Chip connection structure and chip module

Abstract

The utility model discloses a chip connection structure and a chip module, and the chip connection structure comprises a lead frame which comprises a base island and pins; the chip is electrically connected to the surface of the base island through a first connecting piece; the first end of the conductive connecting piece is electrically connected to the pin through a second connecting piece; and the elastic structure is electrically connected to the second end of the conductive connecting piece, and the elastic structure is electrically connected to the surface of the chip through the third connecting piece. According to the utility model, the conductive connecting piece is in flexible contact with the surface of the chip through the elastic structure, and the thermal expansion stress of the plastic package material and the second end of the conductive connecting piece is absorbed by the elastic structure in the packaging process, so that the stress cannot directly act on the surface of the chip; therefore, the technical effects of reducing the stress on the surface of the chip during high-temperature plastic package and preventing the surface and the interior of the chip from generating microcracks are achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of chip manufacturing, and in particular to a chip connection structure and a chip module. Background Art

[0002] In chip packaging, the chip is installed on the base island of the lead frame through solder paste, and the two ends of the copper tape-like conductive connector are connected to the chip surface and the pins of the lead frame through solder paste. Since there is a large metal layer on the chip surface, the contact surface between the solder paste and the conductive connector is rigid contact, and then it goes through the plastic encapsulation and single chip cutting process. After the packaged device is subjected to high temperature thermal shock, due to the large difference in thermal expansion coefficient between the plastic encapsulation material and the metal, the stress generated by its expansion will directly impact the surface of the chip, which is easy to cause micro cracks on the surface and inside of the chip. Utility Model Content

[0003] The main purpose of the utility model is to provide a chip connection structure to solve the problem in the related art that when the chip is packaged, due to the large difference in thermal expansion coefficients between the plastic packaging material and the metal, the stress generated by the expansion will directly impact the surface of the chip, easily causing micro cracks on the surface and inside of the chip.

[0004] In order to achieve the above object, the utility model provides a chip connection structure, which includes:

[0005] Lead frame, including base island and leads;

[0006] A chip is electrically connected to the surface of the base island through a first connecting member;

[0007] A conductive connector, wherein a first end of the conductive connector is electrically connected to the pin via a second connector;

[0008] The elastic structure is electrically connected to the second end of the conductive connecting member, and the elastic structure is electrically connected to the surface of the chip through a third connecting member.

[0009] Further, the elastic structure comprises an elastic portion, and the elastic portion is configured to be compressed in a direction toward the surface of the chip and to stretch in a direction away from the surface of the chip.

[0010] Furthermore, the elastic part is provided in plurality.

[0011] Furthermore, the elastic part is configured as a spring or a spring sheet.

[0012] Furthermore, the spring piece is arranged in an arc shape.

[0013] Furthermore, the elastic structure further comprises a base, a first end of the elastic portion is electrically connected to the base, and a second end of the elastic portion is electrically connected to a second end of the conductive connector;

[0014] The base is electrically connected to the surface of the chip through the third connecting member.

[0015] Further, the base is made of a rigid material.

[0016] Furthermore, the first connecting piece, the second connecting piece and the third connecting piece are all made of hot-melt conductive metal materials.

[0017] Furthermore, the first connector, the second connector and the third connector are all configured as solder paste.

[0018] According to another aspect of the present invention, a chip module is provided, comprising the above-mentioned chip connection structure.

[0019] In the embodiment of the utility model, a lead frame is provided, including a base island and pins; a chip, electrically connected to the surface of the base island through a first connector; a conductive connector, a first end of the conductive connector is electrically connected to the pin through a second connector; an elastic structure, electrically connected to the second end of the conductive connector, and the elastic structure is electrically connected to the surface of the chip through a third connector. On the one hand, the conductive connector is in flexible contact with the surface of the chip through the elastic structure, and the thermal expansion stress of the plastic sealing material and the second end of the conductive connector during the packaging process will be absorbed by the elastic structure, so that the stress will not directly act on the surface of the chip, thereby achieving the technical effect of reducing the stress on the chip surface during high-temperature plastic sealing and avoiding the generation of microcracks on the chip surface and inside, thereby solving the problem in the related art that the stress generated by the expansion of the plastic sealing material and the metal during packaging will directly impact the surface of the chip, which is easy to cause microcracks on the chip surface and inside.

