ELECTRIC COMPONENT WITH PAD FOR A BUMP AND MANUFACTURING METHOD THEREOF

Abstract

A bump pad enclosure providing an improved reliability of a bump connection is provided. The bump pad enclosure comprises an electrode pad, a UBM and a first shield. The first shield covers at least a first perimeter area of the electrode pad. The first shield is provided and configured to shield the first perimeter area from a detrimental influence of the environment.

Claims

1. A bump pad enclosure, comprising: an electrode pad; an under bump metallization; and a first shield, wherein: the first shield covers at least a first perimeter area of the electrode pad, and the first shield is provided and configured to shield the first perimeter area from a detrimental influence of the environment.

2. The bump pad enclosure of claim 1, wherein the first shield is a moisture shield.

3. The bump pad enclosure of claim 1, wherein the first shield has a thickness t with t≤500 nm or t≤400 nm or t≤300 nm.

4. The bump pad enclosure of claim 1, wherein the first shield comprises a material selected from SiN.sub.x, Si.sub.xN.sub.y (with 2.5≤x≤3.5; 3.5≤y≤4.5), Si.sub.3N.sub.4, Al.sub.2O.sub.3, SiO.sub.2, ZrO.sub.2, TiO.sub.2 and SiO.sub.2, Al.sub.2O.sub.3 and SiO.sub.2, Al.sub.2O.sub.3 and ZrO.sub.2, Al.sub.2O.sub.3 and TiO.sub.2.

5. The bump pad enclosure of claim 1, wherein the first shield comprises a single-layer construction or a multi-layer construction.

6. The bump pad enclosure of claim 1, further comprising a covering element covering at least partially an area of a top surface of the first shield.

7. The bump pad enclosure of claim 6, wherein the covering element comprises a material selected from SiN.sub.x, Si.sub.xN.sub.y (with 2.5≤x≤3.5; 3.5≤y≤4.5), Si.sub.3N.sub.4, Al.sub.2O.sub.3, SiO.sub.2, ZrO.sub.2, TiO.sub.2, Si.sub.xN.sub.y (with 2.5≤x≤3.5; 3.5≤y≤4.5) and SiO.sub.2, Si.sub.3N.sub.4 and SiO.sub.2, Al.sub.2O.sub.3 and SiO.sub.2, Al.sub.2O.sub.3 and ZrO.sub.2, Al.sub.2O.sub.3 and TiO.sub.2.

8. The bump pad enclosure of claim 6, wherein the covering element comprises at least one of SiO.sub.2 or a silicon nitride.

9. The bump pad enclosure of claim 1, further comprising a second shield, wherein: the second shield covers at least a second perimeter area of the electrode pad, and the second shield is provided and configured to shield the second perimeter area from a detrimental influence of the environment.

10. The bump pad enclosure of claim 9, wherein the second shield is a moisture shield.

11. The bump pad enclosure of claim 9, wherein the second shield has a thickness t2 with t2≤500 nm or t2≤400 nm or t2≤300 nm.

12. The bump pad enclosure of claim 9, wherein the second shield comprises a material selected from SiN.sub.x, Si.sub.xN.sub.y (with 2.5≤x≤3.5; 3.5≤y≤4.5), Si.sub.3N.sub.4, Al.sub.2O.sub.3, SiO.sub.2, ZrO.sub.2, TiO.sub.2, Si.sub.xN.sub.y (with 2.5≤x≤3.5; 3.5≤y≤4.5) and SiO.sub.2, Si.sub.3N.sub.4 and SiO.sub.2, Al.sub.2O.sub.3 and SiO.sub.2, Al.sub.2O.sub.3 and ZrO.sub.2, Al.sub.2O.sub.3 and TiO.sub.2.

13. The bump pad enclosure of claim 9, wherein the second shield comprises a single-layer construction or a multi-layer construction.

14. The bump pad enclosure of claim 9, wherein the second shield is provided and configured to shield at least partially a vertical flank of the first shield from a detrimental influence of the environment.

15. The bump pad enclosure of claim 1, wherein the bump pad enclosure is part of a bump connector, the bump connector including solder material provided and configured to establish a bump connection.

