Electrical component having a pad for a bump and method of manufacturing the same

Abstract

A bump pad housing is provided to provide improved bump connection reliability. The bump pad housing includes an electrode pad, a UBM and a first shielding cover. The first shielding cover at least covers a first peripheral area of ​​the electrode pad. The first shielding cover is provided and configured to shield the first peripheral area from adverse effects of the environment.

Description

Technical Field

[0001] The present invention relates to a bump pad housing which can improve the corrosion resistance of bump connection and accordingly improve the reliability of electric equipment. Background Art

[0002] Bump connections can be used to electrically and mechanically connect electrode pads of different electrical components to create an electrical device that includes two (and possibly more) electrical components.

[0003] Typically, the bump connection includes a solder material arranged between the two electrode pads. In addition, the contact between one of the electrode pads and the solder material is provided by a first under-bump metallization (UBM) of the first component. The connection between the solder material and the second electrode pad is provided by a corresponding second UBM associated with the second electrical component.

[0004] Conventional bump connections are prone to failure. Specifically, a rupture in one of the components of a bump connection can render the bump connection useless in terms of its electrical and / or mechanical functions. Therefore, if a single bump connection fails, the corresponding device may become unusable.

[0005] Bump connection failures may occur during normal operation of an electrical device. However, failures may have occurred during manufacturing steps of the device or device assembly, for example when potentially hazardous materials are used during processing steps. Specifically, corrosive materials may compromise the bump connection, but may be critical to the processing steps used to manufacture the electrical device or assembly.

[0006] Therefore, there is a need to improve the reliability of bump connections, for example to increase the reliability of electrical devices and components and the yield of manufacturing steps. In particular, there is a need for corrosion-resistant bump connections. Summary of the invention

[0007] To this end, a bump pad housing according to the independent claim is provided. The dependent claims provide preferred embodiments of the bump pad housing, the bump connector, the electrical component, the electrical device and the method for manufacturing the electrical component.

[0008] The bump pad housing includes an electrode pad, a UBM and a first shielding cover. The first shielding cover at least covers a first peripheral area of ​​the electrode pad. The first shielding cover is provided and configured to shield the first peripheral area from adverse effects of the environment.

[0009] The environment may be an environment during a manufacturing process, or an environment where corresponding equipment or components are stored or used by personnel.

[0010] The environment may include corrosive agents and / or water. Specifically, the environment may include moisture.

[0011] The first peripheral region of the first shielding cover may be located at the periphery of the interface between the corresponding solder material connected to the UBM and the UBM.

[0012] The solder material may include tin or silver or a tin-silver alloy. Additionally, the electrode pad may include aluminum, copper, or an aluminum / copper alloy. When the etchant comes into contact with the UBM or the electrode pad, corrosion of the corresponding material occurs, which can lead to damage to the corresponding known bump connection. Therefore, especially the peripheral region of the interface between the solder material and the UBM (since the peripheral region of the interface between the solder material and the UBM is usually horizontally restricted, for example, by the electrode pad defining ring) is prone to defects because this region establishes a path for the etchant to enter the bump pad structure.

[0013] However, instead of being circular, an oval, rectangle, ovoid, or square is also possible.

[0014] In the case of an ovoid, the shape may be defined by a shape similar to the region enclosed by the coordinates (x, y) that conform to the equation

[0015] x 2 / 4 + y 2 / (1 - kx) = 1 (Equation 1)

[0016] where 0 < k < 1; for example, where k = 0.2.

[0017] The footprint of the shape of the UBM may also have a stadium-like shape (i.e., composed of two semi-circles and a rectangle arranged between the two semi-circles).

[0018] The presence of the first shielding cover, especially shielding this sensitive first peripheral region from the adverse effects of the environment through the first shielding cover, substantially reduces the possibility of the etchant entering the sensitive region of the bump pad structure.

[0019] Therefore, the reliability of the corresponding bump connection is substantially increased, and thus the reliability of the corresponding components and devices is also increased.

[0020] For the same reason, the yield rate of the manufacturing process is increased, and the manufacturing cost is also reduced.

