Lead frame and FC-QFN packaging device

Abstract

The embodiment of the invention provides a lead frame and an FC-QFN packaging device. The lead frame comprises a first pin, a front half-etched region, a back half-etched region and a via hole, the first pin comprises a first side surface, a third side surface and a second side surface connected with the first side surface and the third side surface, and the front half-etched region is located on the front surface of the lead frame. The projection of the first pin on the front face of the lead frame covers the projection of the front face half-etching area on the front face of the lead frame, the longest length of the front face half-etching area in the second direction is equal to the length of the second side face in the second direction, and the back face half-etching area is located on the back face of the lead frame and arranged along the side face of the first pin. The inner side face of the back face half-etching area makes contact with the side face of the first pin, and the via hole is located in the area, right opposite to the second side face, of the back face half-etching area and penetrates through the back face half-etching area. According to the lead frame, the problem of layering with a plastic package body can be improved, and the risk of pin breakage can be reduced, so that the reliability of a packaged device can be improved.

Description

Technical Field

[0001] Embodiments of the present disclosure relate to the field of semiconductor packaging technology, and more particularly to a lead frame and an FC-QFN packaging device. Background Art

[0002] The current quad flat no-lead flip chip (FC-QFN) packaged devices have long pins in their lead frames. The long pin design generates greater stress during the packaging process, which in turn causes delamination between the lead frame and the plastic package. Delamination affects the chip bumps, which in turn causes reliability issues for the packaged devices.

[0003] In the prior art, the surface metal of the lead frame is roughened to increase the bonding strength between the lead frame and the plastic package so as to improve the delamination problem between the lead frame and the plastic package. However, although the delamination problem between the lead frame and the plastic package can be improved, the risk of long pin breakage will increase during the packaging process, resulting in lower reliability of the packaged device. Summary of the invention

[0004] The embodiments of the present disclosure provide a lead frame and a QFN package device, which can improve the problem of delamination with the plastic package body and reduce the risk of pin breakage, thereby improving the reliability of the package device.

[0005] In a first aspect, the present disclosure provides a lead frame, comprising:

[0006] A first pin, comprising a first side surface, a second side surface and a third side surface, wherein the first side surface and the third side surface extend along a first direction, the second side surface extends along a second direction, two ends of the second side surface connect one end of the first side surface and one end of the third side surface, and the second direction is perpendicular to the first direction;

[0007] a front half-etched area, located on the front side of the lead frame, wherein the projection of the first lead on the front side of the lead frame covers the projection of the front half-etched area on the front side of the lead frame, and the longest length of the front half-etched area in the second direction is equal to the length of the second side surface in the second direction;

[0008] A back side half-etched area is located on the back side of the lead frame and is arranged along the first side surface, the second side surface and the third side surface, and an inner side surface of the back side half-etched area is in contact with the first side surface, the second side surface and the third side surface;

[0009] A via hole is located in a region of the back half-etched region directly opposite to the second side surface, and penetrates the back half-etched region along a third direction, wherein the third direction is perpendicular to both the first direction and the second direction.

[0010] In some embodiments of the present disclosure, a projection of the front side half-etched area on the front side of the lead frame does not overlap with a projection of the back side half-etched area on the front side of the lead frame.

[0011] In some embodiments of the present disclosure, the first pin includes: an end portion, including a side region of the first side close to the second side, the second side and a side region of the third side close to the second side; a connecting portion, including a side region of the first side away from the second side and a side region of the third side away from the second side;

[0012] The back side half-etched area comprises: a first back side half-etched area, wherein the inner side surface of the first back side half-etched area contacts the side surface of the end portion;

[0013] The front half-etched area includes: a first front half-etched area located on the front side of the connecting portion, and a length of the first front half-etched area in the second direction is equal to a length of the second side surface in the second direction.

[0014] In some embodiments of the present disclosure, the front half-etched region further includes: a second front half-etched region, located on the front side of the connecting portion and on a side of the first front half-etched region away from the second side surface, wherein the length of the second front half-etched region in the second direction is less than the length of the second side surface in the second direction;

[0015] The back side half-etched area also includes: a second back side half-etched area, which is isolated from the first back side half-etched area, the inner side surface of the second back side half-etched area is in contact with the side surface of the connecting part, and the projection of the first pin between the second back side half-etched area and the first back side half-etched area on the front side of the lead frame covers the projection of the first front side half-etched area on the front side of the lead frame and does not overlap.

[0016] In some embodiments of the present disclosure, the number of the second back side half-etched areas is equal to the number of the first front side half-etched areas; when the number of the second back side half-etched areas and the number of the first front side half-etched areas are both multiple, the projection of the first pin between two adjacent second back side half-etched areas on the front side of the lead frame covers the projection of the first front side half-etched area on the front side of the lead frame and does not overlap.

