Package structure and manufacturing method thereof
By using copper as a sintered material in the semiconductor device packaging process to form a homogeneous copper interconnect structure, the high cost and electromigration of silver sintered materials are solved, and the reliability of the packaging structure is improved and manufacturing costs are reduced.
Patent Information
- Application Number
- CN202411276592.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-11
- Publication Date
- 2025-01-14
AI Technical Summary
In the existing semiconductor device packaging process, silver is costly and metal electromigration is prone to occur when used as a sintered material, resulting in complex structure and low reliability at the connection.
Copper is used as the sintering material, and the copper connection part is fixedly connected to the copper pad on the substrate and the copper electrode of the chip to form a homogeneous copper interconnection structure, simplifying the material and structure at the connection.
Improves the reliability of the packaging structure, reduces atomic diffusion and interconnect degradation, reduces contact resistance and thermal resistance, optimizes current distribution, and reduces manufacturing costs.
Smart Images
Figure CN119314963A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the technical field of semiconductor devices, and more particularly, to a packaging structure and a manufacturing method thereof. Background Art
[0002] In the packaging process of semiconductor devices, sintering is an important process step, which is used to fix the connection between the electrode of the tube core and the pad on the substrate. During the sintering process, the sintering material will soften or melt at high temperature, forming a strong connection with the surface of the tube core electrode and the substrate pad, and then solidify after cooling.
[0003] At present, silver is usually used as a sintering material. The connection points formed by sintering silver are resistant to high temperatures and have excellent thermal and electrical conductivity. However, the cost of silver is high, and silver ions are prone to metal electromigration in some special environments. In addition, the use of silver as a sintering material requires a metal layer of a specific material to be set at the connection, which not only makes the material and structure of the connection too complicated, increasing the cost, but also the complex structure of the connection is easy to be damaged, affecting the reliability of the packaging structure. Summary of the invention
[0004] In view of the above problems, the purpose of the present disclosure is to provide a packaging structure and a manufacturing method thereof. By using copper as a sintering material, the copper connecting part is fixedly connected to the copper pad on the substrate and the copper electrode of the chip respectively. The homogeneous interconnection structure composed of the copper sintering layer, the copper connecting part, the copper pad and the copper electrode simplifies the material and structure of the connection, thereby improving the reliability of the packaging structure.
[0005] According to one aspect of an embodiment of the present disclosure, a packaging structure is provided, including:
[0006] substrate;
[0007] A first pad is located on the substrate;
[0008] a tube die, located on the substrate, the tube die comprising a first electrode; and
[0009] a first connecting portion, fixedly connected to the first pad and the first electrode respectively;
[0010] The first pad, the first electrode and the first connection portion are all made of copper. The first connection portion is fixedly connected to the first pad via a first copper sintering layer, and the first connection portion is fixedly connected to the first electrode via a second copper sintering layer.
[0011] Optionally, the first pad, the first copper sintering layer, the first connecting portion, the second copper sintering layer and the first electrode form a homogeneous interconnection structure.
[0012] Optionally, the first connecting portion is a copper wire or a copper strip.
[0013] Optionally, the tube core further includes a second electrode, and the first electrode and the second electrode are respectively arranged on two opposite surfaces of the tube core.
[0014] The packaging structure further includes a second pad located on the substrate.
[0015] The second electrode is fixedly connected to the second pad via a third copper sintering layer.
[0016] Wherein, the second electrode and the second pad are both made of copper.
[0017] Optionally, the second pad, the third copper sintering layer and the second electrode form a homogeneous interconnection structure.
[0018] Optionally, the tube core further includes a third electrode, and the first electrode and the third electrode are respectively arranged on the same surface of the tube core.
[0019] The packaging structure further includes:
[0020] A third pad is located on the substrate; and
[0021] The second connecting portion is fixedly connected to the third pad and the third electrode respectively.
[0022] The third pad, the third electrode and the second connection portion are all made of copper, the second connection portion is fixedly connected to the third pad via a fourth copper sintering layer, and the second connection portion is fixedly connected to the third electrode via a fifth copper sintering layer.
[0023] Optionally, the third pad, the fourth copper sintering layer, the second connecting portion, the fifth copper sintering layer and the third electrode form a homogeneous interconnection structure.
