This disclosure relates generally to substrates, and more specifically, but not exclusively, to substrates with embedded traces.
Current Flip Chip Ball Grid Array (FCBGA) substrates use a thick core, thicker than other semiconductor substrates such as for wire bond, chip scale packages, or similar semiconductor packages, and have a limited fine bump pitch due to the trace pattern exposed on the surface of the substrate. The exposed trace pattern is subject to bump bridge shorts (shorts between the trace and adjoining pad caused by the solder ball connecting the flip chip to the pad on the substrate) and trace peel off risks (the risk of a thin copper trace peeling off of the surface of the substrate). Also conventional embedded trace substrates (ETS) cannot be used for FCBGA applications due to the very thick core needed in FCBGA substrates. Since there is a continuous drive in the industry for finer bump pitches (such as a 90 um pitch with two escape lines/traces) and current approaches have obvious bump shorts and high trace peel off risks, there is a need for systems, apparatus, and methods that overcome the deficiencies of conventional approaches including the methods, system and apparatus provided hereby.
The following presents a simplified summary relating to one or more aspects and/or examples associated with the apparatus and methods disclosed herein. As such, the following summary should not be considered an extensive overview relating to all contemplated aspects and/or examples, nor should the following summary be regarded to identify key or critical elements relating to all contemplated aspects and/or examples or to delineate the scope associated with any particular aspect and/or example. Accordingly, the following summary has the sole purpose to present certain concepts relating to one or more aspects and/or examples relating to the apparatus and methods disclosed herein in a simplified form to precede the detailed description presented below.
In one aspect, a package comprises: a substrate comprising a core, a first dielectric layer on a first side of the core, a second dielectric layer on a second side of the core opposite the first dielectric layer, and a third dielectric layer on the first dielectric layer; a plurality of pads embedded in the third dielectric layer such that a surface of each of the plurality of pads is below a surface of the third dielectric layer, the plurality of pads configured to connect to a flip chip semiconductor die and extend through the third dielectric layer; a plurality of traces embedded in the third dielectric layer such that a surface of each of the plurality of traces is below the surface of the third dielectric layer and extends through the third dielectric layer, at least two of the plurality of traces between each pair of adjoining pads of the plurality of pads; a first via proximate to a first edge of the substrate; and a second via proximate to a second edge of the substrate opposite the first edge.
In another aspect, a package comprises: a substrate comprising a core, a first dielectric layer on a first side of the core, a second dielectric layer on a second side of the core opposite the first dielectric layer, and means for insulation on the first dielectric layer; means for connection embedded in the means for insulation such that a surface of each of the means for connection is below a surface of the means for insulation, the means for connection configured to connect to a flip chip semiconductor die and extend through the means for insulation; means for routing embedded in the means for insulation such that a surface of each of the means for routing is below the surface of the means for insulation and extends through the means for insulation, at least two of the means for routing between each pair of adjoining means for connection; a first via proximate to a first edge of the substrate; and a second via proximate to a second edge of the substrate opposite the first edge.
In still another aspect, a method for forming a package substrate comprises: forming a core; forming a first dielectric layer on the core; forming a second dielectric layer on the core opposite the first dielectric layer; forming a plurality of pads on the first dielectric layer opposite the core; forming a plurality of traces on the first dielectric layer between the plurality of pads; forming a third dielectric layer on the first dielectric layer, the third dielectric layer configured to encapsulate the plurality of pads and the plurality of traces; forming a first via proximate to a first edge of the core; forming a second via proximate to a second edge of the core opposite the first edge of the core; removing a surface of the third dielectric layer such that the plurality of pads and the plurality of traces are exposed; forming a fourth layer on a portion of the third dielectric layer such that the plurality of pads and the plurality of traces are exposed; and removing a portion of each of the plurality of pads and each of the plurality of traces such that a surface of each of the plurality of pads and each of the plurality of traces is recessed from the surface of the third dielectric layer.
Other features and advantages associated with the apparatus and methods disclosed herein will be apparent to those skilled in the art based on the accompanying drawings and detailed description.
A more complete appreciation of aspects of the disclosure and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings which are presented solely for illustration and not limitation of the disclosure, and in which:
In accordance with common practice, the features depicted by the drawings may not be drawn to scale. Accordingly, the dimensions of the depicted features may be arbitrarily expanded or reduced for clarity. In accordance with common practice, some of the drawings are simplified for clarity. Thus, the drawings may not depict all components of a particular apparatus or method. Further, like reference numerals denote like features throughout the specification and figures.
The exemplary methods, apparatus, and systems disclosed herein mitigate shortcomings of the conventional methods, apparatus, and systems, as well as other previously unidentified needs.
