Mounting substrate with image sensor mounted thereon, sensor assembly, and method for manufacturing the same

Abstract

A mounting substrate with an image sensor mounted thereon, a sensor assembly, and a method for manufacturing the same. The sensor assembly is constructed by molding a frame onto a mounting substrate using insert molding, thereby preventing adhesion to components and terminals and reducing damage to the mounting substrate. The sensor assembly includes an image sensor, a mounting substrate with the image sensor mounted thereon, a frame disposed on the mounting substrate in a manner surrounding the image sensor, and a cover mounted on the frame in a manner covering the image sensor. The mounting substrate includes a terminal electrically connected to the image sensor and a groove disposed at a predetermined depth between an area where the frame is disposed and the terminal.

Description

Technical Field

[0001] The present invention relates to a mounting substrate on which an image sensor is mounted, a sensor assembly and a method of manufacturing the same, and more particularly, to a technique of manufacturing the sensor assembly by molding a resin frame around a mounting substrate by insert molding. Background Art

[0002] The following first and second configurations are known as sensor components of an image sensor such as a CMOS sensor for a digital camera. The first configuration mold bonds the image sensor to a ceramic component that can be mounted to a substrate by a reflow soldering method, and is sealed by a cover after a wire bonding process. The second configuration mold bonds the image sensor directly to the substrate, forms a frame around the substrate, and is sealed by a cover after a wire bonding process.

[0003] Although the second configuration has the problem that the image sensor may be warped due to the difference in linear expansion coefficient between the image sensor and the substrate, miniaturization and weight reduction can be achieved since the ceramic component becomes unnecessary. In addition, since the second configuration can shorten the signal distance from the image sensor to the bypass capacitor compared to the first configuration, it has the advantage of reducing the influence of magnetic noise on high-speed signals such as LVDS (Low Voltage Differential Signaling) and SLVS (Scalable Low Voltage Signaling). For this reason, the second configuration rather than the first configuration is becoming mainstream.

[0004] Regarding the second configuration, Japanese Patent Application Laid-Open No. 2009-81358 (JP 2009-81358A) discloses a technique in which a substrate is assembled into a frame having an opening and the inner wall of the frame is adhered to the side surface of the substrate. This makes the sensor assembly thinner and prevents moisture absorption (moisture intrusion) from the side surface of the substrate.

[0005] However, since the technology disclosed in the above publication adheres the inner wall of the frame to the side surface of the substrate, the desired adhesion strength cannot be obtained when the opening size and the outer size of the frame fluctuate greatly. In addition, even if adhesion is possible, the adhesion may fall off due to the warping of the substrate caused by temperature changes or impacts from the outside.

[0006] In order to solve this problem, there is a technology for molding a frame onto a substrate by insert molding. Insert molding is a technology for molding a frame by clamping the upper and lower sides of a substrate using a metal mold and injecting resin into a cavity of the metal mold formed along the periphery of the substrate. Since the frame is firmly connected to the substrate by using insert molding, the concern that the frame will fall off the substrate due to temperature changes or impacts is reduced. In addition, when the cavity of the metal mold is formed to cover the side surface of the substrate, the resin frame is also molded onto the side surface, which prevents moisture from being absorbed from the side surface of the substrate and prevents the diffusion of dust generated when the substrate is cut (dust discharge).

[0007] Meanwhile, when the frame is molded by insert molding, fluctuations in the thickness of the substrate may cause resin leakage when molding the frame. The upper metal mold and the lower metal mold have a gap for clamping the substrate. If the thickness of the substrate is less than the nominal size, an unnecessary gap will appear between the substrate and the clamping portion of the metal mold, which may cause resin leakage when molding the frame. When the resin invades the center of the substrate due to resin leakage, the possibility of causing components and terminals to adhere to the inside of the substrate will become higher. Meanwhile, when the thickness of the substrate is greater than the nominal size, the substrate will be damaged because the clamping portion of the metal mold bites into the substrate. Summary of the invention

[0008] The present invention provides a sensor assembly which is constructed by molding a frame onto a mounting substrate by insert molding and which prevents adhesion to components and terminals and reduces damage to the mounting substrate.