[0024] Optionally, the second connecting portion is a copper wire or a copper strip.
[0025] Optionally, the tube core further includes a semiconductor layer, and a material of the semiconductor layer includes SiC.
[0026] Optionally, the material of the substrate includes ceramics.
[0027] According to another aspect of the present disclosure, a method for manufacturing a package structure is provided, comprising fixing a tube die to a first pad on a substrate, wherein the tube die comprises a first electrode,
[0028] Wherein, the step of fixing the connection comprises:
[0029] forming a first copper sintering layer between the first pad and the first connecting portion; and
[0030] forming a second copper sintered layer between the first connection portion and the first electrode,
[0031] Wherein, the first pad, the first electrode and the first connecting portion are all made of copper.
[0032] Optionally, the tube core further includes a second electrode, and the first electrode and the second electrode are respectively arranged on two opposite surfaces of the tube core.
[0033] The manufacturing method further includes: forming a third copper sintering layer between the second pad on the substrate and the second electrode,
[0034] Wherein, the second electrode and the second pad are both made of copper.
[0035] Optionally, the tube core further includes a third electrode, and the first electrode and the third electrode are respectively arranged on the same surface of the tube core.
[0036] The manufacturing method further comprises:
[0037] forming a fourth copper sintering layer between the third pad and the second connecting portion on the substrate; and
[0038] forming a fifth copper sintered layer between the second connection portion and the third electrode,
[0039] The third pad, the third electrode and the second connection portion are made of copper.
[0040] One of the above technical solutions has the following beneficial effects:
[0041] The copper pad on the substrate is fixedly connected to the copper first connecting part through the copper sintering layer, and the copper electrode on the tube core is fixedly connected to the copper first connecting part through the copper sintering layer. The copper pad, the copper sintering layer, the copper first connecting part and the copper electrode together constitute a homogeneous copper interconnection structure. Compared with the process of using silver as the sintering material, the homogeneous copper interconnection structure simplifies the material and structure of the connection, improves the stability of the connection, and thus improves the reliability of the packaging structure.
[0042] Furthermore, the homogeneous copper interconnect structure and single material composition can significantly reduce atomic diffusion and interconnect degradation caused by chemical reactions between different metals, thereby reducing contact resistance and thermal resistance at the connection and optimizing current distribution. In addition, copper's electrical and thermal conductivity is not inferior to silver, and compared to using silver as a sintering material, the price of copper is only a few tenths of that of silver, which greatly reduces manufacturing costs.
[0043] In some embodiments, the semiconductor layer of the tube core is SiC material, and the substrate is ceramic material. Compared with using silver as the sintering material, the thermal expansion coefficient of copper is closer to SiC and ceramic materials, thereby improving the thermal mismatch problem due to thermal cycle and power cycle conditions.
[0044] It should be noted that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS
[0045] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings of the embodiments will be briefly introduced below. Obviously, the drawings in the following description only relate to some embodiments of the present disclosure, rather than limiting the present disclosure.
[0046] Figure 1 A schematic diagram of a packaging structure in the related art is shown;
[0047] Figure 2 A schematic structural diagram of the packaging structure of an embodiment of the present disclosure is shown. DETAILED DESCRIPTION
[0048] The present disclosure will be described in more detail below with reference to the accompanying drawings. In each of the drawings, the same elements are represented by similar reference numerals. For the sake of clarity, the various parts in the drawings are not drawn to scale. In addition, some well-known parts may not be shown. For the sake of simplicity, the semiconductor structure obtained after several steps can be described in one figure.
[0049] It should be understood that when describing the structure of a device, when a layer or a region is referred to as being "on" or "over" another layer or another region, it may mean that it is directly on the other layer or another region, or that other layers or regions are included between it and the other layer or another region. Furthermore, if the device is turned over, the layer or a region will be "below" or "beneath" another layer or another region.
[0050] If the purpose is to describe the situation of being directly on another layer or another area, this article will use expressions such as "directly on..." or "on... and adjacent to...".
[0051] The power device generally includes an active component region, an edge termination region, and a crack-stop or shielding region. The active component region includes an active component array. The present disclosure relates to an active component structure. The size of the active component may vary depending on product requirements, and there may be body regions between active components in the active component region.
