Packaging structure and forming method thereof

Abstract

The invention discloses a packaging structure and a forming method thereof, and the structure comprises a substrate, the substrate comprises an optical module region, and the optical module region comprises an electric connection region arranged in the edge direction close to the substrate and an edge region adjacent to the electric connection region; the optical device is arranged at the top of the substrate in the optical module area, and the electrical connection area of the substrate is electrically connected with the optical device; the blocking structure is located at the top of the substrate in the edge area, and the surface of the blocking structure is provided with a non-infiltrating material; and the bottom filling layer is located between the optical device and the substrate of the electric connection area, and the bottom filling layer is in contact with the substrate and the optical device. The blocking structure can prevent the bottom filling layer from overflowing towards the direction close to the edge area, the probability that the bottom filling layer overflows out of the periphery of the substrate is reduced, and therefore the reliability and the product yield of the packaging structure are improved.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of semiconductor packaging, and in particular to a packaging structure and a method for forming the same. Background Art

[0002] With the rapid development of data centers and artificial intelligence applications, the market demand for high-speed, high-bandwidth, and low-power optical communication solutions continues to grow. Co-Packaged Optics (CPO) technology has become the preferred solution to meet this market demand due to its excellent integration and transmission efficiency.

[0003] CPO technology is an advanced optical packaging technology that integrates optical devices and chips on a substrate, significantly shortening the electrical signal transmission path, thereby improving signal transmission speed and integrity, thereby reducing size, improving efficiency and reducing power consumption.

[0004] At present, the reliability and product yield of the packaging structure formed by co-packaging optical technology still need to be improved. Summary of the invention

[0005] The problem solved by the embodiment of the present invention is to provide a packaging structure and a method for forming the same, thereby improving the reliability of the packaging structure and the product yield

[0006] To solve the above problems, an embodiment of the present invention provides a packaging structure, including: a substrate, the substrate including an optical module area, the optical module area including an electrical connection area arranged along an edge direction close to the substrate and an edge area adjacent to the substrate; an optical device, arranged on the top of the substrate in the optical module area, and the electrical connection area of ​​the substrate is electrically connected to the optical device; a blocking structure, located on the top of the substrate in the edge area, and the surface of the blocking structure has a non-wetting material; a bottom filling layer, located between the optical device and the substrate in the electrical connection area, and the bottom filling layer is in contact with the substrate and the optical device.

[0007] Optionally, the barrier structure includes an integrated structural layer; or, the barrier structure includes a substrate layer and a barrier layer covering a surface of the substrate layer.

[0008] Optionally, the material of the integrated structural layer includes a non-wetting material; or, the material of the barrier layer includes a non-wetting material.

[0009] Optionally, the non-wetting material includes one or both of silicon oxide and silicon nitride.

[0010] Optionally, taking a direction close to an edge of the substrate as a first direction, the blocking structures extend along a second direction and are arranged in parallel and spaced apart along the first direction, and the first direction and the second direction are perpendicular to each other.

[0011] Optionally, the number of the blocking structures is between 1 and 4.

[0012] Optionally, taking a direction close to an edge of the substrate as a first direction, a size of the blocking structure in the first direction is 10 micrometers to 20 micrometers.

[0013] Optionally, in the normal direction of the substrate, there is a first distance between the optical device and the substrate, and the height of the optical device is between 5% and 25% of the first distance.

[0014] Optionally, the packaging structure also includes: a first conductive bump, located on the surface of the optical device facing the substrate, and the top surface of the first conductive bump is electrically connected to the optical device, and the bottom surface of the first conductive bump is electrically connected to the electrical connection area of ​​the substrate; the bottom filling layer covers the side walls of the first conductive bump; with the direction along the edge close to the substrate as the first direction, the size of the blocking structure and the most adjacent first conductive bump in the first direction is between 100 microns and 300 microns.

[0015] Optionally, the optical device spans across an edge region of the substrate and protrudes out of the substrate.

[0016] Optionally, the blocking structure is also located on a surface of the optical device facing the edge region.

[0017] Optionally, along the direction close to the edge of the substrate, the blocking structure located on the edge area and the blocking structure located on the optical device are staggered; or, along the direction close to the edge of the substrate, the blocking structure located on the edge area and the blocking structure located on the optical device are cross-arranged.

[0018] Optionally, the material of the bottom filling layer includes epoxy resin.

[0019] Correspondingly, an embodiment of the present invention also provides a method for forming a packaging structure, comprising: providing a substrate, the substrate including an optical module area, the optical module area including an electrical connection area arranged along an edge direction close to the substrate and an edge area adjacent to the substrate; arranging an optical device on the top of the substrate in the optical module area, and the electrical connection area of ​​the substrate is electrically connected to the optical device; forming a blocking structure on the top of the substrate in the edge area, and the surface of the blocking structure has a non-wetting material; after forming the optical device and the blocking structure, forming a bottom filling layer between the optical device and the substrate in the electrical connection area, and the bottom filling layer is in contact with the substrate and the optical device.

[0020] Optionally, the barrier structure includes an integrated structural layer; or, the barrier structure includes a substrate layer and a barrier layer covering a surface of the substrate layer.

[0021] Optionally, the material of the integrated structural layer includes a non-wetting material; or, the material of the barrier layer includes a non-wetting material.

[0022] Optionally, the process of forming the blocking structure on the top of the substrate in the edge area includes a spraying process, a printing process or a sputtering process.

[0023] Optionally, the step of setting an optical device on the top of the substrate in the optical module area includes: providing an optical device, wherein a first conductive bump is formed on the surface of the optical device facing the substrate, and the top surface of the first conductive bump is electrically connected to the optical device; soldering the first conductive bump to the electrical connection area of ​​the substrate through a high-temperature reflow process, and the bottom surface of the first conductive bump is electrically connected to the electrical connection area of ​​the substrate; in the step of forming the bottom filling layer, the bottom filling layer covers the side walls of the first conductive bump.

[0024] Optionally, after setting the optical device, a blocking structure is formed on the top of the substrate in the edge area; the step of forming the blocking structure further includes: forming a blocking structure on the surface of the optical device facing the edge area.