[0017] In some embodiments of the present disclosure, the back side half-etched region includes: a third back side half-etched region, which is a region between an outer side surface of the back side half-etched region facing the second side surface and a plane where the second side surface is located;

[0018] The length of the third back side half-etched area in the first direction is greater than or equal to 0.52 mm and less than or equal to 0.54 mm, and the length of the third back side half-etched area in the second direction is greater than or equal to 0.52 mm and less than or equal to 0.54 mm;

[0019] The via hole is located in a central area of ​​the third back side half-etched area, and a diameter of the via hole is greater than or equal to 0.15 mm and less than or equal to 0.2 mm.

[0020] In some embodiments of the present disclosure, a maximum distance between the first side surface and the third side surface and the nearest outer side surface of the back half-etched area is greater than 0.12 mm and less than or equal to 0.15 mm.

[0021] In some embodiments of the present disclosure, the lead frame further includes:

[0022] a plurality of second pins, wherein the length in the second direction is less than the length of the first pin in the first direction, each of the second pins comprises a fourth side surface, a fifth side surface and a sixth side surface, the fourth side surface and the sixth side surface extend along the second direction, and two ends of the fifth side surface are connected to one end of the fourth side surface and one end of the sixth side surface;

[0023] The back half-etched area corresponding to the first pin includes a first area and a second area, the first area is the back half-etched area directly opposite to a portion of the back half-etched area corresponding to the second pin, and the second area is an area outside the first area in the back half-etched area corresponding to the second pin;

[0024] Among them, the length of the first area in the second direction is smaller than the length of the second area in the second direction, so that the minimum distance between the outer side surface of the back half-etched area corresponding to the second pin and the outer side surface of the back half-etched area corresponding to the nearest first pin is greater than or equal to a preset distance.

[0025] In a second aspect, the present disclosure provides a FC-QFN package device, comprising any lead frame provided in the first aspect.

[0026] In some embodiments of the present disclosure, the FC-QFN packaged device further includes:

[0027] A chip, wherein a surface of one side provided with bumps is arranged opposite to the front side of the lead frame, and part of the bumps are welded to the front side of the first pin and the area outside the front side half-etched area;

[0028] A plastic package body, filling the front half-etched area, the back half-etched area and the via hole;

[0029] The electroplating layer is arranged on the back side of the first pin.

[0030] In the technical solution of the embodiment of the present disclosure, the packaging device includes a first pin, a front half-etched area, a back half-etched area and a via hole, the first pin includes a first side surface and a third side surface extending along a first direction and a second side surface extending along a second direction, two ends of the second side surface are connected to one end of the first side surface and one end of the third side surface, the front half-etched area is located on the front side of the lead frame, the projection of the first pin on the front side of the lead frame covers the projection of the front half-etched area on the front side of the lead frame, the longest length of the front half-etched area in the second direction is equal to the length of the second side surface in the second direction, the back half-etched area is located on the back side of the lead frame, and a via hole is provided along the first side surface, the second side surface and the third side surface. The inner side of the back half-etched area is in contact with the first side, the second side and the third side, the via hole is located in the area on the back half-etched area that is opposite to the second side, and penetrates the back half-etched area along the third direction. In this way, the length of the front half-etched area in the second direction and the length of the back half-etched area in the first direction can be increased, and the areas of the front half-etched area and the back half-etched area can be increased, thereby increasing the contact area between the lead frame and the plastic package body, increasing the bonding force between the lead frame and the plastic package body, improving the problem of delamination between the lead frame and the plastic package body, and releasing stress through the via hole. The risk of pin breakage can be reduced, thereby improving the reliability of the packaged device.

[0031] The above description is only an overview of the technical solution of the embodiment of the present application. In order to more clearly understand the technical means of the embodiment of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the embodiment of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present application, a brief introduction will be given below to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0033] Figure 1 The present invention provides a schematic structural diagram of a lead frame provided by the prior art.

[0034] Figure 2 A schematic top view of the structure of a lead frame provided in an embodiment of the present disclosure.

[0035] Figure 3 for Figure 2 The lead frame is shown as a schematic cross-sectional structure diagram along the cross-sectional line AA'.

[0036] Figure 4 A schematic top view of another lead frame provided in an embodiment of the present disclosure.

[0037] Figure 5 A schematic diagram of the structure of an FC-QFN packaging device provided in an embodiment of the present disclosure.

[0038] Figure 6A-6D A schematic diagram of a preparation process of a FC-QFN packaging device provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by those skilled in the art without creative work also fall within the scope of protection of the present disclosure.

[0040] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art to which the disclosed subject matter belongs. It will be further understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the specification and the relevant art, and will not be interpreted in an idealized or overly formal form unless otherwise explicitly defined herein. As used herein, a statement that two or more parts are "connected" together shall mean that the parts are joined together directly or through one or more intermediate components.

[0041] Reference to "embodiments" in this disclosure means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase "embodiments" in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this disclosure may be combined with other embodiments.

[0042] In addition, the terms "first", "second", etc. in the specification and claims of the present disclosure or the above-mentioned drawings are used to distinguish different objects rather than to describe a specific order, and may explicitly or implicitly include one or more of the features.

