Camera module

Abstract

A camera module according to an embodiment includes a printed circuit board, an infrared filter disposed on an upper surface of the printed circuit board, and an image sensor disposed on a lower surface of the printed circuit board, wherein the printed circuit board includes an insulating layer including a cavity that overlaps with at least a portion of the infrared filter and at least a portion of the image sensor in an optical axis direction, and a circuit pattern embedded in the insulating layer and connected to a terminal of the image sensor, and the shape of the cavity is different from the shape of the image sensor.

Description

【Technical Field】 【0001】 The embodiments relate to a camera module. 【Background Art】 【0002】 Recently, there has been an increasing demand for small camera modules for various multimedia fields such as notebook personal computers, mobile phones with cameras, PDAs, smartphones, toys, and also for image input devices such as surveillance cameras and video tape recorders. 【0003】 As the pixel size of sensors applied to camera modules is miniaturized and the height of the module becomes lower, the development of a mount structure for ensuring the mechanical reliability of camera modules, such as management against the inflow of foreign matter and tilt or shift of the lens optical axis, has emerged as a very important topic. 【0004】 Such a camera module includes a printed circuit board on which a sensor is mounted. At this time, the printed circuit board has a structure in which a cavity is formed in a region where the sensor is mounted. The cavity formed in the printed circuit board can be used for various purposes. For example, a reinforcing plate for improving the flatness of the sensor and for heat dissipation of the sensor can be disposed in the cavity. For example, on the printed circuit board, the infrared filter and the sensor may be disposed facing each other on both sides of the substrate with the cavity interposed therebetween, whereby the overall size of the camera module can be reduced. 【0005】 However, foreign matter is generated in the process of forming a cavity in the printed circuit board as described above, and the generated foreign matter flows onto the active pixel region of the sensor, causing reliability problems. 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0006】 In this embodiment, a printed circuit board for a sensor with a new structure and a camera module including the same are provided. 【0007】 Furthermore, the embodiment provides a printed circuit board for a sensor that includes a cavity having a shape different from the shape of the sensor, and a camera module including the same. 【0008】 Furthermore, the embodiment provides a printed circuit board for a sensor that can improve the flatness of the sensor, and a camera module including the same. 【0009】 Furthermore, the embodiment provides a printed circuit board for a sensor that can improve the resolution of the camera module, and a camera module including the same. 【0010】 Furthermore, the embodiment provides a printed circuit board for a sensor and a camera module including the same, which can minimize deviations in the thickness of the circuit pattern. 【0011】 Furthermore, the embodiment provides a printed circuit board for a sensor and a camera module including the same, which can improve high-temperature electrical reliability and durability. 【0012】 The technical problems to be solved in the proposed embodiments are not limited to those mentioned above, and other technical problems not mentioned will be clearly understood by those with ordinary skill in the art to which the proposed embodiments belong, based on the following description. [Means for solving the problem] 【0013】 The camera module according to the embodiment includes a printed circuit board, an infrared filter disposed on the upper surface of the printed circuit board, and an image sensor disposed on the lower surface of the printed circuit board, wherein the printed circuit board includes an insulating layer including a cavity that overlaps with at least a portion of the infrared filter and at least a portion of the image sensor in the optical axis direction, and a circuit pattern embedded in the insulating layer and connected to the terminals of the image sensor, the shape of which is different from the shape of the image sensor. 【0014】 Furthermore, the image sensor has a rectangular shape, and the cavity has a circular shape. 【0015】 Furthermore, the width of the upper surface of the cavity is the same as the width of the lower surface of the cavity. 【0016】 Furthermore, the inner wall of the cavity is perpendicular to the upper or lower surface of the insulating layer. 【0017】 Furthermore, the surface roughness of the inner wall of the cavity is in the range of 0.01 μm to 0.1 μm. 【0018】 Furthermore, the image sensor includes a pixel region and a passivation region, and the image pixel region includes a first region overlapping the cavity in the optical axis direction and a second region overlapping the insulating layer in the optical axis direction. 【0019】 Furthermore, the image sensor includes an active pixel region, a dummy pixel region, and a passivation region, wherein the active pixel region overlaps the cavity in the optical axis direction, and the dummy pixel region includes a first region that overlaps the cavity in the optical axis direction together with the active pixel region, and a second region that overlaps the insulating layer in the optical axis direction. 【0020】 Furthermore, the second region includes the corner region of the dummy pixel area of ​​the image sensor. 【0021】 Furthermore, the printed circuit board includes a first protective layer disposed on the upper surface of the insulating layer, the first protective layer includes a 1-1 protective layer disposed on the upper surface of the insulating layer, and a 1-2 protective layer disposed on the upper surface of the 1-1 protective layer and having a step difference with the 1-1 protective layer. 【0022】 Furthermore, the 1-1 protective layer includes a first aperture that overlaps the cavity in the optical axis direction, the 1-2 protective layer includes a second aperture that overlaps the cavity and the first aperture in the optical axis direction, the second aperture of the 1-2 protective layer overlaps a portion of the upper surface of the 1-1 protective layer in the optical axis direction, and the infrared filter is positioned on the upper surface of the 1-1 protective layer that overlaps the second aperture of the 1-2 protective layer in the optical axis direction. 【0023】 On the other hand, the camera module according to the embodiment includes a lens barrel including a lens, a printed circuit board disposed below the lens barrel and including a cavity that overlaps with the lens in the optical axis direction, an infrared filter disposed on the upper surface of the printed circuit board, and an image sensor disposed on the lower surface of the printed circuit board and directly facing the infrared filter via the cavity, wherein the printed circuit board includes an insulating layer including the cavity and a circuit pattern embedded in the insulating layer and electrically connected to the terminals of the image sensor, and the cavity has a shape different from the shape of the image sensor and has a shape corresponding to the lens. 【0024】 The image sensor has a rectangular shape, and the lens and cavity have a circular shape. 