The substrate 120 may comprise a core 130, a first dielectric layer 140 on a first side of the core 130, a second dielectric layer 150 on a second side of the core 130 opposite the first dielectric layer 140, a third dielectric layer 160 on the first dielectric layer 140, and a fourth layer 190 on a portion of the third dielectric layer 160 such that a plurality of pads 170 and a plurality of traces 180 are exposed and on the second dielectric layer 150 such that portions of a plurality of vias 123 are exposed. The plurality of vias 123 may include a first via 124 proximate to the first edge 121 of the substrate 120 and a second via 125 proximate to the second edge 122 of the substrate 120. The substrate 120 may also include a plurality of pads 170 embedded in the third dielectric layer 160 such that a surface of each of the plurality of pads 170 is recessed below a surface of the third dielectric layer 160 and the plurality of pads 170 are configured to connect to the semiconductor die 110 through the bump array 116 as well as extend entirely through the third dielectric layer 160. The substrate 120 may also include a plurality of traces 180 embedded in the third dielectric layer 160 extending entirely through the third dielectric layer 160 between the plurality of pads 170 such that a surface of each of the plurality of traces 180 is recessed below the surface of the third dielectric layer 160 and two of the plurality of traces 180 are between adjoining ones of the plurality of pads 170 and are configured to route signals from the plurality of pads 170 to other points or connections on and off the substrate 120. The substrate 120 may also include a plurality of vias 123 that extend from the third dielectric layer 160 to the second dielectric layer 150 to allow signals to be routed from a top of the substrate 120 to a bottom of the substrate 120.
The total thickness of package 100 depends on the layer count of substrate 120 and the thickness of semiconductor die 110. As shown the substrate 120 includes four layers but it should be understood that more or less layers may be used, such as 4-12 layers. Unlike conventional embedded trace substrates, the substrate 120 has a core 130 at the center and asymmetric structure about the core 130. The core 130 may comprise one of an organic, a silicon, a silicon dioxide, an aluminum oxide, a sapphire, a germanium, a gallium arsenide, an alloy of silicon and germanium, an indium phosphide, or similar material. The first dielectric layer 140 and the second dielectric layer 150 may be comprised of an ajinomoto-buildup film, for example, or other suitable material. The third dielectric layer 160 may be composed of one of ajinomoto-buildup film, prepreg insulation, resin coated copper, photo-sensitive resistor material, or similar material. The fourth layer 190 may be composed of a photo solder resist material. The thickness of the third dielectric layer 160 may be between 10 to 20 μm with a target of 15 μm. The dimensions of each of the plurality of traces 180 may be between 3 μm/3 μm to 15 μm/15 μm and each of the plurality of pads 170 may be between 16 μm to 40 μm in width. The thickness of the fourth layer 190 may be 15+/−5 μm for both the top and bottom. Each of the plurality of pads 170 and each of the plurality of traces 180 may have a recessed depth of approximately 0 to 4 μm (flat depth) below the surface of the third dielectric layer 160. A distance between one of the plurality of pads 170 and an adjoining one of the plurality of traces 180 may be between approximately 5 to 15 μm. As shown in
As shown in
The active side of a semiconductor or logic die is the part of the die that contains the active components of the die (e.g., transistors, resistors, capacitors, inductors etc.), which perform the operation or function of the die. The back side of the semiconductor die or logic die is the part that contains the active components of the die and is opposite from the active side. Pitch is the center-to-center distance between features of an integrated circuit such as interconnect lines or between a ball pad and a trace. Line and space terms refer to the width of an interconnect line, trace, or routing (the line or first dimension given) and the distance between adjacent interconnect lines, traces, or routings (the space or second dimension given). Substrates may comprise many different types of materials including, but not limited to, coreless, organic, silicon, silicon dioxide, aluminum oxide, sapphire, germanium, gallium arsenide, an alloy of silicon and germanium, or indium phosphide. Each trace may provide an escape line or routing out of the densely packed areas of an integrated circuit or semiconductor package such as between the pads of the bump array underneath the flip chip.
In this description, certain terminology is used to describe certain features. The term “mobile device” can describe, and is not limited to, 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, a computer, a wearable device, a laptop computer, a server, an automotive device in an automotive vehicle, and/or other types of portable electronic devices typically carried by a person and/or having communication capabilities (e.g., wireless, cellular, infrared, short-range radio, etc.). Further, the terms “user equipment” (UE), “mobile terminal,” “mobile device,” and “wireless device,” can be interchangeable.
It will be appreciated that various aspects disclosed herein can be described as functional equivalents to the structures, materials and/or devices described and/or recognized by those skilled in the art. For example, in one aspect, a package (e.g., package 100 or package 200) may comprise a substrate (e.g., substrate 120 or substrate 220) including a core (e.g., core 130 or core 230), a first dielectric layer (e.g., first dielectric layer 140 or first dielectric layer 240) on a first side of the core, a second dielectric layer (e.g., second dielectric layer 150 or second dielectric layer 250) on the first side of the core, and means for insulation (e.g., third dielectric layer 160 or third dielectric layer 260) on the first dielectric layer; means for connection (e.g., plurality of pads 170 or plurality of pads 270) embedded in the means for insulation such that a surface of each of the means for connection is below a surface of the means for insulation, the means for connection configured to connect to a flip chip semiconductor die (e.g., semiconductor die 110); means for routing (e.g., plurality of traces 180 or plurality of traces 280) embedded in the means for insulation such that a surface of each of the means for routing is below the surface of the means for insulation, at least two of the means for routing between each pair of adjoining means for connection; and a photo solder resist layer (e.g., fourth layer 190 or fourth layer 290) on a portion of the means for insulation.