[0043] The term "and / or" in this disclosure is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0044] In the description of the present disclosure, unless otherwise specified, "plurality" and "at least two" mean more than two (including two), and similarly, "multiple groups" and "at least two groups" mean more than two groups (including two).

[0045] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings.

[0046] Figure 1 A schematic diagram of the structure of a lead frame provided by the prior art, such as Figure 1 As shown, the lead frame includes a plurality of lead frame units, each of which includes a long lead 10 , a plurality of short leads 20 , a plurality of first half-etched regions 30 and a plurality of second half-etched regions 40 .

[0047] The length of the long pin 10 is greater than that of the short pin 20, and the symmetry axis of the long pin 10 is used as the symmetry axis, and the multiple short pins 20 are symmetrically distributed on both sides of the symmetry axis. The front of the long pin 10 and the front of each short pin 20 are both provided with a first half-etched area 30, and the side surface where the long side and the short side of the long pin 10 are located is provided with a second half-etched area 40, and the inner side surface of the second half-etched area 40 is in contact with the side surface where the long side and the short side of the long pin 10 are located. The side surface of each short pin 20 close to the side area of ​​the long pin 10 is provided with a second half-etched area 40, and the inner side surface of the second half-etched area 40 is in contact with the side surface of the short pin 20.

[0048] For example, during the packaging process, the long pins 10 will generate greater stress due to their longer length, causing delamination between the lead frame and the plastic package body. The delamination will affect the reliability of the chip Bump and further affect the reliability of the packaged device.

[0049] Usually, the surface metal of the lead frame can be roughened to increase the contact area between the lead frame and the plastic package, thereby increasing the bonding force between the lead frame and the plastic package. The increased bonding force can offset part of the stress generated by the long lead during the packaging process to improve the delamination problem between the lead frame and the plastic package. However, as the bonding force between the lead frame and the plastic package increases, the risk of long lead breakage during the packaging process increases, resulting in lower reliability of the packaged device.

[0050] In order to solve the above problems, an embodiment of the present disclosure provides a lead frame, including a first pin, a front half-etched area, a back half-etched area and a via hole, the first pin includes a first side surface and a third side surface extending along a first direction and a second side surface extending along a second direction, two ends of the second side surface are connected to one end of the first side surface and one end of the third side surface, the front half-etched area is located on the front side of the lead frame, the projection of the first pin on the front side of the lead frame covers the projection of the front half-etched area on the front side of the lead frame, the longest length of the front half-etched area in the second direction is equal to the length of the second side surface in the second direction, the back half-etched area is located on the back side of the lead frame, and along the first side surface, the second side surface and the first side surface The three side surfaces are arranged, the inner side surface of the back half-etched area is in contact with the first side surface, the second side surface and the third side surface, the via hole is located in the area on the back half-etched area opposite to the second side surface, and penetrates the back half-etched area along the third direction. In this way, the length of the front half-etched area in the second direction and the length of the back half-etched area in the first direction can be increased, thereby increasing the area of ​​the front half-etched area and the back half-etched area, thereby increasing the contact area between the lead frame and the plastic package body, increasing the bonding force between the lead frame and the plastic package body, improving the problem of delamination between the lead frame and the plastic package body, and releasing stress through the via hole. The risk of pin breakage can be reduced, thereby improving the reliability of the packaged device.

[0051] The technical solution of the present disclosure is described in detail below with reference to several specific embodiments.

[0052] Figure 2 A schematic diagram of a top view of a lead frame provided in an embodiment of the present disclosure is shown in FIG. Figure 2 As shown, the lead frame 100 includes a first lead 110 , a front side half-etched region 120 , a back side half-etched region 130 , and a via 140 .

[0053] The first pin 110 includes a first side surface 111, a second side surface 112 and a third side surface 113, wherein the first side surface 111 and the third side surface 113 extend along a first direction, the second side surface 112 extends along a second direction, and two ends of the second side surface 112 connect one end of the first side surface 111 and one end of the third side surface 113, wherein the second direction is perpendicular to the first direction.

[0054] For example, Figure 2 As shown, the lead frame 100 includes a plurality of pins, some of which are relatively long and some of which are relatively short, wherein the relatively long pins are defined as long pins, i.e., first pins 110, and the relatively short pins are defined as short pins, and the lead frame 100 includes a plurality of first pins 110 and a plurality of short pins.

[0055] The short pins are symmetrically distributed on both sides of the symmetry axis of the first pin 110. The short pins directly opposite the first side surface 111 and the third side surface 113 are second pins 150. The second pins 150 are arranged along the first direction. The length of the second pins 150 in the second direction is less than the length of the first pins 110 in the first direction. The short pins directly opposite the second side surface 112 are third pins 160. The third pins 160 are arranged along the second direction. The length of the third pins 160 in the first direction is less than the length of the first pins 110 in the first direction.

[0056] Each second pin 150 includes a fourth side surface 151, a fifth side surface 152 and a sixth side surface 153. The fourth side surface 151 and the sixth side surface 153 extend along the second direction. Two ends of the fifth side surface 152 connect one end of the fourth side surface 151 and one end of the sixth side surface 153. The fifth side surfaces 152 of some second pins 150 face the plane where the first side surface 111 is located, and the fifth side surfaces 152 of some second pins 150 face the plane where the third side surface 113 is located.