【0025】 Furthermore, the cavity has an upper width and a lower width that are equal to each other, the inner wall of the cavity is perpendicular to the upper or lower surface of the insulating layer, and the surface roughness of the inner wall of the cavity is in the range of 0.01 μm to 0.1 μm. 【0026】 The image sensor further includes a pixel region including an active pixel region and a dummy pixel region, and a passivation region. The entire region of the active pixel region of the image sensor overlaps with the cavity in the optical axis direction. The dummy pixel region of the image sensor includes a first region that overlaps with the cavity in the optical axis direction and a second region that does not overlap with the cavity. The second region includes a corner region of the dummy pixel region of the image sensor. 【0027】 The printed circuit board further includes a first protective layer disposed on the upper surface of the insulating layer, pads embedded in the lower surface of the insulating layer, a second protective layer disposed on the lower surface of the insulating layer and including an opening for exposing the pads, and solder balls disposed in the opening of the second protective layer and connected to the pads. The first protective layer includes a first-1 protective layer and a first-2 protective layer having different physical properties and forming a step on which the infrared filter is seated. 【0028】 On the one hand, the manufacturing method of the camera module according to the embodiment includes preparing a carrier board, forming a circuit pattern on the carrier board, forming an insulating layer covering the circuit pattern on the carrier board, removing the carrier board so that the lower surface of the circuit pattern embedded in the insulating layer is exposed, forming a first protective layer and a second protective layer on the upper and lower surfaces of the insulating layer, using a CNC drill to form a cavity penetrating the upper and lower surfaces of the insulating layer, attaching an infrared filter to the first protective layer, and mounting an image sensor connected to the circuit pattern on the lower surface of the insulating layer. The image sensor has a rectangular shape, the cavity has a circular shape corresponding to a lens through which light enters, the upper width and the lower width of the cavity are the same as each other, the inner wall of the cavity is perpendicular to the upper or lower surface of the insulating layer, the surface roughness of the inner wall of the cavity ranges from 0.01 μm to 0.1 μm, the image sensor includes a pixel region including an active pixel region and a dummy pixel region and a passivation region, the entire region of the active pixel region of the image sensor overlaps with the cavity in the optical axis direction, the dummy pixel region of the image sensor includes a first region overlapping with the cavity in the optical axis direction and a second region not overlapping with the cavity, the second region includes a corner region of the dummy pixel region of the image sensor, and the first protective layer includes a first-1 protective layer and a first-2 protective layer having different physical properties from each other and forming a step on which the infrared filter is firmly attached. 【Effect of the Invention】 【0029】 The printed circuit board in the embodiment has an ETS structure in which a circuit pattern is embedded in an insulating layer. Thereby, the printed circuit board in the embodiment can achieve miniaturization. Further, in the embodiment, even if the number of terminals increases due to an increase in the pixels of the image sensor through the miniaturization of the circuit pattern, the size of the printed circuit board does not have to be increased, and thus the size of the printed circuit board can be reduced. 【0030】 Furthermore, in the comparative example, when the cavity is formed through laser processing, foreign matter such as burrs remains on the inner wall of the cavity, which later falls onto the image sensor and causes reliability problems. 【0031】 In contrast, in this embodiment, by forming the cavity using a CNC drill, foreign matter present on the inner wall of the cavity can be completely removed, thereby resolving the reliability issues. Furthermore, in this embodiment, by forming the cavity C through a CNC drill, the upper and lower widths of the cavity C may appear to be the same. That is, the inner wall of the cavity C in this embodiment may be perpendicular to the upper or lower surface of the insulating layer 91. As a result, in this embodiment, a cavity C corresponding to the target size can be accurately formed in the insulating layer, thereby resolving the issue of increased substrate size. 【0032】 Furthermore, in this embodiment, a step is formed in the protective layer made of solder resist, and the infrared filter is placed on the step. As a result, in this embodiment, a separate structure for placing the infrared filter is not required, which reduces the unit cost of the product and reduces the overall height of the camera module. [Brief explanation of the drawing] 【0033】 [Figure 1] This figure shows a camera module relating to a comparative example. [Figure 2] Figure 1 is a plan view of the printed circuit board. [Figure 3] This is a cross-sectional view of a camera module according to an embodiment. [Figure 4] Figure 3 is a diagram of a printed circuit board. [Figure 5] This is a diagram showing the combined configuration of a printed circuit board, an image sensor, and an infrared filter according to an embodiment. [Figure 6] This diagram illustrates the cavity of the printed circuit board and the placement of the image sensor according to the embodiment. [Figure 7]This diagram illustrates the cavity of the printed circuit board and the placement of the image sensor according to the embodiment. [Figure 8] This figure shows the manufacturing method of a printed circuit board according to an embodiment, in order of steps. [Figure 9] This figure shows the manufacturing method of a printed circuit board according to an embodiment, in order of steps. [Figure 10] This figure shows the manufacturing method of a printed circuit board according to an embodiment, in order of steps. [Figure 11] This figure shows the manufacturing method of a printed circuit board according to an embodiment, in order of steps. [Figure 12] This figure shows the manufacturing method of a printed circuit board according to an embodiment, in order of steps. [Figure 13] This is a perspective view of a mobile terminal according to an embodiment. [Figure 14] Figure 13 is a diagram showing the configuration of a mobile device. [Modes for carrying out the invention] 【0034】 Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings. 【0035】 However, the technical concept of the present invention is not limited to the several embodiments described, but can be realized in a variety of different forms, and within the scope of the technical concept of the present invention, one or more of its components can be selectively combined or substituted between embodiments. 【0036】 Furthermore, terms used in the embodiments of the present invention (including technical and scientific terms) shall be interpreted as having a meaning that can be generally understood by a person with ordinary skill in the art to which the present invention pertains, unless otherwise clearly defined and described. Commonly used terms, such as those defined in advance, may be interpreted in consideration of their meaning in the context of the relevant art. In addition, terms used in the embodiments of the present invention are for illustrative purposes only and are not intended to limit the present invention. 