and the end position of the frame connecting rib (3) is designed with a stress release groove (4), and the protrusion design (2) is used to increase the support strength of the frame connecting rib (3) and improve the coplanarity of the base island (1); The pressure welding fixture comprises a pressure welding fixture pressure plate window (7), a pressure welding fixture pressure plate boss (8) and a pressure welding fixture pad (9); The pressure welding fixture pressure plate window (7) gives way to the frame connecting bar (3), the pressure welding fixture pressure plate boss (8) gives way to the frame connecting bar (3), and the pressure welding fixture pad (9) is designed with a slot at the position of the frame connecting bar (3); The plastic encapsulation mold is provided with an exhaust groove (14), and the exhaust groove (14) is arranged at the position of the frame connecting rib (3).

2. The structure according to claim 1, characterized in that The distance between the stress deformation point generated during the denting process and the base island (1) meets a preset value.

3. The structure according to claim 1, characterized in that When the design size space of the pressure welding fixture is not satisfied, the pressure welding fixture pressure plate window (7) does not give way to the frame connecting reinforcement (3), and the pressure welding fixture pressure plate boss (8) and the pressure welding fixture pad connecting reinforcement giving way groove (10) give way to the frame connecting reinforcement (3).

4. The structure according to claim 1, characterized in that A preset gap is set between the position of the exhaust groove (14) and the position of the frame connecting rib (3). When the plastic packaging is in mold closing and mold opening, the preset gap is used to prevent the force generated when the plastic packaging mold and the packaging frame are matched from being transmitted from the connecting rib to the base island (1).

5. The structure according to claim 4, characterized in that The preset gap is 20 to 30 microns.

6. The structure according to claim 1, characterized in that A pressure welding fixture vacuum hole (11) is also provided at the center of the base island (1), and the pressure welding fixture vacuum hole (11) is used to adsorb the packaging frame when the pressure welding fixture is bonding wires.

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