[0057] Each third pin 160 includes a seventh side surface 161, an eighth side surface 162 and a ninth side surface 163. The seventh side surface 161 and the ninth side surface 163 extend along the first direction. Two ends of the eighth side surface 162 connect one end of the seventh side surface 161 and one end of the ninth side surface 163. The eighth side surface 162 faces the plane where the second side surface 112 is located.

[0058] Exemplarily, the first direction is the Y direction, the second direction is the X direction, and the third direction is the Z direction. The plane where the first side surface 111 and the third side surface 113 are located is parallel to the YZ plane, the plane where the second side surface 112 is located is parallel to the XZ plane, and the length of the first side surface 111 and the third side surface 113 in the Y direction is greater than the length of the second side surface 112 in the X direction.

[0059] The plane where the fourth side surface 151 and the sixth side surface 153 are located is parallel to the XZ plane, the lengths of the fourth side surface 151 and the sixth side surface 153 in the X direction are greater than the length of the fifth side surface 152 in the Y direction, and the fifth side surface 152 is a curved surface and / or a flat surface. If the fifth side surface 152 is a flat surface, the fifth side surface 152 is parallel to the YZ plane.

[0060] The plane where the seventh side surface 161 and the ninth side surface 163 are located is parallel to the YZ plane. The lengths of the seventh side surface 161 and the ninth side surface 163 in the Y direction are greater than the length of the eighth side surface 162 in the X direction. The eighth side surface 162 is a curved surface and / or a flat surface. If the eighth side surface 162 is a flat surface, the eighth side surface 162 is parallel to the XZ plane.

[0061] In other implementations, the first direction may be the X direction and the second direction may be the Y direction. The present disclosure does not make any specific limitation on this. The present disclosure only takes the first direction as the Y direction and the second direction as the X direction as an example for illustrative description.

[0062] The front half-etched area 120 is located on the front side of the lead frame 100, the projection of the first pin 110 on the front side of the lead frame 100 covers the projection of the front half-etched area 120 on the front side of the lead frame 100, and the longest length of the front half-etched area 120 in the second direction is equal to the length of the second side surface 112 in the second direction.

[0063] For example, Figure 2 As shown, the front sides of the first pin 110, the second pin 150 and the third pin 160 are all provided with front side half-etched areas 120, the projection of the first pin 110 on the front side of the lead frame 100 covers the projection of the front side half-etched area 120 of the first pin 110 on the front side of the lead frame 100, the projection of the second pin 150 on the front side of the lead frame 100 covers the projection of the front side half-etched area 120 of the second pin 150 on the front side of the lead frame 100, and the projection of the third pin 160 on the front side of the lead frame 100 covers the projection of the front side half-etched area 120 of the third pin 160 on the front side of the lead frame 100.

[0064] Among them, the front half-etched area 120 on the front side of the first pin 110 includes a first front half-etched area 121 and a second front half-etched area 122 distributed along the Y direction, wherein the length of the first front half-etched area 121 in the X direction is equal to the length of the second side surface 112 in the X direction, and the length of the second front half-etched area 122 in the X direction is less than the length of the second side surface 112 in the X direction.

[0065] In this way, by increasing the length of the front half-etched area 120 in the second direction, the area of ​​the front half-etched area 120 can be increased, thereby increasing the contact area between the lead frame 100 and the plastic package body, which can increase the bonding force between the lead frame 100 and the plastic package body and improve the delamination problem between the lead frame 100 and the plastic package body, thereby improving the reliability of the packaged device.

[0066] The back side half-etched area 130 is located on the back side of the lead frame 100 , and the back side half-etched area 130 is arranged along the first side surface 111 , the second side surface 112 and the third side surface 113 , and the inner side surface of the back side half-etched area 130 contacts the first side surface 111 , the second side surface 112 and the third side surface 113 .

[0067] Exemplarily, a back side half-etched area 130 corresponding to the first pin 110 is set along the first side 111, the second side 112 and the third side 113, a back side half-etched area 130 corresponding to the second pin 150 is set along the fourth side 151, the fifth side 152 and the sixth side 153, and a back side half-etched area 130 corresponding to the third pin 160 is set along the seventh side 161, the eighth side 162 and the ninth side 163.

[0068] The maximum distance between the first side surface 111 and the outer side surface of the nearest back half-etched area 130 is greater than 0.12 mm and less than or equal to 0.15 mm, and the maximum distance between the third side surface 113 and the outer side surface of the nearest back half-etched area 130 is greater than 0.12 mm and less than or equal to 0.15 mm.