[0025] Optionally, in the step of forming the blocking structure along the direction close to the edge of the substrate, the blocking structure located on the edge area is staggered with the blocking structure located on the optical device; or, in the step of forming the blocking structure along the direction close to the edge of the substrate, the blocking structure located on the edge area is cross-arranged with the blocking structure located on the optical device.

[0026] Optionally, taking a direction close to an edge of the substrate as a first direction, the blocking structures extend along a second direction and are arranged in parallel and spaced apart along the first direction, and the first direction and the second direction are perpendicular to each other.

[0027] Compared with the prior art, the technical solution of the embodiment of the present invention has the following advantages:

[0028] In the packaging structure provided by the embodiment of the present invention, the optical device is arranged on the top of the substrate in the optical module area, and the electrical connection area of ​​the substrate is electrically connected to the optical device, the blocking structure is located on the top of the substrate in the edge area, and the surface of the blocking structure has a non-wetting material. Since the surface of the blocking structure has the non-wetting material, the non-wetting material has the function of blocking the overflow of liquid material. In the process of setting the bottom filling layer between the optical device and the substrate in the electrical connection area, the blocking structure can block the bottom filling layer from overflowing in the direction close to the edge area, reducing the probability of the bottom filling layer overflowing the periphery of the substrate, thereby improving the reliability of the packaging structure and the product yield.

[0029] In the method for forming a packaging structure provided by an embodiment of the present invention, an optical device is arranged on the top of the substrate in the optical module area, and the electrical connection area of ​​the substrate is electrically connected to the optical device, a blocking structure is formed on the top of the substrate in the edge area, and the surface of the blocking structure has a non-wetting material. Since the surface of the blocking structure has the non-wetting material, the non-wetting material has the function of blocking the overflow of liquid material. In the subsequent process of setting a bottom filling layer between the optical device and the substrate in the electrical connection area, the blocking structure can block the bottom filling layer from overflowing in the direction close to the edge area, reducing the probability of the bottom filling layer overflowing from the periphery of the substrate, thereby improving the reliability of the packaging structure and the product yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figures 1 to 3 A structural schematic diagram corresponding to a packaging structure is shown;

[0031] Figures 4 to 7 is a schematic structural diagram corresponding to the first embodiment of the packaging structure of the present invention;

[0032] Figures 8 to 9 A schematic structural diagram corresponding to the second embodiment of the packaging structure of the present invention is shown;

[0033] Figures 10 to 17 is a schematic structural diagram corresponding to each step of the first embodiment of the method for forming a packaging structure of the present invention;

[0034] Figure 18 to Figure 19 The schematic diagram of the structure corresponding to each step in the second embodiment of the method for forming a packaging structure of the present invention is shown. DETAILED DESCRIPTION

[0035] At present, the reliability and product yield of the packaging structure still need to be improved. Now, the reasons why the reliability and product yield of a packaging structure still need to be improved are analyzed in combination with a packaging structure.

[0036] Figures 1 to 3 A schematic diagram of a packaging structure is shown. Figure 1 It is a top view of the packaging structure. Figure 2 This is a top view of the optical module area. Figure 3 yes Figure 2 and Figure 1 Cross-sectional view along direction A1A2.

[0037] refer to Figures 1 to 3 The packaging structure includes: a substrate 10, the substrate 10 includes an optical module area 10C, the optical module area 10C includes an electrical connection area 10A arranged along an edge direction close to the substrate 10 and an edge area 10B adjacent to the electrical connection area 10A; an optical device 11, arranged on the top of the substrate 10 in the optical module area 10C, and the electrical connection area 10A of the substrate 10 is electrically connected to the optical device 11; a bottom filling layer 12, located between the optical device 11 and the substrate 10 in the electrical connection area 10A, and the bottom filling layer 12 is in contact with the substrate 10 and the optical device 11.

[0038] It has been found that in the process of setting the bottom filling layer 12 between the optical device 11 and the substrate 10 in the electrical connection area 10A, the bottom filling layer 12 near the edge area 10B of the substrate 10 cannot be controlled, which increases the overflow of the bottom filling layer 12 to the periphery of the substrate 10 (such as Figure 3 The probability of the package structure being damaged (as shown in the dotted circle) is affected, thereby affecting the reliability of the packaging structure and the product yield.

[0039] In order to solve the above technical problems, an embodiment of the present invention provides a packaging structure, including: a substrate, the substrate including an optical module area, the optical module area including an electrical connection area arranged along an edge direction close to the substrate and an edge area adjacent to the substrate; an optical device, arranged on the top of the substrate in the optical module area, and the electrical connection area of ​​the substrate is electrically connected to the optical device; a blocking structure, located on the top of the substrate in the edge area, and the surface of the blocking structure has a non-wetting material; a bottom filling layer, located between the optical device and the substrate in the electrical connection area, and the bottom filling layer is in contact with the substrate and the optical device.

[0040] In the packaging structure provided by the embodiment of the present invention, the optical device is arranged on the top of the substrate in the optical module area, and the electrical connection area of ​​the substrate is electrically connected to the optical device, the blocking structure is located on the top of the substrate in the edge area, and the surface of the blocking structure has a non-wetting material. Since the surface of the blocking structure has the non-wetting material, the non-wetting material has the function of blocking the overflow of liquid material. In the process of setting the bottom filling layer between the optical device and the substrate in the electrical connection area, the blocking structure can block the bottom filling layer from overflowing in the direction close to the edge area, reducing the probability of the bottom filling layer overflowing the periphery of the substrate, thereby improving the reliability of the packaging structure and the product yield.

[0041] In order to make the above-mentioned purposes, features and advantages of the embodiments of the present invention more obvious and understandable, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0042] Figures 4 to 7 : is a schematic diagram of the structure corresponding to the first embodiment of the packaging structure of the present invention. Figure 4 It is a top view of the packaging structure. Figure 5 This is a top view of the optical module area. Figure 6 yes Figure 5 Cross-sectional view along direction A1A2.