16. The bump pad enclosure of claim 1, wherein the bump connector is part of an electric component.

17. The bump pad enclosure of claim 1, wherein the electric component is part of an electric device.

18. A method of manufacturing an electric component comprising a bump pad enclosure including an electrode pad, an under bump metallization, and a first shield, wherein the first shield covers at least a first perimeter area of the electrode pad and the first shield is provided and configured to shield the first perimeter area from a detrimental influence of the environment, the method comprising: providing the electrode pad; depositing material of the first shield at least in a first perimeter area; and depositing material of the under bump metallization.

Description

[0064] In the figures:

[0065] FIG. 1 shows a cross-section illustrating a possible arrangement of the first shield with respect to the electrode pad and the UBM;

[0066] FIG. 2 shows the arrangement of the structure on a carrier substrate;

[0067] FIG. 3 shows the use of a covering element;

[0068] FIG. 4 shows the height of the UBM extending the height of the covering element;

[0069] FIG. 5 shows the use of the second shield;

[0070] FIG. 6 shows a configuration with the second shield where the thickness of the UBM approximately equals the thickness of the covering element;

[0071] FIG. 7 illustrates the relationship between the bump connector and a solder bump;

[0072] FIG. 8 illustrates details of a bump connection between a UBM of the bump connector to a second UBM; and

[0073] FIG. 9 shows corresponding elements of the bump pad enclosure in a cross-sectional view (top portion) and a top view (bottom portion).

[0074] FIG. 1 shows a cross-section through a segment of a bump pad illustrating the arrangement of the first shield SL1 at the first perimeter area PA1 on the electrode pad EP. Material of a UBM is arranged on the electrode pad EP such that there is an interface area between the UBM and the electrode pad. A critical area is the perimeter surrounding the interface between the UBM and the electrode pad EP establishing the entry of a path P via which corrosive agents can enter the pad construction. The provision of the first shield SL1 at the first perimeter area PA1 establishes an effective blockade for unwanted etching agents such that the path P no longer provides a way to the electrode pad EP.

[0075] The first shield SL1 has a thickness t1. At areas where first shield SL1 is arranged on a horizontal surface of the electrode pad EP the thickness of the first shield SL1 is defined by the extension of the shield's material in the vertical direction z.

[0076] However, it is also possible that material of the first shield SL1 is arranged at vertical or tilted sides of the electrode pad EP, e.g. as shown on the right-hand side of FIG. 1. Then, of course, the thickness of the shield SL1 is defined as its extension along a horizontal direction x.

[0077] In FIG. 1 the UBM provides a solderable interface at its top surface via which the UBM can be connected to another UBM of a further electric component.

[0078] An improved blocking of detrimental agents is specifically obtained by arranging the electrode pad EP, the first shield SL1 and the UBM such that an overlap, specifically in a horizontal direction, is obtained. Thus, there is an area where material of the electrode pad EP is covered by material of the first shield SL1 while simultaneously material of the first shield SL1 is covered by material of the UBM. This overlap OVL substantially reduces the risk of detrimental agents reaching the material of the electrode pad EP.

[0079] FIG. 2 illustrates that the bump connector comprising the first shield SL1 covering the electrode pad EP at least in the first perimeter area PA1 can be arranged on a carrier substrate CS. At the top surface of the carrier substrate CS the electrode pad EP can be extended in one horizontal direction to establish a signal line for connecting the electrode pad EP to an external circuit environment including other circuit elements arranged on or at the carrier substrate CS.

[0080] FIG. 3 shows the possibility of arranging a covering element CE at least partially on a top surface of the first shield SL. The material of the covering element CE can be used to limit the volume of the UBM in a horizontal direction. Thus, the covering element CE can be used to horizontally confine the UBM—and therefore the later bump—to a specific area on the electrode pad EP. Thus, the covering element CE determines the position of the rim area of the UBM.

[0081] The UBM can have a vertical level of its top surface that is below the top level of the covering element CE.

[0082] However, it is also possible that the top level of the UBM and of the covering elements CE are approximately matched.

