Semiconductor package structure and method of forming the same

Abstract

The present invention relates to a semiconductor package structure and a method of forming the same. The semiconductor package structure includes a substrate, a redistribution layer over the substrate, and an underfill between the substrate and the redistribution layer. The underfill extends to at least one side of the redistribution layer, and the underfill adjacent to the at least one side of the redistribution layer is laterally spaced apart from the redistribution layer by a gap.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and more specifically, to a semiconductor packaging structure and a method for forming the same. Background Technology

[0002] In current chip-last manufacturing processes, the chip or die is first bonded to the RDL (Redistribution Layer) and then the entire package structure is flip-chip bonded to the substrate. However, this method cannot measure the quality of the RDL during packaging, which may lead to the dies being sacrificed due to RDL defects. Figure 1 This is a schematic diagram of an existing semiconductor packaging structure. (Example) Figure 1 As shown, although in Figure 1 In the 2.3D package structure shown, RDL 12 can be mounted onto substrate 15 first, and then the circuit measurements between RDL 12 and substrate 15 can be performed. However, if... Figure 1 As shown, in this packaging structure, the under-fill 18 will rise to the side wall of the carrier 20, thus facing the problem that the under-fill 18 cannot detach from the carrier 20 because it has risen to the side wall of the carrier 20. Summary of the Invention

[0003] In response to the problem in related technologies that the bottom filler cannot detach from the carrier due to climbing to the side wall of the carrier, the present invention proposes a semiconductor packaging structure and its formation method, which can at least effectively detach from the carrier in the packaging structure.

[0004] According to one aspect of the present invention, a semiconductor package structure is provided, comprising: a substrate; a redistribution layer located above the substrate; and a bottom filler located between the substrate and the redistribution layer, wherein the bottom filler extends to at least one sidewall of the redistribution layer, and the bottom filler and the at least one sidewall of the redistribution layer are laterally spaced apart by a gap.

[0005] In some embodiments, the gap extends to the sidewall of at least one side of the redistribution layer.

[0006] In some embodiments, the surface of the bottom filler facing the gap includes a cross section.

[0007] In some embodiments, the cut surface has burn marks.

[0008] In some embodiments, the bottom of the gap includes a circular burn mark.

[0009] In some embodiments, the semiconductor package structure further comprises: a die over the redistribution layer; and a second underfill between the die and the redistribution layer.

[0010] In some embodiments, the second underfill extends into the gap.

[0011] In some embodiments, a surface of the underfill facing the gap comprises a facet, and the second underfill is in contact with the facet.

[0012] In some embodiments, the second underfill is in contact with a sidewall of the at least one side of the redistribution layer.

[0013] In some embodiments, a top of the underfill has a sharp corner shape.

[0014] In some embodiments, the top of the underfill is over the redistribution layer.

[0015] According to another aspect of the embodiments of the present application, there is provided a method of forming a semiconductor package structure, comprising: providing a substrate, and bonding a redistribution layer formed on a carrier to the substrate; forming an underfill between the substrate and the redistribution layer, wherein the underfill extends to a sidewall of the carrier; removing the underfill at least at the sidewall of the carrier; and removing the carrier.

[0016] In some embodiments, removing the underfill at least at the sidewall of the carrier comprises: removing the underfill at the sidewall of the carrier with a laser.

[0017] In some embodiments, removing the underfill at least at the sidewall of the carrier comprises: removing at least a portion of the underfill at a sidewall of the redistribution layer as well.

[0018] In some embodiments, removing the underfill at least at the sidewall of the carrier comprises: forming a surface of the underfill remaining adjacent to the redistribution layer as a facet.

[0019] In some embodiments, removing the underfill at least at the sidewall of the carrier comprises: the facet is formed with a scorch mark.

[0020] In some embodiments, after removing the underfill at least at the sidewall of the carrier, a gap is formed between the underfill and the redistribution layer, and a scorch mark in a circular shape is formed at a bottom of the gap.

