Various features relate to anchoring a trace on a substrate to reduce peeling of the trace.
A thermal compression bonding process is a process used to assemble/package a flip chip, die or semiconductor device to a packaging substrate. Such a flip chip is often referred to as a thermal compression flip chip (TCFC). Thermal compression bonding processes provide several advantages over traditional bonding processes. For example, thermal compression bonding processes are generally more accurate than other solder bonding processes. Thus, thermal compression bonding processes are ideal when using fine pitch traces on substrate (e.g., less than 100 microns (μm)). In contrast, other solder bonding processes are limited to a bonding pitch that is greater than 100 microns (μm). Thus, TCFCs are typically higher density chips than chips using other bonding processes. However, during a thermal compression bonding process, the chip and the packaging substrate are subject to a lot of stress (e.g., thermal stress), which can result in failure in the assembly of the chip to the packaging substrate.
During the manufacturing process and/or assembly process of a packaging substrate, the packaging substrate may be subject to various forces which may cause one or more traces on the packaging substrate to peel off. Examples of manufacturing and/or assembly processes include roller process, picker process, handling process, bonding process (e.g., reflow bonding, thermal compression bonding) and post processing. During a thermal compression process, solder is applied to the openings (e.g., openings 210-212) in the solder resist layer 208 and the traces (e.g., traces 204-206) on the packaging substrate to connect a die to the packaging substrate. As the name implies, the solder resist layer 208 protects areas of the packaging substrate and/or traces from the solder, preventing the solder from wetting to portions of the traces. As mentioned above, during this thermal compression process, a lot of stress occurs (e.g., thermal stress). In some instances, the traces are large enough to handle these stresses. However, there has been a trend towards smaller and finer pitch traces. In such cases, these smaller and finer pitch traces are unable to handle the stress and often fail (e.g., peeling of trace).
It should be noted that the peeling off of the traces shown in
Therefore, there is a need for an improved design to increase pad adhesion and ensure that traces do not break or shear off during an assembly/bonding process.
Various features, apparatus and methods described herein provide anchoring a trace on a substrate to reduce peeling of the trace.
A first example provides a semiconductor device that includes a packaging substrate, a trace coupled to the packaging substrate, and a solder resist layer covering a part of the trace. The trace includes a first portion having a first width, and a second portion having a second width that is wider than the first width.
According to one aspect, the solder resist layer further includes an opening such that the second portion of the trace is exposed. In some implementations, the trace further includes a third portion located between the first portion and second portion of the trace. The third portion of the trace is exposed through an opening in the solder resist layer. The second portion of the trace covered with the solder resist layer.
According to an aspect, the second portion of the trace and the first portion of the trace form a T-shape. In some implementations, the second portion of the trace and the first portion of the trace form an L-shape. In some implementations, the second portion of the trace has a rectangular shape. In some implementations, the second portion of the trace has a circular shape.
According to one aspect, the second portion of the trace has a trapezoid shape, the trapezoid shape comprising the second width and a third width. The third width is less than the second width. In some implementations, the semiconductor device further includes a second trace coupled to the packaging substrate. The second trace comprising the first width. The second trace includes a third portion and a fourth portion. The fourth portion has a trapezoid shape that includes the second width and the third width. The trace is aligned in a first direction and the second trace is aligned in a second direction. In some implementations, the first direction is an opposite direction of the second direction.
According to an aspect, the second portion comprising the second width increases the area of the trace coupled to the packaging substrate to reduce the likelihood of the trace peeling from the packaging substrate during a manufacturing process of the packaging substrate.
According to one aspect, the second portion comprising the second width increases the area of the trace coupled to the packaging substrate to reduce the likelihood of the trace peeling from the packaging substrate during an assembly process of the packaging substrate.
According to an aspect, the second portion comprising the second width increases the area of the trace coupled to the packaging substrate to reduce the likelihood of the trace peeling from the packaging substrate during a bonding process of a die to the packaging substrate.
According to one aspect, the semiconductor device further includes a die coupled to the packaging substrate.
According to one aspect, the semiconductor device is incorporated into at least one of a music player, a video player, an entertainment unit, a navigation device, a communications device, a mobile device, a mobile phone, a smartphone, a personal digital assistant, a fixed location terminal, a tablet computer, and/or a laptop computer.
A second example provides an apparatus that includes a packaging substrate, means for providing an electrical path on the packaging substrate, and means for covering a part of the means for providing the electrical path. The means for providing the electrical path includes a first portion having a first width, and a second portion having a second width that is wider than the first width.
According to one aspect, the means for covering further includes an opening such that the second portion of the means for providing the electrical path is exposed.
