Ball grid array packaging image sensor module with anti-glare characteristic

Abstract

The invention relates to the technical field of electronic equipment, and provides a ball grid array packaging image sensor module with an anti-glare characteristic, and the ball grid array packaging image sensor module comprises a substrate, an image sensing chip, a wire, a cover plate, and a glue blocking body. Wherein a blocking colloid with optical density (OD) greater than or equal to 2 is arranged between the edge of the upper surface of the image sensing chip and the cover plate, a filler with volume percentage greater than 20% and average particle size less than 50 microns is doped into the blocking colloid, and the image sensing chip is formed by an ultraviolet light and heat dual curing process or a pure heat curing process. Therefore, the image quality and the manufacturing yield of the image sensing module are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electronic devices, in particular to an image sensor module with anti-glare characteristics, especially to a ball grid array (BGA) packaged image sensor module with anti-glare characteristics. BACKGROUND

[0002] In strong light irradiation or complex light source environment, the traditional image sensor module is prone to flare phenomenon, which is usually caused by reflection or scattering of non-imaging light inside the module (such as packaging material, protective glass surface or side, lens edge, substrate surface), and then enters the image sensing chip, resulting in decreased image contrast, blurred picture, and blurred details, which seriously affects the final image quality. In order to solve the problem of glare, the related technology often applies anti-reflection coating on the surface of the lens or sets a physical light shield. However, these methods increase the manufacturing cost and increase the size of the module, and also cannot completely eliminate the reflection of stray light caused by the packaging structure itself.

[0003] Therefore, how to design an image sensor module with small size, high integration (such as BGA packaging) and effective internal glare suppression has become a technical problem to be solved in the industry. SUMMARY

[0004] The purpose of the present application is to provide a ball grid array (BGA) packaged image sensor module with anti-glare characteristics, which can effectively suppress the glare phenomenon through packaging structure design, thereby improving the image quality and manufacturing yield of the image sensing module.

[0005] To achieve the above purpose, the present application provides a ball grid array (BGA) packaged image sensor module with anti-glare characteristics, which includes a substrate, an image sensing chip, a wire, a cover plate and a glue blocking body. The bottom of the substrate is provided with a plurality of spherical solder joints. The image sensing chip is arranged on the substrate and is used to receive optical signals and convert them into electrical signals. The wire connects the electrodes of the image sensing chip and the circuit on the substrate. The cover plate covers the image sensing chip. The glue blocking body is arranged around the edge of the upper surface of the image sensing chip, and the glue blocking body contacts the bottom surface of the cover plate and covers the connection end of the wire connection electrode, wherein the optical density (OD) of the glue blocking body is greater than or equal to 2, and the glue blocking body is doped with uniformly dispersed fillers, the volume percentage of the fillers is greater than 20%, and the average particle size of the fillers is less than 50 microns, which is formed by a double curing process of ultraviolet light and heat, or a pure heat curing process. Therefore, the present application provides good optical absorption and thermal stability, thereby effectively reducing the glare phenomenon.

[0006] In an embodiment of the present application, the image sensor chip includes an active light sensing area and a non-light sensing area surrounding the active light sensing area; the resist has a gradually changing visual layer from the outer edge to the center after curing, and the resist includes a shadow area inside the resist and surrounding the non-light sensing area, wherein the width of the shadow area is less than half of the width of the resist.

[0007] In an embodiment of the present application, the outer edge of the resist forms an extra area, the width of the extra area is less than 100 microns, and the outer contour of the extra area is in the shape of a circular arc.

[0008] In an embodiment of the present application, the edge of the extra area includes broken or discontinuous segments.

[0009] In an embodiment of the present application, the cross section of the resist is trapezoidal or slightly rectangular, the upper glue width of the resist is greater than the lower glue width, forming a three-dimensional structure gradually shrinking from top to bottom, thereby increasing the packaging strength.

[0010] In an embodiment of the present application, the glue width of the resist is between 150 microns and 450 microns, and the glue height of the resist is between 80 microns and 200 microns, thereby controlling the glue application range and maintaining the structural strength.

[0011] In an embodiment of the present application, the ratio of the glue width to the glue height of the resist is 2 to 4, thereby strengthening the geometric stability and light shielding effect.

[0012] In an embodiment of the present application, the curvature transition ratio of the R corner of the resist to the straight line segment is between 1:1 and 2:1, thereby improving the process yield of the product and the uniformity of the resist.

[0013] In an embodiment of the present application, the edge of the resist includes a discontinuous edge or broken segments.

