Solder mask barrier design

Abstract

This application relates to solder mask barrier designs. An image sensor package includes a transparent material and a substrate adhered to the transparent material. An image sensor is disposed on or within the substrate such that the image sensor is disposed between the substrate and the transparent material to receive light from an optical side of the image sensor package via the transparent material. A solder mask barrier is disposed between the substrate and the transparent material to form a gap between the image sensor and the transparent material, and the solder mask barrier is structured to indicate an orientation of the image sensor when the image sensor is viewed from the optical side.

Description

[0001] Divisional application

[0002] This application is a divisional application of the invention patent application filed on November 5, 2019, with application number 201911072541.4 and invention title "Solder Mask Barrier Design". Technical Field

[0003] This disclosure generally relates to semiconductor device packaging, and specifically, but not exclusively, to image sensor packaging. Background Technology

[0004] Image sensors have become ubiquitous. They are widely used in digital still cameras, cellular phones, security cameras, and in medical, automotive, and other applications. The technologies used to manufacture image sensors have continued to advance at a rapid pace. For example, the need for higher resolution and lower power consumption has driven further miniaturization and integration of these devices.

[0005] A typical image sensor operates as follows: Image light from an external scene is incident on the image sensor. The image sensor contains multiple photosensitive elements, each of which absorbs a portion of the incident image light. Each photosensitive element contained in the image sensor, such as a photodiode, generates an image charge after absorbing the image light. The amount of image charge generated is proportional to the intensity of the image light. The generated image charge can be used to generate an image representing the external scene.

[0006] Image sensor packaging is crucial for preventing degradation of image sensor devices, and it is important because it provides a structure that allows image sensors to be placed within larger electronic devices (e.g., cell phones) without complex soldering procedures. However, the package must be carefully designed to ensure compatibility of the final sensor product with other electronic devices. Summary of the Invention

[0007] According to one aspect of this application, an image sensor package is provided. The image sensor package includes: a transparent material; a substrate adhered to the transparent material; an image sensor disposed on or within the substrate such that the image sensor is positioned between the substrate and the transparent material to receive light from an optical side of the image sensor package via the transparent material; and a solder mask barrier disposed between the substrate and the transparent material to form a gap between the image sensor and the transparent material, wherein the solder mask barrier is structured to indicate the orientation of the image sensor when viewed from the optical side.

[0008] According to another aspect of this application, a method for manufacturing an image sensor package is provided. The method includes: forming an image sensor in or on a substrate; forming a solder mask barrier on a transparent material, wherein the solder mask barrier is asymmetrical; and attaching the transparent material to the substrate such that light travels from an optical side of the image sensor package through the transparent material to the image sensor, wherein the solder mask barrier forms a gap between the image sensor and the transparent material, and the solder mask barrier is attached to the substrate to indicate the orientation of the image sensor when viewed from the optical side. Attached Figure Description

[0009] The following figures illustrate non-limiting and non-exhaustive examples of the invention, wherein, unless otherwise specified, the same reference numerals refer to the same parts throughout the views.

[0010] Figure 1A This illustration shows a cross-section of an image sensor package according to the teachings of this disclosure.

[0011] Figures 1B to 1C Explanation based on the teachings of this disclosure Figure 1A An assembly of image sensor packages.

[0012] Figure 2A to 2T This describes the solder mask barrier design based on the teachings of this disclosure.

[0013] Figure 3 The image sensor system according to the present invention is described.

[0014] Corresponding reference numerals indicate corresponding components in several views of the drawings. Those skilled in the art will understand that the elements in the drawings are shown for simplicity and clarity only and are not necessarily drawn to scale. For example, the dimensions of some elements in the drawings may be enlarged relative to other elements to aid in understanding the various embodiments of the invention. Furthermore, common but well-known elements that are useful or necessary in commercially viable embodiments are generally not depicted in order to present less obstructed views of these various embodiments of the invention. Detailed Implementation

[0015] This document describes examples of apparatus, systems, and methods for solder mask barriers. Numerous specific details are set forth in the following description to provide a thorough description of the examples. However, those skilled in the art will recognize that the techniques described herein can be practiced without one or more of the specific details stated and using other methods, components, materials, etc. In other instances, well-known structures, materials, or operations have not been shown or described in detail to avoid confusion.

