Joint structure

Abstract

Some embodiments of the present application provide a joint structure comprising: a first post extending in a first direction; and a plurality of first lines formed on sidewalls of the first pillar, where each of the plurality of first lines extends in a second direction that is not perpendicular to the first direction. According to the bonding structure provided by the invention, the bonding strength and the corresponding electrical performance of the corresponding bonding structure are improved. Specifically, in the bonding structure provided by some embodiments of the present application, a plurality of first lines are formed on the side wall of the first column as a blocking structure, so that the problem that the bonding strength of the previous first column is difficult to bear warping in the vertical direction and is easy to break is solved, and the electrical performance of the corresponding bonding structure is improved.

Description

Technical Field

[0001] An embodiment of the present application relates to a bonding structure. Background Art

[0002] In the conventional joint structure 10, as Figure 1A As shown, in the case of joint interconnection formed by solder balls 12 between pads 11 arranged on dielectric layers 13 or 15 (respectively arranged on chip 16 or carrier 14), some problems almost occur, such as bridge B, and additional solder balls 12' and pad space S are required, but the additional solder balls 12' and pad space S require higher material and manufacturing costs. Specifically, these problems are due to the need for larger solder balls 12, and the larger solder balls 12 make it necessary to have enough space between the joints (for example, for electronic devices 17 such as MEMS devices) to separate the operating areas. The size of the solder ball 12 increases with the increase of the gap, and the pad space S also increases accordingly. In addition, additional materials (such as additional solder balls 12') and manufacturing also bring high costs.

[0003] In view of the above defects, the current bonding is changed to metal-to-metal bonding, such as copper (Cu)-to-copper bonding. In general, copper-to-copper bonding structures can reduce the use of copper-to-copper bonding in small pitches. Figure 1A The bridge B problem of the solder ball 12 butt joint shown in FIG. 1 is more prone to alignment problems, so a bonding structure with several thin columns is provided. Figure 1B to Figure 1C , Figure 1B The corresponding pre-engaged structure is shown, and Figure 1C A corresponding metal-to-metal (such as copper-to-copper) bonding structure 20 is shown. Figure 1B and Figure 1C As shown, a plurality of thin pillars 22A and 22B can be formed on the upper and lower pads 21 (set on the upper and lower dielectric layers 23), and the side walls 22As and 22Bs are guided and butted to form a joint 22, thereby improving the alignment efficiency. Since the upper and lower thin pillars 22A and 22B extend in the "vertical direction C", the bonding strength of the butt joint of the side walls 22As and 22Bs is difficult to withstand the vertical warping ( Figure 1C The corresponding warping direction D is shown in the figure), which is prone to breakage problems, resulting in poor electrical properties. Utility Model Content

[0004] In order to solve the above problems, in the bonding structure provided in the present application, such as the copper-to-copper bonding structure, a plurality of columns are formed on the upper and lower pads, and a blocking structure is further provided on the plurality of columns, thereby solving the problem that the plurality of columns are previously guided and connected to each other by the side walls, thereby causing the upper and lower columns to extend in the "vertical direction" in the same manner, resulting in the side wall bonding strength being unable to withstand the vertical warping and being easily broken.

[0005] Some embodiments of the present application provide a bonding structure, including: a first column extending in a first direction; and a plurality of first lines formed on a sidewall of the first column, wherein each of the plurality of first lines extends in a second direction that is not perpendicular to the first direction.

[0006] In some embodiments, the bonding structure further includes: a second column electrically connected to the first column, and the second column extends in a third direction opposite to the first direction, wherein the second column overlaps with the first column in a fifth direction perpendicular to the first direction and the third direction.

[0007] In some embodiments, the bonding structure further includes: a plurality of second lines formed on a sidewall of the second pillar, wherein each of the plurality of second lines extends in a fourth direction that is not perpendicular to the third direction.

[0008] In some embodiments, the plurality of second lines are in contact with the plurality of first lines.

[0009] In some embodiments, the second lines overlap corresponding first lines in the fifth direction.

[0010] In some embodiments, the second line is located between the corresponding first line and the first column.

[0011] In some embodiments, the second direction is non-parallel to the fourth direction.

