Packaging routing structure and packaging routing method

Abstract

The invention relates to a packaging wire bonding structure and a packaging wire bonding method. Layered wire bonding is carried out according to the wire bonding density of a single welding spot. Directly routing the low-density welding spots and carrying out plastic package isolation through a layer of plastic package body; the high-density welding spots are staggered through the staggered conductive member, and the area of the welding spots is expanded by using the conductive extension part, so that the routing density of the staggered high-density welding spots is reduced, and the problem of wire punching short circuit in the routing process and in the subsequent process is avoided. According to the wire bonding method, multi-layer layered wire bonding and respective plastic package isolation are adopted, so that wire bonding of each density level is operated in an independently isolated interlayer, the wire bonding density of a single welding spot is reduced, the wire bonding density between wires is also reduced, the wire bonding operation is simplified, and the reliability is improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor packaging, and specifically to a packaging wire bonding structure and a packaging wire bonding method. Background Art

[0002] In the existing PoP packaging, two large copper sheets are pasted on a substrate. After the Molding technology, the surface of the copper sheets is ground, and then inductors are mounted on the surface for normal functions. However, this packaging structure has the following problems: 1. A large amount of copper sheets are required, and the cost of copper sheets is relatively high, resulting in a significant increase in the manufacturing cost. 2. The operation difficulty is relatively large. It is necessary to evenly grind the encapsulant on the copper sheets to ensure that multiple sites can be electrically connected to the inductor. In addition, in the existing package structure, a large number of wire bondings are required, which is likely to cause too high local wire density. On the one hand, it is easy to cause wire short-circuiting and product scrapping; on the other hand, the operation difficulty is extremely high during the actual wire bonding process, and a machine with extremely high precision is required to complete the precise operation, which greatly limits the industrial production application.

[0003] As Figure 1 shown, a chip 1 is carried on a substrate 2. There is a first welding point 11 on the chip 1, and a second welding point 21 on the substrate 2. Electrical connection is achieved between the first welding point 11 and the second welding point 21 through wire bonding. As can be seen from the figure, multiple wires need to be wire-bonded between some of the first welding points 11 and the second welding points 21, and the sizes of the first welding points 11 and the second welding points 21 are limited. Such a high-density wire bonding operation is extremely difficult, and it is easy to cause wire short-circuiting during the wire bonding process and subsequent processes.

[0004] Through retrieval, there are already technical literature on relevant packaging wire bonding structures disclosed in the prior art. For example, the utility model authorization announcement document with the publication number "CN202423264U" and the name "Columnar bump wire bonding structure of semiconductor chip". It discloses a columnar bump wire bonding structure of a semiconductor chip, which includes a carrier board and a chip. The chip is disposed on the carrier board, and the chip has several columnar bumps. The several columnar bumps are electrically connected to the welding points on the carrier board through several wires. Since adjacent columnar bumps have different heights, the horizontal heights of the first welding points of adjacent wires can be different, so that the positions of the first welding points are staggered and the intervals are increased. This prior art solution uses columnar bumps to widen the distance between adjacent first welding points, solves the problem that there is an intersection between each wire bonding in a certain two-dimensional plane, can avoid wire short-circuiting between wires, and reduces the wire bonding density between wires at the same time. However, it cannot solve the problem that multiple wires need to be wire-bonded simultaneously between the two end welding points. Summary of the Invention

[0005] In view of the deficiencies of the prior art, the present invention provides a packaging wire bonding structure, which includes a chip and a substrate. The chip has a first welding point, and the substrate has a second welding point. At least one first welding point and at least one second welding point are respectively provided with a staggered conductive member extending upward. The top of the staggered conductive member has a conductive extension portion. A first wire bonding layer is formed by wire bonding between the first welding point and the second welding point that are not connected to the staggered conductive member; it further includes at least one layer of plastic encapsulation body. The first wire bonding layer is encapsulated and isolated by the first layer of plastic encapsulation body. The conductive extension portions are exposed on the upper surface of the first layer of plastic encapsulation body, and a second wire bonding layer is formed by wire bonding between the conductive extension portions.