[0020] On the other hand, after the conductive connection and the chip surface are flexibly connected by the elastic structure, the mechanical stress acting on the conductive connection will also be absorbed by the elastic structure, making the surface and interior of the chip less likely to be damaged by external mechanical stress. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings constituting a part of the present invention are used to provide a further understanding of the present invention, so that other features, purposes and advantages of the present invention become more obvious. The drawings and descriptions of the schematic embodiments of the present invention are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0022] Figure 1 It is a schematic diagram of the structure of chip connection in the related art;

[0023] Figure 2 is a schematic structural diagram of a chip connection structure according to an embodiment of the present application;

[0024] Among them, 1 is a lead frame, 101 is a base island, 102 is a pin, 2 is an elastic structure, 201 is an elastic part, 202 is a base, 3 is a conductive connector, 4 is a first connector, 5 is a chip, 6 is a third connector, 7 is a second connector, 8 is a second solder paste, 9 is a first solder paste, 10 is a third solder paste, and 11 is a copper tape. DETAILED DESCRIPTION

[0025] In order to enable those skilled in the art to better understand the solution of the utility model, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is only a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the utility model.

[0026] It should be noted that the terms "first", "second", etc. in the specification and claims of the utility model and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so as to describe the embodiments of the utility model described here.

[0027] In the present invention, the directions or positional relationships indicated by the terms "upper", "lower", "inner", etc. are based on the directions or positional relationships shown in the accompanying drawings. These terms are mainly used to better describe the present invention and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific direction, or to be constructed and operated in a specific direction.

[0028] In addition, some of the above terms may be used to express other meanings in addition to indicating orientation or positional relationship. For example, the term "on" may also be used to express a certain dependency or connection relationship in some cases. For those skilled in the art, the specific meanings of these terms in this utility model can be understood according to specific circumstances.

[0029] In addition, the terms "disposed", "provided with", "connected", "fixed" and the like should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements or components. For those of ordinary skill in the art, the specific meanings of the above terms in this utility model can be understood according to specific circumstances.

[0030] In addition, the term "plurality" shall mean two or more.

[0031] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0032] In related technologies, such as Figure 1 As shown, in the chip Clip packaging structure, one end of the copper tape 11 is electrically connected to the surface of the chip 5 through the first solder paste 9, the bottom of the chip 5 is electrically connected to the surface of the base island 101 of the lead frame through the second solder paste 8, and the other end of the copper tape 11 is electrically connected to the pin 102 of the lead frame 1 through the third solder paste 10.

[0033] Since there is a large metal layer on the surface of the chip 5, the contact surface between the solder paste and the conductive connector is rigid, and then the device undergoes plastic encapsulation and singulation. After the packaged device is subjected to high temperature thermal shock, the thermal expansion coefficient of the plastic encapsulation material and the metal is quite different.

[0034] Specifically, in one embodiment, the thermal expansion coefficient CTE of the chip 5 is about 2.6, the thermal expansion coefficient CTE of the copper strip 11 is about 18, and the thermal expansion coefficient CTE of the plastic sealant on the chip 5 connection structure is about 30-40 at high temperature. It can be seen that the thermal expansion coefficients of the plastic sealant and the conductive connector are both greater than the thermal expansion coefficient of the chip 5, especially the thermal expansion coefficient of the plastic sealant is significantly greater than the thermal expansion coefficient of the chip 5. Therefore, the stress generated by the expansion of the plastic sealant and the copper strip 11 will directly impact the surface of the chip 5, which is likely to cause micro cracks on the surface and inside of the chip 5.

[0035] To solve the above technical problems, Figure 2 As shown, an embodiment of the utility model provides a chip connection structure, which includes:

[0036] A lead frame 1, comprising a base island 101 and pins 102;

[0037] The chip 5 is electrically connected to the surface of the base island 101 through the first connecting member 4;

[0038] A conductive connecting member 3, wherein a first end of the conductive connecting member 3 is electrically connected to the pin 102 via a second connecting member 7;

[0039] The elastic structure 2 is electrically connected to the second end of the conductive connection member 3 . The elastic structure 2 is electrically connected to the surface of the chip 5 through the third connection member 6 .

[0040] In this embodiment, the lead frame 1 is a thin metal frame for connecting the contact points of the chip 5 and external wires, and mainly includes a base island 101 and pins 102, wherein the base island 101 can be electrically connected to the contact points on the chip 5 as a chip pad. According to different chip structures, the base island 101 and the pins 102 in the lead frame 1 have different structures and distribution forms.