[0009] Therefore, a first aspect of the present invention provides a sensor assembly, comprising: an image sensor; a mounting substrate on which the image sensor is mounted; a frame provided on the mounting substrate so as to surround the image sensor; and a cover provided on the frame so as to cover the image sensor. The mounting substrate comprises: a terminal electrically connected to the image sensor; and a groove provided at a predetermined depth between an area on which the frame is provided and the terminal.

[0010] Therefore, a second aspect of the present invention provides a mounting substrate on which an image sensor is mounted, the mounting substrate including: a terminal electrically connected to the image sensor; and a groove provided at a predetermined depth between the terminal and a region where a frame is provided to surround the image sensor.

[0011] Therefore, the third aspect of the present invention provides a method for manufacturing a sensor component, the manufacturing method comprising: electrolytic plating a terminal arranged in a mounting substrate, a conductive portion extending from the terminal to the outside of the mounting substrate, and a connecting portion formed outside the terminal and connecting the conductive portion and the terminal; forming a groove in the mounting substrate by removing the connecting portion; and while clamping the mounting substrate with the groove formed by a metal mold, forming a frame by resin outside the groove on the mounting substrate by embedding molding.

[0012] Therefore, the fourth aspect of the present invention provides a method for manufacturing a sensor component, the manufacturing method comprising: electrolytic plating a terminal arranged in a mounting substrate, a conductive portion extending from the terminal to the outside of the mounting substrate, and a connecting portion formed outside the terminal and connecting the conductive portion and the terminal; forming a groove on the mounting substrate by etching away at least a portion of the conductive portion to insulate the terminal and the connecting portion; and while clamping the mounting substrate using a metal mold, forming a frame by anaerobic thermosetting resin outside the connecting portion on the mounting substrate by embedding molding, so that the terminal and the connecting portion are insulated in the mounting substrate.

[0013] Therefore, the fifth aspect of the present invention provides a method for manufacturing a sensor component, the manufacturing method comprising: forming a groove outside a terminal arranged in a mounting substrate; installing a chip in the groove; and while clamping the mounting substrate with the chip installed in the groove using a metal mold, forming a frame by resin outside the groove on the mounting substrate by embedding molding.

[0014] According to the present invention, in a sensor assembly configured by molding a frame into a mounting substrate by insert molding, adhesion of components and terminals is prevented, and damage to the mounting substrate is reduced.

[0015] Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a diagram illustrating a schematic configuration of an image pickup apparatus to which a sensor module according to an embodiment of the present invention is applied.

[0017] Figure 2A and Figure 2B It is a perspective view showing the sensor module according to the first embodiment.

[0018] Figure 3 It is shown Figure 2A Exploded perspective view of the sensor assembly.

[0019] Figure 4A and Figure 4B It is shown that the configuration is Figure 2A An enlarged view of the wiring bonding terminal portion of the printed circuit board of the sensor assembly.

[0020] Figure 5 It is shown along Figure 2A The metal mold is installed on the line AA of Figure 4B A cross-sectional view of the state of a printed circuit board.

[0021] Fig. 6A , Figure 6B and Figure 6C This means that due to the use Figure 5 A diagram showing the problems caused by thickness tolerance of a constructed printed circuit board in area B.

[0022] Figure 7 yes Figure 5 An enlarged view of area B is shown.

[0023] Fig. 8A and Figure 8B It is an enlarged view showing a wiring bonding terminal portion provided in a printed circuit board constituting the sensor module according to the second embodiment.

[0024] Fig. 9 Instructions for use Figure 5 The structure in area B shown in the figure is to install the metal mold on Figure 7 A cross-sectional view of the state of a printed circuit board.

[0025] Fig.10 It is an enlarged view showing a wiring bonding terminal portion provided in a printed circuit board constituting the sensor module according to the third embodiment.

[0026] Fig.11 It is shown along Fig.10 The metal mold is installed on the line BB Fig.10 A cross-sectional view of the state of a printed circuit board.

[0027] Fig.12 It is shown along Fig.10 The metal mold is installed on the line CC of Fig.10 A cross-sectional view of the state of a printed circuit board.