[0006] Further, the plastic encapsulation body is a laminated structure with N layers. The staggered conductive members have N - 1 different heights. The conductive extension portions of the staggered conductive members connected by the Nth wire bonding layer extend upward to the lower surface of the Nth layer of plastic encapsulation body, and the Nth wire bonding layer is encapsulated and isolated by the Nth layer of plastic encapsulation body.

[0007] Further, the staggered conductive member includes a microchannel vertically distributed in the plastic encapsulation body and a conductor formed by curing a conductive slurry poured into the microchannel. The top of the microchannel is a recessed portion, and the conductor in the recessed portion constitutes the conductive extension portion.

[0008] Alternatively, the staggered conductive member includes thick copper wires vertically distributed in the plastic encapsulation body, and solder balls or connection pads are implanted at the top of the thick copper wires to form conductive extension portions.

[0009] A packaging wire bonding method is also proposed. Wire bonding is carried out in layers according to the wire bonding density of the first welding point and the second welding point. The specific steps are as follows: Low - density wire bonding S1: Wire bond between the first welding points and the second welding points with low density respectively for the first layer, and encapsulate and isolate the first wire bonding layer with the first layer of plastic encapsulation body; High - density wire bonding S2: Form staggered conductive members within the space range of the first layer of plastic encapsulation body. The bottom ends of the staggered conductive members are respectively connected to the first welding points and the second welding points with high density, and the top ends extend to the upper surface of the first layer of plastic encapsulation body. Form conductive extension portions at the top ends of the staggered conductive members, and carry out wire bonding between the conductive extension portions to connect the first welding points and the second welding points with high density.

[0010] Further, in the step of high - density wire bonding S2, wire bonding is carried out in different layers according to the wire bonding density levels of the first welding point and the second welding point. The specific steps are as follows: Welding point staggering S21: Form staggered conductive members with the same height within the space range of the previous layer of plastic encapsulation body. Make the bottom ends of the staggered conductive members be respectively connected to the first welding point and the second welding point of the current wire bonding density, and the top ends be exposed on the upper surface of the space range of the previous layer of plastic encapsulation body. Determine whether to form conductive extension portions at the top ends of the staggered conductive members according to the current wire bonding density; The stepped wire bonding S22 is to perform wire bonding between the top of the stepped conductive member or between the conductive extension parts to connect the first welding point and the second welding point with the current wire bonding density.

[0011] Further, forming the stepped conductive member with the same height in the previous layer of the plastic package is specifically: etching vertically downward from the upper surface of the previous layer of the plastic package to form a microchannel communicating with the first welding point or the second welding point, and pouring a conductive slurry into the microchannel and curing it to form the stepped conductive member.

[0012] Further, the formation of the conductive extension part is specifically: when etching the microchannel to the top, extending and etching along the upper surface of the previous layer of the plastic package to form a recessed part, and pouring a conductive slurry into the microchannel and the recessed part and curing it to form the conductive extension part.

[0013] Or, forming the stepped conductive member with the same height in the previous layer of the plastic package is specifically: In the step of low-density wire bonding S1, vertically connecting the non-wired first welding point and the second welding point to thick copper wires respectively, and then encapsulating and isolating the first wire bonding layer with plastic; In the step of high-density wire bonding S2, grinding the plastic package of the previous layer to expose the thick copper wires, and vertically connecting thick copper wires while performing wire bonding on the thick copper wires of the current layer, so as to form a stepped conductive member with the height of the current layer.

[0014] Further, the formation of the conductive extension part is specifically: after grinding the plastic package of the previous layer to expose the thick copper wires, ball planting or soldering pads are formed on the top of the thick copper wires to form the conductive extension part.

[0015] Compared with the prior art, the technical solution of the present application has the following beneficial effects: 1. The wire bonding structure and method involved in the present invention perform hierarchical wire bonding according to the wire bonding density of a single solder joint. The low-density solder joints are directly wire bonded and encapsulated and isolated by a layer of plastic package; the high-density solder joints are stepped through the stepped conductive member, and the conductive extension part is used to expand the solder joint area, so that the wire bonding density of the high-density solder joints after stepping is reduced, and there will be no problems of wire short circuit during the wire bonding process and subsequent processes.

