Manufacturing method of image-sensing module

A manufacturing method of an image-sensing module includes following steps. A substrate is provided. At least one photosensitive chip is disposed on the substrate, and each of the at least one photosensitive chip has an active area. At least one protection layer covers the at least one active area of the at least one photosensitive chip. A first manufacturing process is performed, and dust is generated during the first manufacturing process. The at least one protection layer is suitable for isolating the dust from the at least one active area. The at least one protection layer is removed to expose the at least one active area.

BACKGROUND

Technical Field

The disclosure relates to a manufacturing method; more particularly, the disclosure relates to a manufacturing method of an image-sensing module.

Description of Related Art

In recent years, to comply with the full screen requirements of electronic products, the design of an image-sensing module has become light, thin, short and small. As such, manufacturers are required to develop new manufacturing processes to form an image-sensing module of the required size. During the new manufacturing processes, a significant amount of dust may be generated, which may contaminate the image-sensing module. At present, it is common to perform a cleaning process with use of water after the dust contamination.

However, the above-mentioned rinsing method may not completely remove the dust, and large dust particles easily cause abrasions or scratches to the devices in the image-sensing module, thereby posing a negative impact on the subsequent manufacturing processes. Therefore, how to prevent dust damages to the image-sensing module is what those skilled in the art should strive for.

SUMMARY

The disclosure provides a manufacturing method of an image-sensing module, whereby dust may be isolated by a protection layer, and the manufacturing process may be smoothly carried out.

In an embodiment of the invention, a manufacturing method of an image-sensing module includes following steps. A substrate is provided. At least one photosensitive chip is disposed on the substrate, and each of the at least one photosensitive chip has an active area. The at least one active area of the at least one photosensitive chip is covered by at least one protection layer. A first manufacturing process is performed, and during the first manufacturing process, the at least one protection layer covers the at least one active area. The at least one protection layer is removed to expose the at least one active area.

In an embodiment of the invention, the first manufacturing process includes: disposing a plurality of conductive wires between the at least one photosensitive chip and the substrate to electrically connect the at least one photosensitive chip and the substrate.

In an embodiment of the invention, the manufacturing method of the image-sensing module further includes: performing a second manufacturing process, wherein the at least one protection layer covers the at least one active area during the second manufacturing process, and the second manufacturing process includes: cleaning a surface of the substrate with use of plasma.

In an embodiment of the invention, the manufacturing method of the image-sensing module further includes: performing a third manufacturing process, wherein the at least one protection layer covers the at least one active area during the third manufacturing process, and the third manufacturing process includes: forming a package layer on the substrate, wherein the package layer encapsulates a portion of the at least one photosensitive chip and exposes whole of the at least one protection layer.

In an embodiment of the invention, the number of the at least one photosensitive chip is plural. After the step of forming the package layer on the substrate, the package layer and the substrate are cut to form a plurality of photosensitive assemblies, and during the step of cutting the package layer and the substrate, the at least one protection layer covers the at least one active area.

In an embodiment of the invention, the manufacturing method of the image-sensing module further includes: arranging a lens assembly on the package layer after the step of removing the at least one protection layer, and the lens assembly corresponds to the active area.

In an embodiment of the invention, the manufacturing method of the image-sensing module further includes: performing a cleaning process after the step of removing the at least one protection layer.

In an embodiment of the invention, the first manufacturing process includes one of a step of disposing a plurality of conductive wires between the at least one photosensitive chip and the substrate, a step of cleaning a surface of the substrate with use of plasma, and a step of forming a package layer on the substrate.

In an embodiment of the invention, the manufacturing method of the image-sensing module further includes: arranging a mirror holder on the substrate after the step of removing the at least one protection layer, wherein the mirror holder exposes the active area.

In an embodiment of the invention, the manufacturing method of the image-sensing module further includes: arranging a lens assembly on the mirror holder, the lens assembly corresponding to the active area.

In an embodiment of the invention, the manufacturing method of the image-sensing module further includes: adhering a plurality of passive devices to a surface of the substrate before the step of covering the at least one active area with the at least one protection layer.

In view of the above, according to the manufacturing method of the image-sensing module provided in the disclosure, the protection layer disposed in the active area of the photosensitive chip is applied to isolate the dust generated during the manufacturing process and prevent contamination from the outside. Since the active area of the photosensitive chip is covered, the active area is not subject to dust and contamination and thus may not be hit or scratched. After the manufacturing process is completed, the protection layer is removed to expose the active area. Thereby, the entire process of manufacturing the image-sensing module may be carried out smoothly, and the manufacturing yield may be improved.

In order to make the above features provided in the disclosure more comprehensible, the following embodiments are described in detail below with reference to the accompanying drawings.

