JP2006171248A - Manufacturing method for optical module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inexpensively provide a camera module excellent in quality. <P>SOLUTION: The manufacturing method includes respective processes; (a) first electronic parts are mounted on the first surface of a wiring board, (b) the first electronic parts are sealed by a sealing body, (c) second electronic parts including an image sensor are mounted on the second surface of the wiring board, (d) a lens holder is attached to an upper end side on the second surface of the wiring board and bonding a lens barrel where a filter is placed and fixed at a middle stage so as to cover over the second electronic parts, and (e) a flexible wiring board having an external electrode terminal is connected to the wiring board. In the process (e), the lens barrel is superposed on the wiring board through a second adhesive and also the filter is superposed at the predetermined spot of the lens barrel through a first adhesive, then the first and the second adhesives are simultaneously cured to fix the lens barrel and the filter, whereby the camera module is manufactured. The filter is constituted of a transparent glass base plate and a coating film formed on one surface of the glass base plate, and the filter is bonded to the lens barrel in a state where the coating film is set as an upper surface. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing an optical module, for example, a technique effective when applied to a method for manufacturing an optical module (camera module) mounted on a mobile phone, a video camera, or the like.

  A camera module (solid-state imaging device) is mounted on a mobile phone or a video camera. The camera module captures the light (optical signal) collected by the imaging lens (optical convex lens) into an image sensor such as an image capturing device (solid-state imaging device), CMOS sensor, or CCD sensor mounted on the substrate. This is a device that obtains a predetermined image by converting an optical signal into an electric signal by an arrangement of pixels.

  The solid-state imaging device has a structure in which a solid-state imaging device is mounted on the surface of a circuit board and components including a processor for driving the solid-state imaging device are mounted on the back surface. As a manufacturing method to reduce the size of a solid-state imaging device, after mounting a part including a processor for driving a solid-state imaging device on the back surface of the circuit board, forming a flat plate so as to cover the part on the back side of the circuit board A method is known in which a sealing portion is formed, and then a solid-state imaging device is mounted on the surface of a circuit board and wire bonding is performed (for example, Patent Document 1).

  In the method of manufacturing a solid-state imaging device according to Patent Document 1, a mount base is attached to the surface of the circuit board, and a lens mount is attached to the mount base. A solid-state imaging device is manufactured by attaching a glass filter to the middle of the lens mount, then overlapping the lens on the upper end side of the lens mount, and fixing the lens with a lens cap that fixes the lens mount.

JP 2003-32557 A

  Camera modules incorporated in electronic devices such as mobile phones and video cameras are required to further reduce manufacturing costs.

  The manufacturing method of the camera module has many processes, which causes an increase in the manufacturing cost of the camera module. For example, as described in Patent Document 1, in manufacturing a camera module, a process of attaching a lens barrel called a lens mount to a circuit board (wiring board), and a filter (glass filter) are attached to the lens barrel. The process of attaching to is a separate process.

  This has been clarified by experiments and the like by the present applicant, but it has been found that the following problems occur when the lens barrel is connected and fixed to the wiring board with an adhesive. When the lens barrel with the filter attached is bonded and fixed to the wiring board with, for example, a thermosetting adhesive, the lens barrel portion below the filter mounting location forms a space sealed by the wiring board and the adhesive. become. For this reason, when the adhesive is heated and cured, the air in the sealed space expands to a high pressure state. It has been found that this high pressure causes a phenomenon in which the uncured adhesive that exists between the wiring board and the lens barrel lower surface is blown out. The ejected scattered matter not only adheres to the product and pollutes the product, but also pollutes the surroundings of the assembling apparatus and the like, resulting in interruption of work. In addition, foreign matter enters from the hole formed by the removal of the adhesive and adheres to the image sensor. For this reason, black spots or spots appear on the monitor, and the product itself becomes defective. Even if the hole is not pierced, the product in which the adhesive scatters and adheres from other parts has a poor appearance.

An object of the present invention is to provide an optical module manufacturing method capable of manufacturing an optical module with excellent quality.
The objective of this invention is providing the manufacturing method of the optical module which can reduce a manufacturing process.
An object of the present invention is to provide an optical module manufacturing method capable of achieving an improvement in manufacturing yield.
The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

The following is a brief description of an outline of typical inventions disclosed in the present application.
(1) The manufacturing method of the optical module (camera module) of the present invention includes:
(A) preparing a wiring board having a first surface and a second surface opposite to the first surface;
(B) mounting a first electronic component on the first surface of the wiring board;
(C) sealing the first electronic component with a sealing body;
(D) mounting a second electronic component including an image sensor on the second surface of the wiring board;
(E) A step of attaching a lens holder to the second surface of the wiring board on the upper end side, and joining a lens barrel for mounting and fixing the filter in the middle so as to cover the second electronic component;
(F) connecting a flexible wiring board having external electrode terminals to the wiring board;
In the step (e),
(G) A first adhesive is applied to at least one of the attachment portion of the lens barrel and the filter, and a second adhesive is applied to at least one of the connection portions of the lens barrel and the wiring board. Applying step,
(H) a step of positioning and mounting the filter from above in the lens barrel and positioning and mounting the lens barrel on the wiring board;
(I) a step of curing the first adhesive and the second adhesive;
(J) A step of attaching the lens holder to the lens barrel.