[0012] In some embodiments, the bonding structure further includes: a first pad, the first column is formed on the first pad, wherein the first direction is a direction in which the first column extends away from the first pad.

[0013] In some embodiments, the angle between the first line and the first column is an acute angle.

[0014] In some embodiments, there are plural first pillars, and the first pillars are formed on the same pad.

[0015] In some embodiments, there are plural first pillars, which are formed on different pads.

[0016] In some embodiments, the number of the first pillars and the number of the second pillars are both plural, and the first pillars and the second pillars are staggered.

[0017] In some embodiments, the first columns and the second columns are staggered to form a continuous structure.

[0018] In some embodiments, the first pillars and the second pillars are staggered into a plurality of groups, and wherein adjacent groups in the plurality of groups are spaced apart from each other.

[0019] In some embodiments, the first column is set on a first solder pad, the second column is set on a second solder pad, the first columns in the multiple groups are set on the same or different first solder pads, and the second columns in the multiple groups are set on the same or different second solder pads, and the number of the first solder pads is the same or different from the number of the second solder pads.

[0020] In some embodiments, the bonding structure further includes: a first substrate, the first pad being disposed on the first substrate, wherein the first pad is disposed in one of the following ways: being located above the first substrate, being embedded in the first substrate, or having a first portion extending through the first substrate to connect to a trace in the first substrate and a second portion extending above the first substrate.

[0021] Some other embodiments of the present application provide a bonding structure, including: a first column; and a plurality of first lines formed on a side wall of the first column, wherein an angle between the first line and the first column is an acute angle.

[0022] In some embodiments, the bonding structure also includes: a second column electrically connected to the first column, and a plurality of second lines formed on the side walls of the second column, wherein the angle between the second line and the second column is an acute angle, and wherein the second line is located between the corresponding first line and the first column.

[0023] In some embodiments, the joining structure also includes: a first solder pad, on which the first column is formed; and a second solder pad, on which the second column is formed, wherein the first solder pad has a third line at a position extending beyond the first column, and the second solder pad has a fourth line at a position extending beyond the second column.

[0024] In summary, the bonding structure provided in the present application forms multiple lines on the side walls of the corresponding columns as blocking structures, which not only solves the problem that the bonding strength of the previous multiple columns is difficult to withstand vertical warping and is prone to breakage, but also improves the electrical performance of the corresponding bonding structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] When read in conjunction with the accompanying drawings, various aspects of the present invention can be best understood from the following detailed description. It should be noted that, in accordance with standard practice in the industry, the various components are not drawn to scale. In fact, for the sake of clarity of discussion, the size of the various components can be arbitrarily increased or reduced.

[0026] Figures 1A to 1CA bonding structure in the prior art is shown.

[0027] FIG. 2A to FIG. 2D A bonding structure according to some embodiments of the present application is shown.

[0028] Figures 3 to 8 The bonding structures according to other embodiments of the present application are shown.

[0029] Fig. 9 , 9A to 9E A top view of a bonding structure according to some embodiments of the present application is shown.

[0030] FIG. 10A to FIG. 10B A substrate of a bonding structure according to some embodiments of the present application is shown.

[0031] Figures 11 to 25 , Fig.26A , Fig.26B as well as Figure 27 to Figure 28 A process flow for forming a bonding structure according to some embodiments of the present application is shown. DETAILED DESCRIPTION

[0032] The following disclosure provides many different embodiments or examples for realizing different features of the present invention. Specific examples of components and arrangements are described below to simplify the present invention. Of course, these are merely examples and are not intended to limit the present invention. In addition, when "approximately", "about", "substantially", etc. are used to describe a numerical value or a numerical range, unless otherwise specified, the term is intended to cover a numerical value within ±10% of the described numerical value. For example, the term "about 5nm" covers a size range from 4.5nm to 5.5nm.

[0033] The present application improves the bonding strength and corresponding electrical performance of the corresponding bonding structure by forming multiple wires on the side walls of the corresponding columns as a barrier structure. In addition, the wire bonding structure using multiple wires for bonding provides good interconnection performance for subsequent integrated circuit (IC) packaging. Specifically, these wires are bonded to each other through "cross-linking" and are manufactured on the surface of the higher columns. While providing better bonding strength, these higher columns further provide sufficient space for the large gap required between the two corresponding pads.