[0021] Correspondingly, the first shielding cover may be a moisture-proof shielding cover.

[0022] Therefore, the first shielding cover is a shielding cover that protects the bump pad structure from the entry of water molecules into the structure.

[0023] The first shielding cover may have a thickness t, where t ≤ 500 nm or t ≤ 400 nm or t ≤ 300 nm.

[0024] Additionally, the thickness t of the first shielding cover may be 25 nm or greater.

[0025] The first shield may be provided as a layered structure, wherein the material of the shield extends substantially greater than the thickness in a direction perpendicular to the thickness direction. Thus, the thickness of the first shield is independent of the orientation of the shield. Specifically, the material of the shield may be connected to a horizontal surface at one location and to a vertical or inclined surface (inclined with respect to the horizontal plane) at another location.

[0026] However, it is particularly possible that the provided thickness at least partially defines the thickness of the shield in the vertical (z) direction.

[0027] In this case, the main top surface of the electrical component determines the orientation of the horizontal plane extending in the xy direction. Correspondingly, the z direction extends in the vertical direction.

[0028] The first shield may include or consist of a material selected from the following: x N y (with 2.5≤x≤3.5; 3.5≤y≤4.5) or stoichiometric silicon nitride Si3N4a; aluminum oxide Al2O3; silicon oxide, SiO2; zirconium oxide, ZrO2; titanium oxide, TiO2; compounds including silicon, nitrogen and oxygen, such as compounds including silicon nitride and silicon oxide; compounds including aluminum, oxygen and silicon, such as compounds including aluminum oxide and silicon oxide, such as compounds including Al2O3 and SiO2; compounds including aluminum, oxygen and zirconium, such as compounds including aluminum oxide and zirconium oxide, such as compounds including Al2O3 and ZrO2; compounds including aluminum, oxygen and titanium, such as compounds including aluminum oxide and titanium oxide, such as compounds including Al2O3 and TiO2.

[0029] Generally speaking, it is preferred that the first shield comprises a material that provides a strong barrier against corrosive agents such as water.

[0030] The first shield may be provided using conventional material deposition techniques, such as physical or chemical vapor deposition, such as sputtering or ALD (atomic layer deposition). The first shield may also be obtained by applying a structuring technique comprising depositing a resist material and removing the material of the first shield.

[0031] The first shield may include a single layer construction or a multi-layer construction.

[0032] When the first shield comprises a single layer construction, the first shield is composed of a homogeneous material. If the first shield comprises a multilayer construction, then a plurality of two or more layers (the materials of the layers may be selected from the above options) may be arranged on top of one another to create a multilayer barrier against unwanted corrosive agents.

[0033] Thus, the first shield creates an effective barrier that blocks the path for typical etchants to enter the construction of conventional bump connections.

[0034] The bump pad housing may further include a covering element. The covering element may at least partially cover an area of ​​the top surface of the first shielding can.

[0035] The covering element may also include or consist of a material or material / layer configuration as described above. Specifically, the thickness of the covering element may exceed the thickness of the first shield. The covering element may contribute to the mechanical stability of the bump connection and have an inner vertical side and an outer vertical side. Specifically, the inner vertical side may substantially define the interface area between the UBM and the solder material.

[0036] In a preferred bump pad housing, the cover element comprises silicon oxide, such as SiO2 and / or silicon nitride, such as Si x N y (wherein 2.5≤x≤3.5; 3.5≤y≤4.5), for example Si3N4.

[0037] The bump pad housing may also include a second shielding cover. The second shielding cover at least covers the second peripheral area of ​​the electrode pad. In addition, a second shielding cover may be provided and configured to shield the second peripheral area from adverse effects of the environment.

[0038] In particular, the second shield may reinforce the first shield to protect the configuration of the bump connection against external adverse influences.

[0039] Accordingly, the second shield may be a moisture-proof shield.

[0040] The second shield may have a thickness t2, wherein t2≤500 nm or t2≤400 nm or t2≤300 nm.

[0041] The second shielding cover may also include or consist of the material group described above.