【0037】 In this specification, the singular form may also include the plural form unless otherwise specified in the text, and when it is written as "A and / or at least one of B, C (or more)", it may include one or more of all combinations of A, B, C. In addition, terms such as first, second, A, B, (a), (b), etc. may be used when describing the components of the embodiments of the present invention. 【0038】 Such terminology is used solely to distinguish one component from another, and does not limit the nature, order, or procedure of the component in question. Furthermore, when it is stated that a component is “connected,” “joined,” or “linked” to another component, this includes not only cases where the component is directly connected to or linked to the other component, but also cases where it is “connected,” “joined,” or “linked” by another component that lies between it and the other component. 【0039】 Furthermore, when it is stated that a component is formed or positioned "above (upper part) or below (lower part)" of a component, "above (upper part)" or "below (lower part)" includes not only cases where two components are in direct contact with each other, but also cases where one or more other components are formed or positioned between the two components. Also, when expressed as "above (upper part) or below (lower part)," it can include not only the upward direction but also the downward direction relative to one component. 【0040】 The embodiments of the present invention will be described in detail below with reference to the attached drawings. 【0041】 Figure 1 shows a camera module relating to a comparative example, and Figure 2 is a plan view of the printed circuit board of Figure 1. 【0042】 Referring to Figure 1, the comparative camera module includes a printed circuit board 1, a sensor 2, a cover glass 4, and an infrared filter 3. 【0043】 In the comparative example, the camera module has a sensor 2 bonded to a printed circuit board 1, and then an infrared filter 3 with a cover glass 4 attached is attached to the top of the printed circuit board 1 to prevent contamination by foreign matter and to block infrared (IR) rays. 【0044】 In this case, the camera module of the comparative example described above has a separate mechanism formed on the printed circuit board 1 for fixing or supporting the infrared filter 3, and the infrared filter 3 is fixed on the formed mechanism. 【0045】 As a result, in the comparative example, the overall height of the camera module increases by the height of the aforementioned device. 【0046】 Furthermore, in the comparative example, the camera module has an infrared filter 3 and a sensor 2 arranged facing each other on both sides of the printed circuit board 1. For this purpose, a cavity C is formed in the printed circuit board 1. In the comparative example, the cavity C is formed by laser processing. 【0047】 However, due to the characteristics of the laser process, various foreign substances remain on the inner wall of the cavity C due to laser processing. When the sensor 4 is mounted without completely removing these foreign substances, the foreign substances penetrate the active pixel area of ​​the sensor 4, resulting in a problem of image quality degradation. 【0048】 For example, as shown in Figure 2(b), foreign matter such as burrs caused by laser processing exists on the inner wall of cavity C of the printed circuit board 1. This foreign matter on the inner wall of cavity C falls onto the active pixel area of ​​sensor 2 in the operating environment of the camera module, resulting in image quality degradation. 【0049】 Furthermore, the printed circuit board 1 in the comparative example has limitations in circuit miniaturization due to the increase in the number of sensor pixels. Specifically, the printed circuit board in the comparative example has a structure in which the circuit pattern protrudes from the surface of the insulating layer, which limits the miniaturization of the circuit. And, due to the aforementioned limit in circuit miniaturization, there is a limit to the increase in the number of sensor pixels. 【0050】 The following describes a printed circuit board for a sensor and a camera module including the same, according to an embodiment. 【0051】 Figure 3 is a cross-sectional view of a camera module according to an embodiment, and Figure 4 is a diagram of the printed circuit board of Figure 3. 【0052】 As shown in Figure 3, the camera module in the embodiment includes a case 10, an upper elastic member 20, a lens barrel 30, an actuator 40, a lower elastic member 50, a frame 60, an infrared filter 70, an image sensor 80, and a printed circuit board 90. 【0053】 In this invention, a camera module is shown that includes an actuator 40, which is a movable part that moves the lens barrel 30 along the optical axis O for autofocusing. However, the present invention is also applicable to a camera module in which the actuator 40 is omitted. In a camera module in which the actuator 40 is omitted, the lens barrel 30 is screw-coupled to a holder instead of a bobbin 41. In this invention, the bobbin 41 functions as a holder that fixes the lens barrel 30 in place. 【0054】 Case 10 has a hexahedral shape with an open bottom, and a light-transmitting hole is formed in the center of the top. The bottom of case 10 is supported by frame 60. 【0055】 The case 10 engages with the frame 60 to form a space, which includes the upper elastic member 20, the lens barrel 30, and the actuator 40. 【0056】 Case 10 is preferably made of plastic for insulation between its interior and exterior, and can also be injection molded for mass production. 【0057】 The upper elastic member 20 is inserted into the upper part of the case 10 as a leaf spring, its outer part is supported by the yoke 44 of the actuator 40, and its inner part contacts the bobbin 41 of the actuator 40, pressing on the upper side of the bobbin 41. 【0058】 The lower elastic member 50 acts as a leaf spring, positioned below the actuator 40, and pressurizes the lower side of the bobbin 41. 【0059】 The lower elastic member 50 may be insert-injected from the bobbin 41 or bonded with adhesive. 【0060】 The lens barrel 30 is a means for fixing and protecting multiple lenses, and inside the lens barrel 30, multiple lenses capable of receiving the light image of the subject are stacked sequentially along the optical axis O. 【0061】 The lens barrel 30 has threads formed on its circumferential surface, and these threads are screw-connected to the threads formed on the inner circumferential surface of the bobbin 41. 【0062】 The bobbin 41 has a cylindrical shape with an open top and bottom, and its inner surface has threads corresponding to the threads 31 of the lens barrel 30. In this invention, the camera module can be focused at long distances while screw-connecting the lens barrel 30 to the inner surface of the bobbin 41. 【0063】 A coil 42 that interacts with the permanent magnet 43 is wound around the bobbin 41 in a direction perpendicular to the magnetic flux. 【0064】 A yoke 44 is inserted inside the case 10 to prevent the magnetic field between the coil 42 and the permanent magnet 43 from leaking out. The permanent magnet 43 is mounted inside the yoke 44 so as to face each other with respect to the bobbin 41. The yoke 44 is supported by a frame 60. 