[0034] Specifically, see Figure 2A and Figure 2B , Figure 2A shows a bonding structure 100 according to some embodiments of the present application, and Figure 2B Shows Figure 2ASpecifically, some embodiments of the present application provide a bonding structure 100 including a first column 101 extending in a first direction D1 and a plurality of first lines 101P formed on a sidewall 101S of the first column 101. In the bonding structure 100 of the present application, each of the plurality of first lines 101P extends in a second direction D2 that is not perpendicular to the first direction D1. It should be noted that Figure 2A and Figure 2B The second direction D2 shown is only an example of a schematic extension direction of the first line 101P. Figure 2A As shown, the bonding structure 100 further includes a second pillar 102 electrically connected to the first pillar 101. Figure 2A and Figure 2B As can be seen in FIG. 1 , the second column 102 extends in a third direction D3 opposite to the first direction D1. In a further embodiment, the second column 102 extends in a fifth direction D5 (in a direction perpendicular to the first direction D1 and the third direction D3) perpendicular to the first direction D1 and the third direction D3. Figure 2A and Figure 2B In the cross-sectional view shown in FIG. 1 , the second column 102 overlaps the first column 101 in the horizontal direction. In other words, in the joint structure 100, the second column 102 overlaps the first column 101 when viewed from the fifth direction D5, that is, the second column 102 is located at the same level as the first column 101. In a further embodiment, the joint structure 100 further includes a plurality of second lines 102P formed on the sidewall 102S of the second column 102, and each of the plurality of second lines 102P extends in a fourth direction D4 that is not perpendicular to the third direction D3. It should be noted that Figure 2A The second direction D4 shown is only an example of a schematic extension direction of the second wire 102P. In some embodiments, the second direction D2 is not parallel to the fourth direction D4. In some other embodiments, the second direction D2 is also parallel to the fourth direction D4. In further embodiments, the first wire 101P and the second wire 102P are nanowires. In the above embodiments, it should be noted that Figure 2B The first column 101 shown in FIG. 1 is separated from the second column 102 .

[0035] Next, continue to see Figure 2A ,from Figure 2A It can be seen from the figure that the plurality of second lines 102P are in contact with the plurality of first lines 101P. Further, the second lines 102P overlap with the corresponding first lines 101P in the fifth direction D5, that is, in the bonding structure 100, the second lines 102P overlap with the corresponding first lines 101P when viewed from the fifth direction D5, that is, the second lines 102P and the corresponding first lines 101P are cross-linked and bonded to each other. In a specific embodiment, as shown in FIG. Figure 2A and Figure 2B As shown, the second line 102P is located between the corresponding first line 101P and the first column 101, specifically, see Figure 2B , the second line 102P is located in the space V between the corresponding first line 101P and the first pillar 101.

[0036] Figure 2A The bonding structure 100 shown further includes a first pad 103, the first pillar 101 being formed on the first pad 103 and extending from the first pad 103 to the first column 101. Figure 2A It can be further seen from the figure that the first direction D1 is the direction in which the first column 101 extends away from the first pad 103. Similarly, the second column 102 is formed on the second pad 104, and the third direction D3 is the direction in which the second column 102 extends away from the second pad 104. In addition, the angle between the first line 101P and the first column 101 is an acute angle. Figure 2A In the bonding structure 100 shown in FIG. 1 , the number of first pillars 101 is plural, and they are formed on the same first pad 103, that is, the plurality of first pillars 101 are formed on the same first pad 103. Similarly, in Figure 2A In the embodiment shown, a plurality of second pillars 102 are formed on the same second pad 104. Figure 2A As shown, the number of the first pillars 101 and the second pillars 102 are both multiple, and the first pillars 101 and the second pillars 102 are staggered and staggered to form a continuous structure. In addition, the first pad 103 has a third line 103P at a position extending beyond the first pillar 101, and the second pad 104 has a fourth line 104P at a position extending beyond the second pillar 102. Figure 2A As can be seen in FIG. 1 , the third line 103P exists at a position of the first pad 103 on which the first column 101 is not formed, including at the end of the first pad 103 and at a position of the first pad 103 corresponding to the second column 102. Similarly, the fourth line 104P exists at a position of the second pad 104 on which the second column 102 is not formed, including at the end of the second pad 104 and at a position of the second pad 104 corresponding to the first column 101. In some embodiments, a first seed layer 108 exists between the first column 101 and the first pad 103, and a second seed layer 109 exists between the second column 102 and the second pad 104. In the above embodiments, the first pad 103, the second pad 104, the first column 101, the second column 102, the plurality of first lines 101P, and the plurality of second lines 102P include, but are not limited to, metals such as copper (Cu), gold (Au), silver (Ag), and aluminum (Al), and alloys thereof. In addition, the first seed layer 108 and the second seed layer 109 include, but are not limited to, metals of Cu, Au, Ag, Al, palladium (Pd), platinum (Pt), and nickel (Ni), and alloys thereof.