[0043] The packaging structure includes: a substrate 100, wherein the substrate 100 includes an optical module area 100C, wherein the optical module area 100C includes an electrical connection area 100A arranged along an edge direction close to the substrate 100 and an edge area 100B adjacent to the electrical connection area 100A; an optical device 101, which is arranged on the top of the substrate 100 in the optical module area 100C, and the electrical connection area 100A of the substrate 100 is electrically connected to the optical device 101; a blocking structure 102, which is located on the top of the substrate 100 in the edge area 100B, and the surface of the blocking structure 102 has a non-wetting material; and a bottom filling layer 110, which is located between the optical device 101 and the substrate 100 in the electrical connection area 100A, and the bottom filling layer 110 is in contact with the substrate 100 and the optical device 101.

[0044] It should be noted that the optical device 101 is arranged on the top of the substrate 100 in the optical module area 100C, and the electrical connection area 100A of the substrate 100 is electrically connected to the optical device 101, and the blocking structure 102 is located on the top of the substrate 100 in the edge area 100B, and the surface of the blocking structure 102 has a non-wetting material. Since the surface of the blocking structure 102 has a non-wetting material, the non-wetting material has the function of blocking the overflow of liquid material. In the process of setting the bottom filling layer 110 between the optical device 101 and the substrate 100 in the electrical connection area 100A, the blocking structure 102 can block the bottom filling layer 110 from overflowing in the direction close to the edge area 100B, thereby reducing the probability of the bottom filling layer 110 overflowing from the periphery of the substrate 100, thereby improving the reliability of the packaging structure and the product yield.

[0045] Specifically, the substrate 100 provides a process platform for setting up the optical device 101 to support the optical device 101. At the same time, the substrate 100 has a conductive circuit for supplying power to the optical device 101 or transmitting electrical signals, thereby realizing packaging and circuit integration of the optical device 101.

[0046] In this embodiment, the substrate 100 may be one of a silicon substrate, an RDL substrate (Re-distribution Layer), a resin substrate, a printed circuit board (PCB), a ceramic substrate, a glass substrate, or a flexible circuit board (FPC). In one embodiment, the substrate 100 may be a single-layer board or a multi-layer board. In one embodiment, the substrate 100 may be used as an intermediate board (or adapter board). Specifically, the optical module area 100C is an area where the optical device 101 is subsequently set. By setting the optical device 101 on the substrate 100, the distance between the optical device 101 and other chips can be shortened, the speed of electrical signal transmission can be increased, and lower signal delay and lower power consumption can be achieved.

[0047] As an example, the optical module region 100C includes an electrical connection region 100A disposed along an edge direction close to the substrate 100 and an edge region 100B adjacent thereto.

[0048] It should be noted that the electrical connection area 100A is an area where the optical device 101 is electrically connected to the substrate 100 , specifically, an area where the conductive bump in the optical device 101 is electrically connected to the substrate 100 .

[0049] It should also be noted that the edge area 100B is an area where the blocking structure 102 is set. By setting the blocking structure 102 in the edge area 100B, it is possible to prevent the bottom filling layer 110 from overflowing in the direction close to the edge area 100B, thereby reducing the probability of the bottom filling layer 110 overflowing the periphery of the substrate 100, thereby improving the reliability of the packaging structure and the product yield.

[0050] Specifically, the optical device 101 is used to receive optical signals. By arranging the optical device 101 in the optical module region 100C of the substrate 100 , a shorter optical path can be achieved, thereby improving the efficiency of optical communication.

[0051] As an example, in order to facilitate the optical device 101 to receive an optical signal, the optical device 101 spans the edge region 100B of the substrate 100 and protrudes out of the substrate 100 .

[0052] As an example, the optical device 101 includes one or both of an optoelectronic chip and an optical transceiver.

[0053] In other embodiments, the optical device 101 may be replaced with other types of optical components according to performance requirements.

[0054] In this embodiment, the packaging structure also includes: a first conductive bump 111, which is located on the surface of the optical device 101 facing the substrate 100, and the top surface of the first conductive bump 111 is electrically connected to the optical device 101, and the bottom surface of the first conductive bump 111 is electrically connected to the electrical connection area 100A of the substrate 100.

[0055] It should be noted that the first conductive bump 111 is used to realize setting the optical device 101 on the substrate 100 to reduce the risk of the optical device 101 and the substrate 100 being separated from each other. At the same time, the first conductive bump 111 is also used to realize the electrical connection between the optical device 101 and the substrate 100.

[0056] It should also be noted that, during the formation of the packaging structure, the first conductive bump 111 is formed by an electroplating process, so that the first conductive bump 111 can be formed at a specified position of the electrical connection area 100A of the substrate 100, thereby facilitating the first conductive bump 111 to be bonded to the substrate 100. At the same time, the first conductive bump 111 formed by the electroplating process has the characteristics of high connection reliability, which can reduce the risk of the first conductive bump 111 falling off from the substrate 100.

[0057] As an example, the material of the first conductive bump 111 includes one or more of gold, lead tin, silver tin, gold tin and copper tin.

[0058] It should be noted that the blocking structure 102 is located on the top of the substrate 100 in the edge area 100B, and the surface of the blocking structure 102 has a non-wetting material. Since the surface of the blocking structure 102 has a non-wetting material, the non-wetting material has the function of blocking the overflow of liquid materials. In the process of setting the bottom filling layer 110 between the optical device 101 and the substrate 100 in the electrical connection area 100A, the blocking structure 102 can block the bottom filling layer 110 from overflowing in the direction close to the edge area 100B, thereby reducing the probability of the bottom filling layer 110 overflowing from the periphery of the substrate 100, thereby improving the reliability of the packaging structure and the product yield.

[0059] In this embodiment, the blocking structure 102 includes an integrated structural layer.

[0060] Specifically, the integrated structural layer means that the barrier structure 102 is made of the same material.

[0061] In this embodiment, the material of the integrated structural layer includes a non-wetting material.

[0062] It should be noted that the barrier structures 102 are made of non-wetting materials, which have the function of blocking the overflow of liquid materials, so that the barrier structures 102 can block the bottom filling layer 110 from overflowing toward the edge area 100B.

[0063] In other embodiments, Figure 7 As shown, the blocking structure 102 may further include a substrate layer 1021 and a blocking layer 1022 covering the surface of the substrate layer 1021 .