[0069] like Figure 2 As shown, the back side half-etched area 130 corresponding to the first pin 110 includes a first outer side surface 1311 and a second outer side surface 1312, the outer side surfaces of the back side half-etched area 130 closest to the first side surface 111 are the first outer side surface 1311 and the second outer side surface 1312, the distance between the first side surface 111 and the first outer side surface 1311 is smaller than the distance between the first side surface 111 and the second outer side surface 1312, then the distance between the first side surface 111 and the second outer side surface 1312 is the maximum distance between the first side surface 111 and the nearest outer side surface of the back side half-etched area 130, and the maximum distance can be any value between 0.12 mm and 0.15 mm.

[0070] The back side half-etched area 130 corresponding to the first pin 110 also includes a third outer side surface and a fourth outer side surface. The outer side surfaces of the back side half-etched area 130 closest to the third side surface 113 are the third outer side surface and the fourth outer side surface. The distance between the third side surface 113 and the third outer side surface is smaller than the distance between the third side surface 113 and the fourth outer side surface. The distance between the third side surface 113 and the fourth outer side surface is the maximum distance between the third side surface 113 and the nearest outer side surface of the back side half-etched area 130, and the maximum distance can be any value between 0.12 mm and 0.15 mm.

[0071] Since the distance between the first side surface 111 and the third side surface 113 and the outer side surface of the nearest back half-etched area 130 in the existing design is less than 0.12 mm, the embodiment provided in the present disclosure increases the length of the back half-etched area 130 in the second direction compared with the existing design.

[0072] In this way, by increasing the length of the back half-etched area 130 in the second direction, the area of ​​the back half-etched area 130 can be increased, thereby increasing the contact area between the lead frame 100 and the plastic package, which can increase the bonding force between the lead frame 100 and the plastic package, improve the delamination problem between the lead frame 100 and the plastic package, and improve the reliability of the packaged device.

[0073] The via hole 140 is located in a region of the back half-etched region 130 that is directly opposite to the second side surface 112 , and the via hole 140 penetrates the back half-etched region 130 along the third direction.

[0074] For example, Figure 3 for Figure 2 The schematic diagram of the cross-sectional structure of the lead frame along the section line AA' shown in FIG. Figure 2 and Figure 3 As shown, the back side half-etched area 130 corresponding to the first pin 110 includes a third back side half-etched area 133, and the third back side half-etched area 133 is the area between the outer side surface of the back side half-etched area 130 facing the second side surface 112 and the plane where the second side surface 112 is located. The via 140 penetrates the back side half-etched area 130 along the Z direction. For example, the diameter of the via 140 can generally be set to be greater than or equal to 0.15 mm and less than or equal to 0.2 mm.

[0075] In this way, it is necessary to reserve enough third back half-etched area 133 to set the via 140 that passes through the back half-etched area 130, and it is necessary to increase the length of the back half-etched area 130 in the first direction. By increasing the length of the back half-etched area 130 in the first direction, the area of ​​the back half-etched area 130 can be increased, thereby increasing the contact area between the lead frame 100 and the plastic package body, which can increase the bonding force between the lead frame 100 and the plastic package body, improve the delamination problem between the lead frame 100 and the plastic package body, so as to improve the reliability of the packaged device, and can also release stress through the via 140, which can reduce the risk of pin breakage, so as to improve the reliability of the packaged device.

[0076] In some embodiments, the via 140 is disposed in the central area of ​​the third back side half-etched area 133 , which is beneficial to the stress release balance and reduces the risk of pin breakage, so as to further improve the reliability of the packaged device.

[0077] In some embodiments, considering the limitation of the minimum distance between the edge of the via 140 and the edge of the nearest third back half-etched area 133, the length s1 of the third back half-etched area 133 in the Y direction satisfies: 0.52mm≤s1≤0.54mm, and the length s2 of the third back half-etched area 133 in the X direction satisfies: 0.52mm≤s2≤0.54mm.

[0078] In this way, the length of the third back side half-etched area 133 in the first direction is set to be larger, and the length of the third back side half-etched area 133 in the second direction is also set to be larger, which can increase the length of the back side half-etched area 130 in the first direction and the second direction, that is, increase the area of ​​the back side half-etched area 130, thereby increasing the contact area between the lead frame 100 and the plastic package body, and can increase the bonding force between the lead frame 100 and the plastic package body, improve the problem of stratification between the lead frame 100 and the plastic package body, so as to improve the reliability of the packaged device.

[0079] In some embodiments, a projection of the front side half-etched area 120 on the front side of the lead frame 100 does not overlap with a projection of the back side half-etched area 130 on the front side of the lead frame 100 .

[0080] For example, see Figure 2 The first pin 110 includes an end portion 110a and a connecting portion 110b, the end portion 110a includes a side area of ​​the first side 111 close to the second side 112, the second side 112 and a side area of ​​the third side 113 close to the second side 112, and the connecting portion 110b includes a side area of ​​the first side 111 away from the second side 112 and a side area of ​​the third side 113 away from the second side 112.

[0081] The first front half-etched area 121 is located on the front side of the connecting portion 110b, and the first front half-etched area 121 connects a side area of ​​the first side 111 away from the second side 112 and a side area of ​​the third side 113 away from the second side 112. The back half-etched area 130 includes a first back half-etched area 131, and the inner side of the first back half-etched area 131 contacts the side of the end 110b, and the first back half-etched area 131 connects a side area of ​​the first side 111 close to the second side 112 and a side area of ​​the third side 113 close to the second side 112.