DESCRIPTION OF THE EMBODIMENTS

FIG. 1AtoFIG. 1Fare schematic views illustrating steps of a manufacturing method of an image-sensing module according to an embodiment of the invention. In this embodiment, the image-sensing module100may serve, for instance, as an image-sensing module of a camera in a mobile phone, and the application of the image-sensing module100is not limited to what is disclosed herein. A manufacturing method of the image-sensing module100provided in the present embodiment includes following steps.

First, a substrate110shown inFIG. 1Ais provided. The substrate110is, for instance, a circuit board and has a surface112. In this embodiment, a plurality of passive devices170are provided on the substrate110. The passive devices170are, for instance, capacitors, resistors, or inductors, and the passive devices170are adhered and fixed to the surface112of the substrate110through applying a surface mount technology (SMT). With reference toFIG. 1B, at least one photosensitive chip120is disposed on the substrate110, and the photosensitive chip120may be a complementary metal oxide semiconductor (CMOS) or a charge coupled device (CCD). The photosensitive chip120has an active area122which is, for instance, located on one side away from the substrate110. The active area122is an exposed region on the surface of the photosensitive chip120for receiving light or sensing the intensity of the light. It should be mentioned that the photosensitive chip120provided in the present embodiment is fixed to the surface112of the substrate110through adhesive bonding, and the adhesive is dried by performing a curing process (e.g., heating, ultraviolet curing, and so on), so as to fix the photosensitive chip120to the substrate110, which should however not be construed as a limitation in the disclosure. The photosensitive chip120may also be latched to the substrate110or fixed to the substrate110by other means.

With reference toFIG. 1C, the at least one active area122of the at least one photosensitive chip120is covered by at least one protection layer130to prevent dust or dirt from falling onto the active area122. In the present embodiment, a material of the protection layer130includes but is not limited to epoxy resin. The protection layer130may be a tape or a cover. For instance, the tape is a gel adhesive, silica gel, or another release adhesive. The cover is, for instance, a glass cover whose density is greater than the density of plastic, so that the weight per unit volume is greater. Therefore, the glass cover covering the active area122may be fixed by its own weight and does not easily slide. In other embodiments, the cover may be equipped with a simple positioning structure and thus does not move easily. Certainly, the material of the protection layer130is not limited thereto.

With reference toFIG. 1D, after the step of covering the active area122of the photosensitive chip120with the protection layer130, a first manufacturing process is performed. In the present embodiment, the first manufacturing process is to dispose a plurality of conductive wires160between the photosensitive chip120and the substrate110to electrically connect the photosensitive chip120and the substrate110. In other embodiments, note that the image-sensing module100may also be formed by applying a flip-chip technology. The photosensitive chip12may be placed on the substrate110, and the step of placing the conductive wires160between the photosensitive chip120and the substrate110is omitted. The invention is not limited to the embodiments set forth herein.

During the step of disposing the conductive wires160, dust is generated, and the protection layer130covering the active area122allows the dust to be isolated from the active area122. After the first manufacturing process is completed, a second manufacturing process is performed. In the present embodiment, the second manufacturing process is to clean the surface112of the substrate110by plasma, so that the surface112of the substrate110becomes clean and may then be activated. During the second manufacturing process, the protection layer130is still covering the active area122, and therefore the active area122is not affected by the plasma cleaning step.

With reference toFIG. 1E, after the step of performing the second manufacturing process, a third manufacturing process is performed. In this embodiment, the third manufacturing process is to form a package layer140on the substrate110. The package layer140encapsulates the conductive wires160, the passive devices170, and a portion of the photosensitive chip120, and the package layer140exposes the entire protection layer130. In this embodiment,FIG. 1Eschematically depicts one photosensitive chip120in a side view. In a top view or views at other view angles, the photosensitive120may refer to a plurality of photosensitive chips120. After the step of forming the package layer140on the substrate110, a step of cutting the package layer140and the substrate110is performed, and the photosensitive chips120are singulated to form a plurality of photosensitive assemblies. During the step of cutting the package layer140and the substrate110, the protection layer130covers the active areas122of the photosensitive chips120.

Therefore, during the first manufacturing process, the second manufacturing process, the third manufacturing process, and the cutting step, the active area122of the photosensitive chip120is covered by the protection layer130, and thus the significant amount of dust or dirt generated in these processes is not in contact with the active area122of the photosensitive chip120, and the active area122of the photosensitive chip120remains clean. Certainly, the number and type of manufacturing processes are not limited to those provided above, and the protection layer130may be applied to cover the active area122of the photosensitive chip120at any time when a manufacturing process that may lead to the dust contamination is performed.