[0064] A barrier layer 1022 is formed on the surface of the base material layer 1021 . The surface of the barrier layer 1022 has a non-wetting material, so that the barrier layer 1022 can prevent the bottom filling layer 110 from overflowing toward the edge area 100B, thereby reducing the probability of the bottom filling layer 110 overflowing the periphery of the substrate 100 .

[0065] The substrate layer 1021 supports the barrier layer 1022 , ensuring that the entire barrier structure 102 has a certain strength and height.

[0066] Specifically, the material of the barrier layer 1022 includes a non-wetting material.

[0067] The material of the blocking layer 1022 is a non-wetting material, which has the function of blocking the overflow of liquid materials. Accordingly, in the process of setting the bottom filling layer 110 between the optical device 101 and the substrate 100 in the electrical connection area 100A, the blocking layer 1022 can block the bottom filling layer 110 from overflowing in the direction close to the edge area 100B, thereby reducing the probability of the bottom filling layer 110 overflowing from the periphery of the substrate 100.

[0068] In this embodiment, the non-wetting material includes one or both of silicon oxide and silicon nitride.

[0069] Silicon oxide and silicon nitride have high density and are non-conductive, and will not affect the circuits in the optical device. At the same time, silicon oxide and silicon nitride can prevent the bottom filling layer 110 from overflowing toward the edge area 100B, reducing the probability of the bottom filling layer 110 overflowing the periphery of the substrate 100.

[0070] In this embodiment, the direction close to the edge of the substrate 100 is taken as the first direction (eg Figure 5 The blocking structure 102 is arranged along the second direction (as shown in the X direction). Figure 5 The first and second directions extend in parallel and spaced apart from each other along the first direction, and the first and second directions are perpendicular to each other.

[0071] It should be noted that the blocking structures 102 are arranged in parallel at intervals along the first direction. During the process of setting the bottom filling layer 110 between the optical device 101 and the substrate 100 of the electrical connection area 100A, even if the bottom filling layer 110 overflows over the first blocking structure 102, the subsequent blocking structures 102 in the first direction can still block the overflow of the bottom filling layer 110, thereby reducing the probability of the bottom filling layer 110 overflowing from the periphery of the substrate 100.

[0072] It should also be noted that the blocking structure 102 extends along the second direction, that is, the boundary of the electrical connection area 100A close to the edge of the substrate 100 is closed by the blocking structure 102, so that the overflow of the bottom filling layer 110 in the entire electrical connection area 100A is blocked by the blocking structure 102, further reducing the probability of the bottom filling layer 110 overflowing from the periphery of the substrate 100.

[0073] Specifically, the number of the blocking structures 102 should not be too large. If the number of the blocking structures 102 is too large, it is easy to cause the edge area 100B occupied by the blocking structures 102 to be too large. When the area of ​​the optical module area 100C is constant, the area of ​​the electrical connection area 100A is reduced, thereby reducing the area of ​​the connection between the optical device 101 and the substrate 100, increasing the risk of separation between the optical device 101 and the substrate 100, and also affecting the electrical connection effect between the optical device 101 and the substrate 100. For this reason, in this embodiment, the number of the blocking structures 102 is between 1 and 4.

[0074] It should be noted that, with the direction close to the edge of the substrate 100 as the first direction, the size of the blocking structure 102 in the first direction should not be too small or too large. If the size of the blocking structure 102 in the first direction is too small, the process difficulty of forming the blocking structure 102 is increased in the process of forming the blocking structure 102, and the effect of the blocking structure 102 in blocking the overflow of the liquid material is affected, and the probability of the bottom filling layer 110 overflowing the periphery of the substrate 100 is increased; if the size of the blocking structure 102 in the first direction is too large, it is easy to cause the area of ​​the edge area 100B occupied by the blocking structure 102 to be too large, and when the area of ​​the optical module area 100C is constant, the area of ​​the electrical connection area 100A is reduced, thereby reducing the area of ​​the bonding between the optical device 101 and the substrate 100, and increasing the risk of separation between the optical device 101 and the substrate 100. For this reason, in this embodiment, with the direction close to the edge of the substrate 100 as the first direction, the size of the blocking structure 102 in the first direction is 10 microns to 20 microns.

[0075] Specifically, in the normal direction of the substrate 100, there is a first spacing between the optical device 101 and the substrate 100, and the percentage of the height of the blocking structure 102 between the first spacing should not be too large or too small. If the percentage of the height of the blocking structure 102 between the first spacing is too small, the effect of the blocking structure 102 in blocking the overflow of the liquid material is affected, and the probability of the bottom filling layer 110 overflowing the periphery of the substrate 100 is increased; if the percentage of the height of the blocking structure 102 between the first spacing is too large, the manufacturing difficulty and manufacturing cost of the blocking structure 102 are high. For this reason, in the present embodiment, in the normal direction of the substrate 100, there is a first spacing between the optical device 101 and the substrate 100, and the height of the blocking structure 102 is between 5% and 25% of the first spacing.

[0076] It should be noted that, with the direction close to the edge of the substrate 100 as the first direction, the size of the blocking structure 102 and the first conductive bump 111 that is closest to the substrate 100 in the first direction should not be too small or too large. If the size of the blocking structure 102 and the first conductive bump 111 that is closest to the substrate 100 in the first direction is too small, it is difficult to set the bottom filling layer 110 between the blocking structure 102 and the first conductive bump 111 that is closest to the substrate 100, so that the bottom filling layer 110 cannot completely cover the side wall of the first conductive bump 111, and the risk of the side wall of the first conductive bump 111 that is closest to the blocking structure 102 being exposed is increased, thereby increasing the risk of the first conductive bump 111 being polluted by the air environment, affecting the reliability of the packaging structure; if the size of the blocking structure 102 and the first conductive bump 111 that is closest to the substrate 100 in the first direction is too large, due to the limitation of the substrate space, it is not conducive to setting the blocking structure 102 on the substrate or there is only space to set one blocking structure 102. To this end, in this embodiment, the direction along the edge of the substrate 100 is taken as the first direction, and the size of the blocking structure 102 and the most adjacent first conductive bump 111 in the first direction is between 100 micrometers and 300 micrometers.