  In the step (g), a thermosetting resin is used for the first adhesive and the second adhesive. In the steps (g) to (i), the filter is made of a transparent glass substrate and a coating film formed on one surface of the glass substrate, and the coating film is far from the image sensor. It joins to the above-mentioned barrel in the state which becomes the upper surface so that it may become a position. In the step (e), an air vent hole that communicates the inside and outside of the lens barrel is formed in the lens barrel portion that extends from the filter mounting location to the wiring board connection location. In the step (e), a first locking part is formed on the lens barrel, and a second locking part locked on the first locking part is provided on the wiring board, The lens barrel is positioned by locking the first and second locking portions and bonded onto the wiring board.

  The effects obtained by the representative ones of the inventions disclosed in the present application will be briefly described as follows.

  (1) According to the manufacturing technique of such an optical module, the number of processes can be reduced because (a) the operation of fixing the filter in the lens barrel and the operation of fixing the lens barrel on the wiring board are simultaneously performed. The manufacturing cost can be reduced.

  (B) Since the filter can be attached to the lens barrel so that the coating film is on the upper surface, the coating film is removed from the image sensor compared to the case where the filter is attached to the lens barrel with the coating film on the lower surface. Distant position. As a result, even if foreign matter adheres to the surface of the coating film, the distance from the coating film to the image sensor becomes longer, so it is difficult for the image caused by the foreign matter to be clearly connected to the image sensor surface, and The so-called dirt is less likely to occur. Thereby, a high quality optical module can be manufactured.

  (C) Since an air vent hole that communicates the inside and outside of the lens barrel is formed in the lens barrel portion between the filter mounting location and the connection location of the wiring board, the lens barrel is attached to the wiring board with an adhesive. When bonding, the lens barrel portion between the filter mounting location and the wiring board connection location does not become a sealed space, and a high-pressure state of the sealed space does not occur. As a result, under heating during the adhesive curing process, high-pressure air does not spout out of the lens barrel, preventing the spattering of the adhesive accompanying the spout, improving manufacturing yields, and operating assembly operations. The rate is also improved. As a result, the manufacturing cost of the optical module can be reduced.

  (D) Positioning of the lens barrel and the wiring board is performed by locking the first locking portion and the second locking portion. As a result, positioning between the wiring board and the lens barrel is facilitated, and assembly work is performed. Improves.

  (E) After attaching the filter to the lens barrel, the lens barrel can be attached to the wiring board without being inverted. (After attaching the filter to the lens barrel, the lens barrel is inverted once and then attached to the wiring board. Since it is not necessary to attach, the manufacturing process can be reduced. As a result, the manufacturing cost can be reduced.

  (F) With the above (a) to (e), an optical module with excellent quality, that is, a camera module can be provided at low cost.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In all the drawings for explaining the embodiments of the invention, those having the same function are given the same reference numerals, and their repeated explanation is omitted.

  FIG. 1 to FIG. 18 are diagrams related to the manufacturing method of the optical module of the present embodiment, specifically, diagrams related to the manufacturing of the camera module. 1 and 2 are views showing the structure of a camera module, and FIGS. 3 to 18 are views relating to a method of manufacturing the camera module.

The camera module of the first embodiment can be used for an image input unit such as a mobile phone, a TV phone, a PC camera, a PDA (Personal Digital Assistants: personal digital assistant), an optical mouse, a door phone, a surveillance camera, a fingerprint recognition device, or a toy. It is a camera module.
The camera module 1 (solid-state imaging device) has a structure shown in FIGS. FIG. 1 is a plan view of a CMOS sensor type camera module 1 according to the first embodiment, and FIG. 2 is a cross-sectional view taken along line AA in FIG.

  As shown in FIGS. 1 and 2, the camera module 1 includes a wiring board 2 in appearance and a sealing body 3 formed on the entire first surface 2 a which is the lower surface in FIG. 2 of the wiring board 2. 2 of the wiring board 2, the cylindrical lens barrel 30 fixed to the second surface 2 b which is the upper surface, the lens holder 20 attached to the upper part of the lens barrel 30, and the wiring board detached from the lens barrel 30. And a flexible wiring substrate 8 having an inner end connected to the second surface 2b of the second member by a bonding member 7. A circular window (light receiving window) 5 is provided at the center of the upper surface of the lens holder 20. A lens 6 is attached to the lens holder 20 so that the lens 6 can be seen through the light receiving window 5.

  The wiring board 2 is formed of a multilayer printed wiring board using, for example, glass epoxy resin as an insulating material. The wiring board 2 has a first surface 2a and a second surface 2b that is the opposite surface of the first surface 2a, and system component mounting for mounting system components on the first surface 2a. The second surface 2b has an optical system component mounting surface for mounting an optical system component.

  A first electronic component is mounted on the system component mounting surface of the wiring board 2. The first electronic components are, for example, a logic semiconductor chip (hereinafter simply referred to as a logic chip) 10, a memory semiconductor chip (hereinafter simply referred to as a memory chip) 11, a chip component 12, and the like. The logic chip 10, the memory chip 11, and the chip component 12 are used to process electrical signals obtained by a sensor chip, which is an optical system component to be described later, mounted on the second surface 2b of the wiring board 2, and a CMOS image of the sensor chip. This is an electronic component for system construction that controls the operation of the sensor circuit.