[0021] In some embodiments, after removing the carrier, further comprising: forming a die over the re-routed wiring layer; forming a second underfill between the die and the re-routed wiring layer.

[0022] In some embodiments, the second underfill extends beyond the re-routed wiring layer in a lateral direction and is in contact with the underfill.

[0023] In some embodiments, the second underfill fills a gap between the underfill and the re-routed wiring layer. BRIEF DESCRIPTION OF DRAWINGS

[0024] Various aspects of the application can be best understood from the following detailed description when read with the accompanying drawings in which: It should be noted that the various components are not necessarily drawn to scale. Indeed, the dimensions of the various components can be arbitrarily increased or decreased for clarity sake.

[0025] Figure 1 is a schematic diagram of an existing semiconductor package structure.

[0026] Figures 2 to 4 shows a schematic diagram of a semiconductor package structure according to embodiments of the present application.

[0027] Figure 5 is a flowchart of a method of forming a semiconductor package structure according to embodiments of the present application.

[0028] Figures 6A to 6C is a schematic diagram of various stages of a method of forming a semiconductor package structure according to embodiments of the present application. DETAILED DESCRIPTION

[0029] The following disclosure provides many different embodiments, or examples, for implementing different features of the provided subject matter. Specific examples of elements and arrangements are described below to simplify the present application. These are, of course, merely examples and are not intended to be limiting of the application. For example, in the following description, forming a first component over or on a second component can include embodiments where the first component and the second component are in direct contact, and can also include embodiments where additional components are formed between the first component and the second component such that the first component and the second component can not be in direct contact. Further, the present application can be repeated with reference numeral and / or letter designations that follow a first designation and then repeat the designation. Such repetition is merely for the sake of simplification and clarity and does not itself dictate a relationship between the various embodiments and / or configurations discussed.

[0030] Embodiments according to the present application provide a semiconductor package structure. Figure 2A schematic view of a semiconductor package structure 200 according to one embodiment of the present application is shown. The semiconductor package structure 200 includes a substrate 120 and an RDL (redistribution layer) 110 above the substrate 120. A underfill 130 is disposed between the substrate 120 and the RDL 110. In Figure 2 In the embodiment shown, the RDL 110 is connected to the substrate 120 by conductive connections 115, such as solder balls. The underfill 130 fills in between the RDL 110 and the substrate 120 and around the conductive connections 115.

[0031] The underfill 130 also extends laterally beyond the sidewalls of the RDL 110. The portion of the underfill 130 that extends beyond the sidewalls of the RDL 110 also extends upwardly to the sidewalls of the RDL 110. In Figure 2 In the embodiment shown, the underfill 130 extends to the sidewalls of the RDL 110 on opposite sides. In other embodiments, the underfill 130 extends to the sidewalls of the RDL 110 on any side. The underfill 130 also extends upwardly above the top surface of the RDL 110, with the top of the underfill 130 being above the top surface of the RDL 110. The underfill 130 is laterally spaced apart from the sidewalls of the RDL 110 by a gap 155 in the lateral direction. In this way, even if the underfill 130 climbs up the sidewalls of the carrier on the RDL 110 during processing, by configuring the underfill 130 to be laterally spaced apart from the sidewalls of the RDL 110 by the gap 155, the underfill 130 is prevented from contacting the carrier and thus the carrier is not detached.

[0032] Continuing to refer to Figure 2 As shown, the gap 155 extends to the sidewalls of the RDL 110 in the vertical direction, i.e., the gap 155 extends below the top surface of the RDL 110, and the gap 155 exposes portions of the sidewalls of the RDL 110. In some embodiments, the surface of the underfill 130 facing the gap 155 (the right sidewall and bottom surface of the gap 155) includes a facet 159. That is, the underfill 130 is first formed at the location where the gap 155 is to be formed, and then portions of the underfill 130 are removed to form the gap 155, such that the surface of the underfill 130 at the gap 155 is the facet 159. The top 132 of the underfill 130 is adjacent to the gap 155. In some embodiments, the top 132 of the underfill 130 has a sharp corner shape.