[0052] Many specific details of the present disclosure are described below, such as device structure, materials, dimensions, processing technology and techniques, so as to more clearly understand the present disclosure. However, as those skilled in the art will appreciate, the present disclosure may not be implemented in accordance with these specific details.
[0053] Figure 1 A schematic structural diagram of a packaging structure in the related art is shown.
[0054] like Figure 1 As shown, in the packaging process of the related art, silver is used as the sintering material. Specifically, the packaging structure includes a tube core 100, a substrate 201, a first pad 211, a second pad 212, a third pad 213, a metal layer 220, a first sintering layer 301, a second sintering layer 302, a third sintering layer 303, a first connecting portion 310 and a second connecting portion 320.
[0055] The tube core 100 includes: a semiconductor layer 101, a first electrode 111, a second electrode 112, a third electrode 113, a first connection layer 121, a second connection layer 122, a third connection layer 123 and an isolation layer 130. The first electrode 111 and the third electrode 113 are located on the same side of the tube core 100, and the second electrode 112 and the first electrode 111 are respectively located on different sides of the tube core 100. The first connection layer 121 is located on the surface of the first electrode 111, the second connection layer 122 is located on the surface of the second electrode 112, and the third connection layer 123 is located on the surface of the third electrode 113. The isolation layer 130 is located between the first electrode 111 and the third electrode 113, and also between the first connection layer 121 and the second connection layer 123. The materials of the first electrode 111, the second electrode 112 and the third electrode 113 are aluminum or copper, and the materials of the first connection layer 121, the second connection layer 122 and the third connection layer 123 are one or a combination of titanium, nickel, silver, palladium and gold.
[0056] The substrate 201 has a first surface 21 and a second surface 22 opposite to each other. The substrate 201, the first pad 211, the second pad 212, the third pad 213 and the metal layer 220 are used to form an active metal brazed (AMB) substrate or a direct bond copper (DBC) substrate. The first pad 211, the second pad 212 and the third pad 213 are located on the first surface 21 of the substrate 201, and the metal layer 220 is located on the second surface 22 of the substrate 201, wherein the material of the substrate 201 is ceramic, and the material of the first pad 211, the second pad 212, the third pad 213 and the metal layer 220 is copper.
[0057] The materials of the first sintered layer 301 , the second sintered layer 302 and the third sintered layer 303 are silver, the first connecting portion 310 is, for example, a strip made of copper material (Cu Clip), and the second connecting portion 320 is, for example, a wire made of copper material or aluminum material (Cu or Al Wire).
[0058] In the related art, since the materials of the electrode, pad, and connection part are all aluminum or copper, and the sintering material is silver, when silver is used as the sintering material, the types of interface structures that sintered silver can adapt to are limited, so it is necessary to set a metal layer of a specific material at the connection, such as Figure 1 As shown in the figure, a first connection layer 121, a second connection layer 122 and a third connection layer 123 made of titanium / nickel / silver / palladium / gold materials need to be respectively arranged on the surfaces of the first electrode 111, the second electrode 112 and the third electrode 113. This not only makes the materials and structures of the connections too complicated, thereby increasing the cost, but also the connections with complex structures are easily damaged, thereby affecting the reliability of the packaging structure.
[0059] In addition, when exposed to an electric field or a humid environment for a long time, the silver ions in the sintered layer are prone to metal electromigration problems. For example, the silver ions in the second sintered layer 302 migrate along the isolation layer 130 to the third electrode 113, causing the first electrode 111 and the third electrode 113 to short-circuit, affecting the reliability of the device.
[0060] In view of the above problems, the purpose of the present disclosure is to provide a packaging structure and a manufacturing method thereof. By using copper as a sintering material, the copper connecting part is fixedly connected to the copper pad on the substrate and the copper electrode of the chip respectively. The homogeneous interconnection structure composed of the copper sintering layer, the copper connecting part, the copper pad and the copper electrode simplifies the material and structure of the connection, thereby improving the reliability of the packaging structure.
[0061] Figure 2 A schematic structural diagram of the packaging structure of an embodiment of the present disclosure is shown.