  The logic chip 10 is formed with an arithmetic circuit for digital signal processing such as a DSP (Digital Signal Processor). An electrode (not shown) of the logic chip 10 is electrically connected to a wiring (land) of the wiring board 2 via a wire 15. The memory chip 11 is formed with a nonvolatile memory circuit such as an EEPROM (Electrically Erasable Programmable Read Only Memory). An electrode (not shown) of the memory chip 11 is electrically connected to a wiring (land) of the wiring board 2 through a wire 16. The wires 15 and 16 are made of, for example, gold (Au). The chip component 12 is formed with passive elements such as capacitors and resistors. The electrodes at both ends of the chip component 12 are joined and electrically connected to lands (wirings) of the wiring board 2 by, for example, solder.

  The logic chip 10, the memory chip 11, the chip component 12, the wires 15, 16 and the like on the system system component mounting surface are sealed by the sealing body 3. The sealing body 3 is made of an insulating thermosetting resin such as an epoxy resin with silica filler.

  On the other hand, the second electronic component is mounted on the optical system component mounting surface of the second surface 2 b of the wiring board 2. Specifically, the second electronic component is a semiconductor chip (image sensor, solid-state image sensor, hereinafter simply referred to as a sensor chip) 17 for an optical sensor. The sensor chip 17 has the light receiving surface of the light receiving element exposed, and is the upper surface in FIG. A CMOS image sensor circuit is formed on the main surface of the sensor chip 17. This CMOS image sensor circuit is formed by a CMOS process that is typically used in the manufacturing process of a semiconductor device, and includes a sensor array and an analog circuit that processes electrical signals obtained by the sensor array. Yes. In the sensor array, a plurality of light receiving elements are regularly arranged in the vertical and horizontal directions along the main surface of the sensor chip 17. Each light receiving element is a part for forming a pixel of the CMOS image sensor circuit, and has a photoelectric conversion function for converting an incident optical signal into an electric signal. For example, a photodiode or a phototransistor is used as the light receiving element.

  A plurality of electrodes (bonding pads) are arranged along the outer periphery of the outer peripheral edge of the main surface of the sensor chip 17. This bonding pad is a lead electrode of the CMOS image sensor circuit, and is electrically connected to a land (wiring) of the wiring board 2 through a wire 18. The wire 18 is made of, for example, gold (Au). A lens barrel 30 is fixed on the optical system component mounting surface of the wiring board 2 so as to cover the sensor chip 17.

  The lens barrel 30 is made of an insulating material such as PBT (polybutylene terephthalate). The lens barrel 30 includes a leg portion 31 and a main body 32 on the leg portion 31. A partition plate 33 is provided between the main body 32 and the leg portion 31. At the center of the partition plate 33, that is, at a position facing the sensor array of the sensor chip 17, a planar rectangular opening 34 penetrating the upper and lower surfaces of the partition plate 33 is formed. The opening 34 is closed by a filter (IR filter) 36 bonded to the upper surface of the partition plate 33 via a first adhesive 38.

  The filter 36 includes a transparent glass substrate 36a and a coating film 36b formed on one surface of the glass substrate 36a. The coating film 36b is a film constituting an IR filter, and has a function of blocking unnecessary infrared light having a predetermined frequency or higher while allowing visible light to pass therethrough. The filter 36 is attached to the filter 36 with the glass substrate 36a on the bottom and the coating film 36b on the top surface. That is, the glass substrate 36 a of the filter 36 and the partition plate 33 are bonded with the first adhesive 38. As the first adhesive 38, for example, a thermosetting adhesive (epoxy resin type) is used, and in this embodiment, the first adhesive 38 is cured under the condition that the heat treatment temperature (baking) is 80 ° C. or more and the heat treatment time is 10 minutes or more. ing.

  The attachment of the filter to the lens barrel is not limited to the thermosetting resin applied in the present embodiment, and an UV curable resin adhesive may be used. However, when the UV curable resin is used, the present inventors have found that there are the following problems. First, when the filter 36 is mounted on the lower side of the partition plate 33, the coating film 36 b and the partition plate 33 are bonded via the adhesive 38. When a UV curable resin is used for the adhesive 38, ultraviolet rays for curing are irradiated. However, the spectral property of the coating film 36b itself by ultraviolet irradiation is curing. That is, since the coating film 36b is cured, the adhesive force between the filter 36 and the partition plate 33 is reduced. Secondly, the portion of the main body 32 of the lens barrel 30 becomes a wall, and the ultraviolet rays to be irradiated do not sufficiently hit the UV curable resin, so that the adhesive strength is reduced.

