Package structure
By introducing concentric annular grooves of patterned seed layers into the semiconductor packaging structure, the problem of uneven copper plating thickness was solved, resulting in a more uniform copper plating layer distribution and improved thickness consistency.
Patent Information
- Application Number
- CN202422580303.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-24
- Publication Date
- 2025-12-05
- Estimated Expiration
- 2034-10-24
AI Technical Summary
Existing technologies struggle to effectively address the issue of uneven copper plating thickness in large-size semiconductor packaging, particularly in the edge regions where the thickness is thicker and the uniformity is poor.
A patterned first seed layer is introduced into the packaging structure. By designing multiple concentric annular grooves on the seed layer, the current distribution is controlled, and the thickness uniformity of the electroplated copper layer is improved.
The graphic groove design significantly reduces the thickness variation of the electroplated copper layer, improves the uniformity of the electroplated copper layer thickness per unit length, and reduces the difference between the maximum and minimum thickness.
Smart Images
Figure CN223638362U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a packaging structure. Background Technology
[0002] Figure 1 The diagram shows the current sizes of semiconductor packages, including a 12-inch wafer level (WL) 1, a 300*300mm panel level (PNL) 2 (approximately 1.64 times the size of a 12-inch WL), a 500*500mm PNL 3 (approximately 4.54 times the size of a 12-inch WL), and a 600*600mm PNL 4 (approximately 6.5 times the size of a 12-inch WL). The size of semiconductor packages is gradually trending towards larger sizes.
[0003] As the size of semiconductor packages gradually increases, utilization rates also continue to rise. However, the plating range also increases at the same time. A larger plating range amplifies the effects of uneven copper plating thickness. Problems that were originally present in the plating process, such as thicker plating at the edges and poor thickness uniformity, become more pronounced as the size of semiconductor packages increases.
[0004] by Figure 2 Taking a wafer with a diameter of 30.08 μm as an example, the current distribution on the conductor (e.g., copper) is uneven. Due to the skin effect, the current concentrates at the geometric edges, causing the copper layer to thicken due to the current concentration. Figure 3 As shown, the current density is higher in the edge region and lower in the middle region, resulting in a coating thickness distribution as shown. Figure 4 As shown, the thickness at the point with the largest thickness is 10.17 μm, and the thickness at the point with the smallest thickness is 9.499 μm. Figure 5 This shows a coating thickness curve along a certain diameter of the wafer, with the center as the origin, the coordinates of each point as the horizontal axis, and the coating thickness at each point as the vertical axis. Figure 5 As can be seen, the thickness of the coating gradually increases in the direction away from the center, with a coating thickness difference of about 3% per unit length (single wafer 9) [(maximum thickness - minimum thickness) / diameter of wafer 9, for example (10.17 - 9.499) / 30.08].
[0005] Existing technologies improve the aforementioned problem of uneven electroplating by changing the electroplating solution or adding a dummy pattern as a sacrificial area outside the current density area. This application attempts to improve the electroplating uniformity without changing the electroplating solution or setting up an additional electroplating sacrificial area. Utility Model Content
[0006] The utility model discloses a packaging structure to at least improve the thickness uniformity of electroplated copper layer aims at the problems in the prior art.
[0007] To achieve the above object, the utility model provides a packaging structure, include: first seed layer has a plurality of patterning first recess; first electroplated copper layer sets up on the first seed layer, and first electroplated copper layer includes first upper surface and with the first lower surface of first upper surface opposite, and the first lower surface has a plurality of first protruding portion with first recess corresponding.
[0008] In some embodiments, the packaging structure further includes: a second electroplated copper layer disposed below the first electroplated copper layer, having a second upper surface and a second lower surface opposite to the second upper surface, the second lower surface having a plurality of second protruding portions; an insulating layer disposed on the second upper surface, the insulating layer having an opening exposing the second upper surface, the first seed layer disposed on the insulating layer and conformally lining in the opening, the first electroplated copper layer filling the remaining portion of the opening.
[0009] In some embodiments, the first recesses extend through the first seed layer.
[0010] In some embodiments, a gap is formed within the first recess and extends upwardly to the first electroplated copper layer.
[0011] In some embodiments, within the first recess, the first protruding portions contact the insulating layer.
[0012] In some embodiments, the first recess of the first seed layer is a circular ring having a break, and the first seed layer is not thinned at the break.
[0013] In some embodiments, the plurality of first recesses of the first seed layer are arranged as concentric circular rings.