[0028] Fig.13 So with Figure 7 In the same manner, a diagram showing a state in which a metal mold is attached to a printed circuit board constituting a sensor module according to a fourth embodiment is shown. DETAILED DESCRIPTION

[0029] Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings. First, an imaging device to which a sensor module according to an embodiment of the present invention is applied will be described.

[0030] Figure 1: is a diagram showing a schematic configuration of an image pickup device to which a sensor assembly according to an embodiment of the present invention is applied. Specifically, Figure 1 The imaging device shown is a digital single-lens reflex camera. The imaging device mainly includes a lens unit 10 and a camera body 20.

[0031] The lens unit 10 has a lens group 11, a lens driving unit 12, a lens control circuit 13, and a lens mount contact 14. The lens group 11 includes a zoom lens for freely changing the focal length within a certain range and a focus lens for adjusting the focus on a subject. The lens driving unit 12 has an actuator for moving the zoom lens along the optical axis direction to change the optical magnification of the subject image. In addition, the lens driving unit 12 has an actuator for moving the focus lens along the optical axis direction to adjust the focus on the subject. Although these actuators are, for example, stepping motors or vibration actuators, other mechanisms may also be used.

[0032] The lens control circuit 13 controls the operation of the lens drive unit 12 by supplying a drive signal specifying the movement amount and movement speed of the zoom lens and the focus lens to the lens drive unit 12. When the lens unit 10 is connected to the camera body 20, the lens mount contact 14 is connected with a camera mount contact (not shown) provided in the camera body 20. This enables communication between the CPU 21 provided in the camera body 20 and the lens control circuit 13 mentioned below.

[0033] The camera body 20 has a CPU 21, a mirror unit 22, a mirror driver 23, a viewfinder unit 24, a shutter unit 25, a shutter drive circuit 26, a sensor module 100, an image processor 27, an external memory 28, a display unit 29, and a power source 80. It should be noted that the external memory 28 and the power source 80 are detachably mounted to the camera body 20.

[0034] The CPU 21 is a processor that realizes various functions of the image pickup apparatus by completely controlling the operations of the lens unit 10 and various parts of the camera body 20. The mirror unit 22 has a main mirror 22a and a sub-mirror 22b, and changes the direction of a photographing light beam (incident light beam) passing through the lens unit 10 by changing the angular positions of the main mirror 22a and the sub-mirror 22b. The mirror driver 23 includes a motor, a gear train, etc. (not shown), and drives the main mirror 22a and the sub-mirror 22b in response to a signal received from the CPU 21.

[0035] The viewfinder unit 24 has a pentaprism 24a, which reflects the photographic light beam reflected by the main mirror 22a to convert it into an erect normal image, and a photometric sensor (not shown), which detects the brightness of the subject. The shutter unit 25 is, for example, a mechanical focal plane shutter, and is provided with a mechanism that operates a front blade group and a rear blade group (not shown). The shutter drive circuit 26 controls the operation of the shutter unit 25 in response to a control signal from the CPU 21. When the user observes the subject image through the viewfinder unit 24, the shutter unit 25 is controlled to block the photographic light beam toward the sensor assembly 100. When capturing an image, the control unit 25 is controlled to obtain a desired exposure time in response to a release signal.

[0036] The sensor module 100 has an image sensor 300 (refer to FIG. 2 ) that receives incident light through the lens group 11. Details of the sensor module 100 will be described later.

[0037] The image sensor 300 is, for example, a CMOS sensor, and has an imaging pixel for capturing an object and a phase difference detection pixel for detecting a phase difference of an image of the object (for automatic focusing of an imaging plane phase difference method). The CPU 21 calculates a defocus amount based on a phase difference of an image of the object in a segmented area (a distance between pupil segmented images) obtained from a pixel signal output from the phase difference detection pixel. Then, the CPU 21 sends the calculated defocus amount to the lens control circuit 13 through the lens mount contact 14. The lens drive unit 12 drives the focus lens of the lens group 11 according to a control signal from the lens control circuit 13.