[0062] like Figure 2 As shown, the packaging structure of the embodiment of the present disclosure includes: a tube core 400, a substrate 501, a first solder pad 511, a second solder pad 512, a third solder pad 513, a metal layer 520, a first copper sintering layer 601, a second copper sintering layer 602, a third copper sintering layer 603, a fourth copper sintering layer 604, a fifth copper sintering layer 605, a first connecting part 610 and a second connecting part 620.
[0063] The tube core 400 includes: a semiconductor layer 401, a first electrode 411, a second electrode 412, a third electrode 413 and an isolation layer 430. The first electrode 411 and the third electrode 413 are located on the same surface of the tube core 400, and the second electrode 412 and the first electrode 411 are respectively located on different surfaces opposite to each other of the tube core 400. The isolation layer 430 is located between the first electrode 411 and the third electrode 413. The material of the first electrode 411, the second electrode 412 and the third electrode 413 is copper.
[0064] The semiconductor layer 401 is, for example, a SiC substrate or a stacked structure of a SiC substrate and an epitaxial layer. However, the disclosed embodiments are not limited thereto, and those skilled in the art may make other arrangements for the material and number of layers of the semiconductor layer 401 as required.
[0065] The tube core 400 of this embodiment can be used as a metal-oxide semiconductor field-effect transistor (Metal-Oxide-Semiconductor Field-Effect Transistor, MOSFET), and the first electrode 411, the second electrode 412, and the third electrode 413 are used as a source electrode, a drain electrode, and a gate electrode, respectively. The tube core 400 can also be used as an insulated gate bipolar transistor (Insulated Gate Bipolar Transistor, IGBT). The tube core 400 can also be provided with only the first electrode 411 and the second electrode 412 or only the first electrode 411 and the third electrode 413, so as to act as a diode. However, the embodiments of the present disclosure are not limited thereto, and those skilled in the art can make other settings for the device type of the tube core 400 as needed.
[0066] The substrate 501 has a first surface 51 and a second surface 52 opposite to each other. The substrate 501, the first pad 511, the second pad 512, the third pad 513 and the metal layer 520 are used to form an active metal brazed (AMB) substrate or a direct bond copper (DBC) substrate. The first pad 511, the second pad 512 and the third pad 513 are located on the first surface 51 of the substrate 501, and the metal layer 520 is located on the second surface 52 of the substrate 501, wherein the material of the substrate 501 is ceramic, and the material of the first pad 511, the second pad 512, the third pad 513 and the metal layer 520 is copper. The metal layer 520 is used to connect to the heat sink.
[0067] The first connection portion 610 and the second connection portion 620 are, for example, strips (Cu Clip) or wires (Cu Wire) made of copper material.
[0068] During the packaging process, for example, a copper sintering precursor material is coated on the first pad 511, the second pad 512, the third pad 513, the first electrode 411, and the third electrode 413, and then the tube core 400 is placed on the second pad 512, and the first connection part 610 and the second connection part 620 are placed in corresponding positions. Then, sintering is performed to form a first copper sintering layer 601 between the first pad 511 and the first connection part 610, a second copper sintering layer 602 between the first connection part 610 and the first electrode 411, a third copper sintering layer 603 between the second pad 512 and the second electrode 412, a fourth copper sintering layer 604 between the third pad 513 and the second connection part 620, and a fifth copper sintering layer 605 between the second connection part 620 and the third electrode 413.
[0069] The packaging structure of the disclosed embodiment fixedly connects the copper pad on the substrate to the copper first connecting part through the copper sintering layer, and fixedly connects the copper electrode on the tube core to the copper first connecting part through the copper sintering layer. The copper pad, the copper sintering layer, the copper first connecting part and the copper electrode together constitute a homogeneous copper interconnection structure. Compared with the process of using silver as the sintering material, the homogeneous copper interconnection structure simplifies the material and structure of the connection, improves the stability of the connection, and thus improves the reliability of the packaging structure.
[0070] Furthermore, the homogeneous copper interconnect structure and single material composition can significantly reduce atomic diffusion and interconnect degradation caused by chemical reactions between different metals, thereby reducing contact resistance and thermal resistance at the connection and optimizing current distribution. In addition, the copper sintered layer will not undergo electrometallic migration, and the electrical conductivity and thermal conductivity of copper are not inferior to silver. Compared with the use of silver as a sintering material, the price of copper is only a few tenths of that of silver, which greatly reduces the manufacturing cost.