[0014] In some embodiments, the plurality of first recesses have the same pitch.
[0015] In some embodiments, the pitch is 1.25 μm, and the width of the first recess is 0.25 μm.
[0016] In some embodiments, the pitch of the plurality of first recesses decreases as the distance from the center of the circular ring decreases.
[0017] In some embodiments, the width of the first recess is 0.01 μm.
[0018] In some embodiments, the breaks of adjacent first recesses are staggered in radial projection.
[0019] In some embodiments, the first seed layer includes a titanium layer and a copper layer on the titanium layer.
[0020] Embodiments of the present application also provide a packaging structure, comprising: a second electroplated copper layer comprising a second upper surface and a second lower surface opposite to the second upper surface, the second lower surface having a plurality of second protrusions; an insulating layer disposed on the upper surface of the second electroplated copper layer; a first seed layer disposed on the insulating layer and having a patterned first recess; and a first electroplated copper layer disposed on the first seed layer and comprising a conductive hole electrically connected to the second electroplated copper layer.
[0021] In some embodiments, the first recess is a via.
[0022] In some embodiments, the first recess extends to the insulating layer, and a gap is formed between the first electroplated copper layer and the insulating layer.
[0023] In some embodiments, the first electroplated copper layer extends into the first recess.
[0024] In some embodiments, the portion of the first electroplated copper layer extending into the first recess constitutes a first protrusion of the first electroplated copper layer.
[0025] In some embodiments, the first protrusion and the second protrusion are at least partially staggered in a longitudinal projection.
[0026] In some embodiments, the first seed layer is located between the conductive hole and the second electroplated copper layer.
[0027] In some embodiments, the diameter of the conductive hole decreases in a direction from top to bottom.
[0028] In some embodiments, the first recess has a uniform width.
[0029] The beneficial technical effects of the present application are as follows:
[0030] The first seed layer of the embodiments of the present application has the patterned first recess, which improves the consistency / uniformity of the thickness of the first electroplated copper layer. BRIEF DESCRIPTION OF DRAWINGS
[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor. It should be noted that, according to the standard practice of the industry, the various components are not drawn to scale and are for illustrative purposes only. In fact, for the sake of clarity of discussion, the size of each component can be arbitrarily increased or decreased.
[0032] Figure 1 The size of the current semiconductor package is shown.
[0033] Figure 2 A prior art wafer is shown.
[0034] Figure 3 A current density is shown when electroplating on a prior art wafer.
[0035] Figure 4 A thickness profile of a plating layer resulting from the prior art is shown.
[0036] Figure 5 A plating thickness plot of the prior art is shown.
[0037] Figure 6 A top view of a first seed layer is shown.
[0038] Figure 7 A thickness profile of a second electroplated copper layer is shown.
[0039] Figure 8 A plating thickness plot of a first electroplated copper layer is shown. Figure 5
[0040] Figure 9 A top view of a first seed layer according to a second embodiment of the application is shown.
[0041] Figure 10 A thickness profile of a first electroplated copper layer resulting from the second embodiment is shown.
[0042] Figure 11 A glass carrier is provided.
[0043] Figure 12 A second seed layer is formed.
[0044] Figure 13 A first mask layer is formed.
[0045] Figure 14 The second seed layer is etched.
[0046] Figure 15 The first mask layer is removed.
[0047] Figure 16 A second mask layer is formed.
[0048] Figure 17 A second electroplated copper layer is formed.
[0049] Figure 18 The second mask layer is removed.
[0050] Figure 19 The second seed layer is etched.
[0051] Figure 20 It is shown that upon initiation of the electroplating, a gap is formed within the second recess.
[0052] Figure 21 It is shown that after a period of time of continued electroplating, there is a tendency for the copper material on both sides of the gap to merge inwardly.
[0053] Figure 22 It is shown that after the electroplating is complete, the copper material above the gap merges, leaving the gap in a portion of the second recess.
[0054] Figure 23 It is shown a package structure according to embodiments of the present application.
[0055] Figure 24 It is shown a package structure according to some other embodiments of the present application, wherein a gap is present in a portion of the first recess. DETAILED DESCRIPTION
[0056] For a better understanding of the spirit of the embodiments of the present application, the following further describes the same in conjunction with some preferred embodiments of the present application.