According to an aspect, the means for providing the electrical path farther includes a third portion located between the first portion and second portion. The third portion of the means for providing the electrical path is exposed through an opening in the means for covering. The second portion of the means for providing the electrical path is covered with the means for covering.
According to one aspect, the second portion and the first portion of the means for providing the electrical path form a T-shape. In some implementations, the second portion and the first portion of the means for providing the electrical path form an L-shape. In some implementations, the second portion of the means for providing the electrical path has a rectangular shape. In some implementations, the second portion of the means for providing the electrical path has a circular shape.
According to an aspect, the second portion of the means for providing the electrical path has a trapezoid shape. The trapezoid shape has the second width and a third width. The third width is less than the second width. In some implementations, the apparatus further includes a second means for providing the electrical path on the packaging substrate. The second means for providing the electrical path includes the first width. The second means for providing the electrical path includes a third portion and a fourth portion. The fourth portion has a trapezoid shape that includes the second width and the third width. The means for providing the electrical path is aligned in a first direction and the second means for providing the electrical path is aligned in a second direction. In some implementations, the first direction is an opposite direction of the second direction.
According to one aspect, the second portion comprising the second width increases the area of the means for providing the electrical path coupled to the packaging substrate to reduce the likelihood of the means for providing the electrical path peeling from the packaging substrate during a manufacturing process of the packaging substrate.
According to an aspect, the second portion comprising the second width increases the area of the means for providing the electrical path coupled to the packaging substrate to reduce the likelihood of the means for providing the electrical path peeling from the packaging substrate during an assembly process of the packaging substrate.
According to one aspect, the second portion comprising the second width increases the area of the means for providing the electrical path coupled to the packaging substrate to reduce the likelihood of the means for providing the electrical path peeling from the packaging substrate during a bonding process of a die to the packaging substrate.
According to an aspect, the apparatus further includes a die coupled to the packaging substrate.
According to one aspect, the apparatus is incorporated into at least one of a music player, a video player, an entertainment unit, a navigation device, a communications device, a mobile device, a mobile phone, a smartphone, a personal digital assistant, a fixed location terminal, a tablet computer, and/or a laptop computer.
A third example provides a method for manufacturing a packaging substrate. The method provides a packaging substrate. The method further provides a trace on the packaging substrate. The trace includes a first portion having a first width, and a second portion having a second width that is wider than the first width. The method provides a solder resist layer covering a part of the trace.
According to one aspect, the solder resist layer further comprises an opening such that the second portion of the trace is exposed. In some implementations, the trace further includes a third portion located between the first portion and second portion of the trace. The third portion of the trace is exposed through an opening in the solder resist layer. The second portion of the trace is covered with the solder resist layer.
According to an aspect, the second portion of the trace and the first portion of the trace form a T-shape. In some implementations, the second portion of the trace and the first portion of the trace form an L-shape. In some implementations, the second portion of the trace has a rectangular shape. In some implementations, the second portion of the trace has a circular shape.
According to one aspect, the second portion of the trace has a trapezoid Shape. The trapezoid shape comprises the second width and a third width. The third width being less than the second width. In some implementations, the method farther provides a second trace coupled to the packaging substrate. The second trace has the first width. The second trace includes a third portion and a fourth portion. The fourth portion has a trapezoid shape that includes the second width and the third width. The trace is aligned in a first direction and the second trace is aligned in a second direction. In some implementations, the first direction is an opposite direction of the second direction.
According to an aspect, the second portion comprising the second width increases the area of the trace coupled to the packaging substrate to reduce the likelihood of the trace peeling from the packaging substrate during a manufacturing process of the packaging substrate.
According to one aspect, the second portion comprising the second width increases the area of the trace coupled to the packaging substrate to reduce the likelihood of the trace peeling from the packaging substrate during an assembly process of the packaging substrate.
According to an aspect, the second portion comprising the second width increases the area of the trace coupled to the packaging substrate to reduce the likelihood of the trace peeling from the packaging substrate during a bonding process of a die to the packaging substrate.
Various features, nature and advantages may become apparent from the detailed description set forth below when taken in conjunction with the drawings in which like reference characters identify correspondingly throughout.
In the following description, specific details are given to provide a thorough understanding of the various aspects of the disclosure, However, it will be understood by one of ordinary skill in the art that the aspects may be practiced without these specific details, For example, circuits may be shown in block diagrams in order to avoid obscuring the aspects in unnecessary detail. In other instances, well-known circuits, structures and techniques may not be shown in detail in order not to obscure the aspects of the disclosure.