[0041] In chip packaging, the chip 5 can be first mounted on the base island 101 of the lead frame 1, and the contact point on the lower surface of the chip 5 is electrically connected to the surface of the base island 101 through the first connector 4, and the first connector 4 is a structure with conductive ability. The conductive connector 3 is used as a connecting structure for connecting the chip 5 and the lead frame 1, and it can adopt a copper belt 11 or a similar metal belt with conductive ability. The two ends of the conductive connector 3 need to be electrically connected to the pin 102 and the upper surface of the chip 5 respectively. In this embodiment, the first end of the conductive connector 3 is electrically connected to the pin 102 through the second connector 7, and the second connector 7 is a structure with conductive ability. The elastic structure 2 is arranged at its second end, and the elastic structure 2 is electrically connected to the upper surface of the chip 5 through the third connector 6, and the third connector 6 is a structure with conductive ability.

[0042] In this embodiment, the elastic structure 2 may have the function of elastically expanding and contracting in a direction perpendicular to the upper surface of the chip 5. Of course, it is understandable that the elastic structure 2 may also have the function of elastically expanding and contracting in a direction that is at a certain angle to the upper surface of the chip 5. After the elastic structure 2 is arranged, firstly, the stress generated by the thermal expansion of the conductive connector 3 will act on the elastic structure 2 to cause a certain amount of compression of the elastic structure 2, thereby absorbing the stress generated by the thermal expansion of the conductive connector 3. Secondly, the stress generated by the thermal expansion of the plastic encapsulation material can also act on the elastic structure 2 through the conductive connector 3, and the stress generated by the thermal expansion of the plastic encapsulation material can be absorbed by further compression of the elastic structure 2, thereby reducing the stress acting on the surface of the chip 5.

[0043] It can be seen that, on the one hand, in this embodiment, the conductive connector 3 is in flexible contact with the surface of the chip 5 through the elastic structure 2. During the packaging process, the thermal expansion stress of the plastic packaging material and the second end of the conductive connector 3 will be absorbed by the elastic structure 2, so that the stress will not directly act on the surface of the chip 5, thereby achieving the technical effect of reducing the stress on the surface of the chip 5 during high-temperature plastic packaging and avoiding the generation of microcracks on the surface and inside of the chip 5. This further solves the problem in the related art that when the chip 5 is packaged, the stress generated by the expansion of the plastic packaging material and the metal is quite different, so the stress will directly impact the surface of the chip 5, which may easily cause microcracks on the surface and inside of the chip 5.

[0044] On the other hand, after the conductive connector 3 and the surface of the chip 5 are flexibly connected through the elastic structure 2, the mechanical stress acting on the conductive connector 3 will also be absorbed by the elastic structure 2, making the surface and interior of the chip 5 less likely to be damaged by external mechanical stress.

[0045] In addition, it should be noted that, in order to better protect the chip 5, the amount of compression of the elastic structure 2 should be greater than or equal to the sum of the thermal expansion of the molding compound and the second end of the conductive connector 3 in the direction toward the chip 5 at the molding temperature.

[0046] like Figure 2 As shown, in one embodiment of the elastic structure 2, the elastic structure 2 includes an elastic portion 201, and the elastic portion 201 is configured to be able to be compressed in a direction toward the surface of the chip 5 and to be elongated in a direction away from the surface of the chip 5. Specifically, during the high-temperature plastic encapsulation process, the elastic portion 201 is compressed in a direction toward the surface of the chip 5 after being subjected to the pressure of the plastic encapsulation material and the conductive connector 3. After the temperature is lowered, the thermal expansion of the plastic encapsulation material and the conductive connector 3 is reduced, and the corresponding pressure on the elastic portion 201 is reduced, so that it can be elongated in a direction away from the surface of the chip 5, so as to ensure that after the temperature is lowered, the conductive connector 3 and the chip 5 can still have a sufficiently stable electrical connection.

[0047] After the elastic part 201 is arranged between the conductive connector 3 and the chip 5, the connection between the conductive connector 3 and the chip 5 is changed from a rigid connection to a flexible connection. Therefore, in order to ensure the stability of the electrical connection between the conductive connector 3 and the chip 5 during the flexible connection, the elastic part 201 in this embodiment is provided in plurality, and the plurality of elastic parts 201 can be distributed in various ways between the conductive connector 3 and the chip 5. In one embodiment, at least three elastic parts 201 are provided, and the three elastic parts 201 are distributed in an equidistant triangle manner.