[0014] In an embodiment of the present application, the coefficient of thermal expansion of the resist is less than 50 ppm / °C below the glass transition temperature (Tg) and less than 100 ppm / °C above the glass transition temperature (Tg), thereby effectively reducing the thermal stress between the resist and the EMC material.

[0015] In an embodiment of the present application, the material of the filler includes at least one of carbon, graphite, titanium dioxide (TiO2), ferric oxide (Fe3O4), aluminum oxide (Al2O3), and silicon dioxide (SiO2).

[0016] As described above, the anti-glare ball grid array packaged image sensor module of this application, under the BGA packaging architecture, effectively suppresses glare caused by multi-angle incident light by using a resist with an optical density greater than or equal to 2, combined with fillers, geometry (including adhesive width, adhesive height, and aspect ratio), and edge design that tolerates process variations, thereby improving image quality. Simultaneously, the resist exhibits good thermal expansion control and curing stability, and the overall structure is compatible with current BGA processes (including imBGA (integrated molded ball grid array) or iBGA (image sensor BGA) packaging), offering high reliability and improved mass production quality. It significantly reduces stray light reflection caused by the packaging structure itself, thereby suppressing glare and providing images with higher contrast and clarity, while also maintaining the advantages of module miniaturization and high integration. Attached Figure Description

[0017] Figure 1 This is a cross-sectional schematic diagram of a ball grid array packaged image sensor module with anti-glare properties according to the first embodiment of this application:

[0018] Figure 2 for Figure 1 A perspective view of region A-A' from a top-down perspective;

[0019] Figure 3 for Figure 2 A partially enlarged internal structural diagram along the B-B' section;

[0020] Figure 4 This is a schematic diagram of the trapezoidal cross-sectional shape of the barrier material in this application;

[0021] Figure 5 This is a schematic diagram of the rectangular cross-sectional shape of the barrier material in this application.

[0022] Figure 6 This is a top perspective view of a ball grid array packaged image sensor module with anti-glare properties according to a second embodiment of this application;

[0023] Figure 7 for Figure 6 A schematic diagram of a local region R' in the diagram;

[0024] Figure 8 for Figure 6 A schematic diagram of a local area R' in a pure thermosetting process.

[0025] Explanation of reference numerals in the attached figures:

[0026] 100: Ball grid array packaged image sensor module;

[0027] 110: substrate;

[0028] 112: ball bump;

[0029] 120: image sensor chip;

[0030] 122: active light sensing area;

[0031] 124: non-light sensing area;

[0032] 130: wire;

[0033] 140: cover plate;

[0034] 150: resist;

[0035] 150C, EC: edge;

[0036] S: light color area;

[0037] E: extra outer extension area;

[0038] W-X, W-Y: resist width;

[0039] H: resist height;

[0040] Rr: R corner;

[0041] W: straight line segment;

[0042] DWT: upper resist width;

[0043] DWB: lower resist width;

[0044] D_S, D_E: width;

[0045] A-A': area;

[0046] B-B': section line;

[0047] R': local area. DETAILED DESCRIPTION

[0048] Embodiments of the present application will be further described with reference to the following drawings. In the drawings, like reference numerals are used to indicate like elements throughout the various figures. In the drawings, shape and thickness can be exaggerated for the sake of clarity. It can be understood that elements other than those specifically shown or described can be utilized without departing from the spirit and scope of the present application. Those skilled in the art will recognize that the present application can be practiced with modifications and changes which are not specifically enumerated herein. The following detailed description is not intended to limit the scope of the present application, but to provide an example embodiment of the present application.

[0049] Reference will now be made to Figure 1The present application provides a ball grid array (BGA) package image sensor module 100 with anti-glare property. The BGA package image sensor module 100 comprises a substrate 110, an image sensing chip 120, wires 130, a cover plate 140, and a resist 150.

[0050] The substrate 110 has a plurality of ball-shaped solder joints 112 on the bottom. The image sensing chip 120 is disposed on the substrate 110, which can be a CMOS sensing die, for receiving light signals and converting them into electrical signals. The wires 130 are used to connect the electrodes of the image sensing chip 120 and the circuit of the substrate 110. The image sensing chip 120 is connected to the substrate 110 by wire bonding with gold or copper wires to provide signal transmission. The cover plate 140 is disposed above the image sensing chip 120, which can be a glass cover plate or other light-transmitting material, for protecting the image sensing chip 120 and allowing light to enter the active light sensing area. The resist 150 is annularly disposed on the upper surface edge of the image sensing chip 120, and the resist 150 contacts the bottom surface of the cover plate 140. The resist 150 covers the connection end (i.e., the solder pad) of the wires 130 connecting the electrodes of the image sensing chip 120, and covers a small part of the wires 130. The optical density (OD) of the resist 150 is greater than or equal to 2, and the resist 150 is doped with fillers with a weight percentage greater than 20% and an average particle size less than 50 microns. Figure 1 The fillers are represented by dots, but they are only schematic and not to scale. The resist 150 is formed by a dual curing process of ultraviolet light and heat, or a pure heat curing process. Therefore, the present application can effectively absorb incident stray light, thereby reducing the glare phenomenon, and is suitable for imBGA or iBGA architecture, providing good packaging quality and image performance.