[0042] Specifically, the first shield may include or be made of silicon nitride (eg, Si x N y (2.5≤x≤3.5; 3.5≤y≤4.5), such as Si3N4), and the second shield may include or consist of silicon nitride (such as Si x N y (wherein 2.5≤x≤3.5; 3.5≤y≤4.5), for example Si3N4).

[0043] In addition, the first shield may include or consist of Al2O3, and the second shield may include or consist of silicon nitride (eg, Si x Ny (wherein 2.5≤x≤3.5; 3.5≤y≤4.5), for example Si3N4).

[0044] In addition, the first shield may include or be made of silicon nitride (eg, Si x N y (wherein 2.5≤x≤3.5; 3.5≤y≤4.5), for example Si3N4), and the second shield may include or consist of Al2O3.

[0045] The second shield may include a single layer construction or a multi-layer construction.

[0046] Corresponding to the first shielding cover, when the second shielding cover comprises a single-layer structure, the second shielding cover may have a homogeneous material. Otherwise, the second material may comprise a plurality of two or more layers, wherein each layer may comprise or consist of one of the above materials.

[0047] A second shield may be provided and configured to shield at least vertical sides of the first shield from adverse environmental influences.

[0048] Therefore, there may be an interface region between the first shield and the second shield, wherein material of the first shield is in direct contact with material of the second shield.

[0049] Specifically, this interface region between the first shield and the second shield may be located at a location that is often part of a path for unwanted corrosive agents to enter the formation of the bump connection.

[0050] The bump connector may include a bump pad housing as described above. The bump connector may also include a solder material provided and configured to establish a bump connection.

[0051] The material of the electrode pad of the bump connector can be electrically and mechanically connected to the signal line at the surface of the carrier substrate. Accordingly, the bump connector including the bump pad housing can also be arranged at the surface of the carrier substrate. The surface can be a surface pointing to the corresponding oppositely oriented surface of the second electrical component that is electrically and mechanically connected to the bump connector through the bump connection.

[0052] Additionally, the electrical component may include a bump connector as described above arranged at a top surface of the electrical component.

[0053] The bump connector of an electrical component may be configured and provided for establishing an electrical and mechanical connection to another electrical component such that the two electrical components establish at least a portion of an electrical device.

[0054] Accordingly, the electrical device may include one or two electrical components as described above.The bump connection including solder material between two bump connectors establishes the final electrical and mechanical contact between the two components.

[0055] A method of manufacturing an electronic component including a bump pad housing as described above may include the following steps:

[0056] - provide electrode pads,

[0057] - depositing the material of the first shield at least in the first peripheral area,

[0058] -Deposition of UBM material.

[0059] Therefore, a bump pad housing is provided that improves the reliability of a bump connection. The bump connection includes solder material between two bump connectors, wherein each bump connector is associated with one of the two electrical components, and wherein at least one of the bump connectors includes a bump pad housing as described above. However, it is understood that both bump connectors include a bump pad housing as described above.

[0060] By using such bump connections, the reliability and yield during the manufacturing process are substantially improved. The risk of corrosion-induced damage to the bump connection leading to failure of the entire device is reduced. Specifically, the path of the corrosive agent into the bump pad structure is effectively blocked.

[0061] Providing the first shield and / or the second shield with a thickness of 500 nm or less significantly reduces the risk of cracking of the layer construction.

[0062] The UBM may include a single layer structure or a multilayer structure. Specifically, the UBM may include an adhesive layer, such as titanium for good adhesion to the electrode pad. The UBM may include nickel, or gold, or nickel and gold or nickel / gold alloy at least in the top layer to provide a well-weldable interface layer for the solder material.

[0063] The top level of the UBM may extend - in the vertical direction - beyond the vertical level of the overlying element. However, the vertical level of the UBM may also match and be equal to the vertical level of the overlying element. However, the vertical level may also extend - in the vertical direction away from the material of the electrode pad - the vertical level of the UBM.