[0016] 2. The wire bonding method of multi-layer hierarchical wire bonding and separate encapsulation and isolation enables the wire bonding of each density level to be operated between separately isolated layers. Not only the wire bonding density of a single solder joint is reduced, but also the wire bonding density between wires is reduced, simplifying the wire bonding operation and improving the reliability.

[0017] 3. Using the stepped conductive member to achieve electrical connection of wire bonding consumes fewer metal parts compared with the copper sheet connection in the prior art, and has a lower packaging manufacturing cost. Description of the Drawings

[0018] Figure 1 : Existing technology encapsulation wire bonding structure; Figure 2 : Schematic diagram of a three - layer wire bonding three - dimensional structure; Figure 3 : Schematic diagram of the internal structure of the first - layer wire bonding Figure 1 ; Figure 4 : Schematic diagram of the internal structure of the first - layer wire bonding plastic encapsulation Figure 1 ; Figure 5 : Schematic diagram of the internal structure of the second - layer wire bonding; Figure 6 : Schematic diagram of the internal structure of the third - layer or top - most layer wire bonding; Figure 7 : Schematic diagram of the internal structure of the first - layer wire bonding Figure 2 ; Figure 8 : Schematic diagram of the internal structure of the first - layer wire bonding plastic encapsulation Figure 2 ; Figure 9 : Schematic diagram of the internal structure of the first - layer wire bonding ground - grinding plastic encapsulation layer; Figure 10 : Schematic diagram of the internal structure of the second - layer, third - layer or top - most layer wire bonding. Specific implementation manners

[0019] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts belong to the scope of protection of the present invention.

[0020] The basic structure of the encapsulation wire bonding proposed by the present invention is as Figure 2 and Figure 5 shown. It includes a chip (1) and a substrate (2). The chip (1) has a first welding point (11), and the substrate (2) has a second welding point (21). On at least one first welding point (11) and at least one second welding point (21), there are respectively upward - extending staggered - layer conductive members (5). The top end of the staggered - layer conductive member (5) has a conductive extension part (51). A first wire - bonding layer (41) is formed by wire bonding between the first welding point (11) and the second welding point (21) that are not connected to the staggered - layer conductive member (5). It further includes at least one layer of plastic encapsulation body (3). The first wire - bonding layer (41) is encapsulated and isolated by the first - layer plastic encapsulation body (31). The conductive extension part (51) is exposed on the upper surface of the first - layer plastic encapsulation body (31). A second wire - bonding layer (42) is formed by wire bonding between the conductive extension parts (51).

[0021] Specifically, under this encapsulation and wire bonding structure, the wire bonding between solder joints is at least divided into two-layer structures. The wire bonding between the low-density first solder joint (11) and the second solder joint (21) is directly wire-bonded and connected in the first wire bonding layer (41), and is isolated by the first encapsulant (31). In this way, the wire bonding between low-density solder joints is completely isolated. For high-density solder joints, the staggered conductive member (5) extends upward in a staggered manner. Since its top has a conductive extension portion (51), the conductive extension portion (51) has a larger surface area than the solder joint, and multiple wire bonding operations can be easily performed on a single conductive extension portion (51). The wire bonding between high-density solder joints is operated between the conductive extension portions (51) and above the low-density wire bonding layer. The wire bonding operation is simplified and has higher reliability. The wire bonding between high-density solder joints will not have any impact on the wire bonding in the low-density wire bonding layer that has been encapsulated and isolated.

[0022] In a more preferred embodiment, for the high-density wire bonding layer, a multi-layer hierarchical wire bonding structure is proposed. That is, the encapsulant (3) is a stacked structure with N layers, the staggered conductive member (5) has N - 1 different heights, and the conductive extension portion (51) of the staggered conductive member (5) connected by the Nth wire bonding layer (4N) extends upward to the lower surface of the Nth encapsulant (3N), and the Nth wire bonding layer (4N) is encapsulated and isolated by the Nth encapsulant (3N).