[0033] Die 210 is disposed above the top surface of RDL 110. Die 210 can be connected to a line in RDL 110 via conductive connector 135. Second underfill 140 is formed between die 210 and RDL 110 and surrounds conductive connector 135. Second underfill 140 surrounds the lower part of die 210. Second underfill 140 may be spaced apart from gap 155 in the lateral direction.

[0034] Figure 3 A schematic diagram of a semiconductor package structure 300 according to another embodiment of the present invention is shown. Figure 3 In and Figure 2 Similar components in the illustrated embodiments are represented by the same reference numerals. Figure 3 In the illustrated embodiment, the surface of the bottom filler 130 facing the gap 155 is a cross-section 159, which has burn marks 158. In this embodiment, the gap 155 is formed by laser burning. In some embodiments, the cross-section 159 of the gap 155 includes burn marks 158 formed in a circular shape. Figure 3 Other aspects of the illustrated embodiments may be related to Figure 2 The embodiments shown are similar and will not be described again here.

[0035] Figure 4 A schematic diagram of a semiconductor package structure 400 according to another embodiment of the present invention is shown. Figure 4 In and Figure 2 and Figure 3 Similar components in the illustrated embodiments are represented by the same reference numerals. Figure 4 In the illustrated embodiment, the second bottom filler 140 may extend laterally beyond the sidewall of RDL 110 and into the gap 155 between the bottom filler 130 and RDL 110. The second bottom filler 140 contacts the cross-section 159 of the bottom filler 130 facing the gap 155. Furthermore, the second bottom filler 140 also contacts the sidewall of RDL 110 exposed through the gap 155.

[0036] According to embodiments of the present invention, a method for forming a semiconductor package structure is also provided. Figure 5 This is a flowchart of a method for forming a semiconductor package structure according to an embodiment of the present invention. The method for forming the semiconductor package structure includes steps S102-S108. First, in step S102, a substrate 120 is provided, and an RDL 110 formed on a carrier is bonded to the substrate 120. In step S104, an underfill 130 is formed between the substrate 120 and the RDL 110, wherein the underfill 130 extends to the sidewalls of the carrier. In step S106, the underfill 130 at least at the sidewalls of the carrier is removed. In step S108, the carrier is removed.

[0037] The following will describe a method of forming a semiconductor package structure in conjunction with Figures 6A to 6C . First, refer to step S102 in Figure 6A and Figure 5 , a substrate 120 is provided. A RDL 110 is bonded over a top surface of the substrate 120, the RDL 110 being pre-formed on a carrier 170. In some embodiments, the RDL 110 can be attached to the carrier 170 by an adhesive layer 180. The RDL 110 can be bonded to the substrate 120 by conductive connections 115.

[0038] Refer to step S104 in Figure 6A and Figure 5 , a bottom filler 130 is formed between the substrate 120 and the RDL 110. The formed bottom filler 130 also extends laterally beyond the sidewalls of the RDL 110 and upwardly to contact the sidewalls of the RDL 110 and the sidewalls of the carrier 170.

[0039] Refer to step S106 in Figure 6B and Figure 5 , at least the bottom filler 130 at the sidewalls of the carrier 170 is removed. The removal of the bottom filler 130 can form a gap 155 between the bottom filler 130 and the sidewalls of the carrier 170. A bottom surface of the gap 155 can extend downwardly below a top surface of the RDL 110. In some embodiments, as shown in Figure 6B , the removal of the bottom filler 130 includes removing at least a portion of the bottom filler 130 at the sidewalls of the RDL 110, such that the gap 155 extends downwardly below the top surface of the RDL 110 and exposes a portion of the sidewalls of the RDL 110 through the gap 155.

[0040] By removing the bottom filler 130, a surface of the remaining bottom filler 130 facing the carrier 170 and the RDL 110 can be formed as a facet 159. In some embodiments, the removal of the bottom filler 130 can be performed with a laser process. The laser process causes the facet 159 of the bottom filler 130 to be formed with a scorch mark, as shown in Figure 3 . In some embodiments, the laser process forms a circular shaped scorch mark at the bottom of the gap 155, as shown in Figure 3 .