[0071] In some embodiments, the semiconductor layer of the tube core is SiC material, and the substrate is ceramic material. Compared with using silver as the sintering material, the thermal expansion coefficient of copper is closer to SiC and ceramic materials, thereby improving the thermal mismatch problem due to thermal cycle and power cycle conditions.
[0072] The embodiments of the present disclosure are described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present disclosure. The scope of the present disclosure is defined by the appended claims and their equivalents. Without departing from the scope of the present disclosure, a person skilled in the art may make a variety of substitutions and modifications, which should all fall within the scope of the present disclosure.
Claims
1. A packaging structure, comprising: substrate; A first pad, located on the substrate; A tube die is located on the substrate, and the tube die includes a first electrode; as well as a first connecting portion, fixedly connected to the first pad and the first electrode respectively; The first pad, the first electrode and the first connection portion are all made of copper. The first connection portion is fixedly connected to the first pad via a first copper sintering layer, and the first connection portion is fixedly connected to the first electrode via a second copper sintering layer.
2. The packaging structure according to claim 1, wherein: The first pad, the first copper sintering layer, the first connecting portion, the second copper sintering layer, and the first electrode constitute a homogeneous interconnection structure.
3. The packaging structure according to claim 1, wherein: The first connecting portion is a copper wire or a copper strip.
4. The packaging structure according to claim 1, wherein: The tube core further includes a second electrode, wherein the first electrode and the second electrode are respectively arranged on two opposite surfaces of the tube core. The packaging structure further includes a second pad located on the substrate. The second electrode is fixedly connected to the second pad via a third copper sintering layer. Wherein, the second electrode and the second pad are both made of copper.
5. The packaging structure according to claim 4, wherein: The second pad, the third copper sintering layer and the second electrode form a homogeneous interconnection structure.
6. The packaging structure according to any one of claims 1 to 5, wherein: The tube core further includes a third electrode, and the first electrode and the third electrode are respectively arranged on the same surface of the tube core. The packaging structure further includes: A third pad is located on the substrate; and The second connecting portion is fixedly connected to the third pad and the third electrode respectively. The third pad, the third electrode and the second connection portion are all made of copper, the second connection portion is fixedly connected to the third pad via a fourth copper sintering layer, and the second connection portion is fixedly connected to the third electrode via a fifth copper sintering layer.
7. The packaging structure according to claim 6, wherein: The third pad, the fourth copper sintering layer, the second connection portion, the fifth copper sintering layer, and the third electrode constitute a homogeneous interconnection structure.
8. The packaging structure according to claim 6, wherein: The second connecting portion is a copper wire or a copper strip.
9. The packaging structure according to any one of claims 1 to 5, wherein: The tube core also includes a semiconductor layer, and the material of the semiconductor layer includes SiC.
10. The packaging structure according to any one of claims 1 to 5, wherein: The material of the substrate includes ceramic.
11. A method for manufacturing a packaging structure, comprising fixing a tube die to a first pad on a substrate, wherein the tube die comprises a first electrode, in, The step of fixing the connection comprises: forming a first copper sintering layer between the first pad and the first connecting portion; and forming a second copper sintered layer between the first connection portion and the first electrode, Wherein, the first pad, the first electrode and the first connecting portion are all made of copper.
12. The manufacturing method according to claim 11, wherein: The tube core further includes a second electrode, wherein the first electrode and the second electrode are respectively arranged on two opposite surfaces of the tube core. The manufacturing method further includes: forming a third copper sintering layer between the second pad on the substrate and the second electrode, Wherein, the second electrode and the second pad are both made of copper.
13. The manufacturing method according to claim 11 or 12, wherein: The tube core further includes a third electrode, and the first electrode and the third electrode are respectively arranged on the same surface of the tube core. The manufacturing method further comprises: forming a fourth copper sintering layer between the third pad and the second connecting portion on the substrate; and forming a fifth copper sintered layer between the second connection portion and the third electrode, Wherein, the third pad, the third electrode and the second connecting portion are all made of copper.