[0023] Specifically, still refer to Figure 2 , and a three-layer wire bonding structure is adopted as a whole. The first layer is the low-density solder joint wire bonding layer, which is directly wire-bonded and connected as described in the above embodiment and is isolated by the first encapsulant (31). Correspondingly, the second layer is the second wire bonding layer (42) with medium density. The corresponding two-end solder joints are all extended in a staggered manner to the second layer by the staggered conductive member (5), and the wire bonding between the corresponding conductive extension portions (51) constitutes the second wire bonding layer (42), and this layer is encapsulated and isolated by the second encapsulant (32). The high-density wire bonding layer is the third layer, that is, the top layer. The corresponding staggered conductive member (5) is extended to the lower surface of this layer. Similarly, the wire bonding between the corresponding conductive extension portions (51) constitutes the third wire bonding layer (43). This layer is the top layer. After the wire bonding of this layer is completed, the third encapsulant (33) can be used to encapsulate and isolate this layer. Such a hierarchical wire bonding structure wires in a staggered manner with different density levels, and expands the wire bonding area by using the conductive extension portion (51) on the top surface of the staggered conductive member (5) as needed, thereby simplifying the wire bonding operation with higher density. The wire bonding layers with different densities are separately encapsulated and isolated, so that the wire bonding operation of the current layer will not have any impact on the lower wire bonding layer, greatly improving the reliability.

[0024] For the staggered conductive member (5) and the conductive extension portion (51), one embodiment can be referred to Figure 5The stepped conductive member (5) is formed by curing a conductive slurry poured into a microchannel (52) etched therein, and a conductor (53) leads the solder joints in a stepped manner to the current wire bonding layer. For the conductive extension portion (51), a recessed portion (54) is etched at the top of the microchannel (52), and the recessed portion (54) has a larger surface area than the microchannel (52). After pouring the conductive slurry and filling it into the recessed portion (54), the cured conductor (53) forms the conductive extension portion (51).

[0025] Another implementation of the stepped conductive member (5) and the conductive extension portion (51) can be seen in Figure 10 。In this implementation, the stepped conductive member (5) is composed of thick copper wires (55) connecting the solder joints. Ball planting or connecting pads at the top of the thick copper wires (55) can form the conductive extension portion (51). It can be understood that ball planting or connecting pads will increase the surface area of the thick copper wires (55).

[0026] A wire bonding method for packaging is also proposed. The wire bonding is carried out in layers according to the wire bonding density of the first solder joint (11) and the second solder joint (21) as a whole. The specific steps are as follows: As Figure 3 and Figure 4 shown, for low-density wire bonding S1, the first layer of wire bonding is respectively carried out between the low-density first solder joint (11) and the second solder joint (21), and the first wire bonding layer (41) is encapsulated and isolated by the first encapsulation body (31). As Figure 5 shown, for high-density wire bonding S2, a stepped conductive member (5) is formed within the first encapsulation body (31). The bottom end of the stepped conductive member (5) is respectively connected to the high-density first solder joint (11) and the second solder joint (21), and the top end extends to the upper surface of the first encapsulation body (31). A conductive extension portion (51) is formed at the top end of the stepped conductive member (5), and wire bonding is carried out between the conductive extension portions (51) to connect the high-density first solder joint (11) and the second solder joint (21).

[0027] In this implementation, the wire bonding operation is at least divided into two layers of wire bonding. For those with a relatively low wire bonding density for a single solder joint, such as single wire bonding, the wire bonding operation can be directly carried out in the first layer. After connecting the first solder joint (11) and the second solder joint (21), the first encapsulation body (31) is used for isolation. In this way, the low-density wire bonding layer can be electrically isolated, and any other wire bonding operations above this layer will have no impact on this layer.

[0028] The high-density wire bonding layer operates on top of the low-density wire bonding layer. During this process, a staggered conductive member (5) for leading out solder joints in a staggered manner needs to be formed within the first encapsulant body (31), and a conductive extension portion (51) is formed on the top of the staggered conductive member (5) to expand the surface area of the high-density wire bonding solder joints. The conductive extension portion (51) will directly extend to the upper surface of the height layer where the first encapsulant body (31) is located, so that all subsequent operations of wire bonding the conductive extension portion (51) can be carried out on the layer above the first encapsulant body (31). After completing the wire bonding operation of the high-density wire bonding layer, the second encapsulant body (32) can be used again to encapsulate it.