[0038] Furthermore, the subject image (optical image) formed on the imaging pixels of the image sensor 300 is converted into an imaging signal (analog signal) by photoelectric conversion, and the imaging signal is sent to the image processor 27. The image processor 27 converts the analog signal sent from the image sensor 300 into a digital signal, and then generates image data into the digital signal by applying image processing such as color correction processing, demosaic processing, tone correction (gamma correction) processing, and YC separation processing.

[0039] The external memory 28 is a non-volatile memory such as an SD memory card or a compact flash memory that can be removed from the camera body 20 and can be installed in the camera body 20. The image data generated by the image processor 27 is compressed by a predetermined compression technology (such as a JPEG system). The compressed image data is stored in the external memory 28. The display unit 29 includes a TFT liquid crystal panel and is openable and rotatable. The display unit 29 can display an image of the image data converted by the image processor 27, and can display an image of the image data read from the external memory 28 and stretched. In addition, during motion picture shooting, the image processor 27 converts the subject image formed on the image sensor 300 into a motion picture of a predetermined frame rate. The display unit 29 displays the motion picture. The power supply 80 is a secondary battery, a household AC adapter, etc. that can be removed from the camera body 20, and the power supply 80 supplies power to various parts of the camera device.

[0040] Next, the sensor assembly 100 relating to the first embodiment will be described in detail. Figure 2A 1 is a perspective view showing the sensor module 100 as viewed from the front side. Figure 2B 1 is a perspective view showing the sensor module 100 as viewed from the rear side. Figure 3 is an exploded perspective view showing the sensor assembly 100 .

[0041] The sensor assembly 100 is provided with a printed circuit board 200, an image sensor 300, a frame 400 and a cover 500. It should be noted that an X-axis, a Y-axis and a Z-axis that intersect each other perpendicularly are defined so that Figure 2A , Figure 2B and Figure 3 The correlation of the various parts is shown in the drawings shown. The Z axis intersects the image plane of the image sensor 300 at a right angle. The Y axis is parallel to the short side of the image sensor 300. The X axis is parallel to the long side of the image sensor 300. Figure 4A The coordinates are similarly shown in the accompanying drawings of FIG.

[0042] The sensor assembly 100 is a hollow assembly constructed by die bonding the image sensor 300 to the printed circuit board 200, and the opening (front side) of the frame 400 is sealed by the cover 500 after the frame 400 is mounted so as to surround the image sensor 300. The printed circuit board 200 is an example of a mounting substrate on which the image sensor 300 is mounted. The mounting substrate is not limited thereto.

[0043] The printed circuit board 200 is a laminated substrate, which is formed by stacking an insulator and a copper pattern like glass cloth in a wafer form and forming an interlayer connection through hole by using a laser beam processing. The solder resist layer is formed on the copper pattern of the uppermost layer (front) and the lowermost layer (back) of the printed circuit board 200 by spraying or mask printing for insulation. The solder resist layer is not formed on the terminals for mounting components or applying wiring bonding processing on the front and back of the printed circuit board 200. The terminals are electrolytically plated with gold to maintain connection reliability. It should be noted that in the non-electrolytic gold plating process, the thickness of the gold plating layer is generally 0.1 micron to 0.3 micron. In the electrolytic gold plating process, the thickness can be set to several microns. Therefore, the electrolytic gold plating process is suitable for the gold plating process of the wiring bonding processing terminal applied to the welding gold wire.

[0044] A chip bonding region 201 mounting the image sensor 300 and a frame region 202 mounting the frame 400 are established on the printed circuit board 200. Wire bonding terminals 203 connecting the image sensor 300 by wire bonding are provided in a region outside the chip bonding region 201 and inside the frame region 202.

[0045] The image sensor 300 is a solid-state imaging device in which a light receiving element and an amplifier are configured for each unit cell, and an image signal is output by reading an electrical signal that has been photoelectrically converted. The image sensor 300 is fixed to a paste-like silver adhesive applied to a die bonding area 201 of a printed circuit board 200 using a die bonding device. An effective image sensing area 301 corresponding to the field angle at the time of shooting is established in the central portion of the image sensor 300. Wiring bonding terminals 302 for connecting to wiring bonding terminals 203 of the printed circuit board 200 are provided at the periphery of the image sensor 300. Through the wiring bonding process, the wiring bonding terminals 203 of the printed circuit board 200 are connected to the wiring bonding terminals 302 of the image sensor 300 through gold wires having a diameter of several tens of micrometers, respectively, and they are electrically connected.