[0048] In another embodiment, at least four elastic parts 201 are provided, and the four elastic parts 201 are divided into two symmetrical groups and respectively distributed on both sides of the conductive connector 3. It should be noted that the above description of the specific distribution of the multiple elastic parts 201 is not restrictive, and those skilled in the art can design it according to actual needs.

[0049] In an implementation manner of the elastic portion 201 , the elastic portion 201 is configured as a spring or a spring sheet. When a spring sheet is used, the spring sheet may be configured in an arc shape.

[0050] On the basis that the elastic structure 2 includes the elastic portion 201, as Figure 2As shown, the elastic structure 2 in this embodiment also includes a base 202, the first end of the elastic part 201 is electrically connected to the base 202, and the second end of the elastic part 201 is electrically connected to the second end of the conductive connector 3; the base 202 is electrically connected to the surface of the chip 5 through the third connector 6.

[0051] In this embodiment, the upper surface of the base 202 serves as the connection base of the elastic part 201, and the lower surface of the base 202 serves as the connection base with the upper surface of the chip 5 through the third connection member 6. To facilitate the connection of the elastic part 201, the upper surface of the base 202 in this embodiment is a relatively flat surface. When the elastic part 201 is set as a spring, its lower end can be fixed to the upper surface of the base 202 by welding, and its upper end can also be fixed to the second end of the conductive connection member 3 by welding. The lower surface of the base 202 is also a relatively flat surface, so that the contact area with the third connection member 6 can be increased, and then the stability of the connection with the chip 5 can be increased.

[0052] In this embodiment, by setting the base 202, firstly, the local stress of the elastic part 201 on the surface of the chip 5 is reduced by using its larger action area compared with the elastic part 201, so that the stress is dispersed to the surface of the chip 5, and secondly, the upper and lower surfaces thereof are used as the connection base of the elastic part 201 and the base for stable connection with the chip 5, respectively. In order to further improve the stability of the connection, the base 202 in this embodiment is made of a rigid material, for example, it can be made of an alloy with excellent conductive properties such as Cu, CuAl, etc.

[0053] According to the packaging process of the chip 5, the first connector 4, the second connector 7 and the third connector 6 in this embodiment are all made of hot-melt conductive metal materials. Further, the first connector 4, the second connector 7 and the third connector 6 are all set to solder paste.

[0054] According to another aspect of the present invention, a chip 5 module is provided, comprising the above-mentioned chip 5 connection structure.

[0055] According to another aspect of the present invention, an electronic device is provided, comprising the above-mentioned chip 5 connection structure, or the above-mentioned chip 5 module.

[0056] The above description is only the preferred embodiment of the utility model and is not intended to limit the utility model. For those skilled in the art, the utility model may have various modifications and changes. Within the spirit and principle of the utility model, any modification, equivalent replacement, improvement, etc. made shall be included in the protection scope of the utility model.

Claims

1. A chip connection structure, characterized in that: include: Lead frame, including base island and leads; A chip is electrically connected to the surface of the base island through a first connecting member; A conductive connector, wherein a first end of the conductive connector is electrically connected to the pin via a second connector; The elastic structure is electrically connected to the second end of the conductive connecting member, and the elastic structure is electrically connected to the surface of the chip through a third connecting member.

2. The chip connection structure according to claim 1, characterized in that: The elastic structure includes an elastic portion, and the elastic portion is configured to be compressible in a direction toward a surface of the chip and to be elongated in a direction away from the surface of the chip.

3. The chip connection structure according to claim 2, characterized in that: The elastic part is provided in plurality.

4. The chip connection structure according to claim 2, characterized in that: The elastic part is configured as a spring or a spring sheet.

5. The chip connection structure according to claim 4, characterized in that: The spring piece is arranged in an arc shape.

6. The chip connection structure according to any one of claims 2 to 5, characterized in that: The elastic structure further comprises a base, a first end of the elastic portion is electrically connected to the base, and a second end of the elastic portion is electrically connected to a second end of the conductive connector; The base is electrically connected to the surface of the chip through the third connecting member.

7. The chip connection structure according to claim 6, characterized in that: The base is made of a rigid material.

8. The chip connection structure according to claim 1, characterized in that: The first connecting piece, the second connecting piece and the third connecting piece are all made of hot-melt conductive metal materials.

9. The chip connection structure according to claim 7, characterized in that: The first connecting member, the second connecting member and the third connecting member are all configured as solder paste.

10. A chip module, characterized in that: The invention comprises a chip connection structure as claimed in any one of claims 1 to 9.

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