[0016] Throughout this specification, references to "an example" or "an embodiment" mean that a particular feature, structure, or characteristic described in connection with the example is included in at least one embodiment of the invention. Therefore, the phrases "in one example" or "in one embodiment" appearing in different places throughout this specification do not necessarily refer to the same example. Furthermore, the specific feature, structure, or characteristic may be combined in one or more examples.

[0017] Previously, the offset orientation of an image sensor within its package was readily apparent from visual inspection due to the sensor's own displacement. Automated orientation inspection systems could rely on the shifted sensor area to determine orientation. However, due to changed packaging requirements, the offset has become less noticeable. Such chip designs (with slight or no offset) can be ubiquitous. Consequently, automated orientation inspection systems will no longer encounter specific patterns to identify image sensor orientation. Incorrect orientation identification can lead to manufacturing problems.

[0018] Therefore, this paper presents examples of unique patterns of solder mask barriers (SMDGs) on glass to address the problem of automated orientation inspection systems: the solder mask barriers are constructed to elicit orientation information from visual inspection. In general, several broad categories of barrier designs have been proposed (e.g., see...). Figure 2A to 2T ): Modify the external barrier pattern to have a unique pattern at the corner or one of the four sides, modify the internal barrier pattern, add a connection between the internal and external barriers, create discontinuities in the internal and / or external barriers (to form open, unclosed tori), add a unique barrier pattern in the empty area between the internal and external barriers, or any combination thereof.

[0019] The following disclosure will further describe the embodiments discussed above, as well as other embodiments, as they relate to the accompanying drawings.

[0020] Figure 1A The image sensor package 100 according to the teachings of this disclosure is shown in cross-section. The image sensor package 100 includes an image sensor 101 (e.g., a CMOS image sensor, etc.), a transparent material 103 (e.g., glass, quartz, sapphire, etc.), a solder mask barrier 105 (e.g., a polymer material containing negative or positive photoresist, etc.), a cavity 107 (e.g., filled with air, inert gas, vacuum, etc.), and a substrate 109 (e.g., silicon, dopant, oxide layer, support circuitry for the image sensor 101, etc.).

[0021] On the back side of substrate 109 are a redistribution layer (“RDL”; for example, a layer on an electronic chip to make pads for integrated circuits available in many locations, which may contain layers of Ti / Cu, Ni / Au), a buffer layer, an oxide layer (e.g., silicon oxide, etc.), a metal shielding layer, a passivation layer (e.g., a solder mask), S / L openings (e.g., locations where silicon is etched out from scribe lines), and solder balls. Solder balls can be used to attach the image sensor package 100 to other circuitry, such as a printed circuit board containing a processor, etc. In the depicted example, contact pads may be formed on the edges of the image sensor package.

[0022] As depicted, a transparent material 103 is adhered to a substrate 109, and an image sensor 101 is disposed on or within the substrate 109 (e.g., here, the substrate 109 comprises a silicon wafer, and the image sensor 101 is formed in silicon) such that the image sensor 101 is disposed between the substrate 109 and the transparent material 103 to receive light from the optical side of the image sensor package 100 (e.g., the image sensor side from which image light originates) via the transparent material 103. A solder mask barrier 105 is disposed between the substrate 109 and the transparent material 103 to form a gap 107 between the image sensor 101 and the transparent material 103. In other words, the solder mask barrier 105 acts as a spacer between the substrate 109 and the transparent material 103. Figure 2A to 2T As shown, the solder mask barrier 105 is structured to indicate the orientation of the image sensor 101 when viewed from the optical side.

[0023] Figures 1B to 1C Description of manufacturing based on the teachings of this disclosure Figure 1A A method for packaging an image sensor 100. Those skilled in the art will understand that... Figure 1A The components depicted in the text have been removed from Figure 1B Omitted to avoid obscuring certain aspects of this disclosure. Furthermore, the operations can occur in any order, and even in parallel.