[0046] The frame 400 is molded to the frame region 202 of the printed circuit board 200 using a thermosetting resin (hereinafter referred to as "resin") by insert molding mentioned later. The thickness of the frame 400 in the X direction or the Y direction is greater than the thickness of the image sensor 300. The cover 500 is fixed to the front side of the frame 400 using an adhesive, thereby sealing the sensor assembly 100.

[0047] The frame 400 also covers the side surface 204 of the printed circuit board 200. The printed circuit board 200 is generally manufactured by dividing a large substrate on which many substrates are printed into individual substrates by router cutting or dicing. When dust such as glass cloth or copper pattern generated from the side surface of the printed circuit board 200 adheres to the wiring bonding terminal 203 when dividing, the strength of the wiring bonding will become insufficient. In the present embodiment, since the side surface 204 of the printed circuit board 200 is covered by the frame 400, dust discharge from the side surface 204 is prevented. The cover 500 is made of glass or crystal, and plays the role of sealing the sensor assembly 100 and the role of reducing moire and aberration by using birefringence.

[0048] The component mounting area 205 is provided in a surface opposite to a surface on which the image sensor 300 is mounted. Various components 208 for outputting an image signal such as a bypass capacitor for noise suppression, a regulator for supplying power to the image sensor 300, and a connector for connecting to the outside are soldered to the component mounting area 205 by reflow mounting.

[0049] Figure 4A and Figure 4B 1 is an enlarged view showing the wire bonding terminal 203 provided on the printed circuit board 200 and its vicinity (hereinafter referred to as a “wire bonding terminal portion”). Figure 4A 1 shows the state before the etching back process described later. Figure 4B 1 shows the state after the etch-back process. Figure 4A and Figure 4B As shown, the wire bonding terminal portion has a portion parallel to the X axis and a portion parallel to the Y axis. The configurations of these portions are the same.

[0050] exist Figure 4A In the embodiment of the present invention, the wiring bonding terminal 203 is subjected to electrolytic gold plating treatment in order to improve the connection reliability with the gold wire as described above. In order to perform the electrolytic gold plating treatment, it is necessary to extend the plating strip (conductive portion) 206 from the wiring bonding terminal 203 to the outside of the substrate (from the side surface 204 to the outside), and form a gold plating film while supplying current. When many wiring bonding terminals 203 that transmit image signals, power signals, GND signals, etc. are arranged on the printed circuit board 200, if the plating strip 206 is taken out from all the wiring bonding terminals 203 to the outside of the substrate, the following disadvantages will occur.

[0051] One of the disadvantages is the influence on the signal characteristics because the plating strip 206 is taken out from the wiring bonding terminal 203 and remains in the printed circuit board 200 as a stub. In particular, since the image signal processes high-speed signals such as LVDS and SLVS, the influence will significantly reduce the signal characteristics. In addition, another disadvantage is the reduction of the GND characteristics of the printed circuit board 200. This is because the GND solid pattern originally formed in the frame area 202 around the printed circuit board 200 to maintain the GND characteristics of the printed circuit board 200 will be divided so that the plating strip 206 is taken out to the outside of the substrate.

[0052] Therefore, the sensor assembly 100 is configured such that the plating strips 206 are connected to the respective wiring bonding terminals 203 in the initial manufacturing state of the printed circuit board 200. Then, an etch-back process is performed to finally remove the plating strips by etching.

[0053] In more detail, Figure 4A As shown in FIG. 1 , in the manufacturing process of the printed circuit board 200, the plating strip 206 is connected in the etched back area 207, and the plating strip connection part 206a is provided. The copper pattern is exposed without applying a solder resist to the etched back area 207. In addition, the plating strip 206b is provided from the plating strip connection part 206a to the outside of the substrate. When the current is supplied to the plating strip 206 from the outside of the substrate, the copper pattern is exposed. Figure 4A When the electrolytic gold plating process is performed in the state of , a gold plated film is formed on the wiring bonding terminal 203.