  By attaching the filter 36 to the upper side with respect to the partition plate 33, the number of manufacturing steps can be reduced. This will be explained later. Compared with the case where the filter 36 is attached to the lower side with respect to the partition plate 33, the coating film 36b is located far from the image sensor (sensor chip 17). As a result, even if foreign matter adheres to the surface of the coating film 36b, the distance from the coating film 36b to the image sensor is increased, so that an image caused by the foreign matter is not easily formed on the image sensor surface, and the image is stained. It becomes difficult to generate the dirt called. The occurrence rate of defects due to stains is determined by the size of the foreign matter, the focal length of the lens, etc., but increasing the distance from the foreign matter to the image sensor can reduce the rate of occurrence of stain failures relative to the size of the foreign matter. it can. For example, the distance from the foreign material to the image sensor necessary to prevent a foreign material of 30 μm or less from being recognized as a spot on the filter is examined. If a 1/3 inch image sensor, a lens with an F value (lens aperture value) of about 5 is used, and the focal length f is about 5 mm, the distance from the foreign object to the image sensor must be at least 1.1 mm. . By increasing the distance as much as 1.1 mm within an allowable range, the incidence of defects can be reduced.

  In addition, when the filter 36 is mounted, the coating surface 36b is mounted so as to be positioned further above the glass substrate 36a, so that the distance from the sensor chip 17 is longer than when the coating surface 36b is mounted on the partition plate 33. It can be (larger). According to the inventor's study, when the partition plate 33 and the coating surface 36b are bonded so that the coating surface 36b is positioned below the glass substrate 36a, the lens barrel made of the coating film 36b and the PBT material is used. As a result, it was found that sufficient adhesive force between the filter 36 and the lens barrel 30 cannot be obtained. As a result, by mounting the coating surface 36b on the upper side of the glass substrate 36a, the adhesive force between the filter 36 and the lens barrel 30 is improved, and further, the stain defect countermeasure can be further improved.

  The lower part of the leg part 31 of the lens barrel 30 has a cylindrical shape, and the lower surface thereof is bonded to the optical system component mounting surface of the wiring board 2 via the second adhesive 39. As the second adhesive 39, a thermosetting adhesive similar to the first adhesive 38 is used. This is because when the lens barrel 30 is bonded to the wiring board 2, the filter 36 is previously mounted on the partition plate 33 (the lens barrel 30) via the adhesive 38, and the thermosetting process of the adhesives 38 and 39 is performed. Since it can be performed simultaneously, the number of manufacturing processes can be reduced.

  A lens holder (lens holding portion) 20 is attached to the upper portion (head portion) of the lens barrel 30 so as to block the opening of the head portion of the lens barrel 30. The lens holder 20 and the lens barrel 30 are formed by screwing a female screw formed on the inner peripheral surface of the lens barrel 30 on the head side and a male screw formed on the lower outer peripheral surface of the lens holder 20. Further, they are connected and firmly fixed by an adhesive (not shown) applied to the outer periphery of the connecting portion.

  The lens holder 20 is made of the same material as that of the lens barrel 30, for example. A lens (optical lens) 6 is accommodated inside the lens holder 20 in a state where it is firmly supported by a back diaphragm plate 21 made of metal or the like. The lens 6 is composed of a convex lens for receiving light, is made of an inexpensive and lightweight material such as plastic, and is disposed so as to face the sensor array on the main surface of the sensor chip 17. On the upper surface of the lens holder 20, for example, a planar circular light receiving window 5 is opened in a state in which the relative planar position with the lens 6 is aligned. Light from the outside of the camera module 1 passes through the light receiving window 5, the lens 6, and the filter 36 in this order and is irradiated onto the sensor array of the sensor chip 17.

  Further, a plurality of connection terminals 37 are arranged side by side along one side of the wiring board 2 on the second surface 2 b of the wiring board 2 that is out of the fixing region of the lens barrel 30. The connection terminal 37 is a terminal for electrically connecting a circuit in the camera module 1 and an external device. That is, the connection terminal 37 is electrically connected to the circuit in the camera module 1 through the wiring of the wiring board 2. The connection terminal 37 is electrically connected to the wiring of the flexible wiring board 8 through a joining member 7 such as an ACF (Anisotropic Conductive Film), for example, and further connected to an external device through the flexible wiring board 8. And is electrically connected. In FIG. 1, the flexible wiring board 8 has external electrode terminals formed at a predetermined pitch on the outer edge (right end) on the lower surface side thereof. For example, the flexible wiring board 8 overlaps with a land (wiring) on the upper surface of a mounting board of a mobile phone. Connected.

  Next, an example of a method for manufacturing the camera module 1 according to the first embodiment will be described with reference to FIGS. As shown in the flowchart of FIG. 3, the camera module 1 is provided with a wiring mother board (wiring board) preparation (S01), component mounting (S02), wire bonding (S03), resin layer formation (S04), and substrate half dicing (S05). ), Component mounting (S06), wire bonding (S07), lens barrel and filter bonding (S08), lens holder fixing (S09), wiring mother board cutting (S10), and flexible wiring board connection (S11). Manufactured.

  In manufacturing the camera module 1, a wiring mother board (wiring board) 2f as shown in FIGS. 4 to 6 is prepared (S01).