[0077] It should be noted that the bottom filling layer 110 is used to adhere the optical device 101 to the substrate 100, to prevent the risk of loosening or falling off between the optical device 101 and the substrate 100, and to improve the reliability of the packaging structure. At the same time, the bottom filling layer 110 also protects the optical device 101 and the substrate 100, and prevents dust or moisture in the external environment from damaging the packaging structure.

[0078] In this embodiment, the bottom filling layer 110 covers the sidewalls of the first conductive bump 111 .

[0079] Specifically, the bottom filling layer 110 covers the sidewalls of the first conductive bump 111 , thereby reducing the exposure of the first conductive bump 111 to the air environment, reducing the risk of the first conductive bump 111 being contaminated by dust or moisture, and improving the reliability of the packaging structure.

[0080] As an example, the material of the bottom filling layer 110 includes epoxy resin.

[0081] Accordingly, Figures 8 to 9 A structural schematic diagram corresponding to the second embodiment of the packaging structure of the present invention is shown.

[0082] The similarities between the packaging structure of the present invention and the first embodiment are not described in detail here. The differences between the packaging structure of the present invention and the first embodiment are as follows:

[0083] refer to Figures 8 to 9The blocking structure 202 is also located on the surface of the optical device 201 facing the edge region.

[0084] It should be noted that the blocking structure 202 is also located on the surface of the optical device 201 facing the edge area. In the process of setting the bottom filling layer between the optical device 201 and the substrate of the electrical connection area, the blocking structure 202 can also prevent the probability of the bottom filling layer overflowing from the periphery of the substrate through the surface of the optical device 201 facing the edge area, thereby further improving the reliability of the packaging structure and the product yield.

[0085] like Figure 8 As shown, in this embodiment, along the direction close to the edge of the substrate, the blocking structure 202 located on the edge area and the blocking structure 202 located on the optical device 201 are arranged alternately.

[0086] Specifically, the blocking structure 202 on the edge area is staggered with the blocking structure 202 on the optical device 201, so that the blocking structure 202 on the edge area and the blocking structure 202 on the optical device 201 form a tooth-like structure. In the process of setting the bottom filling layer between the optical device 201 and the substrate of the electrical connection area, even if the bottom filling layer overflows the first blocking structure 202, the tooth-like structure formed by the blocking structure 202 can still prevent the bottom filling layer from overflowing the periphery of the substrate, thereby further improving the blocking effect of the blocking structure 202.

[0087] like Fig. 9 As shown, in other embodiments, along a direction close to the edge of the substrate, the blocking structure 202 located on the edge region and the blocking structure 202 located on the optical device 201 are arranged crosswise.

[0088] Specifically, the blocking structure 202 on the edge area is cross-arranged with the blocking structure 202 on the optical device 201, so that the blocking structure 202 on the edge area and the blocking structure 202 on the optical device 201 form a comb-like structure, and the blocking structures 202 of the comb-like structure have overlapping areas in the longitudinal direction. In the process of setting the bottom filling layer between the optical device 201 and the substrate of the electrical connection area, the comb-like structure composed of multiple blocking structures 202 can further prevent the bottom filling layer from overflowing from the periphery of the substrate, thereby further improving the blocking effect of the blocking structure 202.

[0089] Accordingly, an embodiment of the present invention further provides a method for forming a packaging structure. Figures 10 to 17 It is a schematic structural diagram corresponding to each step of the first embodiment of the method for forming a packaging structure of the present invention.

[0090] refer to Figures 10 to 12 ,in, Fig.10is a top view of the substrate, Fig.11 This is a top view of the optical module area. Fig.12 yes Fig.11 A cross-sectional view along the A1A2 direction shows a substrate 300 , wherein the substrate 300 includes an optical module region 300C. The optical module region 300C includes an electrical connection region 300A disposed along an edge direction close to the substrate 300 and an edge region 300B adjacent thereto.

[0091] Specifically, the substrate 300 provides a process platform for setting up the optical device to support the optical device. At the same time, the substrate 300 has a conductive circuit, which is used to supply power to the optical device or transmit electrical signals, thereby realizing the packaging and circuit integration of the optical device.

[0092] In this embodiment, the substrate 300 may be one of a silicon substrate, an RDL substrate (Re-distribution Layer), a resin substrate, a printed circuit board (PCB), a ceramic substrate, a glass substrate, or a flexible circuit board (FPC). In one embodiment, the substrate 100 may be a single-layer board or a multi-layer board. In one embodiment, the substrate 100 may be used as an intermediate board (or adapter board).

[0093] Specifically, the optical module area 300C is an area where optical devices are subsequently set. By setting optical devices on the substrate 300, the distance between the optical devices and other chips can be shortened, the speed of electrical signal transmission can be increased, and lower signal delay and lower power consumption can be achieved.

[0094] As an example, the optical module region 300C includes an electrical connection region 300A disposed along an edge direction close to the substrate 300 and an edge region 300B adjacent thereto.

[0095] It should be noted that the electrical connection area 300A is an area where the optical device is electrically connected to the substrate 300 , specifically, an area where the conductive bump in the optical device is electrically connected to the substrate 300 .

[0096] It should also be noted that the edge area 300B is an area where a blocking structure is set. By setting a blocking structure in the edge area 300B, it is possible to prevent the bottom filling layer from overflowing in the direction close to the edge area 300B, thereby reducing the probability of the bottom filling layer overflowing the periphery of the substrate 300, thereby improving the reliability of the packaging structure and the product yield.

[0097] refer to Figures 13 to 15 ,in, Fig.13 This is a top view of the optical module area. Fig.14 yes Fig.13In the cross-sectional view along the A1A2 direction, a blocking structure 302 is formed on the top of the substrate 300 in the edge region 300B, and the surface of the blocking structure 302 has a non-wetting material.

[0098] It should be noted that a blocking structure 302 is formed on the top of the substrate 300 in the edge area 300B, and the surface of the blocking structure 302 has a non-wetting material. Since the surface of the blocking structure 302 has a non-wetting material, the non-wetting material has the function of blocking the overflow of liquid material. In the subsequent process of forming the bottom filling layer, the blocking structure 302 can block the bottom filling layer from overflowing in the direction close to the edge area 300B, thereby reducing the probability of the bottom filling layer overflowing the periphery of the substrate 300, thereby improving the reliability of the packaging structure and the product yield.