【0065】 When a voltage is applied to the coil 42, the current flowing through the coil interacts with the magnetic field of the permanent magnet 43 (Fleming's left-hand rule), causing the bobbin 41 to experience an upward force along the optical axis. At this time, the greater the strength of the current applied to the coil 42, the longer the distance that the lens barrel 30 and the bobbin 41 move upward along the optical axis. 【0066】 Next, when the voltage applied to the coil 42 is cut off, the elastic force of the upper elastic member 20 and the lower elastic member 50 causes the lens barrel 30 and bobbin 41 to move downward along the optical axis and return to their original position. 【0067】 The frame 60 is square-shaped with a central opening that allows the light image to pass through to the image sensor 80, and the frame 60 is located below the lens barrel 30. 【0068】 Such camera modules can be either AF (Auto Focus) camera modules or OIS (Optical Image Stabilizer) camera modules. An AF camera module is one that can only perform autofocus functions, while an OIS camera module is one that can perform both autofocus and OIS (Optical Image Stabilizer) functions. For example, the lens drive unit 100 may be an AF lens drive unit or an OIS lens drive unit, and the meanings of "AF" and "OIS" here may be the same as those explained for AF camera modules and OIS camera modules. 【0069】 Therefore, actuator 40 could be a lens drive device for OIS. Alternatively, actuator 40 could be a lens drive device for AF. 【0070】 The camera module may further include a sensing magnet (not shown) located on the bobbin 41 and an AF position sensor (e.g., a Hall sensor (not shown)) located on the case. 【0071】 In other embodiments, the AF position sensor may be located on the bobbin, and the AF position sensor may be located on the case. 【0072】 The AF position sensor can output an output signal based on the result of sensing the strength of the magnetic field of the sensing magnet due to the movement of the bobbin 100. The AF position sensor can be electrically connected to the printed circuit board 90 via an upper elastic member (or lower elastic member) and / or a support member. The printed circuit board 90 can provide a drive signal to the AF position sensor, and the output of the AF position sensor can be transmitted to the printed circuit board 90. However, it is not limited to this, and the output of the AF position sensor can be electrically connected to another board (not shown) electrically connected to the printed circuit board 90, thereby being immediately transmitted as a signal to the other board. 【0073】 In this embodiment, the coil 42 may be supplied with a drive signal (e.g., a drive current), and the bobbin may be moved in the optical axis direction by the electromagnetic force resulting from the interaction between the coil 42 and the permanent magnet 43. In other embodiments, the positions of the coil 42 and the permanent magnet 43 may be different from each other. 【0074】 An image sensor 80 and an infrared filter 70 may be attached to the printed circuit board 90. That is, the printed circuit board 90 may be a sensor board for mounting the image sensor 80. As another example, the printed circuit board 90 may be a filter board for attaching the infrared filter 70. 【0075】 A cavity C may be formed in the printed circuit board 90. The image sensor 80 and the infrared filter 70 may be arranged on different surfaces of the printed circuit board 90, with the cavity C in between. For example, the image sensor 80 may be mounted on the lower surface of the printed circuit board 90. For example, the infrared filter 70 may be attached to the upper surface of the printed circuit board 90. As a result, at least a portion of the lower surface of the infrared filter 70 and at least a portion of the upper surface of the image sensor 80 can be positioned directly opposite each other with the cavity C in between. 【0076】 Referring to Figure 4, the printed circuit board 90 may include an insulating layer 91, a circuit pattern 92, a pad 93, a first protective layer 94, and a second protective layer 95. 【0077】 The printed circuit board 90 in the embodiment may include a single insulating layer. That is, the printed circuit board 90 may have a single-layer structure based on the insulating layer. 【0078】 Furthermore, the printed circuit board 90 may include a single-layer patterned portion. Here, the patterned portion may include a circuit pattern 92 and a pad 93. That is, in the embodiment, the printed circuit board 90 may have a patterned portion including the circuit pattern 92 and the pad 93 arranged on only one side of one of the insulating layers 91. 【0079】 The insulating layer 91 can include all printed circuit boards, wiring boards, and insulating substrates made of insulating material on which an electrical circuit can be arranged and on which a circuit pattern can be formed on the surface, and on which a circuit pattern can be formed. 【0080】 For example, the insulating layer 91 can be rigid or flexible. For example, the insulating layer 91 may include glass or plastic. More specifically, the insulating layer 91 may include chemically strengthened / semi-strengthened glass such as soda-lime glass or aluminosilicate glass, or strengthened or flexible plastics such as polyimide (PI), polyethylene terephthalate (PET), propylene glycol (PPG), or polycarbonate (PC), or it may include sapphire. 【0081】 Furthermore, the insulating layer 91 may include an optically isotropic film. For example, the insulating layer 91 may include COC (Cyclic Olefin Copolymer), COP (Cyclic Olefin Polymer), optically isotropic polycarbonate (PC), or optically isotropic polymethyl methacrylate (PMMA). Curved, bent 【0082】 Furthermore, the insulating layer 91 may bend with a partially curved surface. That is, the insulating layer 91 may bend with a partially flat surface and a partially curved surface. More specifically, the insulating layer 91 may bend or bend with a curved end, or with a surface that includes random curvature. 【0083】 Furthermore, the insulating layer 91 may be a flexible substrate having flexible properties. The insulating layer 91 may also be a curved or bent substrate. In this case, the insulating layer 91 can represent electrical wiring connecting circuit components based on the circuit design using wiring diagrams, and can reproduce electrical conductors on the insulator. Additionally, at least one of the insulating layers 120 can form wiring that connects electrical components in a circuit-like manner, and can mechanically fix components other than those providing electrical connection functions. 【0084】 A patterned portion may be arranged on the surface of the insulating layer 91. In this case, the printed circuit board 90 in the embodiment may be a cross-sectional printed circuit board. Therefore, the printed circuit board 90 may include one insulating layer and a patterned portion arranged on only one surface of the insulating layer. 【0085】 The pattern portion may include a circuit pattern 92 and a pad 93. The circuit pattern 92 is for signal transmission and may be a pattern on which an image sensor 80 is mounted. The pad 93 may be a bonding pad for attaching the camera module described above to an optical device such as a mobile terminal. The circuit pattern 92 and the pad 93 may be formed simultaneously in the same process. However, since the circuit pattern 92 and the pad 93 have different functions, they may have different widths. 