  The wiring mother board 2f is a wiring board having a plurality of product forming portions in order to manufacture a large number of camera modules 1. 4 and 5, the product forming unit 40 is indicated by a square dotted line. A thin region between the product forming portions 40 adjacent to each other is a region finally removed by cutting. The wiring mother board 2f has a structure in which 15 product forming portions 40 are arranged in 3 columns and 5 rows in total. This numerical value is for convenience of explanation, and is larger in actual manufacturing. The structure of each product forming unit 40 is the structure of the wiring board 2 already described. 4 shows the first surface 2a of the wiring motherboard 2f, and FIG. 5 shows the second surface 2b of the wiring motherboard 2f. Further, a guide hole 41 made of a circular hole and a guide hole 42 made of a long hole are provided at the corner of the wiring mother board 2f. These guide holes 41, 42 are used for positioning the wiring mother board 2f.

  The thickness of the wiring mother board 1 is extremely thin, for example, about 0.3 mm. The wiring mother board 2f has a multilayer wiring structure using, for example, glass epoxy resin as an insulating material, and is formed by, for example, a subtractive method.

  The first surface 2a of the product forming unit 40 is provided with a wiring pattern for mounting system components, but is omitted in FIG. 4 for easy viewing of the drawing. Further, the second surface 2b of the product forming unit 40 is provided with a wiring pattern for mounting the optical system components. However, in order to make the drawing easy to see, the second surface 2b is arranged on one side of the product forming unit 40 in FIG. Other than the plurality of connection terminals 37 are omitted. Since the product forming unit 40 becomes the wiring board 2 by cutting the wiring mother board 2f, wiring is formed inside as well as the front and back surfaces. It is omitted. Note that the connection terminal 37 is also omitted in FIGS.

  The wiring material of the wiring mother board 2f is made of, for example, copper (Cu). In addition, a plating film is formed on the surface of a wiring portion for forming a semiconductor chip mounting portion, a chip component electrode attaching portion, a wire connecting portion (land, wire bonding pad, etc.) and the like. The plating film is plated with, for example, nickel (Ni) and gold (Au).

  Next, as shown in FIG. 6, the first electronic component constituting the system component is mounted on the first surface 2a of each product forming section 40 of the wiring motherboard 2f (S02). That is, the logic chip 10, the memory chip 11, and the chip component 12 are mounted as the first electronic components. FIG. 6 shows three adjacent product forming portions 40. The range indicated by the arrow is the product forming portion 40 portion. Until the wiring mother board 2f is divided, in the following drawings, description will be made mainly with three adjacent product forming portions 40.

  Next, as shown in FIG. 7, wire bonding is performed at a place where wire bonding is required (S03). That is, the electrodes of the logic chip 10 and the memory chip 11 and the wiring of the wiring mother board 2 f are connected by the conductive wires 15 and 16.

  Next, as shown in FIG. 8, a resin layer (sealing body) 3f made of an insulating resin is formed to a predetermined thickness on the first surface 2a side of each product forming portion 40, so that the logic chip 10 and the memory The chip 11, the chip component 12, etc. are covered (S04). This resin layer 3f protects the first electronic component. As the resin, for example, a thermosetting resin such as an epoxy resin with silica filler is used. In this embodiment, the resin layer 3f employs a collective sealing method in which substantially the entire surface of the wiring mother board 2f is collectively sealed. As a batch sealing method, for example, a transfer molding method is used.

  Next, as shown in FIG. 9, a cutting groove 45 extending from the surface of the resin layer 3f to the surface layer of the wiring mother board 2f is formed (S05). As shown in FIG. 10, the cutting groove 45 is formed vertically and horizontally along the boundary of each product forming portion 40. As a result, the resin layer 3 f is divided into the sealing body 3. In FIG. 9 and subsequent figures, the cutting groove 45 is indicated by a thick solid line. The wiring mother board 2f is not cut completely because the depth of the cutting groove 45 stops at a depth of, for example, about 2/3 in the thickness direction of the wiring mother board 2f. By separating the collective sealing body (resin layer) 3f by the cutting groove 45 in this way, warping, twisting, etc. of the wiring mother board 2f due to shrinkage of the collective sealing body (resin layer) 3f can be reduced. Bondability of wires for wire bonding with optical system components described later can be improved, and the manufacturing yield of the camera module 1 can be improved. The cutting groove 45 completely separates the collective sealing body (resin layer) 3f, but does not have to reach the first surface 2a of the wiring mother board 2f. Even in this case, the stress on the wiring mother board 2f due to the shrinkage of the collective sealing body (resin layer) 3f can be relieved. Moreover, the cutting groove 45 may reach the position in the middle of the thickness direction of the collective sealing body (resin layer) 3f without completely separating the collective sealing body (resin layer) 3f. Even in this case, the stress can be alleviated to some extent.

  Next, as shown in FIG. 11, the second electronic component is mounted on the optical system component mounting surface of the second surface 2b of each product forming section 40 with the second surface 2b of the wiring mother board 2f as the upper surface. (S06). As the second electronic component, the sensor chip 17 is mounted with the light receiving surface facing upward. Then, as shown in FIG. 12, in the product formation part 40, the electrode of the sensor chip 17 and the wiring of the wiring mother board 2f are connected by the conductive wire 18 (S07). In this wire bonding, since the wiring mother board 2f is not warped or twisted due to the presence of the aforementioned cutting groove 45, good wire bonding is possible, bondability is improved, and manufacturing yield is improved. be able to.