[0037] like Figure 2AAs shown, the bonding structure 100 also includes a first substrate 105 on which the first pad 103 is disposed. In some embodiments, the first substrate 105 can be a non-conductive material, such as an organic material such as polyimide, epoxy resin, Ajinomoto Enhanced Film (ABF), polypropylene or / and acrylic resin, or an inorganic material such as ceramic, silicon, glass, quartz and / or gallium arsenide (GaAs); or the first substrate 105 can also be an organic photosensitive or / and non-photosensitive liquid material or / and dry film material. In a further embodiment, there is a third seed layer 110 between the first substrate 105 and the first pad 103. In some embodiments, the third seed layer 110 includes the same or similar material as the first seed layer 108 and the second seed layer 109. In other embodiments, the bonding structure 100 also includes a second substrate 106 on which the second pad 104 is disposed. In some embodiments, the second substrate 106 includes but is not limited to a chip. In some other embodiments, the second substrate 106 has the same or similar material as the first substrate 105. In addition, in the bonding structure 100, the first pad 103, the second pad 104, and the first column 101 and the second column 103 are surrounded and sealed by a protective layer 107. In some embodiments, the protective layer 107 may be a molding compound, such as a molding compound, etc. In some other embodiments, the protective layer 107 may include a dielectric material such as polyimide, epoxy resin, Ajinomoto Enhanced Film (ABF), polypropylene or / and acrylic resin, etc., and may also include an organic photosensitive or / and non-photosensitive liquid material or / and a dry film material.

[0038] Figure 2C to Figure 2D They are shown respectively Figure 2A The illustrated joining structure 100 and Figure 2B The dimensions of the components of the region A of the bonding structure 100 are shown, and it should be noted that for ease of illustration, Figure 2C and Figure 2D Only marked Figure 2A The illustrated joining structure 100 and Figure 2B The components of the region A of the bonding structure 100 are shown, and the unlabeled components are respectively Figure 2A and Figure 2B The structure shown is the same and will not be described in detail here. Figure 2C and Figure 2DAs shown, the diameter or maximum width PS of the first column 101 and the second column 102 in the fifth direction D5 (horizontal direction) is in the range of 5μm to 30μm, the diameter or maximum width (nano Wire Size, NWS) of the multiple first wires 101P and the multiple second wires 102P is in the range of several nanometers to hundreds of nanometers, and the height of the multiple first wires 101P and the multiple second wires 102P in the fifth direction D5 and the height (nano Wire Height, NWH) of the third wire 103P and the fourth wire 104P in the first direction D1 and the second direction D2 are respectively in the range of 0.1μm to 5μm. In addition, the gap (Gap bonded, GB) between the first pad 103 and the second pad 104 is in the range of 5μm to 200μm, the gap GI between the first substrate 105 and the second substrate 106 is in the range of 20μm to 250μm, and the size of the first pad 103 and the second pad 104 in the fifth direction D5 is in the range of 1μm to 20μm.

[0039] Figure 3 FIG. 2 shows a bonding structure 200 according to some other embodiments of the present application. Figure 3 The illustrated engagement structure 200 is Figure 2A The joint structure 100 shown is similar, except that Figure 3 In the illustrated joint structure 200, the first pillars 101 and the second pillars 102 are staggered to form a plurality of groups such as G1 and G2. However, it can be understood by those skilled in the art that Figure 3 Only G1 and G2 are schematically shown in FIG. 1 , and other groups may be included. Further, adjacent groups (such as G1 and G2) in the plurality of groups (such as G1 and G2) are spaced apart from each other.