[0099] In this embodiment, the blocking structure 302 includes an integrated structural layer.

[0100] Specifically, the integrated structural layer means that the blocking structure 302 is made of the same material.

[0101] In this embodiment, the material of the integrated structural layer includes a non-wetting material.

[0102] It should be noted that the barrier structures 302 are all made of non-wetting materials, which have the function of blocking the overflow of liquid materials, so that the barrier structures 302 can block the bottom filling layer from overflowing toward the edge area 300B.

[0103] In other embodiments, Fig.15 As shown, the blocking structure 302 may further include a substrate layer 3021 and a blocking layer 3022 covering the surface of the substrate layer 3021 .

[0104] A barrier layer 3022 is formed on the surface of the base material layer 3021 . The surface of the barrier layer 3022 has a non-wetting material, so that the barrier layer 3022 can prevent the bottom filling layer from overflowing toward the edge area 300B, thereby reducing the probability of the bottom filling layer overflowing the periphery of the substrate 300 .

[0105] The substrate layer 3021 supports the barrier layer 3022 , ensuring that the entire barrier structure 302 has a certain strength and height.

[0106] Specifically, the material of the barrier layer 3022 includes a non-wetting material.

[0107] The material of the blocking layer 3022 is a non-wetting material, which has the function of blocking the overflow of liquid materials. Accordingly, in the process of setting a bottom filling layer between the subsequently formed optical device and the substrate 300 of the electrical connection area 300A, the blocking layer 3022 can block the bottom filling layer from overflowing in the direction close to the edge area 300B, thereby reducing the probability of the bottom filling layer overflowing from the periphery of the substrate 300.

[0108] In this embodiment, the non-wetting material includes one or both of silicon oxide and silicon nitride.

[0109] Silicon oxide and silicon nitride have high density and are non-conductive, and will not affect the circuits in the subsequently formed optical devices. At the same time, silicon oxide and silicon nitride can prevent the subsequently formed bottom filling layer from overflowing toward the edge area 300B, reducing the probability of the bottom filling layer overflowing the periphery of the substrate 300.

[0110] As an example, the process of forming the blocking structure 302 on the top of the substrate 300 in the edge area 300B includes a spraying process, a printing process or a sputtering process.

[0111] In this embodiment, the direction close to the edge of the substrate 300 is taken as the first direction (eg Fig.13 The blocking structure 302 is arranged along the second direction (as shown in the X direction). Fig.13 The first and second directions extend in parallel and spaced apart from each other along the first direction, and the first and second directions are perpendicular to each other.

[0112] It should be noted that the blocking structures 302 are arranged in parallel at intervals along the first direction. In the process of setting a bottom filling layer between the subsequently formed optical device and the substrate 300 of the electrical connection area 300A, even if the bottom filling layer overflows over the first blocking structure 302, the subsequent blocking structures 302 in the first direction can still block the overflow of the bottom filling layer, thereby reducing the probability of the bottom filling layer overflowing from the periphery of the substrate 300.

[0113] It should also be noted that the blocking structure 302 extends along the second direction, that is, the boundary of the electrical connection area 300A close to the edge of the substrate 300 is closed by the blocking structure 302, so that the overflow of the bottom filling layer in the entire electrical connection area 300A is blocked by the blocking structure 302, further reducing the probability of the bottom filling layer overflowing the periphery of the substrate 300.

[0114] Specifically, the number of the blocking structures 302 should not be too large. If the number of the blocking structures 302 is too large, it is easy to cause the edge area 300B occupied by the blocking structures 302 to be too large. When the area of ​​the optical module area 300C is constant, the area of ​​the electrical connection area 300A is reduced, thereby reducing the area of ​​the subsequent bonding between the optical device and the substrate 300, increasing the risk of separation between the optical device and the substrate 300, and also affecting the electrical connection effect between the optical device and the substrate 300. For this reason, in this embodiment, the number of the blocking structures 302 is between 1 and 4.

[0115] It should be noted that, with the direction close to the edge of the substrate 300 as the first direction, the size of the blocking structure 302 in the first direction should not be too small or too large. If the size of the blocking structure 302 in the first direction is too small, the process difficulty of forming the blocking structure 302 is increased in the process of forming the blocking structure 302, and the effect of the blocking structure 302 in blocking the overflow of the liquid material is affected, and the probability of the bottom filling layer overflowing the periphery of the substrate 300 is increased; if the size of the blocking structure 302 in the first direction is too large, it is easy to cause the area of ​​the edge area 300B occupied by the blocking structure 302 to be too large, and when the area of ​​the optical module area 300C is constant, the area of ​​the electrical connection area 300A is reduced, thereby reducing the area of ​​the subsequent optical device and the substrate 300, and increasing the risk of separation between the optical device and the substrate 300. For this reason, in this embodiment, with the direction close to the edge of the substrate 300 as the first direction, the size of the blocking structure 302 in the first direction is 10 microns to 20 microns.

[0116] Specifically, in the normal direction of the substrate 300, there is a first spacing between the optical device to be formed later and the substrate 300, and the percentage of the height of the blocking structure 302 between the first spacing should not be too large or too small. If the percentage of the height of the blocking structure 302 between the first spacing is too small, the effect of the blocking structure 302 in blocking the overflow of the liquid material is affected, and the probability of the bottom filling layer overflowing the periphery of the substrate 300 is increased; if the percentage of the height of the blocking structure 302 between the first spacing is too large, the difficulty and cost of manufacturing the blocking structure 302 are high. For this reason, in the present embodiment, in the normal direction of the substrate 300, there is a first spacing between the optical device and the substrate 300, and the height of the blocking structure 302 is between 5% and 25% of the first spacing.