  Next, as shown in FIG. 13, in each product forming unit 40, the lens barrel 30 is joined to the wiring motherboard 2 f by the second adhesive 39 so as to cover the sensor chip 17, and the first lens barrel 30 is connected to the first lens barrel 30. The filter 36 is joined by the adhesive 38 (S08). The curing process (baking process) of the first adhesive 38 and the second adhesive 39 is performed by a single curing process. FIG. 14 is a schematic diagram for explaining a method of joining (fixing) the filter 36 and the lens barrel 30. The first adhesive 38 is applied in a ring shape to the upper surface of the partition plate 33 of the lens barrel 30 using, for example, a dispenser, and the legs 31 of the lens barrel 30 are attached to the upper surface portion of the wiring mother board 2f that fixes the lens barrel 30. The second adhesive 39 is applied in a ring shape at a position opposite to. By applying the adhesives 38 and 39 in a ring shape, the gap between the lens barrel 30 and the wiring mother board 2f can be completely filled, so that the entry of foreign matter from the outside of the camera module 1 can be suppressed. When the filter 36 is fixed to the lower side of the partition plate 33, it is necessary to fix the lens barrel 30 in an inverted state and to first perform a curing process so that the filter 36 does not fall off the lens barrel 30. After the curing process, after the lens barrel 30 is inverted, the process of fixing the lens barrel 30 to the wiring mother board 2f via the adhesive 39 increases the number of manufacturing steps, thereby reducing the manufacturing cost. It was difficult. On the other hand, in this embodiment, the filter 36 is fixed to the upper side of the partition plate 33 via an adhesive 38 made of the same material as the adhesive 39 for fixing the lens barrel 30 to the wiring mother board 2f. Since the curing process can be performed in the same process, the number of manufacturing processes can be reduced.

  In fixing the lens barrel 30, using a device capable of image recognition, first, the light receiving surface of the image sensor on the wiring board is recognized, and then the outer shape or the opening (window frame) of the lens barrel is recognized. The optical axis of the image sensor and the optical axis of the lens mounted on the lens barrel are aligned with an accuracy of at least about ± 100 μm. Thereby, the optical axis alignment and focusing of the lens 6 become possible, and the camera module 1 with excellent quality can be manufactured.

  Next, the filter 36 is placed in the main body 32 of the lens barrel 30, and the filter 36 is placed on the partition plate 33. At this time, the filter 36 is positioned and placed on the first adhesive 38 on the partition plate 33 so that the glass substrate 36a of the filter 36 becomes the lower surface and the coating film 36b becomes the upper surface. Further, the lens barrel 30 with the filter 36 inserted and mounted is positioned and mounted on the second surface 2b of the wiring motherboard 2f so as to cover the sensor chip 17. The lower surface of the leg portion 31 of the lens barrel 30 is placed on the second adhesive 39. As the first adhesive 38 and the second adhesive 39, for example, an adhesive made of a thermosetting epoxy resin is used.

  Next, although not shown, the wiring mother board 2f is put in a baking furnace, and a baking process is performed at a predetermined temperature (for example, 80 ° C. or more) for a predetermined time (for example, 90 minutes or more), thereby the first adhesive. 38 and the second adhesive 39 are cured. By this curing process, as shown in FIG. 13, the filter 36 is fixed to the lens barrel 30, and the lens barrel 30 is fixed to the wiring motherboard 2f.

  Next, as shown in FIG. 15, the lens holder 20 is fixed to the head (upper part) of the lens barrel 30 (S09). FIG. 16 is a schematic diagram for illustrating a method of joining (fixing) the lens holder 20 to the lens barrel 30. The lens 6 is inserted into the lens holder 20 and fixed by a back diaphragm plate 21. Since a male screw is formed on the lower outer peripheral surface of the lens holder 20, the lower part is inserted into the opening of the upper part (head) of the lens barrel 30, and fitted into the female screw formed in the opening, The lens holder 20 is connected and fixed to the lens barrel 30 by screwing. Moreover, although not shown in figure, an adhesive agent is apply | coated to the outer periphery of a connection part and it seals. Thereby, as shown in FIG. 15, the lens holder 20 is fixed to the lens barrel 30.

  Next, the wiring motherboard 2f is cut at the bottom of the cutting groove 45 to form a plurality of pieces 50 as shown in FIG. 17 (S10).

  Next, the flexible wiring board 8 is attached to the connection terminal 37 which is omitted in FIG. 17 of each piece 50 via the joining member 7, and a plurality of camera modules 1 as shown in FIG. 18 are manufactured.

The first embodiment has the following effects.
(1) Since the work for fixing the filter 36 in the lens barrel 30 and the work for fixing the lens barrel 30 on the wiring board 2 (wiring mother board 2f) are simultaneously performed, the number of processes can be reduced, and the camera module 1 Manufacturing cost can be reduced.

  (2) Since the filter 36 is attached to the lens barrel 30 so that the coating film 36b is on the upper surface, the image sensor (sensor chip 17) is compared with the case where the filter 36 is attached to the lens barrel with the coating film on the lower surface. The coating film 36b is far from the position. As a result, even if foreign matter adheres to the surface of the coating film 36b, the distance from the coating film to the image sensor is increased, so that an image caused by the foreign matter is difficult to be clearly connected to the image sensor surface, and the image is stained. It becomes difficult to generate the dirt called. As a result, the camera module 1 with excellent quality (characteristics) can be manufactured.