[0040] Figure 4 and Figure 5 1 and 2 respectively show bonding structures 300 and 400 according to other embodiments of the present application. Figure 4 The illustrated engagement structure 300 and Figure 5 The illustrated engagement structure 400 is Figure 2A The joint structure 100 shown is similar, except that Figure 4 and Figure 5 In the illustrated joint structures 300 and 400, the first pillars 101 and the second pillars 102 are staggered to form a plurality of groups such as G1 and G2. However, it can be understood by those skilled in the art that Figure 4 and Figure 5 Only G1 and G2 are schematically shown, and other groups may be included. Further, adjacent groups (such as G1 and G2) in a plurality of groups such as G1 and G2 are spaced apart from each other. Specifically, Figure 4In the illustrated bonding structure 300, the second pillars 102 of the plurality of groups G1 and G2 are disposed on the same second pad 104, while the first pillars 101 are disposed on different pads. For example, the first pillars 101 of the G1 group are disposed on a first pad 103A, while the first pillars 101 of the G2 group are disposed on another first pad 103B. Similarly, in Figure 5 In the bonding structure 400 shown, the first columns 101 of the multiple groups set as G1 and G2 are set on the same first pad 103, while the second columns 102 are set on different pads. For example, the second column 102 set as the G1 group is set on the second pad 104A, while the second column 102 set as the G2 group is set on another second pad 104B. In some other embodiments, when the first columns 101 set as the multiple groups are formed on different pads, the second columns 102 can also be formed on different pads. It can be seen that the multiple first columns 101 in the multiple groups can be formed on the same or different first pads 103 / 103A / 103B, and the multiple second columns 102 in the multiple groups can also be formed on the same or different second pads 104 / 104A / 104B, and the number of the first pads 103 / 103A / 103B and the second pads 104 / 104A / 104B are the same or different, such as Figure 2A As shown, a first pad 103 corresponds to a second pad 104. Figure 4 The two first pads 103A shown correspond to one second pad 104, as shown in FIG. Figure 5 One first pad 103 shown corresponds to two second pads 104A and a plurality of first pads 103 not shown corresponds to a plurality of first pads 104 .

[0041] Afterwards, see Figure 6 and Figure 7 , Figure 6 and Figure 7 1 and 2 respectively show bonding structures 500 and 600 according to other embodiments of the present application. Figure 6 The illustrated engagement structure 500 and Figure 7 The illustrated engagement structure 600 is Figure 2A The joint structure 100 shown is similar, except that Figure 2A In the bonding structure 100 shown, the first pad 103 is disposed above the first substrate 105, and Figure 6 In the bonding structure 500 shown in FIG. 1 , the first pad 103 is embedded in the first substrate 105 and exposed from the first substrate 105. Figure 7In the illustrated bonding structure 600, the first pad 103 is configured to have a first portion 103-1 extending through the first substrate 105 to connect with the trace 111 in the first substrate 105 and a second portion 103-2 extending above the first substrate 105. Figure 2A as well as Figure 6 and Figure 7 As can be seen in FIG. 1 , a third seed layer 110 may be provided between the first pad 103 and the first substrate 105 (see FIG. 1 ). Figure 2A and Figure 7 ), in some cases, the third seed layer 110 may not be provided (see Figure 6 ). However, for Figure 6 The bonding structure 500 shown in FIG. 1 may also be provided with a third seed layer 110. Figure 7 In the illustrated bonding structure 600 , the thickness of the first portion 103 - 1 of the first pad 103 in the first direction D1 is in a range of 1 μm to 20 μm.

[0042] See also Figure 8 , Figure 8 Shown by multiple Figure 2A The bonding structure 100 shown forms a bonding structure 700. Figure 8 As can be seen in the figure, the bonding structure 100 of the present application is used to form Figure 8 The bonding structure 700 shown can: 1) make the gap G1 between the available first pad 103 and the second pad 104, as well as the gap G2 between adjacent first pads 103 and the gap G2 between adjacent second pads 104 smaller; 2) the bonding structure 700 of the present application can be solderless, which avoids some problems, such as bridging, the need for additional solder balls and pad space (because the soldering area is less than the size of the soldering pad (such as the first pad 103) because there is a non-soldering area Z); and 3) reduce costs and provide a low-cost solution because no additional space, materials and manufacturing processes are required (compared to Figures 1A to 1C Compared to the solder interconnect shown, the bonding structure 700 provided in the present application requires the same pad size (such as the first pad 103).