[0029] During high-density wire bonding operations, the wire bonding density of solder joints may vary, and there may also be differences or intersections in the wire bonding density between lines. At this time, the operations of the high-density wire bonding layer can be carried out in different layers according to the wire bonding density. For specific reference, see Figure 6 Figure. Three-layer wire bonding operations are adopted in the figure. When performing low-density wire bonding, referring to the steps of low-density wire bonding S1, the first solder joints (11) and the second solder joints (21) with low density can be directly wire bonded in the first layer and encapsulated and isolated respectively.

[0030] During the high-density wire bonding layer-by-layer operation, it is necessary to first execute the step of staggered solder joints S21, that is, a staggered conductive member (5) with the same height is formed within the space range of the previous encapsulant body (3), and the bottom ends of the staggered conductive member (5) are respectively connected to the first solder joint (11) and the second solder joint (21) with the current wire bonding density, and the top end is exposed on the upper surface of the previous encapsulant body (3). Whether to form a conductive extension portion (51) at the top end of the staggered conductive member (5) is determined according to the current wire bonding density.

[0031] For example, when performing medium-density wire bonding operations on the current second layer, it is necessary to first form a staggered conductive member (5) with the height of this layer within the encapsulant body (3) where the second wire bonding layer, that is, the current layer, is located. It should be noted that the staggered conductive member (5) can be fabricated after the formation of the previous encapsulant body (3) or before its formation. At this time, the staggered conductive member (5) will extend to the height of the encapsulant body (3) where the second wire bonding layer is located, and the top end is exposed on the upper surface of the space range of the second encapsulant body (3). Since the wire bonding density of the second-layer solder joints is medium, whether to form a conductive extension portion (51) at the top end of the staggered conductive member (5) can be determined according to actual needs.

[0032] Then continue to execute the staggered wire bonding S22, that is, wire bond between the top end of the staggered conductive member (5) or the conductive extension portion (51) to connect the first solder joint (11) and the second solder joint (21) with the current wire bonding density, and then encapsulate with the encapsulant body (3) to form a medium-density wire bonding layer.

[0033] The high-density wire bonding layer, i.e., the third-layer wire bonding, will continue to perform the solder joint staggered layer S21 and the staggered wire bonding S22. First, the high-density solder joints are led to the third layer by using the staggered conductive member (5), and then the third-layer wire bonding operation is performed between the conductive extension parts (51). Finally, this layer is encapsulated to complete the entire hierarchical wire bonding.

[0034] Based on the above-mentioned embodiments, there are two different implementation manners for the formation method of the staggered conductive member (5).

[0035] One of the implementation manners can be seen in Figure 5 and Figure 6 . Specifically, to form the staggered conductive member (5) with the same height within the space range of the previous-layer encapsulant (3), a microchannel (52) that communicates with the first solder joint (11) or the second solder joint (21) is vertically etched downward on the upper surface of the previous-layer encapsulant (3), and conductive slurry is poured into the microchannel (52) and cured to form the staggered conductive member (5).

[0036] Taking the three-layer wire bonding layer as an example, before wire bonding the second layer, it is necessary to first form the staggered conductive member (5) with the same height within the space range of the first-layer encapsulant (31). In this embodiment, after the first-layer encapsulant (31) has been encapsulated, a microchannel (52) that communicates with the first solder joint (11) or the second solder joint (21) is vertically etched downward on its upper surface, and conductive slurry is poured into the microchannel (52) and cured to form the staggered conductive member (5). After completing the wire bonding of the second layer and being encapsulated and isolated by the second-layer encapsulant (32), the third-layer wire bonding is started. The microchannel (52) is continuously vertically etched downward on the upper surface of the second-layer encapsulant (31) to form the staggered conductive member (5), and then the third-layer wire bonding is completed. Finally, it is encapsulated and isolated by the second-layer encapsulant (33). Since the microchannel (52) is locally etched downward on the surface of the encapsulant, it can be directly etched downward when wire bonding the topmost layer, and continuously etched through multiple layers of encapsulants until it communicates with the solder joints. This formation method of the staggered conductive member (5) is relatively simple, efficient, and accurately positioned.