[0064] Central aspects and details of preferred embodiments of a bump pad housing, a corresponding bump connection, a bump connector, an electrical assembly or an electrical device are shown in the accompanying schematic drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] In the figure:

[0066] Figure 1shows a cross section illustrating a possible arrangement of a first shield with respect to an electrode pad and a UBM;

[0067] Figure 2 shows the arrangement of the structures on the carrier substrate;

[0068] Figure 3 The use of a covering element is shown;

[0069] Figure 4 The height of the UBM extending over the height of the element is shown;

[0070] Figure 5 shows the use of a second shield;

[0071] Figure 6 shows a second shield configuration in which the thickness of the UBM is substantially equal to the thickness of the cover element;

[0072] Figure 7 The relationship between the bump connector and the solder bump is explained;

[0073] Figure 8 Details of the bump connection between the UBM of the bump connector and the second UBM are described; and

[0074] Fig. 9 Corresponding elements of the bump pad housing are shown in cross-sectional view (top) and in top view (bottom). DETAILED DESCRIPTION

[0075] Figure 1 A cross section through a portion of a bump pad is shown illustrating the placement of a first shield SL1 at a first peripheral area PA1 on an electrode pad EP. The material of the UBM is placed on the electrode pad EP such that an interface region exists between the UBM and the electrode pad. A critical region is the perimeter around the interface between the UBM and the electrode pad EP, which establishes an entry to a path P through which an etchant can enter the pad construction. Providing a first shield SL1 at the first peripheral area PA1 establishes an effective block to unwanted etchants such that the path P no longer provides access to the electrode pad EP.

[0076] The first shield cover SL1 has a thickness t1. The thickness of the first shield cover SL1 is defined by the extension of the material of the shield cover in the vertical direction z at the area where the first shield cover SL1 is arranged on the horizontal surface of the electrode pad EP.

[0077] However, the material of the first shield cover SL1 may also be arranged at the vertical or inclined side of the electrode pad EP, for example as Figure 1 Then, of course, the thickness of the shielding case SL1 is defined as its extension in the horizontal direction x.

[0078] exist Figure 1 In the embodiment, the UBM provides a solderable interface at its top surface, through which the UBM can be connected to another UBM of another electrical component.

[0079] By arranging the electrode pad EP, the first shielding cover SL1 and the UBM so that an overlap, in particular in the horizontal direction, is obtained, an improved blocking of harmful agents is obtained in particular. Thus, there is an area where the material of the electrode pad EP is covered by the material of the first shielding cover SL1 and at the same time the material of the first shielding cover SL1 is covered by the material of the UBM. This overlap OVL substantially reduces the risk of harmful agents reaching the material of the electrode pad EP.

[0080] Figure 2 It is illustrated that a bump connector including a first shielding cover SL1 covering at least the electrode pad EP in the first peripheral area PA1 can be arranged on a carrier substrate CS. At the top surface of the carrier substrate CS, the electrode pad EP can extend in a horizontal direction to establish a signal line for connecting the electrode pad EP to an external circuit environment, the external circuit environment including other circuit elements arranged on or at the carrier substrate CS.

[0081] Figure 3 The possibility of arranging the cover element CE at least partially on the top surface of the first shielding cover SL1 is shown. The material of the cover element CE can be used to limit the volume of the UBM in the horizontal direction. Therefore, the cover element CE can be used to limit the UBM - and therefore the subsequent bump - horizontally to a specific area on the electrode pad EP. Therefore, the cover element CE determines the position of the edge area of ​​the UBM.

[0082] The vertical level of the top surface of the UBM may be lower than the top level of the cover element CE.

[0083] However, it is also possible that the top level of the UBM and the top level of the cover element CE approximately match.

[0084] In contrast, Figure 4 The possibility of having the top level of the UBM exceed the top level position of the covering element CE is described. Then, the inner side of the covering element CE, i.e. the vertical side of the covering element CE pointing to the center of the bump connection in the horizontal direction, no longer establishes the horizontal limit of the UBM. The UBM can exceed the inner side of the covering element CE in the horizontal direction.