[0054] When Figure 4A In the state shown in FIG. 1 , after the wiring bonding terminal 203 is subjected to electrolytic gold plating, the etch-back region 207 is etched. Figure 4B The copper pattern is removed as shown. A groove 209 ( Figure 7 ).exist Figure 4B In the state of being, the wire bonding terminal 203 is subjected to electrolytic gold plating, and the number of plating strips extending toward the outside of the substrate is small. Thus, the above-mentioned disadvantages are overcome. That is, since the plating strips do not become short stubs that reduce signal characteristics and the GND characteristics are not reduced, it is possible to form a wire bonding terminal 203 suitable for wire bonding processing.

[0055] Next, a process of molding the frame 400 into the frame region 202 of the printed circuit board 200 by insert molding will be described. Figure 5 In the metal mold 600 ( Figure 2A 400) is mounted on the printed circuit board 200 so as to form the frame 400, along Figure 2A A cross-sectional view taken along line AA is shown.

[0056] The metal mold 600 includes an upper metal mold 601 and a lower metal mold 602 that clamp the printed circuit board 200 in the thickness direction of the printed circuit board 200. The contact of the upper mold 601 with the chip bonding area 201 of the printed circuit board 200 causes an insulation failure of the solder resist applied to the copper pattern. In addition, if the upper mold 601 contacts the wiring bonding terminal 203, cracks will occur on the wiring bonding terminal 203, and dust particles will be transferred. In order to avoid such problems, a space 605 is set above the wiring bonding terminal 203. At the same time, the frame 400 is miniaturized by making the inner wall 401 of the frame 400 close to the wiring bonding terminal 203, which makes the sensor component 100 miniaturized. As a result of these circumstances, the upper metal mold 601 has a holding portion that holds the outer side of the wiring bonding terminal 203 of the printed circuit board 200 in a frame shape in a narrow clamping area 603. In order to avoid interference with the component 208 mounted on the printed circuit board 200, a space 606 that supports the printed circuit board 200 is established in the lower metal mold 602.

[0057] Since the printed circuit board 200 is manufactured by laminating an insulating layer and a copper pattern layer, the thickness tolerance of the completed substrate becomes ± tens of micrometers to hundreds of micrometers due to the thickness variation of the layers. As the number of stacked layers increases, the thickness tolerance increases, which results in the following reference to FIG. 6A to FIG. 6C Description of the problem.

[0058] FIG. 6A to FIG. 6C 4 is a diagram illustrating a problem that occurs due to a thickness tolerance of the printed circuit board 200 when the frame 400 is molded to the printed circuit board 200 by insert molding. FIG. 6A to FIG. 6C Shows Figure 5 The structure of area B is shown.

[0059] Fig. 6A The relationship between the printed circuit board 200 and the metal mold 600 is shown in the case where the thickness of the completed printed circuit board 200 is equal to the designed value. In this case, since the gap in the clamping area 603 where the upper metal mold 601 clamps the printed circuit board 200 becomes zero (0), the frame 400 is properly molded by injection molding of the resin from the outside.

[0060] Figure 6BThe relationship between the printed circuit board 200 and the metal mold 600 is shown when the thickness of the completed printed circuit board 200 is greater (thicker) than the design value. In this case, the clamping area 603 of the upper metal mold 601 sinks into the printed circuit board 200 (extends into (inroad)), which seriously damages the printed circuit board 200. Specifically, the solder resist layer of the printed circuit board 200 may damage the copper pattern or the copper pattern may be cut. As a result, the printed circuit board 200 may be damaged. Even if it is not damaged, the dust generated due to the damage of the solder resist layer may also adhere to the wiring bonding terminal 203, which causes trouble in the wiring bonding process.