[0041] Refer to step S108 in Figure 6C and Figure 5At step S108 in FIG. 1, the carrier 170 is removed. In embodiments where the carrier 170 is attached to the RDL 110 by an adhesive layer 180, the adhesive layer 180 is also removed at the same time as the carrier 170 is removed. Even if the underfill 130 climbs onto the RDL 110, the underfill 130 formed on the sidewall of the carrier 170 during the process is removed so that the carrier 170 is laterally spaced apart from the underfill 130 by the gap 155 without contact, thus avoiding the problem that the carrier 170 cannot be detached.

[0042] Then, in optional embodiments, a die 210 is bonded over the RDL 110 and a second underfill 140 is formed between the die 210 and the RDL 110 to form any one of the semiconductor package structures 200, 300, 400 as shown in FIGS. 2, 3, and 4, respectively. That is, the second underfill 140 can be formed only over the RDL 110 (as shown in FIG. 2), or the second underfill 140 formed can laterally extend beyond the RDL 110 and fill into the gap 155 between the underfill 130 and the RDL 110 (as shown in FIGS. 3 and 4). Figures 2 to 4 Figure 2 Figure 3 Figure 4

[0043] The foregoing is a summary of several embodiments and features of the embodiments to enable a person skilled in the art to better understand various aspects of the present disclosure. Those skilled in the art should understand that other processes and structures can be easily designed or modified using the present application as a basis to achieve the same purpose and / or achieve the same advantages as the embodiments described in the present application. Those skilled in the art should also realize that these equivalent structures do not deviate from the spirit and scope of the present application, and various changes, substitutions and modifications can be made without deviating from the spirit and scope of the present application.​​​​

Claims

1. A semiconductor package structure, comprising: A semiconductor package structure comprising: a substrate; a redistribution layer over the substrate; an underfill between the substrate and the redistribution layer; a die over the redistribution layer; a second underfill between the die and the redistribution layer, wherein the underfill extends to at least one sidewall of the redistribution layer, the underfill and the at least one sidewall of the redistribution layer are laterally spaced apart by a gap, a bottom of the gap comprises a circular shaped scribe mark, and the gap extends from a top of the underfill to a bottom of the underfill, wherein the gap extends to the sidewall of the at least one side of the redistribution layer, a surface of the underfill facing the gap comprises a facet having a scribe mark, wherein the second underfill extends into the gap.

2. The semiconductor package structure of claim 1, wherein: a surface of the underfill facing the gap comprises a facet, and the second underfill is in contact with the facet.

3. The semiconductor package structure of claim 1, wherein: the second underfill is in contact with the sidewall of the at least one side of the redistribution layer.

4. The semiconductor package structure of claim 1, wherein: a top of the underfill has a sharp corner shape.

5. The semiconductor package structure of claim 1, wherein: the top of the underfill is over the redistribution layer.

6. A method of forming a semiconductor package structure, comprising: A method for fabricating a semiconductor package structure comprising: providing a substrate and bonding a redistribution layer formed on a carrier to the substrate; forming an underfill between the substrate and the redistribution layer, wherein the underfill extends to a sidewall of the carrier; removing at least the underfill at the sidewall of the carrier with a laser; removing the carrier; forming a die over the redistribution layer; forming a second underfill between the die and the redistribution layer, wherein removing at least the underfill at the sidewall of the carrier comprises: further removing at least a portion of the underfill at a sidewall of the redistribution layer, such that the underfill and the at least one sidewall of the redistribution layer are laterally spaced apart by a gap, and a surface of the underfill adjacent to the redistribution layer is formed as a facet, the facet is formed with a scribe mark, the gap extends from a top of the underfill to a bottom of the underfill, wherein the second underfill fills the gap between the underfill and the redistribution layer.

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