[0057] Embodiments of the present application will be described in detail below. Throughout the specification, like or similar components and components having like or similar functions are denoted by like reference numerals. The embodiments described herein with reference to the accompanying drawings are illustrative in nature, diagrammatic in nature and are provided to give an overall understanding of the present application. The embodiments of the present application should not be construed as limiting the present application.
[0058] As used herein, the terms "approximately," "substantially," "about," and "generally" are used to describe and account for small variations. When utilized in connection with an event or circumstance, such terms can refer to instances in which the event or circumstance occurs exactly, as well as instances in which the event or circumstance occurs with a minor approximation.
[0059] In this specification, unless specifically stated or limited to the contrary, relative terms, such as "central," "longitudinal," "lateral," "forward," "rearward," "rightward," "leftward," "internal," "external," "lower," "upper," "horizontal," "vertical," "above," "below," "top," "bottom," and derivatives of these terms (e.g., "horizontally," "downwardly," "upwardly," etc.) should be construed to refer to the orientation as then described or as shown in the drawing under discussion. These relative terms are for convenience of description only and do not require that the application be practiced with any particular orientation.
[0060] For ease of description, "first," "second," "third," and so on can be used herein to distinguish between different components of one figure or series of figures. "First," "second," "third," and so on are not intended to describe the corresponding components.
[0061] Figure 6 A top view of the first seed layer 30 or the second seed layer 60 (hereinafter, the first seed layer 30 is taken as an example for description) in the packaging structure 100 according to the embodiments of the present application is shown, for example, the diameter of the first seed layer 30 is 30.08 μm, and a plurality of first grooves 32 as through holes are formed in the first seed layer 30 and pass through the first seed layer 30. The plurality of first grooves 32 are arranged in concentric circular rings, and the first grooves 32 are circular rings with discontinuities 34, and the first seed layer 30 is not thinned at the discontinuities 34. In some embodiments, the discontinuities 34 of adjacent first grooves 32 are staggered along the radial projection, for example, the discontinuities 34 of the plurality of first grooves 32 are located Figure 6 in the plurality of solid box regions.
[0062] In some embodiments, the width of the first grooves 32 is 0.01 μm, and the width of the first grooves 32 can be uniform. The pitch of the first grooves 32 can be controlled, and it can be known from the distribution map of the general current that the middle region is the region with the least current, so the first grooves 32 can be specially strengthened for the middle region through patterning, the first grooves 32 are more dense towards the middle region, and the pitch of the first grooves 32 decreases with the distance from the center, for example, from the inside to the outside, the radius of the innermost circular ring is 1 μm, the pitch between the innermost circular ring and the second circular ring is 2 μm, the pitch between the second circular ring and the third circular ring is 3 μm, the pitch between the third circular ring and the fourth circular ring is 4 μm, and the pitch between the fourth circular ring and the boundary of the first seed layer 30 is 5 μm.
[0063] Figure 7 A thickness distribution of the first electroplated copper layer 10 obtained by electroplating on the first seed layer 30 or the second electroplated copper layer 20 obtained by electroplating on the second seed layer 60 (hereinafter, the first seed layer 30 and the first electroplated copper layer 10 are taken as an example for description) is shown, in order to show the relationship between the thickness of the first electroplated copper layer 10 and the position of the first grooves 32 of the first seed layer 30, and the first grooves 32 are also shown, it can be understood that after the first electroplated copper layer 10 is electroplated on the first seed layer 30, the first grooves 32 are covered by the first electroplated copper layer 10 and thus cannot actually be seen. Figure 7 The thickness value at the point with the maximum thickness of the first electroplated copper layer 10 is 9.763 μm, and the thickness at the point with the minimum thickness is 9.751 μm. Figure 8 In Figure 5A curve of the thickness of the first electroplated copper layer 10 is shown on the basis of the first electroplated copper layer 10 at a certain diameter, with the center of the circle as the origin, the coordinates of the points as the horizontal axis, and the thickness of the first electroplated copper layer 10 at the points as the vertical axis. Figure 8 where the thickness of the part of the first electroplated copper layer 10 filled into the first groove 32 is ignored.
[0064] Embodiments of the present application make the first groove 32 of the first seed layer 30 for electroplating the first electroplated copper layer 10 patterned, so that the current can be concentrated at the first groove 32, and the edge area of the electroplating is averaged, thereby obtaining a first electroplated copper layer 10 with a more uniform thickness. Embodiments of the present application provide a method for improving and enhancing the electroplating flatness of the first electroplated copper layer 10 by improving the geometry of the first seed layer 30, so that the electroplating thickness difference per unit length (single wafer) of the first electroplated copper layer 10 is as low as about 0.07%. In Figure 7 In the embodiment shown, the electroplating thickness difference per unit length is calculated as (9.763-9.751) / 30.08.