[0037] Continuing with the above-described embodiment, during the manufacturing process of the stepped conductive member (5), the conductive extension portion (51) can be fabricated simultaneously by etching. Taking the second wire bonding layer as an example, when etching the top of the microchannel (52) vertically downward from the first encapsulant (31), an etched recess (54) is formed by extending the etching along the upper surface of the first encapsulant (31). After pouring and curing a conductive slurry in the recess (54), the conductive extension portion (51) is formed. In this embodiment, the formation of the conductive extension portion (51) will be more flexible, and the shape and size of the recess (54) can be flexibly selected according to the wire bonding density requirements; moreover, the extension direction of the recess (54) can be flexibly chosen according to the wire bonding direction. For example, the recess (54) can be formed in different shapes such as circular, rectangular, star-shaped, or strip-shaped, with different extension directions.

[0038] Different from the foregoing embodiment, the stepped conductive member (5) is fabricated in another way. Refer to Figure 8 , Figure 9 and Figure 10 . In this embodiment, the stepped conductive member (5) is formed before the encapsulant isolation. Still taking the third wire bonding as an example, the following is an illustration.

[0039] In the low-density wire bonding step S1, the unbonded first solder joint (11) and second solder joint (21) are respectively vertically connected to thick copper wires (55), and then the first wire bonding layer (41) is encapsulated and isolated. In the high-density wire bonding step S2, the first encapsulant (31) is ground to expose all the thick copper wires (55). At this time, among the thick copper wires (55), some are for wire bonding in the second layer, and some need to continue to be stepped up to the third layer. After wire bonding the thick copper wires (55) that need wire bonding in the second layer, the thick copper wires (55) that do not need wire bonding are continuously vertically connected to thick copper wires (55) and stepped up to the third layer, and then encapsulated and isolated with the second encapsulant (32). The same principle applies during the third wire bonding. The second encapsulant (32) is ground to expose all the thick copper wires (55). Since the third layer is the top layer at this time, all the exposed thick copper wires 55 need to be wire bonded. Therefore, after wire bonding, they can be encapsulated and isolated with the third encapsulant (33). The thick copper wires (55) can be fabricated by using a wire bonding device for connection. Since in each wire bonding layer, the solder joints or thick copper wires 55 that do not need wire bonding also need to be continuously connected to thick copper wires (55) and stepped up, the wire bonding operation process is relatively complex. Moreover, it is difficult to control the grinding depth because there may be a certain error in the height of the thick copper wires (55) fabricated by the wire bonding device. When grinding, all the thick copper wires (55) need to be exposed. Therefore, the maximum grinding depth is adopted, but grinding too deep may expose or damage the wire bonding layer of the previous layer. Therefore, the accuracy requirement for the grinding operation is relatively high.

[0040] Continuing with the above-described embodiment, after exposing the thick copper wire (55) on the previous layer of the molded body (3) before grinding, ball implantation or soldering pads can be formed on the top of the thick copper wire (55) to form the conductive extension part (51), so as to expand the surface area of the top of the thick copper wire (55) and achieve a higher density of wire bonding.

[0041] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the phrase "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0042] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An encapsulation wire bonding structure, comprising a chip (1) and a substrate (2). The chip (1) has a first solder joint (11), and the substrate (2) has a second solder joint (21), characterized in that, There are stepped conductive members (5) extending upwardly respectively on at least one first solder joint (11) and at least one second solder joint (21). The top end of the stepped conductive member (5) has a conductive extension portion (51). A first wire bonding layer (41) is formed by wire bonding between the first solder joint (11) and the second solder joint (21) which are not connected to the stepped conductive member (5). It further includes at least one layer of encapsulant (3). The first wire bonding layer (41) is encapsulated and isolated by the first layer of encapsulant (31). The conductive extension portion (51) is exposed on the upper surface of the first layer of encapsulant (31). A second wire bonding layer (42) is formed by wire bonding between the conductive extension portions (51).

2. The encapsulation wire bonding structure according to claim 1, characterized in that, The encapsulant (3) has a stacked structure with N layers. The stepped conductive member (5) has N - 1 different heights. The conductive extension portion (51) of the stepped conductive member (5) connected by the Nth wire bonding layer (4N) extends upward to the lower surface of the Nth layer of encapsulant (3N). The Nth wire bonding layer (4N) is encapsulated and isolated by the Nth layer of encapsulant (3N).