[0082] The projection of the first front half-etched area 121 on the front of the lead frame 100 and the projection of the first back half-etched area 131 on the front of the lead frame 100 do not overlap, which can avoid the appearance of through holes and through gaps in the area between the front half-etched area 120 and the back half-etched area 130. During the packaging process, these through holes and through gaps will combine with the plastic package body and affect the reliability of the packaged device. In this way, the embodiments provided by the present disclosure can avoid the reliability problems caused by the combination of through holes and through gaps with the plastic package body, thereby improving the reliability of the packaged device.

[0083] In some embodiments, see Figure 2The front half-etched area 120 includes a second front half-etched area 122, and the second front half-etched area 122 is located on the side of the first front half-etched area 121 on the front side of the connecting portion 110b away from the second side surface 112. The second back half-etched area 132 also connects the side area of ​​the first side surface 111 away from the second side surface 112 and the side area of ​​the third side surface 113 away from the second side surface 112.

[0084] In this way, by increasing the number of front half-etched areas 120, the area of ​​the front half-etched areas 120 can be increased, thereby increasing the contact area between the lead frame 100 and the plastic package, increasing the bonding force between the lead frame 100 and the plastic package, and improving the problem of delamination between the lead frame 100 and the plastic package, thereby improving the reliability of the packaged device.

[0085] For example, see Figure 2 The back side half-etched area 130 also includes a second back side half-etched area 132, which is isolated from the first back side half-etched area 131, and the inner side of the second back side half-etched area 132 contacts the side of the connecting portion 110b, so that the second back side half-etched area 132 connects a side area of ​​the first side 111 away from the second side 112 and a side area of ​​the third side 113 away from the second side 112.

[0086] The projection of the first pin 110 between the second back half-etched area 132 and the first back half-etched area 131 on the front side of the lead frame 100 covers the projection of the first front half-etched area 121 on the front side of the lead frame 100 and does not overlap. Then, the three areas on the first side 111 connected to the first front half-etched area 121, the first back half-etched area 131 and the second back half-etched area 132 are different and isolated areas, and the three areas on the third side 113 connected to the first front half-etched area 121, the first back half-etched area 131 and the second back half-etched area 132 are different and isolated areas.

[0087] In this way, the projection of the first front half-etched area 121 on the front side of the lead frame 100 and the projection of the second back half-etched area 132 on the front side of the lead frame 100 do not overlap, which can avoid the appearance of through holes and through gaps in the area between the front half-etched area 120 and the back half-etched area 130, thereby improving the reliability of the packaged device.

[0088] In some embodiments, the front half-etched region 120 includes a first front half-etched region 121, and the back half-etched region 130 includes a second back half-etched region 132. Figure 2 shown.

[0089] In other embodiments, Figure 4 Another schematic diagram of a top view structure of a lead frame provided in an embodiment of the present disclosure is shown in FIG. Figure 4 As shown, the front half-etched area 120 includes a plurality of first front half-etched areas 121 , and the back half-etched area 130 includes a plurality of second back half-etched areas 132 , and the number of the second back half-etched areas 132 is equal to the number of the first front half-etched areas 121 .

[0090] The projection of the first lead 110 between two adjacent second back half-etched areas 132 on the front surface of the lead frame 100 covers the projection of the first front half-etched area 121 on the front surface of the lead frame 100 and does not overlap.

[0091] For example, Figure 4 As shown, the front side half-etched region 120 includes a first front side half-etched region 1211 and a first front side half-etched region 1212 , and the back side half-etched region 130 includes a second back side half-etched region 1321 and a second back side half-etched region 1322 .

[0092] Among them, the projection of the first pin 110 between the second back half-etched area 1321 and the second back half-etched area 1322 on the front side of the lead frame 100 covers the projection of the first front half-etched area 1211 on the front side of the lead frame 100 and does not overlap. Then, the three areas on the first side 111 connected to the first front half-etched area 1211, the second back half-etched area 1321 and the second back half-etched area 1322 are different and isolated areas, and the three areas on the third side 113 connected to the first front half-etched area 1211, the second back half-etched area 1321 and the second back half-etched area 1322 are different and isolated areas.

[0093] It should be noted that Figure 4 The number of the second back side half-etched areas 132 and the number of the first front side half-etched areas 121 are illustrated by taking two as an example. In practical applications, the number of the second back side half-etched areas 132 and the number of the first front side half-etched areas 121 can also be three or more. The present disclosure does not make any specific restrictions on this, and only limits the number of the second back side half-etched areas 132 to be equal to the number of the first front side half-etched areas 121.

[0094] In this way, the projections of the multiple first front half-etched areas 121 on the front side of the lead frame 100 and the projections of the second back half-etched areas 132 on the front side of the lead frame 100 do not overlap, which can avoid the appearance of through holes and through gaps in the area between the front half-etched area 120 and the back half-etched area 130, and can improve the reliability of the packaged device.