[0065] Figure 9 A top view of the first seed layer 30 according to the second embodiment of the present application is shown, which has a diameter of, for example, 30.08 μm, and the first groove 32 has a pitch of, for example, 1.25 μm and a width of, for example, 0.25 μm. Figure 6 The difference between the embodiment shown and the second embodiment is that the pitch of the first groove 32 of the second embodiment is unchanged, for example, 1.25 μm, and the width of the first groove 32 is, for example, 0.25 μm. The second embodiment improves the electroplating flatness of the first electroplated copper layer 10 by increasing the number of the first groove 32.
[0066] Figure 10 The thickness distribution of the first electroplated copper layer 10 obtained by electroplating on the first seed layer 30 of the second embodiment is shown. In order to show the relationship between the thickness of the first electroplated copper layer 10 and the position of the first groove 32 of the first seed layer 30, the first groove 32 is also shown. It can be understood that after the first electroplated copper layer 10 is electroplated on the first seed layer 30, the first groove 32 is covered by the first electroplated copper layer 10 and thus cannot be seen in fact. Figure 10 The thickness value at the point with the maximum thickness of the first electroplated copper layer 10 in the second embodiment is 10 μm, and the thickness at the point with the minimum thickness is 9.521 μm, where the thickness of the part of the first electroplated copper layer 10 filled into the first groove 32 is ignored.
[0067] Figures 11 to 23 The forming process of the packaging structure 100 according to the embodiments of the present application is shown.
[0068] Figure 11 The glass carrier 50 is provided, and the carrier 50 is cleaned.
[0069] Figure 12 The diagram shows a second seed layer 60 formed on a carrier 50, the second seed layer 60 comprising a titanium layer and a copper layer on the titanium layer.
[0070] Figure 13 A patterned first mask layer 130 is shown formed on a second seed layer 60, the first mask layer 130 being, for example, a photoresist (PR) coating.
[0071] Figure 14 The diagram illustrates etching a second seed layer 60 using a first mask layer 130 as a mask to transfer the pattern of the first mask layer 130 to the second seed layer 60, forming a second groove 62 penetrating the second seed layer 60. The top view shape of the second groove 62 is similar to... Figure 6 , Figure 9 The first groove 32 shown has the same or similar shape, which is understandable. Figure 14 The diagram illustrates a portion of the encapsulation structure 100 to be formed, thus only half of the cross-section of the three annular second grooves 62 is shown.
[0072] Figure 15 The first mask layer 130 is shown being removed.
[0073] Figure 16 A patterned second mask layer 160 is shown formed on a second seed layer 60, the second mask layer 160 being, for example, a PR coating.
[0074] Figure 17 The diagram shows that a second copper plating layer 20 is obtained by electroplating, for example, a copper material on a second seed layer 60 exposed by a second mask layer 160. The second copper plating layer 20 has a second upper surface 22 and a second lower surface 24 opposite to the second upper surface 22. The portions of the second copper plating layer 20 extending into the second groove 62 constitute a plurality of second protrusions 26 on the second lower surface 24.
[0075] Figure 18 The removal of the second mask layer 160 is shown.
[0076] Figure 19 The second seed layer 60 is etched using the second electroplated copper layer 20 as a mask.
[0077] Figures 20 to 22 Some embodiments according to this application are shown. Figure 17 The specific process of the electroplating steps shown is as follows. Figure 20 This shows that when electroplating begins, since there is no second seed layer 62 at the bottom of the second groove 62, some sections of the second groove 62 may not be electroplated with copper material, so gap 64 is formed in the second groove 62. Figure 21 This shows that after electroplating continues for a period of time, the copper material on both sides of gap 64 becomes wider and wider, showing a tendency to merge inwards, as...Figure 22 After the electroplating is completed, the copper material above the gap 64 is merged, and the gap 64 is left in a partial section of the second recess 62 and extends upward to the second electroplated copper layer 20, so that the gap 64 is filled with the second electroplated copper layer 20. Figure 22 The cross section shown is in an elongated shape.