[0083] In contrast, FIG. 4 illustrates the possibility of having a top level of the UBM exceeding the top level position of the covering element CE. Then, an inner flank of the covering element CE, i.e. a vertical flank of the covering element CE pointing towards the center of the bump connection in a horizontal direction, no longer establishes the horizontal confinement of the UBM. The UBM can go beyond the inner flank of the covering element CE in a horizontal direction.

[0084] FIG. 5 illustrates the possibility of providing the second shield SL2 to further improve the resistance of the bump pad enclosure against unwanted agents. The second shield SL2 can have a second thickness t2. Further, the second shield SL2 can be in direct contact with the electrode pad EP at a second perimeter area PA2. The second perimeter area PA2 can be within the area surrounded by the first perimeter area PA1.

[0085] In particular, it is possible that the material of the second shield SL2 is in direct contact to—and therefore protects—the vertical flank VF of the material of the first shield SL pointing towards the center of the bump connection. Further, an additional overlap where material of the second shield SL2 overlaps material of the covering element CE exists such that a potential path for unwanted agents entering the construction is further blocked.

[0086] The vertical top level position of the UBM can exceed the vertical top level of a top surface of the second shield SL2 and of a vertical top level position of the covering element CE. Additionally, the vertical top level position of the second shield SL2 can extend beyond—in the vertical direction—the top level position of the covering element CE.

[0087] In contrast, FIG. 6 illustrates the possibility of having the top level position of the second shield SL2 extending beyond the top level position—in a vertical direction—of the UBM and of the covering element CE while the top level positions of the UBM and of the covering element are approximately matched. Then, the upper inner vertical flank of the second shield SL2 essentially determines the extension of the UBM in the lateral direction.

[0088] FIG. 7 shows a configuration where solder material establishing at least partially a bump sphere of a bump BU is arranged on the UBM. The bump BU can be essentially symmetrical with respect to a rotation symmetry having a symmetry line SYML being aligned orthogonal to the horizontal plane. Thus, the symmetry line SYML essentially extends along the vertical direction z. The bump pad enclosure comprising the first shield SL1 and the UBM and—if present—the covering element CE can also be symmetric with respect to the rotational symmetry having the symmetry line SYML.

[0089] Thus, with respect to a top view, the bump pad enclosure can follow the perimeter of a circle. However, it is also possible that the bump pad enclosure has an elliptical, rectangular, oval or quadratic shape.

[0090] FIG. 8 illustrates the material of the bump BU in a connected configuration. Specifically, the solder material of the bump BU electrically and mechanically connects the UBM of the bump pad having the bump pad enclosure as described above and a second UBM, UBM2, that is part of a second bump connector. Thus, two bump connectors belonging to two different electric components can be connected. Thus, reliable electrical and mechanical connections between different electrical components, e.g. to establish an electric device, can be obtained.

[0091] The round symmetry—with respect to a vertical symmetry line—as described above in a top view perspective is illustrated in the bottom part of FIG. 9 illustrating the relationship to the elements shown in the cross-sections of FIGS. 1 to 8. The material of the first shield SL1 is overlapped by material of the UBM at each rim position of the UBM such that a full overlap is obtained such that potential paths for unwanted agents are effectively blocked at every lateral rim position of the bump pad connector.

[0092] Neither the bump pad enclosure nor the corresponding bump connector nor the electric component nor the electric device nor the method of manufacturing an electric component are limited by the technical details explained above and shown in the figures. Bump connections can comprise further elements such as further layers enhancing electrical conductivity, mechanical stability and physical adhesion of the layer system. Also, further shield elements and overlap regions are also possible.

LIST OF REFERENCE SIGNS

[0093] BU: bump [0094] CE: covering element [0095] CS: carrier substrate [0096] EP: electrode pad [0097] OVL: overlap region [0098] P: possible path for unwanted agents [0099] PA1: first perimeter area [0100] PA2: second perimeter area [0101] SL1, SL2: first, second shield [0102] SL2SYML: symmetry line [0103] t1, t2: thickness of first, second shield [0104] UBM: under bump metallization [0105] UBM2: second UBM, UBM of a second electric component [0106] VF: vertical flank of the first shield SL [0107] x, y: horizontal directions [0108] z: vertical direction