[0085] Figure 5The possibility of providing a second shield cover SL2 to further improve the bump pad housing against unwanted agents is described. The second shield cover SL2 may have a second thickness t2. In addition, the second shield cover SL2 may be in direct contact with the electrode pad EP at the second peripheral area PA2. The second peripheral area PA2 may be within the area surrounded by the first peripheral area PA1.

[0086] In particular, the material of the second shield SL2 may directly contact - and therefore protect - the vertical side VF of the material of the first shield SL1, which is directed toward the center of the bump connection. In addition, there is an additional overlap of the material of the second shield SL2 with the material of the covering element CE, which serves to further block potential paths for unwanted agents to enter the structure.

[0087] The vertical top level of the UBM can exceed the vertical top level of the top surface of the second shielding cover SL2 and the vertical top level of the vertical top level of the covering element CE. In addition, the vertical top level of the second shielding cover SL2 can - in the vertical direction - extend beyond the top level of the covering element CE.

[0088] In contrast, Figure 6 The following possibility is described: make the top horizontal position of the second shielding cover SL2 extend - in the vertical direction - beyond the top horizontal position of the UBM and the top horizontal position of the covering element CE, while the top horizontal position of the UBM roughly matches the top horizontal position of the covering element CE. The upper inner vertical side of the second shielding cover SL2 then substantially determines the extension of the UBM in the lateral direction.

[0089] Figure 7 A configuration is shown in which the solder material of the bump sphere of the bump BU, which at least partially establishes it, is arranged on the UBM. The bump BU can be substantially symmetrical about a rotational symmetry having a symmetry line SYML, which is aligned orthogonally to the horizontal plane. Therefore, the symmetry line SYML extends substantially in the vertical direction z. The bump pad housing including the first shielding cover SL1 and the UBM and - if present - the covering element CE can also be symmetrical about the rotational symmetry having the symmetry line SYML.

[0090] Thus, with respect to a top view, the bump pad housing may follow the circumference of a circle. However, the bump pad housing may also have an elliptical, rectangular, oval, or square shape.

[0091] Figure 8The material of the bump BU in the form of a connection configuration is described. Specifically, the solder material of the bump BU electrically and mechanically connects the UBM having the bump pad of the bump pad housing as described above with the second UBM, UBM2 as part of the second bump connector. Thus, two bump connectors belonging to two different electrical components can be connected. Thus, a reliable electrical and mechanical connection between different electrical components can be obtained, for example, to establish an electrical device.

[0092] As described above in the top perspective view, the circular symmetry - about the vertical symmetry line - Fig. 9 As stated at the bottom of Fig. 9 Explains the Figures 1 to 8 The material of the first shield SL1 overlaps the material of the UBM at each edge of the UBM so that a complete overlap is achieved, effectively blocking a potential path for unwanted agents at each lateral edge of the bump pad connector.

[0093] The manufacturing method of the bump pad housing or the corresponding bump connector or the electrical component or the electrical device or the electrical component is not limited by the technical details explained above and shown in the figures. The bump connection may include other elements, such as other layers that enhance the conductivity, mechanical stability and physical adhesion of the layer system. In addition, more shielding elements and overlapping areas are also possible.

[0094] Reference Mark List

[0095] BU: Bump

[0096] CE: Covering element

[0097] CS: Carrier substrate

[0098] EP: Electrode pad

[0099] OVL: Overlapping area

[0100] P: Possible pathways for unwanted agents

[0101] PA1: First peripheral area

[0102] PA2: Second peripheral area

[0103] SL1, SL2: first and second shielding covers

[0104] SL2SYML: Line of Symmetry

[0105] t1, t2: thickness of the first and second shielding covers

[0106] UBM: Under Bump Metallization

[0107] UBM2: second UBM, UBM of the second electrical component

[0108] VF: vertical side of the first shielding cover SL1

[0109] x,y: horizontal direction

[0110] z: vertical direction

Claims

1. A bump pad housing, comprising: an electrode pad having an electrode pad central surface and a first peripheral region located on the surface of the electrode pad, wherein the first peripheral region surrounds the electrode pad central surface, an under-bump metallization portion located on or above the center surface of the electrode pad; a first shield configured to shield the first peripheral region from adverse environmental influences, wherein the first shield covers at least a first peripheral region of the electrode pad; as well as A covering member is formed on the first shield cover, wherein the first shield cover is located between the first peripheral area and the covering member, and wherein the first shield cover is located between the electrode pad and the covering member. 2 . The bump pad housing of claim 1 , wherein the first shield is a moisture resistant shield. 3 . The bump pad housing of claim 1 , wherein the first shield has a thickness t, wherein t≤500 nm or t≤400 nm or t≤300 nm.