  (3) According to the above (1) and (2), the camera module 1 with excellent quality can be manufactured at low cost.

  19 to 21 are diagrams relating to a camera module which is Embodiment 2 of the present invention. 19 is a plan view of the camera module, FIG. 20 is a cross-sectional view of the camera module of FIG. 19, and FIG. 21 shows a state in which a filter is attached to the lens barrel at the same time when the lens barrel is attached to the wiring motherboard in manufacturing the camera module. It is typical sectional drawing.

  In the manufacture of the camera module 1 according to the second embodiment, the camera module 1 according to the second embodiment has a lens barrel 30 that extends from an attachment location of the filter 36 to a connection location of the wiring board 2 (wiring motherboard) as shown in FIG. An air vent hole 55 that communicates the inside and outside of the lens barrel 30 is formed in the portion. The air vent hole 55 is provided in the upper surface of the leg part 31, as shown in FIG. As shown in FIG. 19, the air vent hole 55 is provided at one location on the upper surface of the leg portion 31 of the lens barrel 30. When the lens barrel 30 is fixed to the wiring board 2 by the air vent hole 55, the space formed by the lens barrel 30 below the filter 36 is not sealed, and the inside and outside of the lens barrel 30 are communicated. For the air vent hole 55, it is more preferable to use, for example, a room temperature curable adhesive (adhesive) or an ultraviolet curable adhesive (adhesive) after the heat curing treatment of the adhesives 38 and 39 is completed. As a result, the air vent hole 55 can be filled without performing heat treatment. Therefore, the air that has been heated and expanded in the lens barrel 30 by filling the air vent hole 55 and sealing the lens barrel 30 can be used as the lens barrel. 30 can be prevented from being ejected outside.

Therefore, the inside of the space does not become a high pressure state due to heat when the first adhesive 38 and the second adhesive 39 are cured. As a result, there is no occurrence of a phenomenon in which the adhesive is ejected to the outside of the lens barrel, the production yield and the operation rate of the assembling apparatus are not lowered due to the ejection of the adhesive, and the production cost of the camera module 1 is reduced. it can.
Further, since the air vent hole 55 finally fills the opening, it is possible to newly suppress the entry of foreign matter from the outside of the camera module 1.

  The camera module 1 of the second embodiment can be accurately positioned when the lens barrel 30 is fixed to the wiring board 2 (wiring mother board) in the manufacture of the camera module 1 of the first embodiment. As shown in FIGS. 19 and 21, pins 56 serving as locking portions are attached to two locations on the lower surface of the leg portion 31 of the lens barrel 30 (positions outside the outer dimensions of the lens barrel 30). An insertion hole 57 is provided on the second surface 2b of the wiring board 2 (wiring mother board) corresponding to these locking portions as a locking portion into which the pin 56 can be inserted. More specifically, the sealing body 3 is disposed at a position that does not overlap with the place where the sealing body 3 is formed. Thereby, when forming the sealing body 3, the sealing resin does not leak from the first surface 2a of the wiring board 2 to the second surface 2b.

  Then, as shown in FIG. 21, when the lens barrel 30 is placed on the wiring mother board 2f, the pin 56, which is the first locking portion provided on the lens barrel 30, is provided on the wiring mother board 2f. The lens barrel 30 is fixed to the wiring mother board 2 f with the second adhesive 39. When the lens barrel 30 is fixed and the wiring mother board 2f is separated, the pins 56 are also cut, so that the pins 56 do not remain in the camera module 1 finally.

  As a result, the positioning between the wiring mother board 2f (wiring board 2) and the lens barrel 30 is facilitated, the assembling workability is improved, and the manufacturing cost can be reduced. In FIG. 21, in order to clarify the insertion hole 57, the second adhesive 39 applied to the right insertion hole 57 is omitted. Further, the locking portion and the arrangement position thereof are not limited to the structure of the above embodiment. For example, the peripheral surface of the lens barrel 30 may be partially projected, and a locking portion may be formed on the lower surface of the protruding portion. Moreover, the number and arrangement | positioning location of the air vent hole 55 are not limited to an Example, You may provide in another place.

  In the above description, the case where the invention made mainly by the present inventor is applied to a camera module using a CMOS image sensor which is a field of use as the background has been described. However, the present invention is not limited thereto. It can also be applied to other camera modules such as a camera module using a charge coupled device) image sensor. The present invention can be applied to the manufacture of at least other optical modules.