[0117] It should be noted that, with the direction close to the edge of the substrate 300 as the first direction, the size of the blocking structure 302 and the first conductive bump 311 that is closest to the substrate 300 in the first direction should not be too small or too large. If the size of the blocking structure 302 and the first conductive bump 311 that is closest to the substrate 300 in the first direction is too small, it is difficult to set a bottom filling layer between the blocking structure 302 and the first conductive bump 311 that is closest to the substrate 300, so that the bottom filling layer cannot completely cover the side wall of the first conductive bump 311, and the risk of the side wall of the first conductive bump 311 that is closest to the blocking structure 302 being exposed is increased, thereby increasing the risk of the first conductive bump 311 being polluted by the air environment, affecting the reliability of the packaging structure; if the size of the blocking structure 302 and the first conductive bump 311 that is closest to the substrate 300 in the first direction is too large, due to the limitation of the substrate space, it is not conducive to setting the blocking structure 302 on the substrate or there is only space to set one blocking structure 302. To this end, in this embodiment, the direction close to the edge of the substrate 300 is taken as the first direction, and the size of the blocking structure 302 and the most adjacent first conductive bump 311 in the first direction is between 100 micrometers and 300 micrometers.

[0118] refer to Fig.16 An optical device 301 is disposed on the top of the substrate 300 in the optical module area 300C, and the electrical connection area 300A of the substrate 300 is electrically connected to the optical device 301 .

[0119] Specifically, the optical device 301 is used to receive an optical signal. By arranging the optical device 301 in the optical module region 300C of the substrate 300 , a shorter optical path can be achieved, thereby improving the efficiency of optical communication.

[0120] As an example, in order to facilitate the optical device 301 to receive the optical signal, a portion of the optical device 301 protrudes from the periphery of the substrate 300 .

[0121] As an example, the optical device 301 includes one or both of an optoelectronic chip and an optical transceiver.

[0122] In this embodiment, the step of setting an optical device 301 on the top of the substrate 300 in the optical module area 300C includes: providing an optical device 301, wherein a first conductive bump 311 is formed on the surface of the optical device 301 facing the substrate 300, and the top surface of the first conductive bump 311 is electrically connected to the optical device 301; soldering the first conductive bump 311 to the electrical connection area 300A of the substrate 300 through a high-temperature reflow process, and the bottom surface of the first conductive bump 311 is electrically connected to the electrical connection area 300A of the substrate 300.

[0123] It should be noted that the first conductive bump 311 is used to realize setting the optical device 301 on the substrate 300 to reduce the risk of the optical device 301 and the substrate 300 being separated from each other. At the same time, the first conductive bump 311 is also used to realize the electrical connection between the optical device 301 and the substrate 300.

[0124] It should also be noted that by forming the first conductive bump 311 on the surface of the optical device 301 facing the substrate 300 through the electroplating process, the first conductive bump 311 can be formed at a specified position of the electrical connection area 300A of the substrate 300. At the same time, the first conductive bump 311 formed by the electroplating process has the characteristics of high connection reliability, which can reduce the risk of the first conductive bump 311 and the substrate 300 falling off.

[0125] As an example, the material of the first conductive bump 311 includes one or more of gold, lead tin, silver tin, gold tin and copper tin.

[0126] Specifically, the high-temperature reflow process can only locally heat the first conductive bump 311 and the substrate 300 to complete the welding, reducing the probability of thermal shock to other components of the packaging structure. At the same time, the high-temperature reflow process can allow the excess flux in the first conductive bump 311 to fully volatilize, reducing the residue after welding, thereby improving the welding quality.

[0127] refer to Fig.17 After forming the optical device 301 and the blocking structure 302 , a bottom filling layer 310 is formed between the optical device 301 and the substrate 300 in the electrical connection area 300A, and the bottom filling layer 310 is in contact with the substrate 300 and the optical device 301 .

[0128] It should be noted that the bottom filling layer 310 is used to adhere the optical device 301 to the substrate 300, to prevent the risk of loosening or falling off between the optical device 301 and the substrate 300, and to improve the reliability of the packaging structure. At the same time, the bottom filling layer 310 also protects the optical device 301 and the substrate 300, and prevents dust or moisture in the external environment from damaging the packaging structure.

[0129] In this embodiment, in the step of forming the bottom filling layer 310 , the bottom filling layer 310 covers the sidewalls of the first conductive bump 311 .

[0130] Specifically, the bottom filling layer 310 covers the sidewalls of the first conductive bump 311 , thereby reducing the exposure of the first conductive bump 311 to the air environment, reducing the risk of the first conductive bump 311 being contaminated by dust or moisture, and improving the reliability of the packaging structure.

[0131] As an example, the material of the bottom filling layer 310 includes epoxy resin.

[0132] Accordingly, Figure 18 to Figure 19 The schematic diagram of the structure corresponding to each step in the second embodiment of the method for forming a packaging structure of the present invention is shown.

[0133] The similarities between the method for forming the package structure of the present invention and the first embodiment are not described in detail here. The differences between the method for forming the package structure of the present invention and the first embodiment are as follows:

[0134] refer to Figure 18 to Figure 19 In the step of forming the blocking structure 402, it also includes: forming a blocking structure 402 on the surface of the optical device 401 facing the edge area.

[0135] It should be noted that, in the process of forming a blocking structure 402 on the surface of the optical device 401 facing the edge area and forming a bottom filling layer 410 between the optical device 401 and the substrate 400 in the electrical connection area, the blocking structure 402 can also block the probability of the bottom filling layer 410 overflowing from the periphery of the substrate 400 through the surface of the optical device 401 facing the edge area, thereby further improving the reliability of the packaging structure and the product yield.

[0136] like Fig.18 As shown, in this embodiment, along the direction close to the edge of the substrate 400 , in the step of forming the blocking structure 402 , the blocking structure 402 located on the edge area and the blocking structure 402 located on the optical device 401 are alternately arranged.

[0137] Specifically, the blocking structure 402 on the edge area is alternately arranged with the blocking structure 402 on the optical device 401, so that the blocking structure 402 on the edge area and the blocking structure 402 on the optical device 401 form a tooth-like structure. In the process of forming the bottom filling layer 410 between the optical device 401 and the substrate 400 in the electrical connection area, even if the bottom filling layer 410 overflows the first blocking structure 402, the tooth-like structure formed by the blocking structure 402 can still prevent the bottom filling layer 410 from overflowing from the periphery of the substrate 400, thereby further improving the blocking effect of the blocking structure 402.

[0138] like Fig.19 As shown, in other embodiments, along the direction close to the edge of the substrate 400 , in the step of forming the blocking structure 402 , the blocking structure 402 located on the edge area and the blocking structure 402 located on the optical device 401 are arranged crosswise.