3. The encapsulation wire bonding structure according to claim 2, wherein The stepped conductive member (5) includes microchannels (52) vertically distributed in the encapsulant (3) and a conductor (53) formed by curing conductive slurry poured into the microchannels (52). The top end of the microchannel (52) is a recessed portion (54). The conductor (53) in the recessed portion (54) constitutes the conductive extension portion (51).

4. The encapsulation wire bonding structure according to claim 2, wherein, The stepped conductive member (5) includes thick copper wires (55) vertically distributed in the encapsulant (3). The top of the thick copper wire (55) is ball - implanted or connected to a pad to form the conductive extension portion (51).

5. A wire bonding method for encapsulation, characterized in that, Wire bonding is carried out in layers according to the wire bonding density of the first solder joint (11) and the second solder joint (21). The specific steps are as follows: Low - density wire bonding S1: Wire bonding is respectively carried out between the low - density first solder joint (11) and the second solder joint (21) for the first layer, and the first wire bonding layer (41) is encapsulated and isolated by the first layer of encapsulant (31). High - density wire bonding S2: Stepped conductive members (5) are formed within the space range of the first layer of encapsulant (31). The bottom ends of the stepped conductive members (5) are respectively connected to the high - density first solder joint (11) and the second solder joint (21), and the top ends extend to the upper surface of the first layer of encapsulant (31). A conductive extension portion (51) is formed at the top end of the stepped conductive member (5). Wire bonding is carried out between the conductive extension portions (51) to connect the high - density first solder joint (11) and the second solder joint (21).

6. The wire bonding method for packaging according to claim 5, wherein, In the step of high - density wire bonding S2, wire bonding is carried out in different layers according to the wire bonding density levels of the first solder joint (11) and the second solder joint (21). The specific steps are as follows: Solder joint staggering S21: Stepped conductive members (5) with the same height are formed within the space range of the previous layer of encapsulant (3). The bottom ends of the stepped conductive members (5) are respectively connected to the first solder joint (11) and the second solder joint (21) of the current wire bonding density, and the top ends are exposed on the upper surface of the space range of the previous layer of encapsulant. It is determined whether to form a conductive extension portion (51) at the top end of the stepped conductive member (5) according to the current wire bonding density. The stepped wire bonding S22 is to perform wire bonding between the top of the stepped conductive member (5) or between the conductive extension parts (51) to connect the first welding point (11) and the second welding point (21) of the current wire bonding density, and then encapsulate the current wire bonding layer with the encapsulant (3).

7. The wire bonding method for packaging according to claim 6, characterized in that, Specifically, to form the stepped conductive member (5) with the same height within the space range of the previous layer of encapsulant (3), a microchannel (52) communicating with the first welding point (11) or the second welding point (21) is vertically etched downward on the upper surface of the previous layer of encapsulant (3), and conductive slurry is poured into the microchannel (52) and cured to form the stepped conductive member (5).

8. The wire bonding method for packaging according to claim 7, wherein Specifically, the formation of the conductive extension part (51) is to expand and etch to form a recessed part (54) along the upper surface of the previous layer of encapsulant (3) when etching the microchannel (52) to the top, and after pouring and curing the conductive slurry in the microchannel (52) and the recessed part (54), the conductive extension part (51) is formed.

9. The wire bonding method for packaging according to claim 6, wherein Specifically, to form the stepped conductive member (5) with the same height within the space range of the previous layer of encapsulant (3): In the step of low-density wire bonding S1, the first welding point (11) and the second welding point (21) without wire bonding are respectively vertically connected to the thick copper wires (55), and then the first wire bonding layer (41) is encapsulated and isolated. In the step of high-density wire bonding S2, the previous layer of encapsulant (3) is polished to expose the thick copper wires (55). After wire bonding the thick copper wires (55) of the current layer, the thick copper wires (55) that do not need wire bonding are continuously vertically connected to the thick copper wires (55), thereby forming the stepped conductive member (5) with the height of the current layer.

10. The wire bonding method for encapsulation according to claim 9, wherein, Specifically, the formation of the conductive extension part (51) is to form the conductive extension part (51) by ball planting or soldering pads on the top of the thick copper wires (55) after polishing the previous layer of encapsulant (3) to expose the thick copper wires (55).

Images