It is a top view of the camera module which is Example 1 of this invention. It is sectional drawing which follows the AA line of FIG. It is a flowchart which shows the manufacturing method of the said camera module. It is a top view which shows the 1st surface of the wiring mother board which has a some product formation part used by manufacture of the said camera module. It is a top view which shows the 2nd surface of the said wiring mother board. It is sectional drawing which shows the wiring mother board which mounted the chip component and semiconductor chip as a 1st electronic component on the 1st surface of each said product formation part. It is sectional drawing which shows the wiring mother board which connected the said semiconductor chip and the said wiring mother board with the wire. It is sectional drawing which shows the wiring motherboard which shows the state which provided the resin layer collectively on the 1st surface of the said wiring motherboard, and covered the said 1st electronic component. It is sectional drawing which shows the wiring motherboard which formed the cutting groove from the surface of the said resin layer to the surface of a wiring motherboard. It is a top view of the wiring motherboard provided with the said cutting groove. It is sectional drawing which shows the wiring motherboard which mounted the 2nd electronic component which forms an image sensor in the 2nd surface of each said product formation part. It is sectional drawing which shows the wiring motherboard which connected the said 2nd electronic component and the said wiring motherboard with the wire. It is sectional drawing which shows the wiring mother board which attached the lens-barrel so that an image sensor might be covered on the 2nd surface of each said product formation part. FIG. 5 is a schematic cross-sectional view showing a state where a filter is attached to the lens barrel at the same time when the lens barrel is attached to the wiring motherboard. It is sectional drawing of the wiring motherboard which shows the state which attached the lens holder to each said lens-barrel. It is typical sectional drawing which shows the state which attaches a lens holder to each said lens-barrel. It is sectional drawing which shows the state which divided | segmented the said wiring mother board | substrate for every product formation part, and formed the piece containing a wiring board. It is a front view which shows the state which connected the flexible wiring board to the said wiring board. It is a top view of the camera module which is Example 2 of this invention. It is sectional drawing of the camera module of FIG. In manufacture of the camera module of the present Example 2, when attaching a lens-barrel to a wiring motherboard, it is a typical sectional view showing a state where a filter is attached to a lens-barrel at the same time.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Camera module, 2 ... Wiring board, 2a ... 1st surface, 2b ... 2nd surface, 2f ... Wiring mother board, 3 ... Sealing body, 3f ... Resin layer, 5 ... Window (light-receiving window), 6 DESCRIPTION OF SYMBOLS ... Lens, 7 ... Joining member, 8 ... Flexible wiring board, 10 ... Logic semiconductor chip (logic chip), 11 ... Memory semiconductor chip (memory chip), 12 ... Chip components, 15, 16 ... Wire, 17 ... Semiconductor chip (sensor chip) for optical sensor, 18 ... Wire, 20 ... Lens holder (lens holding part), 21 ... Back diaphragm plate, 30 ... Lens barrel, 31 ... Leg part, 32 ... Main body, 33 ... Partition plate 34 ... opening, 36 ... filter (IR filter), 36a ... glass substrate, 36b ... coating film, 37 ... connection terminal, 38 ... first adhesive, 39 ... second adhesive, 40 ... product forming part 41, 42 ... guide holes, 5 ... cutting groove, 50 ... piece 55 ... air escape hole, 56 ... pin 57 ... insertion hole

Claims (6)

(A) preparing a wiring board having a first surface and a second surface opposite to the first surface;
(B) mounting a first electronic component on the first surface of the wiring board;
(C) sealing the first electronic component with a sealing body;
(D) mounting a second electronic component including an image sensor on the second surface of the wiring board;
(E) A step of attaching a lens holder to the second surface of the wiring board on the upper end side, and joining a lens barrel for mounting and fixing the filter in the middle so as to cover the second electronic component;
(F) connecting a flexible wiring board having external electrode terminals to the wiring board;
In the step (e),
(G) Applying a first adhesive to at least one of the mounting portion of the lens barrel and the filter, and applying a second adhesive to at least one of the connecting portion of the lens barrel and the wiring board Applying step,
(H) a step of positioning and mounting the filter from above in the lens barrel and positioning and mounting the lens barrel on the wiring board;
(I) a step of curing the first adhesive and the second adhesive;
(J) A method of manufacturing an optical module, comprising a step of attaching the lens holder to the lens barrel.   2. The method of manufacturing an optical module according to claim 1, wherein, in the step (g), the first adhesive and the second adhesive use a thermosetting resin. 3.   In the method of manufacturing an optical module according to claim 1, in the steps (g) to (i), a filter made of a transparent glass substrate and a coating film formed on one surface of the glass substrate is used. A method of manufacturing an optical module, wherein the coating film is bonded to the lens barrel in a state of being an upper surface so that the coating film is positioned far from the image sensor.   2. The method of manufacturing an optical module according to claim 1, wherein in the step (e), an air vent hole that communicates the inside and outside of the lens barrel is formed in a lens barrel portion that extends from the filter attachment location to the connection location of the wiring board. An optical module manufacturing method characterized by comprising:   2. The method of manufacturing an optical module according to claim 1, wherein in the step (e), a first locking portion is formed on the lens barrel, and the first locking portion is locked on the wiring board. A method of manufacturing an optical module, comprising: two locking portions; and positioning the lens barrel by locking the first and second locking portions and bonding the lens barrel onto the wiring board.   2. The method of manufacturing an optical module according to claim 1, wherein in the step (e), the light receiving surface of the image sensor on the wiring board is first recognized using an apparatus capable of image recognition, and then the lens barrel is formed. A method for manufacturing an optical module, comprising recognizing an outer shape or a window frame and aligning an optical axis of an image sensor and an optical axis of a lens mounted on a lens barrel with an accuracy of at least ± 100 μm.

Images