【0086】 The circuit pattern 92 in the embodiment can have a line width of 6 μm ± 1 μm. Furthermore, the circuit pattern 92 in the embodiment can have a pitch of 6 μm ± 1 μm. In other words, the circuit pattern 92 in the embodiment is a fine circuit pattern. 【0087】 In other words, to improve the performance of recent camera modules, there is a trend towards increasing the resolution of image sensors. As a result, the number of terminals arranged on the image sensor 80 and connected to the circuit pattern 92 on the printed circuit board 90 increases in response to the increase in resolution. In this case, if the circuit pattern 92 is not a fine circuit pattern, the area on which the circuit pattern 92 is arranged increases to accommodate the increase in the resolution of the image sensor 80, which increases the overall size of the camera module. In contrast, in this embodiment, the circuit pattern 92 is formed using an ETS (Embedded Trace Substrate) structure. As a result, the circuit pattern 92 is a fine circuit pattern and may be embedded within an insulating layer 91. 【0088】 The circuit pattern 92 and pad 93 are wirings that transmit electrical signals and can be formed from a highly electrically conductive metallic material. For this reason, the circuit pattern 92 and pad 93 can be formed from at least one metallic material selected from gold (Au), silver (Ag), platinum (Pt), titanium (Ti), tin (Sn), copper (Cu), and zinc (Zn). Alternatively, the circuit pattern 92 and pad 93 can be formed from a paste or solder paste containing at least one metallic material selected from gold (Au), silver (Ag), platinum (Pt), titanium (Ti), tin (Sn), copper (Cu), and zinc (Zn), which have excellent bonding strength. Preferably, the circuit pattern 92 and pad 93 can be formed from copper (Cu), which has high electrical conductivity and is relatively inexpensive. 【0089】 A first protective layer 94 may be formed on the upper surface of the insulating layer 91. A second protective layer 95 may be formed on the lower surface of the insulating layer 91. 【0090】 The first protective layer 94 may be a protective layer that protects the upper surface of the insulating layer 91. The first protective layer 94 may be an attachment area to which the infrared filter 70 is attached. 【0091】 The second protective layer 95 may be a protective layer that protects the lower surface of the insulating layer 91 and the lower surface of the circuit pattern 92 or pad 93. 【0092】 The first protective layer 94 and the second protective layer 95 can be formed in at least one layer using one or more of SOR (Solder Resist), oxide, and Au. Preferably, the first protective layer 94 and the second protective layer 95 can be solder resist. 【0093】 The first protective layer 94 and the second protective layer 95 may have different layer structures. For example, the first protective layer 94 may have a two-layer structure, while the second protective layer 95 may have a single-layer structure. 【0094】 The first protective layer 94 may have a two-layer structure. For example, the first protective layer 94 may include a first-first protective layer 94-1 disposed on the upper surface of the insulating layer 91, and a first-second protective layer 94-2 disposed on the upper surface of the first-first protective layer 94-1. 【0095】 The 1-1 protective layer 94-1 may be in direct contact with the upper surface of the insulating layer 91. The 1-1 protective layer 94-1 may have a first opening (not shown) that exposes the area on the upper surface of the insulating layer 91 where the cavity C is formed. For example, the first opening formed in the 1-1 protective layer 94-1 may expose the area where the infrared filter 70 is placed. The first opening may be larger in size than the cavity C. The first opening may be smaller in width than the width of the infrared filter 70. Therefore, at least a portion of the 1-1 protective layer 94-1 may overlap with the infrared filter 70 in the optical axis direction. 【0096】 A first-second protective layer 94-2 may be placed on top of the first-first protective layer 94-1. The first-second protective layer 94-2 may be in direct contact with the upper surface of the first-first protective layer 94-1. The first-second protective layer 94-2 may have a second opening (not shown) that exposes the region where the cavity C is formed. The second opening of the first-second protective layer 94-2 may also overlap with the first opening of the first-first protective layer 94-1 in the optical axis direction. Preferably, the second opening of the first-second protective layer 94-2 may have a width greater than the cavity C and the first opening. For example, the second opening of the first-second protective layer 94-2 may be the same width as the infrared filter 70, or it may be greater than the width of the infrared filter 70. 【0097】 In this embodiment, the second opening of the first-2 protective layer 94-2 may expose a portion of the upper surface of the first-1 protective layer 94-1. The upper surface of the first-1 protective layer 94-1 exposed through the second opening can function as a mounting area to which the infrared filter 70 is attached. 【0098】 In the embodiment, the first protective layer 94, which includes the 1-1 protective layer 94-1 and the 1-2 protective layer 94-2, may have a step due to the difference in width between the first opening and the second opening as described above. The step allows the infrared filter 70 to be stably attached. 【0099】 On the other hand, the 1-1 protective layer 94-1 and the 1-2 protective layer 94-2 may have a structure in which the resin and filler are mixed. The 1-1 protective layer 94-1 and the 1-2 protective layer 94-2 can be embodied in a photosolder resist film. 【0100】 The 1-1 protective layer 94-1 and the 1-2 protective layer 94-2 may have different physical properties. Here, these physical properties may include the coefficient of thermal expansion (CTE) and the filler content. 【0101】 In this case, the thermal expansion coefficient of the 1-1 protective layer 94-1 may be smaller than that of the 1-2 protective layer 94-2. For example, the 1-1 protective layer 94-1 may have a thermal expansion coefficient of 10 to 25 ppm (@alpha1). For example, the 1-2 protective layer 94-2 may have a thermal expansion coefficient of 30 to 50 ppm (@alpha1). That is, in this embodiment, by prioritizing the placement of the 1-1 protective layer 94-1, which has a lower thermal expansion coefficient, on the insulating layer 91, and placing the 1-2 protective layer 94-2, which has a higher thermal expansion coefficient, on top of the 1-1 protective layer 94-1, the occurrence of warping of the printed circuit board due to CTE relaxation can be minimized. 【0102】 The second protective layer 95 is positioned on the lower surface of the insulating layer 91. The second protective layer 95 may have openings that expose the area on which the image sensor 80 is mounted and the area on which the solder balls 96 (described later) are placed. 【0103】 On the other hand, a cavity C may be formed in the insulating layer 91, penetrating both the upper and lower surfaces. In this case, the cavity C may be formed by a CNC drill. As a result, the cavity C may have a circular shape. That is, the cavity C formed in the printed circuit board 90 may have a different shape from that of the image sensor 80. For example, the image sensor 80 may have a rectangular shape, and the cavity C of the printed circuit board 90 may have a circular shape different from that of the image sensor 80. 