[0024] exist Figure 1B In this process, a solder mask barrier 105 is formed (e.g., via photolithography or printing) on ​​a transparent material 103, and the solder mask barrier 105 is asymmetrical (e.g., see [reference needed]). Figure 2A to 2T ).

[0025] Figure 1CAn image sensor 101 is depicted formed in (or on) a substrate 109, and a transparent material 103 is attached to the substrate 109 such that light travels from the optical side of the image sensor package through the transparent material 103 to the image sensor 101. As shown, a solder mask barrier 105 forms a gap between the image sensor 101 and the transparent material 103, and the solder mask barrier 105 is attached to the substrate to indicate the orientation of the image sensor 101 (when the image sensor 101 is viewed from the optical side). In the depicted example, attaching the transparent material 103 to the substrate 109 includes applying an adhesive 131 (e.g., glue, etc.) between the solder mask barrier 105 and the substrate 109 to attach the solder mask barrier 105 to the substrate 109.

[0026] In the depicted example, the dashed lines depict scribing lines used to separate (e.g., via cutting) the image sensor package from multiple image sensor packages (after the transparent material 103 is attached to the substrate 109).

[0027] Figure 2A to 2T This describes solder mask barrier designs based on the teachings of this disclosure (when viewed via the optical side of an image sensor package). Those skilled in the art will understand that these are merely examples and other designs may be used. It should be understood that many of the same structures are repeated in the various embodiments / examples, and in... Figure 2A to 2T The structures depicted are not mutually exclusive (e.g., multiple asymmetric markers may be combined in the same embodiment to indicate the orientation of the image sensor package or the location of certain device architectures within the image sensor package with higher accuracy).

[0028] Those skilled in the art will understand that the solder mask barrier example shown is "generally rectangular," comprising a rectangular shape with protrusions, partial cutouts, discontinuities, connectors between multiple barriers, non-straight lines, etc. Furthermore, the generally rectangular shape may have serrated / triangular inner and / or outer edges, and may have rounded inner / outer corners.

[0029] Figure 2AA solder mask barrier 205A / 205B is depicted, comprising an inner barrier 205A and an outer barrier 205B. The inner barrier 205A surrounds the image sensor 201, and the outer barrier 205B surrounds the inner barrier 205A. As shown, the inner barrier 205A is closer to the image sensor 201 than the outer barrier 205B. As shown, the solder mask barriers 205A / 205B are generally rectangular, and are structured to indicate the orientation of the image sensor 201 through asymmetrical shaping. Here, the asymmetry is the upper left corner of the filled triangle of the outer barrier 205B. According to the teachings of this disclosure, because the package is visually asymmetrical, an automated orientation inspection system can reliably determine the sensor orientation.

[0030] Figure 2B Description of solder mask barrier 205A / 205B, which includes inner barrier 205A and outer barrier 205B. Figure 2B The solder mask barrier 205A / 205B in the middle is similar to Figure 2A The barriers within; however Figure 2B The asymmetry is in the filled rectangle (a protrusion extending from the outer barrier 205B toward the inner barrier 205A) in the upper right corner of the outer barrier 205B.

[0031] Figure 2C Description of solder mask barrier 205A / 205B, which includes inner barrier 205A and outer barrier 205B. Figure 2C The solder mask barrier 205A / 205B in the middle is similar to Figure 2B The barrier; however Figure 2C The asymmetry is the filled rectangular shape (e.g., a protrusion extending from the outer barrier 205B toward the inner barrier 205A) in the middle and on the long side of the rectangular outer barrier 205B.

[0032] Figure 2D Description of solder mask barrier 205A / 205B, which includes inner barrier 205A and outer barrier 205B. Figure 2D The solder mask barrier 205A / 205B in the middle is similar to Figure 2C The barriers within; however Figure 2D The asymmetry is the filled rectangular shape that bridges the inner barrier 205A and the outer barrier 205B in the upper left corner. Figure 2D It also has triangular protrusions extending from the inner barrier 205A toward the outer barrier 205B.