[0043] Next, see Figures 9 to 9E , Fig. 9 Shows Figure 2A The partial structure of the bonding structure 100 shown, and 9A to 9E FIG. 1 shows a top view of the first pillar 101 and its corresponding plurality of first lines 101P and first pads 103 in the partial structure. 9A to 9E In the figure, for the convenience of explanation, the first pillar 101 and its corresponding plurality of first lines 101P are labeled as 101+101P to indicate the shape they form together. 9A to 9EAs can be seen from the figure, the first pillar 101 and its corresponding plurality of first lines 101P can be formed as follows: Fig. 9A The square shown, Fig. 9B The circle shown, Fig. 9C The polygon shown, Fig.9D Irregular shapes as shown and / or Fig.9E In addition, the first pad 103 may be formed as follows 9A to 9D The square shown and / or Fig.9E The rectangular shape shown. In addition, FIG. 10A to FIG. 10B Different shapes of the first substrate 105 are shown, namely, Figure 2A as well as Figures 3 to 8 In the illustrated bonding structures 100 - 700 , different substrates, such as square or circular substrates (or carriers) may be used. The shape of the first substrate 105 is also applicable to the second substrate 106 , which will not be described in detail herein.

[0044] See also Figure 2A and Figure 2B , other embodiments of the present application provide a bonding structure 100, which includes: a first column 101; and a plurality of first lines 101P formed on a sidewall 101S of the first column 101. In the bonding structure 100, the angle between the first line 101P and the first column 101 is an acute angle. In some embodiments, the bonding structure 100 also includes a second column 102 electrically connected to the first column 101, and a plurality of second lines 102P formed on a sidewall 102S of the second column 102. Similarly, the angle between the second line 102P and the second column 102 is an acute angle, and the second line 102P is located between the corresponding first line 101P and the first column 101, that is, a portion of the second line 102P is located in a space V between the corresponding first line 101P and the first column 101, as shown Figure 1B As shown. Further, the bonding structure 100 further includes: a first pad 103 on which the first column 101 is formed; and a second pad 104 on which the second column 102 is formed. In addition, Figure 2A , the first pad 103 has a third line 103P at a position extending beyond the first column 101, and the second pad 104 has a fourth line 104P at a position extending beyond the second column 102. In other words, the third line 103P exists at a position of the first pad 103 on which the first column 101 is not formed, including at the end of the first pad 103 and at a position of the first pad 103 corresponding to the second column 102. Similarly, the fourth line 104P exists at a position of the second pad 104 on which the second column 102 is not formed, including at the end of the second pad 104 and at a position of the second pad 104 corresponding to the first column 101.

[0045] In summary, for the bonding structures 100 to 700 provided in the present application, nanowires of a plurality of first wires 101P on the first column 101 and a plurality of second wires 102P on the second column 102 are used as barrier structures, thereby improving the bonding strength and corresponding electrical performance of the corresponding bonding structures 100 to 700. In addition, the nanowire bonding structure of a plurality of first wires 101P on the higher first column 101 and a plurality of second wires 102P on the higher second column 102 provides good interconnection performance for subsequent integrated circuit (IC) packaging. Further, these first wires 101P and second wires 102P are respectively manufactured on the higher column surfaces (the sidewalls 101S of the first column 101 and the sidewalls 102S of the second column 102), and are bonded to each other by "cross-linking", and the bonding uses the higher first column 101 and the second column 102 to provide sufficient space and sufficient available height for the large gap required between the two interfaces (the first substrate 105 and the second substrate 106) (to replace the large solder balls (see Figure 1A In the bonding structures 100 to 700 provided in the present application, the higher first column 101 and the second column 102 may also have the ability to provide the support strength of the bonding structures 100 to 700, and the plurality of first wires 101P on the first column 101 and the plurality of second wires 102P on the second column 102 provide sufficient contact for electrical interconnection and heat transfer between the first column 101 and the second column 102.