[0061] Figure 6C The relationship between the printed circuit board 200 and the metal mold 600 is shown in the case where the printed circuit board 200 does not have the etch-back area 207 and the thickness of the completed printed circuit board 200 is smaller (thinner) than the designed value. In this case, a gap 604 of several micrometers or several tens of micrometers is generated between the clamping area 603 of the upper metal mold 601 and the printed circuit board 200. When resin is injected into the cavity of the metal mold 600 from the outside to mold the frame 400, the resin leaks toward the printed circuit board 200 in the clamping area 603 through the gap 604. Since the inner wall 401 of the frame 400 is close to the wire bonding terminal 203, when the leaked resin adheres to the wire bonding terminal 203, trouble occurs in the wire bonding process and the yield is reduced.

[0062] A method such as providing a spacer between the upper metal mold 601 and the lower metal mold 602 according to the thickness of the printed circuit board 200 can be considered to avoid Figure 6B and Figure 6C However, if the thickness of each printed circuit board 200 is measured one by one and the metal mold 600 is adjusted according to the measurement result, the productivity will be reduced and the manufacturing cost will be increased. Figure 7 The construction of the instructions addresses these issues.

[0063] Figure 7 FIG. 2 is a diagram showing a structure of a printed circuit board 200 according to the present embodiment, and is Figure 5 It should be noted that in Figure 7 The hatching lines showing the cross sections of the components are omitted in order to show the sizes of the parts.

[0064] As reference Figure 4A As shown, the etch-back region 207 is provided outside the wiring bonding terminal 203 of the printed circuit board 200. When the thickness of the completed printed circuit board 200 is smaller than the designed value, Figure 6CAs in the case of FIG. 6A , the resin leaks through the gap 604 between the printed circuit board 200 and the upper metal mold 601 .

[0065] However, since the etch-back region 207 is provided between the gap 604 and the wiring bonding terminal 203, the leaked resin accumulates in the groove 209 provided in the etch-back region 207. The depth T2 of the groove 209 is equal to the sum of the thickness of the solder resist and the thickness of the copper pattern of the outer layer, and is several tens of micrometers to several hundred micrometers. The depth T2 is larger than the height T1 of the gap 604 of several micrometers to several tens of micrometers. In addition, the width W2 of the groove 209 is designed so that the cross-sectional area of ​​the groove 209 obtained by the product of the height T2 of the groove 209 and the width W2 will be larger than the cross-sectional area of ​​the gap 604 in the same cross section obtained by the product of the height T1 of the gap 604 and the width W1. This prevents the leaked resin from reaching the wiring bonding terminal 203 above the groove 209.

[0066] As described above, the printed circuit board 200 constituting the sensor assembly 100 relating to the first embodiment is provided with the groove 209 formed by etching back between the wiring bonding terminal 203 and the frame 400. This prevents adhesion of the resin leaked when the frame 400 is molded to the wiring bonding terminal 203 even in the case where the gap 604 occurs between the metal mold 600 and the printed circuit board 200. In addition, even if the metal mold 600 is adjusted so that the gap 604 will always occur in consideration of manufacturing variations in the thickness of the printed circuit board 200, the frame 400 is stably molded by insert molding, which avoids an increase in manufacturing cost.

[0067] Next, a sensor assembly relating to a second embodiment will be described. Fig. 8A and Figure 8B It is an enlarged view showing the wiring joint terminals provided in the printed circuit board 200A constituting the sensor assembly related to the second embodiment. It should be noted that components of the printed circuit board 200A common to those of the printed circuit board 200 are described by using the same names and the same reference numerals. Fig. 8A shows the state of the printed circuit board 200A before the etch-back process, and Figure 8B The state of the printed circuit board 200A after the etch-back process is shown.

[0068] In the state before the etching back process, the plating strip 206 pulled out from the wiring bonding terminal 203 and the plating strip connecting portion 206a are merged in the resist opening area 210, and one plating strip 206b is led out of the merged portion to the outside of the substrate. By performing the electrolytic gold plating process in this state, the gold plating process is applied to each wiring bonding terminal 203.