[0033] Figure 2E Description of solder mask barrier 205A / 205B, which includes inner barrier 205A and outer barrier 205B. Figure 2EThe solder mask barrier 205A / 205B in the middle is similar to Figure 2D The barriers within; however Figure 2E The asymmetry is achieved by multiple filled rectangular shapes bridging the inner barrier 205A and the outer barrier 205B along the long side of the rectangle at the bottom center of the device.

[0034] Figure 2F Description of solder mask barrier 205A / 205B, which includes inner barrier 205A and outer barrier 205B. Figure 2F The solder mask barrier 205A / 205B in the middle is similar to Figure 2E The barriers within; however Figure 2F The asymmetry is that the filled rectangle (longer than the width) bridging the inner barrier 205A and the outer barrier 205B along the short side of the rectangular structure on the left side of the device.

[0035] Figure 2G Description of solder mask barrier 205A / 205B, which includes inner barrier 205A and outer barrier 205B. Figure 2G The solder mask barrier 205A / 205B in the middle is similar to Figure 2F The barriers within; however Figure 2G The asymmetry is the discontinuity in the inner barrier 205A near the upper left corner (e.g., the absence of barrier material).

[0036] Figure 2H Description of solder mask barrier 205A / 205B, which includes inner barrier 205A and outer barrier 205B. Figure 2H The solder mask barrier 205A / 205B in the middle is similar to Figure 2G The barriers within; however Figure 2H The asymmetry is the discontinuity at the lower left corner of the internal barrier 205A (e.g., the absence of barrier material).

[0037] Figure 2I Description of solder mask barrier 205A / 205B, which includes inner barrier 205A and outer barrier 205B. Figure 2I The solder mask barrier 205A / 205B in the middle is similar to Figure 2H The barriers within; however Figure 2I The asymmetry is the discontinuity in the inner barrier 205A on the right (smaller) side of the rectangular structure (e.g., the absence of barrier material). Therefore, the inner barrier 205A at least partially surrounds the image sensor 101.

[0038] Figure 2J Description of solder mask barrier 205A / 205B, which includes inner barrier 205A and outer barrier 205B. Figure 2JThe solder mask barrier 205A / 205B in the middle is similar to Figure 2I The barriers within; however Figure 2J The asymmetry is the rectangular inclusion in the upper left corner between the inner barrier 205A and the outer barrier 205B.

[0039] Figure 2K Description of solder mask barrier 205A / 205B, which includes inner barrier 205A and outer barrier 205B. Figure 2K The solder mask barrier 205A / 205B in the middle is similar to Figure 2J The barriers within; however Figure 2K The asymmetry is the circular inclusion in the upper right side between the inner barrier 205A and the outer barrier 205B.

[0040] Figure 2L Description of solder mask barrier 205A / 205B, which includes inner barrier 205A and outer barrier 205B. Figure 2L The solder mask barrier 205A / 205B in the middle is similar to Figure 2K The barriers within; however Figure 2L The asymmetry is the rectangular inclusion in the upper right side between the inner barrier 205A and the outer barrier 205B.

[0041] Figure 2M Description of solder mask barrier 205 containing a single barrier. Figure 2M The solder mask barrier 205A / 205B in the middle is similar to Figure 2A The barrier in the diagram. In the depicted example, the asymmetry includes the lower left corner of the triangle in solder mask barrier 205.

[0042] Figure 2N Description of solder mask barrier 205 containing a single barrier. Figure 2N The solder mask barrier 205A / 205B in the middle is similar to Figure 2B The barrier in the middle, due to its asymmetry, is contained in the filled rectangle in the upper right corner of the rectangular structure (a protrusion extending from the barrier 205 toward the image sensor 201).

[0043] Figure 2O The description includes a solder mask barrier 205 containing a single barrier. The asymmetry described herein is contained in a triangular protrusion on the left (smaller) edge of the rectangle (a protrusion extending from barrier 205 toward image sensor 201).