【0104】 Specifically, the cavity C formed in the insulating layer 91 can have the same circular shape as the lens positioned in the lens barrel 30. This allows the cavity C and the lens to have the same shape, thereby minimizing the loss of light incident through the lens. However, the active pixel area of ​​the image sensor 80 is generally a rectangular area, and the size of the cavity C is adjusted to prevent the active pixel area of ​​the image sensor 80 from being covered by the cavity C. This will be explained in detail below. 【0105】 In this embodiment, since the cavity C is formed by a CNC drill as described above, a more reliable printed circuit board 90 can be provided compared to the comparative example. 【0106】 Specifically, when forming a cavity C by laser processing, the upper and lower widths of the cavity C appear to be different from each other. In other words, when forming a cavity by laser processing, the inner wall of the cavity C can have a certain inclination with respect to the upper or lower surface of the insulating layer. As a result, in the comparative example, the size of the cavity C had to be made larger than the target size by the region corresponding to the inclination, which led to the problem of increased substrate size. 【0107】 In contrast, in this embodiment, the upper and lower widths of the cavity C may appear to be the same as those of the cavity C by forming the cavity C through a CNC drill. That is, the inner wall of the cavity C in this embodiment may be perpendicular to the upper or lower surface of the insulating layer 91. This makes it possible to accurately form a cavity C corresponding to the target size in the insulating layer 91 in this embodiment, thereby solving the problem of increased substrate size. 【0108】 Furthermore, in the comparative example, the formation of the cavity C through laser processing leaves foreign matter such as burrs on the inner wall of the cavity C, which later causes reliability problems for the image sensor 80. 【0109】 In contrast, in this embodiment, by forming the cavity C using a CNC drill, foreign matter present on the inner wall of the cavity C can be completely removed, thereby resolving the reliability issues. 【0110】 For example, the surface roughness of the inner wall of the cavity C in the insulating layer 91 in the embodiment can be 0.01 μm to 0.1 μm. In contrast, the surface roughness of the inner wall of the cavity in the comparative example can be 0.1 μm or more. As a result, in the embodiment, by reducing the surface roughness of the inner wall of the cavity C compared to the comparative example, the problem of foreign matter present on the inner wall of the cavity C detaching from the insulating layer 91 and falling onto the image sensor 80 can be solved. 【0111】 On the other hand, the insulating layer 91 in the embodiment may include through-holes 90a which serve as air passages. These through-holes 90a can be air outlet passages through which expanded air between the infrared filter 70 and the image sensor 80 flows to the outside. 【0112】 Figure 5 is a diagram showing the combined configuration of a printed circuit board, an image sensor, and an infrared filter according to an embodiment. 【0113】 Referring to Figure 5, in the embodiment, the infrared filter 70 can be positioned in the step created by the change in the size of the first and second openings of the first-1 protective layer 94-1 and the first-2 protective layer 94-2. That is, in the embodiment, no separate structure is required to position the infrared filter 70, thereby reducing the unit cost of the product and reducing the overall height of the camera module. On the other hand, an adhesive (not shown) can be applied between the step of the first protective layer 94 and the infrared filter 70. The adhesive may include epoxy, thermosetting adhesive, UV-curing adhesive, etc. 【0114】 On the other hand, the second protective layer 95 can expose the underside of the circuit pattern 92 and pad 93 located on the underside of the insulating layer 91. The image sensor 80 can be attached to the exposed circuit pattern 92 using a flip-chip bonding method. Solder balls 96 can be placed under the exposed pad 93. 【0115】 Figures 6 and 7 are diagrams illustrating the cavity of the printed circuit board and the placement of the image sensor according to the embodiment. 【0116】 Referring to Figures 6 and 7, the image sensor 80 includes a pixel region consisting of multiple pixels that sense a light image (image information) incident through the lens, and a passivation region 83 other than the pixel region. 【0117】 Furthermore, the pixel area of ​​the image sensor 80 may include an active pixel area 81 used to sense actual image information, and a dummy pixel area 82 between the active pixel area 81 and the passivation area 83. 【0118】 In this case, the cavity C may overlap with the active pixel area 81 of the image sensor 80 in the optical axis direction. In other words, the entire active pixel area 81 of the image sensor 80 may overlap with the cavity C in the optical axis direction. Therefore, the entire area of ​​the active pixel area 81 of the image sensor 80 may be exposed through the cavity C. 【0119】 On the other hand, the dummy pixel region 82 of the image sensor 80 may include a first region 82-1 that does not overlap with the cavity C in the optical axis direction and a second region 82-2 that overlaps with the cavity C in the optical axis direction. 【0120】 In other words, in the embodiment, only a portion of the dummy pixel area 82 of the image sensor 80 may be exposed to the upper region through the cavity C. In this case, the dummy pixel area 82 is a pixel area that is not used for sensing the image information, and therefore, not exposing it through the cavity C does not affect reliability issues. 【0121】 However, while it is possible to expose the entire area of ​​the dummy pixel region 82 to the upper region via the cavity C, in this embodiment only a portion of the area is exposed. 【0122】 For example, in this embodiment, the corner regions of the dummy pixel region 82 are configured not to overlap with the cavity C in the optical axis direction. Therefore, during the process of mounting the image sensor 80 on the lower surface of the insulating layer 91, the corner regions of the dummy pixel region 82 can be supported by the insulating layer 91. 【0123】 Here, the entire area of ​​the dummy pixel area 82 is exposed through the cavity, so that the corner area of ​​the passivation area 83, rather than the dummy pixel area 82, is supported by the insulating layer 91. However, in this case, problems may occur with the flatness of the image sensor 80. That is, in this case, the passivation area 83 of the image sensor 80 may be subjected to heat and pressure during the flip-chip bonding process of the image sensor, which may cause warping of the active pixel area 81 of the image sensor 80. 【0124】 In contrast, in this embodiment, the warping problem of the active pixel region 81 adjacent to the dummy pixel region 82 can be minimized while the corner region of the dummy pixel region 82 is supported by the insulating layer 91 as described above. 【0125】 The printed circuit board in the embodiment has an ETS structure in which the circuit pattern is embedded within an insulating layer. This enables miniaturization of the printed circuit board in the embodiment. Furthermore, in the embodiment, even if the number of terminals increases due to the increase in the number of pixels of the image sensor through the miniaturization of the circuit pattern, the size of the printed circuit board does not need to be increased, and the size of the printed circuit board can be reduced as a result. 