With reference toFIG. 1F, after the step of forming the package layer140on the substrate110and the cutting step are performed, the protection layer130disposed on the active area122is removed to expose the active area122. Since a significant amount of dust or dirt is accumulated on the substrate110during the first manufacturing process, the second manufacturing process, and the third manufacturing process, a cleaning process may be performed on the region of the substrate110that is not covered by the protection layer130before or after the step of removing the protection layer130, so as to completely remove the dust generated in the manufacturing processes. This is conducive to carrying out subsequent manufacturing processes.

With reference toFIG. 1F, after the step of removing the protection layer130, a transparent plate180is disposed above the photosensitive chip120to complete the manufacture of the image-sensing module100provided in the present embodiment.FIG. 1Gis a schematic three-dimensional exploded view illustrating the image-sensing module depicted inFIG. 1F. In order to make the illustration simple and easy to understand, note thatFIG. 1Gonly schematically shows some of the devices provided in the disclosure. As shown inFIG. 1G, in the present embodiment, a lens assembly150may be arranged on the package layer140, and the lens assembly150corresponds to the active area122. The lens assembly150includes a bracket151that supports devices to be subsequently installed, such as a voice coil motor152, a lens barrel154(Lens Barrel), and so on.

It is worth mentioning that since the lens assembly150provided in this embodiment is installed on the package layer140(i.e., above the passive devices170), the lens assembly150does not occupy the space on the substrate110. Therefore, the width of the image-sensing module100provided in this embodiment may be further reduced, which contributes to the compliance with the full screen requirement. In addition, the transparent plate180is, for instance, a filter film or a filter lens, e.g., Blue Glass, and a voice coil motor152, a lens barrel154, or the like may be mounted on the bracket151of the lens assembly150. Here, the voice coil motor152may be configured to move the lenses for adjusting the focal length, while the type of the transparent plate180and the types of parts mounted on the lens assembly150are not limited in the disclosure.

FIG. 2AandFIG. 2Bare schematic views illustrating steps of a manufacturing method of an image-sensing module according to another embodiment of the invention. In this embodiment, the manufacturing method of the image-sensing module200is similar to the manufacturing method of the image-sensing module100provided in the previous embodiment and shown inFIG. 1AtoFIG. 1D. Therefore, the reference numbers and some descriptions provided in the previous embodiments are also used in the present embodiment. Here, the same reference numbers are applied to represent the same or similar devices, and the description of the same technical content is omitted. The omitted descriptions and steps may be deduced from the previous embodiments and thus will not be further explained in the present embodiment. The differences between the steps described in the previous embodiment and those provided in the present embodiment will be elaborated hereinafter.

With reference toFIG. 2A, after the step of disposing the conductive wires160between the substrate110and the photosensitive chip120and the step of cleaning the surface112of the substrate110with use of plasma (i.e., after the step shown inFIG. 1D) are performed, the manufacturing method of the image-sensing module200provided in the present embodiment does not include the formation of the package layer140of the image-sensing module100as provided in the previous embodiment nor the step of cutting the substrate110and the package layer140; instead, in the present embodiment, the manufacturing method of the image-sensing module200includes a step of directly removing the protection layer130to expose the active area122of the photosensitive chip120. After that, the region of the substrate110that is not covered by the protection layer130is cleaned, and the dust generated in the step of disposing the conductive wires160between the substrate110and the photosensitive chip120and the step of cleaning the surface112of the substrate110with use of plasma is cleaned, so as to ensure the cleanness of a region of the substrate110where the mirror holder190is installed and ensure the subsequent installation process to be performed smoothly. After the step of removing the protection layer130as shown inFIG. 2A, the mirror holder190is placed on the substrate110, and the mirror holder190exposes the active area122of the photosensitive chip120. A transparent plate180is then disposed on the mirror holder190, and the lens assembly150corresponding to the active area122is disposed on the mirror holder190, so as to complete the manufacture of the image-sensing module200shown inFIG. 2B.

To sum up, according to the manufacturing method of the image-sensing module provided in one or more embodiments of the invention, the protection layer covering the active area is configured to prevent the dust generated in the manufacturing processes from falling onto the active area of the photosensitive chip. As such, the active area may be protected from scratches or damages caused by the impact of dust, and the manufacturing yield may be improved. In addition, when the protection layer is removed from the active area, no residual adhesive is left, so that the active area remains clean. Moreover, the arrangement of the lens assembly on the package layer is conducive to the improvement of the utilization rate of the space on the substrate and the reduction of the overall size of the image-sensing module, thereby contributing to the compliance with the fill screen requirement on the market.

It will be apparent to those skilled in the art that various modifications and variations can be made to the structure provided herein without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the disclosure provide modifications and variations provided they fall within the scope of the following claims and their equivalents.