Some exemplary implementations of this disclosure pertain to a semiconductor device that includes a packaging substrate, a trace coupled to the packaging substrate, and a solder resist layer that covers part of the trace. The trace includes a first portion having a first width, and a second portion having a second width that is wider than the first width. In some implementations, the second portion having the second width increases the area of the trace coupled to the packaging substrate to reduce the likelihood of the trace peeling from the packaging substrate. In some implementations, the solder resist layer further includes an opening such that the second portion of the trace is exposed. In some implementations, the trace further includes a third portion located between the first portion and second portion of the trace and where the third portion of the trace is exposed through an opening in the solder resist layer. In some implementations, the second portion of the trace is covered with the solder resist layer.
The solder resist layer 402 is positioned on top of the packaging substrate 400 and over a portion of the traces. The solder resist layer 402 includes an opening 410. The opening 410 in the solder resist layer 402 exposes parts/portions of the traces (e.g., traces 406, 408) and part of the packaging substrate 400. Thus, any part of a trace or a packaging substrate that is in the opening 410 is free of any solder resist in some implementations. For example, as shown in
In some implementations, the anchor portion (e.g., second portion of the trace) increases the surface area of the trace, effectively increasing the area of the trace that is connected to the packaging substrate. This increase in the surface area coupled to the packaging substrate allows the trace to absorb more stress (e.g., more force), as stress will be spread out over a larger area of the trace which includes the anchor portion. As a result, the traces are less likely to break, shear and/or peel off from the packaging substrate during a manufacturing process and/or assembly process of the packaging substrate (e.g., during a thermal compression bonding process). As such, adding an anchor portion (e.g., second portion) to the trace increases the likelihood of good electrical connections between a die and a packaging substrate. Examples of manufacturing and/or assembly processes include roller process, picker process, handling process, bonding process (e.g., reflow bonding, thermal compression bonding) and post processing. As described above, force and/or stress that can cause traces to break, shear and/or peel off may be applied to the traces during any stage of the manufacturing and/or assembly process. The term “peel off” as used herein may include shearing and breaking.
As shown in
The top diagram of
The bottom diagram of
The bottom diagram of
The various examples illustrated in
Having described a packaging substrate that includes traces with anchor portions a method for manufacturing such a packaging substrate will now be described. below.
Exemplary Method for Manufacturing a Packaging Substrate that Includes Traces with an Anchor Portion
The method provides (at 905) a packaging substrate. In some implementations, providing a packaging substrate includes manufacturing a packaging substrate. The method provides (at 910) several traces on the packaging substrate. In some implementations, providing several traces includes defining/manufacturing several traces on the packaging substrate. Different implementations may use different traces. In some implementations, the traces are copper traces. The traces provided on the packaging substrate may have a first width. For example, a first portion of a trace may have a first width. In some implementations, a trace may have a third portion that also has a first width.
The method provides (at 915) several anchor portions (e.g., second portion of a trace) on the packaging substrate. In some implementations, an anchor portion is provided to a respective trace on the packaging substrate. More specifically, the anchor portion may be provided to an end portion of a respective trace on the packaging substrate. The anchor portions may have a second width or diameter. The second width or diameter of the anchor portion may be greater/wider than the first width of the traces (e.g., first width of the first portion and/or third portion of a trace). The anchor portions may have different shapes (e.g., circle, rectangle, square, oval, trapezoid). In some implementations, the anchor portions are provided to the packaging substrate such that the anchor portion and the trace form a T-shaped trace or an L-shaped trace. For example, a second portion of the trace and the first portion of the trace may form a T-shaped trace or an L-shaped trace. In addition, in some implementations, a second portion of the trace and the third portion of the trace may form a T-shaped trace or an L-shaped trace. In some implementations, providing the anchor portions (e.g., second portion) includes defining/manufacturing anchor portions on the packaging substrate. The anchor portions may be made of the same material as the traces on the packaging substrate. For example, the anchor portions may be made of copper in some implementations. Although
Once the packaging substrate, the traces and the anchor portions are provided, the method provides (at 920) a solder resist layer on top of the substrate, trace and/or anchor portions of the traces. Different implementations may provide the solder resist layer differently. In sonic implementations, providing a solder resist layer includes providing a solder resist layer that includes one continuous opening. The opening may expose several portions of traces (e.g., first portion and/or third portion) and several anchor portions (e.g., second portion) in some implementations. Examples of one continuous opening in a solder resist layer that exposes several portions of traces and several anchor portions are shown in
Having described a method for manufacturing a packaging substrate that includes traces having anchor portions, a sequence of how to manufacture a packaging substrate that includes traces having anchor portions will now be described.