[0095] In some embodiments, see Figure 4The back side half-etched area 130 corresponding to the first pin 110 includes a first area 130a and a second area 130b. The first area 130a is the back side half-etched area 130 directly opposite to the back side half-etched area 130 corresponding to a portion of the second pin 150, and the second area 130b is the area outside the first area 130a in the back side half-etched area 130 corresponding to the second pin 150.

[0096] Among them, the length of the first area 130a in the second direction is smaller than the length of the second area 130b in the second direction, so that the minimum distance between the outer side surface of the back half-etched area 130 corresponding to the second pin 150 and the outer side surface of the back half-etched area 130 corresponding to the nearest first pin 110 is greater than or equal to the preset distance.

[0097] For example, Figure 4 As shown, the back side half-etched area 130 corresponding to each second pin 150 extends in a direction close to the first pin 110. When the minimum distance between the outer side surface of the back side half-etched area 130 corresponding to the second pin 150 and the outer side surface of the back side half-etched area 130 corresponding to the nearest first pin 110 is less than the preset distance, that is, the distance between the metal edges of adjacent pins is less than the preset distance. If the distance between the metal edges of adjacent pins is too small, the reliability of the packaged device will be reduced.

[0098] In the embodiment of the present disclosure, by setting the length of the first area 130a in the X direction to be smaller than the length of the second area 130b in the X direction, the distance between the outer side surface of the first area 130a and the outer side surface of the back side half-etched area 130 corresponding to the nearest second pin 150 can be increased, thereby increasing the minimum distance between the outer side surface of the back side half-etched area 130 corresponding to the second pin 150 and the outer side surface of the back side half-etched area 130 corresponding to the nearest first pin 110, so that the minimum distance between the outer side surface of the back side half-etched area 130 corresponding to the second pin 150 and the outer side surface of the back side half-etched area 130 corresponding to the nearest first pin 110 is greater than or equal to the preset distance, thereby improving the reliability of the packaged device.

[0099] The embodiments of the present disclosure further provide a FC-QFN package device, comprising the lead frame 100 provided in any of the above embodiments.

[0100] Figure 5 A schematic diagram of the structure of a FC-QFN package device provided in an embodiment of the present disclosure is shown in FIG. Figure 5 As shown, the FC-QFN package device 200 includes a lead frame 100 , a chip 210 , a plastic package 220 and an electroplating layer 230 .

[0101] Exemplarily, one side surface of the chip 210 is provided with a bump 211 which is arranged opposite to the front side of the lead frame 100, part of the bump 211 is welded to the area outside the front half-etched area of ​​the first pin, the plastic package 220 fills the front half-etched area, the back half-etched area and the via, and the electroplating layer 230 is arranged on the back side of the first pin.

[0102] Figure 6A-6D A schematic diagram of a preparation process of a FC-QFN packaged device provided in an embodiment of the present disclosure, such as Fig. 6A As shown, first, a lead frame 100 is provided, and a film is attached to the back side of the lead frame 100 .

[0103] Next, the surface of the chip 210 provided with the bump 211 faces the front surface of the lead frame 100, and the bump 211 is welded to the front surface of the first lead and the bump 211 is located outside the front half-etched area, such as Figure 6B shown.

[0104] Then, the plastic encapsulation material is injected to fill the front half-etched area, the back half-etched area and the via hole, and after solidification, a plastic encapsulation body 220 covering the chip 210 and higher than the chip 210 is formed. Figure 6C shown.

[0105] Then, the film on the back side of the lead frame 100 is torn off. Fig.6D As shown, tin is electroplated on the back of the first pin to form an electroplating layer 230, as shown in FIG. Figure 5 shown.

[0106] The FC-QFN package device 200 provided in the embodiment of the present disclosure includes the lead frame 100 provided in any of the above embodiments, and has the same functional modules and beneficial effects as the lead frame 100, which will not be repeated here.

[0107] Unless the context clearly indicates otherwise, the singular form of the words used herein and in the appended claims includes the plural and vice versa. Thus, when referring to the singular, the plural form of the corresponding term is generally included. Similarly, the words "comprise" and "include" are to be interpreted as inclusive rather than exclusive. Likewise, the terms "include" and "or" should be interpreted as inclusive unless such interpretation is expressly prohibited herein. Where the term "example" is used herein, particularly when it is located after a group of terms, the "example" is merely exemplary and illustrative and should not be considered exclusive or comprehensive.

[0108] Further aspects and scopes of adaptability become apparent from the description provided herein. It should be understood that various aspects of the present application can be implemented individually or in combination with one or more other aspects. It should also be understood that the description and specific embodiments herein are intended for purposes of illustration only and are not intended to limit the scope of the present application.

[0109] Several embodiments of the present disclosure are described in detail above, but it is obvious that those skilled in the art can make various modifications and variations to the embodiments of the present disclosure without departing from the spirit and scope of the present disclosure. The protection scope of the present disclosure is defined by the attached claims.