[0139] Specifically, the blocking structure 402 on the edge area is cross-arranged with the blocking structure 402 on the optical device 401, so that the blocking structure 402 on the edge area and the blocking structure 402 on the optical device 401 form a comb-like structure, and the blocking structure 402 of the comb-like structure has overlapping areas in the longitudinal direction. In the process of forming the bottom filling layer 410 between the optical device 401 and the substrate 400 in the electrical connection area, the comb-like structure composed of multiple blocking structures 402 can further prevent the bottom filling layer 410 from overflowing from the periphery of the substrate 400, thereby further improving the blocking effect of the blocking structure 402.

[0140] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A packaging structure, characterized in that: include: A substrate, the substrate comprising an optical module region, the optical module region comprising an electrical connection region arranged along an edge direction close to the substrate and an edge region adjacent thereto; An optical device is disposed on the top of the substrate in the optical module area, and the electrical connection area of ​​the substrate is electrically connected to the optical device; a barrier structure, located on top of the substrate in the edge region, and having a non-wetting material on a surface of the barrier structure; The bottom filling layer is located between the optical device and the substrate in the electrical connection area, and the bottom filling layer is in contact with the substrate and the optical device.

2. The packaging structure according to claim 1, characterized in that: The barrier structure includes an integral structural layer; or, The barrier structure includes a substrate layer and a barrier layer covering the surface of the substrate layer.

3. The packaging structure according to claim 2, characterized in that: The material of the integrated structural layer includes a non-wetting material; Alternatively, the material of the barrier layer includes a non-wetting material.

4. The packaging structure according to claim 1 or 3, characterized in that: The non-wetting material includes one or both of silicon oxide and silicon nitride.

5. The packaging structure according to claim 1, characterized in that: Taking the direction close to the edge of the substrate as the first direction, the blocking structures extend along the second direction and are arranged in parallel with each other at intervals along the first direction, and the first direction and the second direction are perpendicular to each other.

6. The packaging structure according to claim 1, characterized in that: The number of the blocking structures ranges from 1 to 4.

7. The packaging structure according to claim 1, characterized in that: Taking a direction close to the edge of the substrate as a first direction, a size of the blocking structure in the first direction is 10 micrometers to 20 micrometers.

8. The packaging structure according to claim 1, characterized in that: In the normal direction of the substrate, there is a first distance between the optical device and the substrate, and the height of the blocking structure is between 5% and 25% of the first distance.

9. The packaging structure according to claim 1, characterized in that: The packaging structure further includes: a first conductive bump, located on a surface of the optical device facing the substrate, wherein a top surface of the first conductive bump is electrically connected to the optical device, and a bottom surface of the first conductive bump is electrically connected to an electrical connection region of the substrate; The bottom filling layer covers the sidewalls of the first conductive bump; Taking the direction close to the edge of the substrate as the first direction, the size of the blocking structure and the first conductive bump that is most adjacent to the first direction is between 100 micrometers and 300 micrometers.

10. The packaging structure according to claim 1, wherein: The optical device spans across an edge region of the substrate and protrudes beyond the substrate.

11. The packaging structure according to claim 1 or 10, characterized in that: The blocking structure is also located on a surface of the optical device facing the edge region.

12. The packaging structure according to claim 11, characterized in that: Along a direction close to the edge of the substrate, the blocking structure located on the edge area and the blocking structure located on the optical device are arranged alternately; or, Along a direction close to the edge of the substrate, the blocking structure located on the edge region is arranged to cross the blocking structure located on the optical device.

13. The packaging structure according to claim 1, characterized in that: The material of the bottom filling layer includes epoxy resin.

14. A method for forming a packaging structure, characterized in that: include: Providing a substrate, the substrate comprising an optical module area, the optical module area comprising an electrical connection area arranged along an edge direction close to the substrate and an edge area adjacent to the electrical connection area; forming a barrier structure on top of the substrate in the edge region, wherein a surface of the barrier structure has a non-wetting material; After forming the blocking structure, an optical device is arranged on the top of the substrate in the optical module area, and the electrical connection area of ​​the substrate is electrically connected to the optical device; After the optical device and the blocking structure are formed, an underfill layer is formed between the optical device and the substrate in the electrical connection area, and the underfill layer is in contact with the substrate and the optical device.

15. The method for forming a package structure according to claim 14, wherein: The barrier structure includes an integrated structural layer; or, the barrier structure includes a substrate layer and a barrier layer covering a surface of the substrate layer.

16. The method for forming a package structure according to claim 15, wherein: The material of the integrated structural layer includes a non-wetting material; or the material of the barrier layer includes a non-wetting material.

17. The method for forming a package structure according to claim 14, wherein: The process of forming the barrier structure on the top of the substrate in the edge area includes a spraying process, a printing process or a sputtering process.

18. The method for forming a package structure according to claim 14, wherein: The step of arranging an optical device on the top of the substrate in the optical module area includes: providing an optical device, wherein a first conductive bump is formed on the surface of the optical device facing the substrate, and the top surface of the first conductive bump is electrically connected to the optical device; soldering the first conductive bump to the electrical connection area of ​​the substrate through a high-temperature reflow process, and the bottom surface of the first conductive bump is electrically connected to the electrical connection area of ​​the substrate; In the step of forming the bottom filling layer, the bottom filling layer covers the sidewalls of the first conductive bump.

19. The method for forming a package structure according to claim 14, wherein: The step of forming the blocking structure further includes: forming a blocking structure on a surface of the optical device facing the edge region.

20. The method for forming a package structure according to claim 19, wherein: Along a direction close to the edge of the substrate, in the step of forming the blocking structure, the blocking structure located on the edge area and the blocking structure located on the optical device are arranged alternately; or, Along a direction close to the edge of the substrate, in the step of forming the blocking structure, the blocking structure located on the edge region is arranged to cross with the blocking structure located on the optical device.

21. The method for forming a package structure according to claim 14, wherein: Taking the direction close to the edge of the substrate as the first direction, the blocking structures extend along the second direction and are arranged in parallel with each other at intervals along the first direction, and the first direction and the second direction are perpendicular to each other.

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