[0051] In actual processes, the weight percentage of fillers also has its process limit. If the proportion of fillers is too high, it can easily cause poor flowability, which can cause dispensing failure, resist breaking, and incomplete coating. After the heat curing process, it can even cause brittle fracture. If the average particle size of the fillers is too small, it can cause increased viscosity or van der Waals force, resulting in poor dispersibility. Therefore, although theoretically the optical density of the resist 150 and the volume percentage of the fillers can be infinite, and the average particle size of the fillers can be infinitely small, in order to balance the manufacturability and process yield, in the preferred embodiment of the present application, the optical density of the resist 150 is between 2 and 4, the volume percentage of the fillers is between 20% and 95%, and the average particle size of the fillers is between 1 and 50 microns, to meet the best needs of the process and improve the process yield and product stability of the present application.

[0052] In other embodiments of the present application, the material of the filler includes at least one of carbon, graphite, titanium dioxide (TiO2), triiron tetroxide (Fe3O4), aluminum oxide (Al2O3), silicon dioxide (SiO2), to improve the light-blocking ability, mechanical strength, and thermal stability of the light-blocking body 150, and effectively improve its ability to absorb oblique stray light, to improve the glare phenomenon of the image sensing chip 120.

[0053] Please refer to Figures 1 to 3 , Figure 2 for Figure 1 the perspective view of the top direction of the A-A' area, Figure 3 for Figure 2 the partially enlarged internal structure schematic diagram of the B-B' section line. The image sensing chip 120 includes an active light-sensing area 122 (Active Area) and a non-light-sensing area 124 (Dummy Area). The non-light-sensing area 124 surrounds the active light-sensing area 122 and does not participate in light sensing. It should be noted that any area that does not belong to the active light-sensing area 122 (Active Area) is considered as the non-light-sensing area 124. The non-light-sensing area 124 may differ in configuration position, area, and shape according to different product designs, so the present specification does not make detailed descriptions or drawings of the size and structure of the non-light-sensing area 124. The technical features of the present application are mainly in the material composition, geometric structure, and packaging function of the light-blocking body 150. For the design of the non-light-sensing area 124, those skilled in the art can adjust it according to the application requirements without affecting the implementation of the present application.

[0054] In order to clearly show the size range of the light-blocking body 150, the symbol in Figure 2 , Figure 3 is explained as follows:

[0055] W-X, W-Y respectively represent the colloid width of the straight line segment W of the light-blocking body 150 along the X-axis and Y-axis directions, indicated by bidirectional arrows; wherein the edges of the colloid width W-X, W-Y are based on the outermost edge of the light-blocking body 150, whether its edge 150C is continuous or broken, and the colloid width is defined by the farthest distance. Rr points to the R corner of the light-blocking body 150 at the round corner, hereinafter referred to as the R corner.

[0056] The light-blocking body 150 of the present application is formed by a dual-curing process of ultraviolet light and heat, or a pure heat curing process, and meets the following geometric characteristics:

[0057] The colloid width W-X, W-Y of the straight line segment W is between 150 to 450 microns, and the colloid height H is between 80 to 200 microns, to specifically define the actual colloid range and flow control, and to maintain the structural strength. The ratio of the colloid width W-X, W-Y to the colloid height H of the colloid 150 is between 2 to 4, i.e. the ratio of the colloid width W-X, W-Y to the colloid height H is between 2:1 to 4:1. For example, when the colloid width is 200 microns, the colloid height is 100 microns, and the ratio is 2:1; when the colloid width is 400 microns, the colloid height is 100 microns, and the ratio is 4:1. The ratio of the colloid 150 at the R corner Rr of the colloid to the curvature turning of the straight line segment W is between 1:1 to 2:1, which is beneficial to the flow design in manufacturing, to improve the process yield of the product and the uniformity of the colloid 150.