4. The bump pad housing of claim 1 , wherein the first shield comprises a material selected from the group consisting of: SiN x 、Si x N y (where 2.5≤x≤3.5; 3.5≤y≤4.5), Si3N4, Al2O3, SiO2, ZrO2, TiO2 and SiO2, Al2O3 and SiO2, Al2O3 and ZrO2, Al2O3 and TiO2. The bump pad housing of claim 1 , wherein the first shielding can comprises a single layer structure or a multi-layer structure.

6. The bump pad housing of claim 1 , wherein the cover element comprises a material selected from the group consisting of: SiN x 、Si x N y (where 2.5≤x≤3.5; 3.5≤y≤4.5), Si3N4, Al2O3, SiO2, ZrO2, TiO2, Si x N y (where 2.5≤x≤3.5; 3.5≤y≤4.5) and SiO2, Si3N4 and SiO2, Al2O3 and SiO2, Al2O3 and ZrO2, Al2O3 and TiO2. 7 . The bump pad housing of claim 1 , wherein the capping element comprises at least one of SiO 2 or silicon nitride.

8. The bump pad housing according to claim 1, further comprising a second shielding cover, in: The second shielding cover at least covers the second peripheral area of ​​the electrode pad. The second shield is provided and configured to shield the second peripheral area from adverse effects of the environment.

9. The bump pad housing of claim 8, wherein the second shield is a moisture resistant shield. 10 . The bump pad housing of claim 8 , wherein the second shield has a thickness t2 , wherein t2 ≤ 500 nm or t2 ≤ 400 nm or t2 ≤ 300 nm.

11. The bump pad housing of claim 8, wherein the second shield comprises a material selected from the group consisting of: SiN x 、Si x N y (where 2.5≤x≤3.5; 3.5≤y≤4.5), Si3N4, Al2O3, SiO2, ZrO2, TiO2, Si x N y (where 2.5≤x≤3.5; 3.5≤y≤4.5) and SiO2, Si3N4 and SiO2, Al2O3 and SiO2, Al2O3 and ZrO2, Al2O3 and TiO2. 12 . The bump pad housing of claim 8 , wherein the second shielding can comprises a single layer structure or a multi-layer structure.

13. The bump pad housing of claim 8, wherein the second shielding can is provided and configured to at least partially shield vertical sides of the first shielding can from adverse environmental influences.

14. The bump pad housing of claim 1, wherein the bump pad housing is part of a bump connector, the bump connector comprising a solder material provided and configured to establish a bump connection.

15. The bump pad housing of claim 1, wherein the bump pad housing is part of an electrical component.

16. The bump pad housing of claim 1, wherein the bump pad housing is part of an electrical device.

17. A method of manufacturing an electrical component, the electrical component comprising a bump pad housing, the bump pad housing comprising an electrode pad, an under bump metallization, a covering element and a first shielding cover, wherein the first shielding cover covers at least a first peripheral area of ​​the electrode pad, and the first shielding cover is configured to shield the first peripheral area from adverse effects of the environment, the method comprising the following steps: Providing the electrode pad with an electrode pad central surface and a first peripheral region located on the surface of the electrode pad, wherein the first peripheral region surrounds the electrode pad central surface; depositing material of the first shield at least on or over a first peripheral region; depositing material of the under bump metallization at least on or above the central surface of the electrode pad; as well as The material of the cover element is formed on or over the material of the first shield, wherein the cover element is formed such that the first shield is between the first peripheral region and the cover element.

Images