[0044] Figure 2P The description includes a solder mask barrier 205 containing a single barrier. The asymmetry depicted here includes an "L"-shaped inclusion located on the upper left side of the package between the image sensor 201 and the barrier 205.

[0045] Figure 2Q The diagram illustrates a solder mask barrier 205 containing a single barrier. The asymmetry depicted here is contained in a triangular inclusion between the image sensor 201 and the barrier 205 in the upper right corner of the package.

[0046] Figure 2R The description includes a solder mask barrier 205 containing a single barrier. The asymmetry described herein is contained in a circular inclusion in the lower right corner of the package between the image sensor 201 and the barrier 205.

[0047] Figure 2S This describes a solder mask barrier 205 containing a single barrier. The asymmetry described herein is contained within a triangular protrusion in the upper left inner corner of barrier 205.

[0048] Figure 2T The description includes a solder mask barrier 205 containing a single barrier. The asymmetry depicted here is contained in a rectangular protrusion from the solder mask barrier 205 near the upper left corner of the image sensor 201.

[0049] Figure 3 This describes an imaging system 300 according to the teachings of this disclosure. The image sensor system 300 may be included in... Figures 1A to 1C The image sensor package contains an imaging system 300. The imaging system 300 includes a pixel array 305, control circuitry 321, readout circuitry 311, and functional logic 315. In one example, the pixel array 305 is a two-dimensional (2D) array of photodiodes or image sensor pixels (e.g., pixels P1, P2…, pixels Pn). As illustrated, photodiodes are arranged in rows (e.g., rows R1 to Ry) and columns (e.g., columns C1 to Cx) to acquire image data of people, places, objects, etc., which can then be used to render a 2D image of said people, places, objects, etc. However, photodiodes need not be arranged in rows and columns, and other configurations are possible.

[0050] In one example, after each pixel in the image sensor photodiode / pixel array 305 has acquired its image data or image charge, the image data is read out by readout circuitry 311 and then transmitted to functional logic 315. In various examples, readout circuitry 311 may include amplification circuitry, analog-to-digital (ADC) conversion circuitry, or other circuitry. Functional logic 315 may simply store the image data, or even manipulate the image data by applying post-processing image effects (e.g., autofocus, cropping, rotation, red-eye removal, brightness adjustment, contrast adjustment, or other effects). In one example, readout circuitry 311 may read out one row of image data at a time along the (described) readout column lines, or may use various other techniques (not described) to read out the image data, such as serial readout or simultaneous, fully parallel readout of all pixels.

[0051] In one example, control circuitry 321 is coupled to pixel array 305 to control the operation of multiple photodiodes within pixel array 305. For instance, control circuitry 321 may generate a shutter signal for controlling image acquisition. In the depicted example, the shutter signal is a global shutter signal used to simultaneously enable all pixels within pixel array 305 to capture their respective image data during a single acquisition window. In another example, image acquisition is synchronized with lighting effects such as flash.

[0052] The imaging system 300 can be coupled to various other hardware components, such as processors (general purpose or other), memory elements, outputs (USB ports, wireless transmitters, HDMI ports, etc.), lighting devices / flash memory, electrical inputs (keyboards, touch displays, trackpads, mice, microphones, etc.), and / or displays. These other hardware components can deliver instructions to the imaging system 300, retrieve image data from the imaging system 300, or manipulate image data supplied by the imaging system 300.

[0053] The above description of the illustrative examples of the invention (including those described in the abstract) is not intended to be exhaustive or to limit the invention to the precise forms disclosed. While specific examples of the invention have been described herein for illustrative purposes, various modifications are possible within the scope of the invention, as will be recognized by those skilled in the art.

[0054] These modifications may be made to the invention in light of the above detailed description. The terminology used in the appended claims should not be construed as limiting the invention to the specific instances disclosed in this specification. In fact, the scope of the invention should be fully defined by the appended claims, and the appended claims should be interpreted according to the established principles of their interpretation.