[0046] The following will refer to Figures 11 to 28 To introduce the formation Figure 2A The process flow of the bonding structure 100 is shown.

[0047] First, see Figures 11 to 17 , Figures 11 to 17 The formation of the first pad 103, the first column 101 and the plurality of first lines 101P thereof on the first substrate 105 is shown. Fig.11 , a first substrate 105 on which a first pad 103 is formed is provided, the first substrate 105 may be a silicon wafer, and the first pad 103 may be a copper pad. In addition, a third seed layer 110 is formed between the first pad 103 and the first substrate 105, and the third seed layer 110 may be made of copper. In some embodiments, the first pad 103 and the third seed layer 110 may be formed by physical vapor deposition (PVD), plating such as electroplating, chemical plating, and printing, potting metal, etc. See Fig.12, a seed layer 108' is formed over the first substrate 105 and the first pad 103, such as by physical vapor deposition, plating such as electroplating, chemical plating, printing, or encapsulating metal. In some embodiments, the seed layer 108' may be a metal layer, such as a copper layer. After forming the seed layer 108', a photoresist 1001 is deposited or laminated over the seed layer 108', such as Fig.13 The photoresist 1001 is exposed and developed P1, thereby forming an opening 1001O in the photoresist 1001, as shown in FIG. Fig.14 As shown. Fig.14 As shown, a metal pillar 101' is plated in the opening 1001O. The metal pillar 101' is made of metal, and in this embodiment, is made of copper. The metal pillar 101' can be formed by plating such as electroplating or chemical plating. The metal pillar 101' has a sidewall 101S'.

[0048] Next, see Fig.15 , the photoresist 1001 is removed by a stripping or etching process, and the etching process may be an etching process using, for example, an oxygen plasma dry etching process. Fig.15 As shown, the portion of the seed layer 108 ′ not covered by the metal pillar 101 ′ is further removed by an etching process, thereby forming a first seed layer 108 .

[0049] Next, see Fig.16 , an etching chemical 1002 (including other or liquid etching substances) is used to etch the sidewall 101S' of the metal pillar 101' to form a first pillar 101 and a plurality of first lines 101P located on the sidewall 101S of the first pillar 101. In addition, while etching the sidewall 101S' of the metal pillar 101', the first pad 103 is also etched, thereby forming a third line 103P at a position of the first pad 103 where the first pillar 101 is not formed. In the present embodiment, the first line 101P and the third line 103P are nanowires, and the etching chemical 1002 may include an etching gas such as oxygen or nitrogen, and may also include an etching liquid such as hydrochloric acid or nitric acid. In an embodiment of the present application, the extension direction D2 (such as ) of the plurality of first lines 101P can be controlled by controlling the etching angle of the etching chemical 1002. Figure 2A As shown), the extension direction D2 of the plurality of first lines 101P is not perpendicular to the extension direction D1 of the first column 101 and the angle between the plurality of first lines 101P and the first column 101 is an acute angle.

[0050] and Figures 11 to 17 The process shown is similar to Figures 18 to 24The formation of the second pad 104 , the second pillar 102 and the plurality of second lines 102P thereof over the second substrate 106 is shown, except that a seed layer may or may not be formed between the second pad 104 and the second substrate 106 , which will not be described in detail here.

[0051] Next, see Fig.25 ,Will Fig.24 The resulting structure flips and Fig.17 The resulting structure is bonded, such as by a pick-and-place process or a press process T. Fig.26A , further bonding the plurality of first wires 101P to the second wires 102P, the first wires 101P to the corresponding fourth wires 104P, and the second wires 102P to the corresponding third wires 103P by a sintering process, such as a sintering process above the glass transition temperature of copper. Fig.26B Shows Fig.26A A magnified view of area A'. Fig.26B As can be seen in FIG. 1 , the second line 102P extends into the space V between the first line 101P and the corresponding first column 101. Fig. 27 , such as by a capillary flow process with a protective material 107 'sealing the first pad 103 and the second pad 104 and the corresponding first line 101P and the second line 102P and the third line 103P and the fourth line 104P, thereby forming Fig.28 The protective layer 107 shown in FIG. 1 is made of epoxy resin material and fills the gaps between the first line 101P and the second line 102P and the third line 103P and the fourth line 104P. Figure 2A The engagement structure 100 is shown.