[0058] For example, when the colloid width is less than 150 microns, the corresponding colloid height will decrease to about 70 microns, which will be lower than the wire loop height (about 80 microns) of the wire 130 connected to the image sensor chip 120. The wire loop height refers to the vertical distance from the highest point of the wire segment to the surface of the die when the image sensor chip 120 is connected to the substrate 110 by gold or aluminum wires (i.e. the wire 130). Therefore, when the process proceeds to the step of covering the cover plate 140, the upper cover plate 140 may press the gold wire, causing the wire to be damaged or the packaging to fail. Therefore, the colloid width W-X, W-Y of the colloid 150 must be greater than 150 microns, and the colloid height H must be greater than 80 microns, to avoid the edge of the colloid 150 from breaking and to ensure the reliability and yield of the overall packaging manufacturing.

[0059] Figure 2 The center of the image sensor chip 120 is marked as the effective photosensitive area 122, and the non-photosensitive area 124 surrounds the effective photosensitive area 122 and does not participate in photosensing. The colloid 150 forms a ring-shaped covering along the edge of the upper surface of the image sensor chip 120, but does not cover the central effective photosensitive area 122 of the image sensor chip 120. Figure 2 Although the position of the wire 130 is not shown, it should be understood that the colloid 150 will cover the connection end of the wire 130 connected to the electrode of the image sensor chip 120, to prevent lateral incident stray light from entering the effective photosensitive area 122. The outermost edge of the outer edge 150C of the colloid 150 is defined as the colloid width, regardless of whether the edge 150C is a continuous segment or a partially broken segment. The colloid 150 can form a ring-shaped or strip-shaped dam to limit the flow area of the subsequent packaging glue, to avoid contaminating the effective photosensitive area 122 or the optical components.

[0060] As Figure 3As shown, the upper adhesive width DWT of the resist 150 is greater than the lower adhesive width DWB, thus forming a three-dimensional structure that gradually tapers from top to bottom. This can improve the light-blocking effect and also enhance the structural stability and stress resistance of the resist 150.

[0061] Please see Figure 4 and Figure 5 In some embodiments of this application, the contact angle between the resist 150 and the cover plate 140 or the image sensing chip 120 can be set to an acute angle. For example... Figure 4 As shown, the cross-sectional shape of the barrier 150 can be trapezoidal, or as shown in the figure. Figure 5 As shown, the cross-sectional shape of the barrier 150 can also be slightly rectangular, and is not limited to this.

[0062] Please see Figure 6 and Figure 7 , Figure 6 This is a top perspective view of a ball grid array packaged image sensor module with anti-glare properties according to a second embodiment of this application. Figure 7 for Figure 6 A schematic diagram of a local area R' in the diagram. The edge 150C of the resist 150 may form a discontinuous edge or a slightly broken section. After the resist 150 is cured, the surface of the resist 150 exhibits a gradual visual gradient from the outer edge to the center, forming a light-colored area S (Shadow Area). The light-colored area S is located inside the resist 150 and surrounds the non-photosensitive area 124. Figure 6 The width of the light-colored region S is denoted as D_S, and the width D_S of the light-colored region S is less than half of the widths WX and WY of the colloid. This can improve the geometric stability of the colloid 150 and enhance its ability to block stray light.

[0063] Please see Figure 8 In this embodiment, under a pure thermosetting process, an additional extended area E (Extra Area) will be formed at the outer edge of the resist 150. Figure 8 In this context, D_E represents the maximum width of the additional expansion region E formed under pure thermosetting processes. The maximum width D_E of the additional expansion region E is less than 100 micrometers, and the edge EC may include broken or discontinuous segments. The additional expansion region E is caused by the initial decrease in material viscosity, resulting in an expansion of the width of the resist 150. The degree of expansion varies depending on the thermosetting process conditions (e.g., temperature, time), but does not affect the colloid height H or structural integrity. Through the above structural and material design, incident stray light can be effectively absorbed, reducing glare, and it is suitable for imBGA or iBGA architectures, providing excellent packaging and image performance.

[0064] In an embodiment of the present application, the thermal expansion coefficient of the blocking glue 150 is less than 50 ppm / °C below the glass transition temperature (Tg) and less than 100 ppm / °C above the glass transition temperature (Tg), which can effectively reduce the thermal stress between the blocking glue 150 and the EMC material.

[0065] Specifically, a higher filling volume percentage can significantly improve the absorption and shielding effect of the blocking glue 150 on the incident stray light, and due to the difference in thermal expansion behavior between the filler and the resin body, it helps to adjust the thermal expansion matching between the blocking glue 150 and the EMC material. Too high filler content will reduce the flowability of the glue, which is prone to produce irregular edges in the dispensing process. Therefore, the present application selects a filler with a weight percentage greater than 20% to maintain good process and mechanical strength, and also achieve the best light shielding effect.