【0126】 Furthermore, in the comparative example, when the cavity is formed through laser processing, foreign matter such as burrs remains on the inner wall of the cavity, which later falls onto the image sensor and causes reliability problems. 【0127】 In contrast, in this embodiment, by forming the cavity using a CNC drill, foreign matter present on the inner wall of the cavity can be completely removed, thereby resolving the reliability issues. Furthermore, in this embodiment, by forming the cavity C through a CNC drill, the upper and lower widths of the cavity C may appear to be the same. That is, the inner wall of the cavity C in this embodiment may be perpendicular to the upper or lower surface of the insulating layer 91. As a result, in this embodiment, a cavity C corresponding to the target size can be accurately formed in the insulating layer, thereby resolving the issue of increased substrate size. 【0128】 Furthermore, in this embodiment, a step is formed in the protective layer made of solder resist, and the infrared filter is placed on the step. As a result, in this embodiment, a separate structure for placing the infrared filter is not required, which reduces the unit cost of the product and reduces the overall height of the camera module. 【0129】 Figures 8 to 12 are diagrams showing the manufacturing method of a printed circuit board according to an embodiment, in order of steps. 【0130】 Referring to Figure 8, in this embodiment, a carrier board CB can be prepared for manufacturing a printed circuit board. The carrier board CB may have a structure in which an insulating member CB-1 and a metal layer CB-2 are arranged on the insulating member CB-1. 【0131】 Next, referring to Figure 9, a plating process can be performed to form the circuit pattern 92 and pad 93 on the carrier substrate CB. 【0132】 Next, referring to Figure 10, in this embodiment, an insulating layer 91 can be formed on the carrier substrate CB to cover the circuit pattern 92 and the pad 93. 【0133】 Next, referring to Figure 11, in the embodiment, after the insulating layer 91 is formed, the carrier substrate CB can be removed. Then, in the embodiment, once the carrier substrate CB is removed, the first protective layer 94 can be formed on the upper surface of the insulating layer 91, and the second protective layer 95 can be formed on the lower surface of the insulating layer 91. At this time, the first protective layer 94 may have a two-layer structure including a 1-1 protective layer 94-1 and a 1-2 protective layer 94-2. The first region 82-1 may have steps through changes in the size of the openings of the two-layer protective layer. 【0134】 Next, referring to Figure 12, a step can be performed to form cavities C that penetrate the upper and lower surfaces of the insulating layer 91 using a CNC drill. 【0135】 The printed circuit board in the embodiment has an ETS structure in which the circuit pattern is embedded within an insulating layer. This enables miniaturization of the printed circuit board in the embodiment. Furthermore, in the embodiment, even if the number of terminals increases due to the increase in the number of pixels of the image sensor through the miniaturization of the circuit pattern, the size of the printed circuit board does not need to be increased, and the size of the printed circuit board can be reduced as a result. 【0136】 Furthermore, in the comparative example, when the cavity is formed through laser processing, foreign matter such as burrs remains on the inner wall of the cavity, which later falls onto the image sensor and causes reliability problems. 【0137】 In contrast, in this embodiment, by forming the cavity using a CNC drill, foreign matter present on the inner wall of the cavity can be completely removed, thereby resolving the reliability issues. Furthermore, in this embodiment, by forming the cavity C through a CNC drill, the upper and lower widths of the cavity C may appear to be the same. That is, the inner wall of the cavity C in this embodiment may be perpendicular to the upper or lower surface of the insulating layer 91. As a result, in this embodiment, a cavity C corresponding to the target size can be accurately formed in the insulating layer, thereby resolving the issue of increased substrate size. 【0138】 Furthermore, in this embodiment, a step is formed in the protective layer made of solder resist, and the infrared filter is placed on the step. As a result, in this embodiment, a separate structure for placing the infrared filter is not required, which reduces the unit cost of the product and reduces the overall height of the camera module. 【0139】 Figure 13 shows a perspective view of the mobile terminal 200A according to the embodiment, and Figure 14 shows a configuration diagram of the mobile terminal shown in Figure 13. 【0140】 Referring to Figures 13 and 14, the portable terminal 200A (hereinafter referred to as "terminal") may include a body 850, a wireless communication unit 710, an A / V input unit 720, a sensing unit 740, an input / output unit 750, a memory unit 760, an interface unit 770, a control unit 780, and a power supply unit 790. 【0141】 The body 850 shown in Figure 13 is in the form of a bar, but is not limited to this, and can have various structures such as a slide type, folder type, swing type, or swirl type in which two or more sub-bodies are connected in a way that allows for relative movement. 【0142】 The body 850 may include an external case (casing, housing, cover, etc.). For example, the body 850 may be divided into a front case 851 and a rear case 852. Various electronic components of the terminal device may be incorporated into the space formed between the front case 851 and the rear case 852. 【0143】 The wireless communication unit 710 may be configured to include one or more modules that enable wireless communication between the terminal 200A and the wireless communication system, or between the terminal 200A and the network on which the terminal 200A is located. For example, the wireless communication unit 710 may be configured to include a broadcast receiving module 711, a mobile communication module 712, a wireless internet module 713, a short-range communication module 714, and a location information module 715. 【0144】 The A / V (Audio / Video) input section 720 is for inputting audio or video signals and may include a camera 721 and a microphone 722, etc. 【0145】 The camera 721 may include a camera module according to the embodiment shown in Figure 3. 【0146】 The sensing unit 740 can sense the current state of the terminal 200A, such as its open / closed state, position, presence or absence of user contact, orientation, and acceleration / deceleration, and generate sensing signals to control the operation of the terminal 200A. For example, if the terminal 200A is in the form of a slide phone, it can sense whether the slide phone can be opened or closed. It also handles sensing functions related to the presence or absence of power supply from the power supply unit 790 and the possibility of connecting external devices to the interface unit 770. 【0147】 The input / output unit 750 is for generating inputs or outputs related to vision, hearing, or touch. The input / output unit 750 can generate input data for controlling the operation of the terminal 200A and can also display information processed by the terminal 200A. 