It will be appreciated that the aforementioned aspects are merely provided as examples and the various aspects claimed are not limited to the specific references and/or illustrations cited as examples.
One or more of the components, processes, features, and/or functions illustrated in
The wireless communication between electronic devices can be based on different technologies, such as code division multiple access (CDMA), W-CDMA, time division multiple access (TDMA), frequency division multiple access (FDMA), Orthogonal Frequency Division Multiplexing (OFDM), Global System for Mobile Communications (GSM), 3GPP Long Term Evolution (LTE) or other protocols that may be used in a wireless communications network or a data communications network.
The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any details described herein as “exemplary” is not to be construed as advantageous over other examples. Likewise, the term “examples” does not mean that all examples include the discussed feature, advantage or mode of operation. Furthermore, a particular feature and/or structure can be combined with one or more other features and/or structures. Moreover, at least a portion of the apparatus described hereby can be configured to perform at least a portion of a method described hereby.
The terminology used herein is for the purpose of describing particular examples and is not intended to be limiting of examples of the disclosure. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes,” and/or “including,” when used herein, specify the presence of stated features, integers, actions, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, actions, operations, elements, components, and/or groups thereof.
It should be noted that the terms “connected,” “coupled,” or any variant thereof, mean any connection or coupling, either direct or indirect, between elements, and can encompass a presence of an intermediate element between two elements that are “connected” or “coupled” together via the intermediate element.
Any reference herein to an element using a designation such as “first,” “second,” and so forth does not limit the quantity and/or order of those elements. Rather, these designations are used as a convenient method of distinguishing between two or more elements and/or instances of an element. Also, unless stated otherwise, a set of elements can comprise one or more elements.
Nothing stated or illustrated depicted in this application is intended to dedicate any component, action, feature, benefit, advantage, or equivalent to the public, regardless of whether the component, action, feature, benefit, advantage, or the equivalent is recited in the claims.
Although some aspects have been described in connection with a device, it goes without saying that these aspects also constitute a description of the corresponding method, and so a block or a component of a device should also be understood as a corresponding method action or as a feature of a method action. Analogously thereto, aspects described in connection with or as a method action also constitute a description of a corresponding block or detail or feature of a corresponding device. Some or all of the method actions can be performed by a hardware apparatus (or using a hardware apparatus), such as, for example, a microprocessor, a programmable computer or an electronic circuit. In some examples, some or a plurality of the most important method actions can be performed by such an apparatus.
In the detailed description above it can be seen that different features are grouped together in examples. This manner of disclosure should not be understood as an intention that the claimed examples have more features than are explicitly mentioned in the respective claim. Rather, the situation is such that inventive content may reside in fewer than all features of an individual example disclosed. Therefore, the following claims should hereby be deemed to be incorporated in the description, wherein each claim by itself can stand as a separate example. Although each claim by itself can stand as a separate example, it should be noted that—although a dependent claim can refer in the claims to a specific combination with one or a plurality of claims—other examples can also encompass or include a combination of said dependent claim with the subject matter of any other dependent claim or a combination of any feature with other dependent and independent claims. Such combinations are proposed herein, unless it is explicitly expressed that a specific combination is not intended. Furthermore, it is also intended that features of a claim can be included in any other independent claim, even if said claim is not directly dependent on the independent claim.
It should furthermore be noted that methods, systems, and apparatus disclosed in the description or in the claims can be implemented by a device comprising means for performing the respective actions of this method.
Furthermore, in some examples, an individual action can be subdivided into a plurality of sub-actions or contain a plurality of sub-actions. Such sub-actions can be contained in the disclosure of the individual action and be part of the disclosure of the individual action.
While the foregoing disclosure shows illustrative examples of the disclosure, it should be noted that various changes and modifications could be made herein without departing from the scope of the disclosure as defined by the appended claims. The functions and/or actions of the method claims in accordance with the examples of the disclosure described herein need not be performed in any particular order. Additionally, well-known elements will not be described in detail or may be omitted so as to not obscure the relevant details of the aspects and examples disclosed herein. Furthermore, although elements of the disclosure may be described or claimed in the singular, the plural is contemplated unless limitation to the singular is explicitly stated.
The present Application for Patent claims the benefit of U.S. Provisional Application No. 62/513,985, entitled “SYMMETRIC EMBEDDED TRACE SUBSTRATE”, filed Jun. 1, 2017, assigned to the assignee hereof, and expressly incorporated herein by reference in its entirety.
Number | Date | Country | |
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62513985 | Jun 2017 | US |