[0066] The thermal expansion coefficient (CTE1<50 ppm / °C, CTE2<100 ppm / °C) of the blocking glue 150 of the present application is designed to be similar to the epoxy plastic packaging material (EMC / LES) used in the same package, which can avoid the problem of micro-cracks or peeling at the interface between the blocking glue 150 and the encapsulating material due to inconsistent expansion or shrinkage rates, thereby improving adhesion and structural integrity, and effectively reducing process yield fluctuations to ensure the reliability and stability of the final product.

[0067] In summary, through experimental measurement, the maximum glare value of the ball grid array package image sensor module 100 of the present application is reduced from 0.77% of the traditional POR glue to only 0.17%, and the stray light intensity is reduced from 0.008 lm to 0.0017 lm, the overall glare phenomenon is reduced by about 78%, which shows that the blocking glue 150 of the present application can effectively absorb and suppress stray light under multi-angle strong light incidence conditions, significantly improve the imaging contrast and image clarity, while taking into account the reliability of the process, structural integrity and packaging yield.

[0068] The above is only for example to illustrate the preferred embodiments of the present application, and is not limited to the scope of the implementation. Any simple substitution and equivalent change made in accordance with the scope of the claims and the content of the patent specification is within the scope of the present application.

Claims

1. A ball grid array packaged image sensor module with anti-glare properties, characterized in that, include: A substrate, wherein the bottom of the substrate is provided with a plurality of spherical solder joints; An image sensing chip is disposed on the substrate for receiving optical signals and converting them into electrical signals; Wires connect the electrodes of the image sensing chip to the circuitry on the substrate. A cover plate, covering the image sensing chip; and An adhesive resist is disposed around the upper surface edge of the image sensing chip, and the adhesive resist contacts the bottom surface of the cover plate and covers the connection end of the wire connecting the electrode. The optical density of the adhesive resist is greater than or equal to 2, and it is doped with a filler. The volume percentage of the filler is greater than 20% and the average particle size of the filler is less than 50 micrometers. The adhesive resist is formed by a dual curing process of ultraviolet light and heat, or a pure thermal curing process.

2. The ball grid array packaged image sensor module with anti-glare properties as described in claim 1, characterized in that, The image sensing chip includes an effective photosensitive area and a non-photosensitive area, and the non-photosensitive area surrounds the effective photosensitive area; After curing, the resist exhibits a gradual visual gradient from the outer edge to the center on its surface. The resist includes a light-colored area located inside the resist and surrounding the non-photosensitive area. The width of the light-colored area is less than half the width of the resist.

3. The ball grid array packaged image sensor module with anti-glare properties as described in claim 1, characterized in that, The outer edge of the resist forms an additional extended region under the pure thermosetting process. The width of the additional extended region is less than 100 micrometers, and the outer contour of the additional extended region is arc-shaped.

4. The ball grid array packaged image sensor module with anti-glare properties as described in claim 3, characterized in that, The edges of the additional extended region include broken or discontinuous segments.

5. The ball grid array packaged image sensor module with anti-glare properties as described in claim 1, characterized in that, The upper adhesive width of the resist is greater than the lower adhesive width, forming a three-dimensional structure that gradually shrinks from top to bottom.

6. The ball grid array packaged image sensor module with anti-glare properties as described in claim 1, characterized in that, The cross-section of the barrier colloid is trapezoidal or rectangular.

7. The ball grid array packaged image sensor module with anti-glare properties as described in claim 1, characterized in that, The colloidal width of the barrier is between 150 micrometers and 450 micrometers.

8. The ball grid array packaged image sensor module with anti-glare properties as described in claim 1, characterized in that, The curvature transition ratio between the R-angle of the resist and the straight line segment is between 1:1 and 2:

1.

9. The ball grid array packaged image sensor module with anti-glare properties as described in claim 1, characterized in that, The colloidal height of the barrier is between 80 micrometers and 200 micrometers.

10. The ball grid array packaged image sensor module with anti-glare properties as described in claim 1, characterized in that, The ratio of the width to the height of the barrier colloid is between 2 and 4.

11. The ball grid array packaged image sensor module with anti-glare properties as described in claim 1, characterized in that, The edges of the barrier include discontinuous edges or broken sections.

12. The ball grid array packaged image sensor module with anti-glare properties as described in claim 1, characterized in that, The coefficient of thermal expansion of the barrier is less than 50 ppm / °C below the glass transition temperature and less than 100 ppm / °C above the glass transition temperature.

13. The ball grid array packaged image sensor module with anti-glare properties as described in claim 1, characterized in that, The filler material includes at least one of carbon, graphite, titanium dioxide, iron tetroxide, aluminum oxide, and silicon dioxide.

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