[0078] Figure 23 It is shown that the insulating layer 40 is formed on the second electroplated copper layer 20, and the steps of Figures 12 to 19 forming the first seed layer 30, the first electroplated copper layer 10 on the insulating layer 40 are repeated to obtain the packaging structure 100 according to the embodiments of the present application. The first seed layer 30 has a plurality of patterned first recesses 32, and the first electroplated copper layer 10 includes a first upper surface 12 and a first lower surface 14 opposite to the first upper surface 12, and the first lower surface 14 has a plurality of first protrusions 16 corresponding to the first recesses 32. The first seed layer 30 includes a titanium layer 36 and a copper layer 38 on the titanium layer 36. The top view shape of the first recess 32 of the first seed layer 30 is as shown in Figure 6 or Figure 9 As shown, the pitch of the plurality of first recesses 32 is the same or gradually decreases from the outside to the inside, and it can be understood that Figure 23 The structure shown is a schematic example of a part of the packaging structure 100, so only half of the cross section of the two annular first recesses 32 is shown. Optionally, the second seed layer 60 is removed by etching or grinding. The first seed layer 30 of the embodiments of the present application has patterned first recesses 32, and the current is uniformly distributed when the first electroplated copper layer 10 is formed by electroplating, which improves the consistency / uniformity of the thickness of the first electroplated copper layer 10. The first electroplated copper layer 10 and the second electroplated copper layer 20 of the embodiments of the present application can be used in various electrical connection structures, such as metal lines, pads, etc., that is, the structures and methods of the embodiments of the present application can be used when various electrical connection structures need to be formed by electroplating.
[0079] The insulating layer 40 has an opening 42 exposing the second upper surface 22, the first seed layer 30 is disposed on the insulating layer 40 and conformally lines in the opening 42, and the first electroplated copper layer 10 fills the remaining part of the opening 42 to form a conductive hole 18 electrically connected to the second electroplated copper layer 20, the first seed layer 30 is located between the conductive hole 18 and the second electroplated copper layer 20, and the diameter of the conductive hole 18 decreases in the direction from top to bottom.
[0080] The first recess 32 extends to the insulating layer 40, and the part of the first electroplated copper layer 10 extending into the first recess 32 constitutes the first protrusion 16 of the first electroplated copper layer 10. In the longitudinal projection, the first protrusion 16 and the second protrusion 26 are at least partially staggered.
[0081] In the first recess 32, the first protrusion 16 contacts the insulating layer 40, that is, when the first electroplated copper layer 10 is formed by electroplating, the copper material fills the first recess 32. Alternatively, as shown in Figure 24 , when the first electroplated copper layer 10 is formed by electroplating, there can be a gap 64' in a partial section of the first recess 32, and the gap 64' extends upward to the first electroplated copper layer 10, and neither of the above two cases affects the electrical properties. Figures 20 to 22
[0082] The above only describes preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims
1. A package structure, characterized by, Comprising: a first seed layer having a plurality of patterned first grooves extending through the first seed layer; a first electroplated copper layer disposed on the first seed layer, the first electroplated copper layer including a first upper surface and a first lower surface opposite the first upper surface, the first lower surface having a plurality of first protrusions corresponding to the first grooves.
2. The package structure of claim 1, wherein, Further comprising: a second electroplated copper layer disposed below the first electroplated copper layer, the second electroplated copper layer having a second upper surface and a second lower surface opposite the second upper surface, the second lower surface having a plurality of second protrusions; an insulating layer disposed on the second upper surface, the insulating layer having an opening exposing the second upper surface, the first seed layer disposed on the insulating layer and conformally lining the opening, the first electroplated copper layer filling a remaining portion of the opening.
3. The package structure of claim 2, wherein, a gap is formed within the first grooves and extends upwardly to the first electroplated copper layer.
4. The package structure of claim 2, wherein, Within the first grooves, the first protrusions contact the insulating layer.
5. The package structure of claim 1, wherein, The first grooves of the first seed layer are circular rings having discontinuities, the first seed layer not being thinned at the discontinuities.
6. The package structure of claim 5, wherein, The plurality of first grooves of the first seed layer are arranged as concentric circular rings.
7. The package structure of claim 6, wherein, The plurality of first grooves have a same pitch.
8. The package structure of claim 6, wherein, The plurality of first grooves have a pitch that decreases with distance from a center of the circular rings.
9. The package structure of claim 6, wherein, Along a radial projection, the discontinuities of adjacent first grooves are staggered.