Claims

1. A lead frame, characterized in that: include: A first pin, comprising a first side surface, a second side surface and a third side surface, wherein the first side surface and the third side surface extend along a first direction, the second side surface extends along a second direction, two ends of the second side surface connect one end of the first side surface and one end of the third side surface, and the second direction is perpendicular to the first direction; a front half-etched area, located on the front side of the lead frame, wherein the projection of the first lead on the front side of the lead frame covers the projection of the front half-etched area on the front side of the lead frame, and the longest length of the front half-etched area in the second direction is equal to the length of the second side surface in the second direction; A back side half-etched area is located on the back side of the lead frame and is arranged along the first side surface, the second side surface and the third side surface, and an inner side surface of the back side half-etched area is in contact with the first side surface, the second side surface and the third side surface; A via hole is located in a region of the back half-etched region directly opposite to the second side surface, and penetrates the back half-etched region along a third direction, wherein the third direction is perpendicular to both the first direction and the second direction.

2. The lead frame according to claim 1, characterized in that: A projection of the front side half-etched area on the front side of the lead frame does not overlap with a projection of the back side half-etched area on the front side of the lead frame.

3. The lead frame according to claim 2, characterized in that: The first pin comprises: an end portion, including a side region of the first side surface close to the second side surface, the second side surface, and a side region of the third side surface close to the second side surface; a connecting portion, comprising a side region of the first side away from the second side and a side region of the third side away from the second side; The back side half-etching area comprises: a first back side half-etched region, wherein an inner side surface of the first back side half-etched region contacts a side surface of the end portion; The front half-etching area comprises: The first front side half-etched area is located on the front side of the connecting portion, and the length of the first front side half-etched area in the second direction is equal to the length of the second side surface in the second direction.

4. The lead frame according to claim 3, characterized in that: The front half-etching area also includes: A second front half-etched area is located on the front side of the connecting portion and on a side of the first front half-etched area away from the second side surface, wherein a length of the second front half-etched area in the second direction is smaller than a length of the second side surface in the second direction; The back side half-etching area also includes: The second back side half-etched area is isolated from the first back side half-etched area, the inner side surface of the second back side half-etched area is in contact with the side surface of the connecting portion, and the projection of the first pin between the second back side half-etched area and the first back side half-etched area on the front side of the lead frame covers the projection of the first front side half-etched area on the front side of the lead frame and does not overlap.

5. The lead frame according to claim 4, characterized in that: The number of the second back side half-etched areas is equal to the number of the first front side half-etched areas; When the number of the second back side half-etched areas and the number of the first front side half-etched areas are both multiple, the projection of the first pin between two adjacent second back side half-etched areas on the front side of the lead frame covers the projection of the first front side half-etched area on the front side of the lead frame and does not overlap.

6. The lead frame according to claim 1, wherein: The back side half-etching area comprises: A third back side half-etched area is a region between an outer side surface of the back side half-etched area facing the second side surface and a plane where the second side surface is located; The length of the third back side half-etched area in the first direction is greater than or equal to 0.52 mm and less than or equal to 0.54 mm, and the length of the third back side half-etched area in the second direction is greater than or equal to 0.52 mm and less than or equal to 0.54 mm; The via hole is located in a central area of ​​the third back side half-etched area, and a diameter of the via hole is greater than or equal to 0.15 mm and less than or equal to 0.2 mm.

7. The lead frame according to claim 1, wherein: The maximum distance between the first side surface and the third side surface and the nearest outer side surface of the back half-etched area is greater than 0.12 mm and less than or equal to 0.15 mm.

8. The lead frame according to claim 1, wherein: The lead frame further comprises: a plurality of second pins, wherein the length in the second direction is less than the length of the first pin in the first direction, each of the second pins comprises a fourth side surface, a fifth side surface and a sixth side surface, the fourth side surface and the sixth side surface extend along the second direction, and two ends of the fifth side surface are connected to one end of the fourth side surface and one end of the sixth side surface; The back half-etched area corresponding to the first pin includes a first area and a second area, the first area is the back half-etched area directly opposite to a portion of the back half-etched area corresponding to the second pin, and the second area is an area outside the first area in the back half-etched area corresponding to the second pin; Among them, the length of the first area in the second direction is smaller than the length of the second area in the second direction, so that the minimum distance between the outer side surface of the back half-etched area corresponding to the second pin and the outer side surface of the back half-etched area corresponding to the nearest first pin is greater than or equal to a preset distance.

9. An FC-QFN packaged device, characterized in that: The lead frame comprises the lead frame according to any one of claims 1 to 8.

10. The FC-QFN packaged device according to claim 9, characterized in that: The FC-QFN packaged device further comprises: A chip, wherein a surface of one side provided with bumps is arranged opposite to the front side of the lead frame, and part of the bumps are welded to the front side of the first pin and the area outside the front side half-etched area; A plastic package body, filling the front half-etched area, the back half-etched area and the via hole; The electroplating layer is arranged on the back side of the first pin.

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