【0148】 The input / output unit 750 may include a keypad unit 730, a display module 751, an audio output module 752, and a touchscreen panel 753. The keypad unit 730 can generate input data through keypad input. 【0149】 The display module 751 may include multiple pixels whose color changes in response to an electrical signal. For example, the display module 751 may include at least one of the following: a liquid crystal display, a thin-film transistor-liquid crystal display, an organic light-emitting diode, a flexible display, or a 3D display. 【0150】 The audio output module 752 can output audio data received from the wireless communication unit 710 in call signal reception, communication mode, recording mode, voice recognition mode, or broadcast reception mode, or it can output audio data stored in the memory unit 760. 【0151】 The touchscreen panel 753 can convert changes in capacitance caused by a user touching a specific area of ​​the touchscreen into an electrical input signal. 【0152】 The memory unit 760 may store programs for processing and controlling the control unit 780, and can temporarily store input / output data (e.g., phone book, messages, audio, still images, photographs, videos, etc.). For example, the memory unit 760 can store images captured by the camera 721, such as photographs or videos. 【0153】 The interface unit 770 acts as a passage connecting to external devices connected to the terminal unit 200A. The interface unit 770 receives data transmission from external devices, receives power supply and transmits it to various components inside the terminal unit 200A, and transmits data inside the terminal unit 200A to external devices. For example, the interface unit 770 may include a wired / wireless headset port, an external charger port, a wired / wireless data port, a memory card port, a port for connecting a device equipped with an identification module, an audio I / O (input / output) port, a video I / O (input / output) port, and an earphone port. 【0154】 The control unit 780 can control the overall operation of the terminal 200A. For example, the control unit 780 can perform related controls and processing for voice calls, data communications, video calls, etc. 【0155】 The control unit 780 may include a multimedia module 781 for multimedia playback. The multimedia module 781 may be implemented within the control unit 180 or separately from the control unit 780. 【0156】 The control unit 780 can perform pattern recognition processing that recognizes handwritten input or drawing input performed on the touchscreen as characters and images, respectively. 【0157】 The power supply unit 790 can receive an external or internal power supply under the control of the control unit 780, and can supply the power necessary for the operation of each component. 【0158】 The features, structures, and effects described in the examples above are included in at least one example and are not necessarily limited to just one example. Furthermore, the features, structures, and effects exemplified in each example can be combined or modified and implemented in other examples by a person with ordinary skill in the art to which the example belongs. Therefore, content related to such combinations and modifications should be interpreted as being included within the scope of the examples.

Claims

[Claim 1] Image sensor and A circuit board placed on the image sensor, The circuit board includes an infrared filter disposed on the circuit board, The aforementioned circuit board is An insulating layer including a cavity that overlaps in the optical axis direction with at least a portion of the infrared filter and at least a portion of the image sensor, A circuit pattern embedded in the insulating layer and connected to the terminals of the image sensor, The insulating layer includes a first protective layer disposed on the insulating layer, The planar shape of the cavity differs from the planar shape of the image sensor. The first protective layer is, A first layer disposed on the insulating layer and including a first aperture that overlaps the cavity and the optical axis direction, The second layer is disposed on the first layer, overlaps the cavity and the first aperture in the optical axis direction, includes a second aperture having a width greater than the width of the first aperture, and has a step difference with respect to the first layer, The infrared filter is placed at the step in the first protective layer, The first layer and the second layer of the first protective layer have different physical properties from each other. The infrared filter is in contact with the first layer and the second layer, The aforementioned physical properties include the coefficient of thermal expansion and the filler content. The thermal expansion coefficient of the second layer is greater than that of the first layer. The thermal expansion coefficient of the first layer is in the range of 10 to 25 ppm (@alpha1), A camera module having a thermal expansion coefficient of 30 to 50 ppm (@alpha1) of the second layer. [Claim 2] The planar shape of the aforementioned image sensor is rectangular. The camera module according to claim 1, wherein the planar shape of the cavity is circular. [Claim 3] The camera module according to claim 1 or claim 2, wherein the cavity has the same upper and lower widths. [Claim 4] The camera module according to claim 3, wherein the inner wall of the cavity is perpendicular to the upper or lower surface of the insulating layer. [Claim 5] The camera module according to any one of claims 1 to 4, wherein the surface roughness of the inner wall of the cavity is in the range of 0.01 μm to 0.1 μm. [Claim 6] The image sensor includes a pixel region and a passivation region. The camera module according to any one of claims 1 to 5, wherein the pixel region includes a first region overlapping the cavity in the optical axis direction and a second region overlapping the insulating layer in the optical axis direction. [Claim 7] The image sensor includes an active pixel region, a dummy pixel region, and a passivation region. The active pixel region overlaps with the cavity in the optical axis direction. The camera module according to any one of claims 1 to 5, wherein the dummy pixel region includes a first region that overlaps with the cavity in the optical axis direction together with the active pixel region, and a second region that overlaps with the insulating layer in the optical axis direction. [Claim 8] The camera module according to claim 7, wherein the second region includes the corner region of the dummy pixel region of the image sensor. [Claim 9] The aforementioned circuit board is A pad embedded in the lower part of the insulating layer, A second protective layer including an opening that overlaps with the pad in the optical axis direction, A camera module according to any one of claims 1 to 8, comprising: a solder ball disposed within the opening of the second protective layer. [Claim 10] A lens barrel arranged on the circuit board, A camera module according to any one of claims 1 to 9, comprising a lens disposed within the lens barrel. [Claim 11] The camera module according to claim 10, wherein the planar shape of the lens is different from the planar shape of the image sensor. [Claim 12] The camera module according to claim 11, wherein the planar shape of the lens is the same as the planar shape of the cavity.

Images