[0052] In summary, in this application Figures 11 to 28 In the formation process of the provided bonding structure 100, firstly, a metal column 101' or 102' is manufactured from a first seed layer 108 on a first pad 103 of a first substrate 105 or a second substrate 106 or a second seed layer 109 on a second pad 104 by a photolithography process using a photoresist and a plating process, and then, a surface 101S' or 102S' of the metal column 101' or 102' is etched to form a nanowire (a first wire 101P or a second wire 102P) on the surface thereof. Next, the first wire 101P or the second wire 102P, which is a nanowire, is bonded together in a face-to-face (F2F) manner, and interconnections are formed by cross-linking the first wire 101P or the second wire 102P, and finally, the gaps between the first wires 101P or the second wire 102P and the space between the first substrate 105 and the second substrate 106 are filled with a protective layer 107.

[0053] It can be seen that in the present application, metal-to-metal bonding is formed by bonding nanowires (first wire 101P or second wire 102P), so that the nanowires (first wire 101P or second wire 102P) form a blocking structure, so that the bonding strength of the formed bonding structure 100 can withstand vertical warping without being easily broken.

[0054] In addition, the bonding structure 100 prepared by the method of the present application is Figures 1A to 1C Compared to the solder interconnect shown, the advantages are:

[0055] 1) Provides a thin full package (PKG) structure solution that does not require welding;

[0056] 2) because the metal-to-metal nanowire cross-linking bonding, such as copper-to-copper cross-linking bonding, makes the bonding interconnect have a shorter path and good material properties, and thus has better electrical performance; and

[0057] 3) Lower cost and different available pad sizes (e.g. reduced size) because if it is a pad under the solder ball (e.g. Figure 1A As shown), additional redistribution layer manufacturing and required materials are required.

[0058] The features of several embodiments are summarized above so that those skilled in the art can better understand aspects of the present invention. Those skilled in the art should understand that they can easily use the present invention as a basis to design or modify other processes and structures for implementing the same purpose and / or achieving the same advantages as the embodiments described herein. Those skilled in the art should also appreciate that such equivalent constructions do not deviate from the spirit and scope of the present invention, and that they can make various changes, substitutions, and modifications herein without departing from the spirit and scope of the present invention.

Claims

1. A joining structure, characterized in that: include: a first column extending in a first direction; as well as a plurality of first lines formed on the sidewalls of the first pillars, Each of the plurality of first lines extends in a second direction that is not perpendicular to the first direction.

2. The joining structure according to claim 1, characterized in that: Also includes: a second column electrically connected to the first column, and the second column extends in a third direction opposite to the first direction, Wherein, in a fifth direction perpendicular to the first direction and the third direction, the second column overlaps with the first column.

3. The joining structure according to claim 2, characterized in that: Also includes: a plurality of second lines formed on the sidewalls of the second pillars, Wherein, each of the plurality of second lines extends in a fourth direction which is not perpendicular to the third direction.

4. The joining structure according to claim 3, characterized in that: The plurality of second lines are in contact with the plurality of first lines.

5. The joining structure according to claim 3, characterized in that: The second lines overlap corresponding first lines in the fifth direction.

6. The joining structure according to claim 1, characterized in that: Also includes: a first pad, the first column being formed on the first pad, The first direction is a direction in which the first column extends away from the first pad.

7. The joining structure according to claim 1, characterized in that: The angle between the first line and the first column is an acute angle.

8. The joining structure according to claim 6, characterized in that: Also includes: a first substrate, wherein the first pad is disposed on the first substrate, The first pad is configured in one of the following ways: located above the first substrate, embedded in the first substrate, or having a first portion extending through the first substrate to connect to a trace in the first substrate and a second portion extending above the first substrate.

9. A joining structure, characterized in that: include: First column; as well as a plurality of first lines formed on the sidewalls of the first pillars, Wherein, the angle between the first line and the first column is an acute angle.

10. The joining structure according to claim 9, characterized in that: Also includes: a second column electrically connected to the first column, a plurality of second lines formed on the sidewalls of the second pillars, The angle between the second line and the second column is an acute angle, and the second line is located between the corresponding first line and the first column.

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