Claims

1. An image sensor package, comprising: Transparent materials; A substrate, which is adhered to the transparent material; An image sensor is disposed on or within the substrate such that the image sensor is positioned between the substrate and the transparent material to receive light from the optical side of the image sensor package via the transparent material; as well as A solder mask barrier is disposed between the substrate and the transparent material to form a gap between the image sensor and the transparent material, wherein the solder mask barrier is structured to indicate the orientation of the image sensor when viewed from the optical side. The solder mask barrier is structured by asymmetric shaping to indicate the orientation of the image sensor.

2. The image sensor package of claim 1, wherein the solder mask barrier surrounds the image sensor.

3. The image sensor package according to claim 2, wherein the solder mask barrier is generally rectangular.

4. The image sensor package of claim 1, wherein the solder mask barrier comprises an inner barrier and an outer barrier, wherein the inner barrier at least partially surrounds the image sensor, and the outer barrier at least partially surrounds the inner barrier, and wherein the inner barrier is closer to the image sensor than the outer barrier.

5. The image sensor package of claim 4, wherein the solder mask barrier is asymmetrically formed by comprising at least one of the following: a protrusion extending from the outer barrier toward the inner barrier, a protrusion extending from the inner barrier toward the outer barrier, a protrusion bridging the inner barrier and the outer barrier, a discontinuity in the inner barrier, or an inclusion between the inner barrier and the outer barrier.

6. The image sensor package of claim 1, wherein the solder mask barrier is asymmetrically shaped by comprising at least one of the following: a protrusion extending from the solder mask barrier toward the image sensor, a cutout in the solder mask barrier, or an inclusion between the image sensor and the barrier.

7. The image sensor package of claim 1, further comprising an adhesive disposed between the solder mask barrier and the substrate to attach the solder mask barrier to the substrate.

8. The image sensor package of claim 1, wherein the substrate comprises a silicon wafer, and wherein the image sensor is formed in the silicon wafer.

9. The image sensor package of claim 1, wherein the transparent material comprises a glass layer and the gap comprises air.

10. A method for manufacturing an image sensor package, comprising: An image sensor is formed in or on a substrate; A solder mask barrier is formed on a transparent material, wherein the solder mask barrier is asymmetric; as well as The transparent material is attached to the substrate such that light travels from the optical side of the image sensor package through the transparent material to the image sensor, wherein the solder mask barrier forms a gap between the image sensor and the transparent material, and the solder mask barrier is attached to the substrate to indicate the orientation of the image sensor when viewed from the optical side. The asymmetry of the solder mask barrier indicates the orientation of the image sensor.

11. The method of claim 10, wherein attaching the transparent material to the substrate comprises applying an adhesive between the solder mask barrier and the substrate to attach the solder mask barrier to the substrate.

12. The method of claim 10, wherein forming the solder mask barrier comprises structuring the solder mask barrier such that it surrounds the image sensor after the transparent material is attached to the substrate.

13. The method of claim 12, wherein forming the solder mask barrier comprises forming a generally rectangular solder mask barrier.

14. The method of claim 10, wherein forming the solder mask barrier comprises forming an inner barrier and an outer barrier, wherein the inner barrier at least partially surrounds the image sensor, and the outer barrier at least partially surrounds the inner barrier, and wherein the inner barrier is closer to the image sensor than the outer barrier.

15. The method of claim 14, wherein the solder mask barrier is asymmetrically formed by comprising at least one of the following: a protrusion extending from the outer barrier toward the inner barrier, a protrusion extending from the inner barrier toward the outer barrier, a protrusion bridging the inner barrier and the outer barrier, a discontinuity in the inner barrier, or an inclusion between the inner barrier and the outer barrier.

16. The method of claim 10, wherein the solder mask barrier is asymmetrically shaped by comprising at least one of the following: a protrusion extending from the solder mask barrier toward the image sensor, a cutout in the solder mask barrier, or an inclusion between the image sensor and the solder mask barrier.

17. The method of claim 10, further comprising separating the image sensor package from a plurality of image sensor packages after attaching the transparent material to the substrate.

18. The method of claim 17, wherein separation comprises cutting.

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