Exemplary Sequence for Manufacturing a Packaging Substrate that Includes Traces with an Anchor Portion
At stage 1, a packaging substrate 1000 is provided. As further shown in stage 1, the packaging substrate 1000 includes several traces (e.g., traces 1002, 1004) and several anchor portions (e.g., anchor portions 1003, 1004). Different implementations may use different traces (e.g., first portion) and/or anchor portions (e.g., second portion). The traces and the anchor portions may be provided at the same time as the packaging substrate in some implementations (e.g., may be provided as a single structure at the same time). In some instances, the trace (e.g., first portion and/or third portion) and anchor portions (e.g., second portion) are provided after a packaging substrate is provided (e.g., defined). In some implementations, the traces and anchor portions are copper traces. The traces may have a first width. For example, a first portion and/or a third portion of a trace may have a first width. The anchor portion may be provided to an end portion of a respective trace on the packaging substrate. The anchor portions (e.g., second portion) may have a second width or diameter. The second width or diameter of the anchor portion may be greater/wider than the first width of the traces (e.g., first and/or third portions of the trace). The anchor portions (e.g., second portion) may have different shapes (e.g., circle, rectangle, square, oval, trapezoid). In some implementations, the anchor portions are provided to the packaging substrate such that the anchor portion and the trace form a T-shaped trace or an L-shaped trace.
At stage 2, a solder resist layer 1006 is provided on top of the packaging substrate 1000, portions of the traces and/or anchor portions of the traces. The solder resist layer 1006 includes a continuous opening 1008. The opening 1008 is positioned above portions of the traces and anchor portions. Different implementations may provide the solder resist layer 1006 differently. In some implementations, the opening 1008 is an area of the packaging substrate 1000 that a die is coupled to during a bonding process (e.g., thermal compression bonding process).
The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any implementation or aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects of the disclosure. Likewise, the term “aspects” does not require that all aspects of the disclosure include the discussed feature, advantage or mode of operation. The term “coupled” is used herein to refer to the direct or indirect coupling between two objects. For example, if object A physically touches object B, and object B touches object C, then objects A and C may still be considered coupled to one another even if they do not directly physically touch each other. For instance, the substrate of the die may he coupled to the packaging substrate even though the substrate of the die is never directly physically in contact with the packaging substrate.
The terms wafer and substrate may be used herein to include any structure having an exposed surface with which to form an integrated circuit (IC) according to aspects of the present disclosure. The term die may be used herein to include an IC. The term substrate is understood to include semiconductor wafers. The term substrate is also used to refer to semiconductor structures during fabrication, and may include other layers that have been fabricated thereupon. The term substrate includes doped and undoped semiconductors, epitaxial semiconductor layers supported by a base semiconductor, or semiconductor layers supported by an insulator, as well as other semiconductor structures well known to one skilled in the art. The term insulator is defined to include any material that is less electrically conductive than materials generally referred to as conductors by those skilled in the art. The term “horizontal” is defined as a plane substantially parallel to the conventional plane or surface of a wafer or substrate, regardless of the orientation of the wafer or substrate. The term “vertical” refers to a direction substantially perpendicular to the horizontal as defined above. Prepositions, such as “on,” “upper,” “side,” “higher,” “lower,” “over,” and “under” when used with respect to the integrated circuits described, herein are defined with respect to the conventional plane or surface being on the top surface of the wafer or substrate, regardless of the orientation of the wafer or substrate. The prepositions “on,” “upper,” “side,” “higher,” “lower,” “over,” and “under” are thereby defined with respect to “horizontal” and “vertical.”
One or more of the components, steps, features, and/or functions illustrated in
Also, it is noted that the aspects of the present disclosure may be described as a process that is depicted as a flowchart, a flow diagram, a structure diagram, or a block diagram. Although a flowchart may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be re-arranged. A process is terminated when its operations are completed.
The various features of the invention described herein can be implemented in different systems without departing from the invention. It should be noted that the foregoing aspects of the disclosure are merely examples and are not to be construed as limiting the invention. The description of the aspects of the present disclosure is intended to be illustrative, and not to limit the scope of the claims. As such, the present teachings can be readily applied to other types of apparatuses and many alternatives, modifications, and variations will be apparent to those skilled in the art.
The present application claims priority to U.S. Provisional Application No. 61/740,885 entitled “Anchoring a Trace on a Substrate to Reduce Peeling of The Trace”, filed Dec. 21, 2012, which is hereby expressly incorporated by reference herein.
Number | Date | Country | |
---|---|---|---|
61740885 | Dec 2012 | US |