[0069] After that, an etch-back process according to the description in the first embodiment is performed. In the first embodiment, the plating strip connecting portion 206a of the printed circuit board 200 is etched back to remove the pattern. In contrast, in the second embodiment, an etch-back process is performed on an etch-back region 211 between the plating strip 206 and the plating strip connecting portion 206a of the printed circuit board 200A. Since a portion of the plating strip 206 is removed in the etch-back region 211, the plating strip connecting portion 206a is insulated from the wiring bonding terminal 203. Therefore, after the etch-back process, the plating strip connecting portion 206a (conductor portion) remains on the printed circuit board 200A, and as shown in FIG. Figure 8B Exposed to the surface as shown.

[0070] Fig. 9 Instructions for use Figure 5 The configuration in the area B shown is a cross-sectional view of a state where the metal mold 600 is mounted on the printed circuit board 200A. The upper metal mold 601 of the metal mold 600 has a gap 604 relative to the printed circuit board 200A. The resin poured into the cavity of the metal mold 600 to form the frame 400 leaks to the inside of the printed circuit board 200 through the gap 604. The copper pattern of the outer layer in the solder resist and the resist opening area 210 shown in FIG. 8 is partially removed and a groove 209 of several tens of micrometers to several hundreds of micrometers is formed.

[0071] The resin (thermosetting resin) used to form the frame 400 is generally an anaerobic resin. The anaerobic resin combines (cures) by intercepting oxygen in the presence of metal ions. Liquid acrylic resin, which is an example of an anaerobic resin, will not cure in air, but will accelerate curing when in contact with metal.

[0072] like Figure 8B As shown, the plating bar connection portion 206a is exposed in the printed circuit board 200A. Therefore, the resin leaking through the gap 604 first enters the groove 209. Since the plating bar connection portion 206a is exposed in the groove 209, the resin contacts the plating bar connection portion 206a and accelerates the curing. This prevents the resin from invading the wiring bonding terminal 203 in the plating bar connection portion 206a.

[0073] As described above, even if the gap 604 occurs between the metal mold 600 and the printed circuit board 200, since the groove 209 and the plating strip connecting portion 206a are exposed between the wiring joint terminal 203 and the frame 400 in the second embodiment, the leaked resin is absorbed by the groove 209 and the curing is accelerated by contacting the plating strip connecting portion 206a. As a result, since the frame 400 is stably molded to the printed circuit board 200A by insert molding while preventing the leaked resin from adhering to the wiring joint terminal 203, an increase in manufacturing cost is prevented. In addition, since the allowable range of thickness variation of the printed circuit board 200A is expanded, the manufacturing yield of the printed circuit board 200A is increased, which reduces the manufacturing cost of the sensor assembly.

[0074] Next, a sensor assembly relating to a third embodiment will be described. Fig.10 200B is an enlarged view showing a wiring joint terminal portion provided in a printed circuit board 200B constituting a sensor assembly related to the third embodiment. It should be noted that components of the printed circuit board 200B identical to those of the printed circuit boards 200 and 200A are described by using the same names and the same reference numerals.

[0075] The printed circuit board 200B is a multilayer substrate having a through hole 212 between the wiring junction terminal portion and the frame 400 shown in the dotted line. The through hole 212 is formed by forming a hole in the insulating layer between the wiring layers by means of a laser or a drill and by electroplating the inner wall of the hole. The through hole 212 is used to guide the signal of the outer layer or the inner layer to other layers in the printed circuit board 200B. It should be noted that the wiring junction terminal 203 is connected to the through hole 212 respectively by wiring (not shown) and becomes the same potential. However, these do not necessarily have to be the same potential. The wiring junction terminal 203 is electrolytically plated with gold using the wiring connected to the through hole 212.

[0076] Fig.11 It is shown along Fig.10 2 is a cross-sectional view taken along line BB of the embodiment in which the metal mold 600 is mounted on the printed circuit board 200B. Fig.11 The cross section shown corresponds to Figure 5 Area B shown. Fig.11 The cross-section lines showing the cross-sections of the components are omitted in order to reveal the size of each component. In addition, the same names and the same reference numerals are used to explain Fig.11 As shown in FIG. 6A to FIG. 7 The components shown are identical components to simplify the description.

[0077] The upper metal mold 601 of the metal mold 600 has a gap 604 relative to the printed circuit board 200B. The resin injected into the cavity of the metal mold 600 to form the frame 400 leaks into the printed circuit board 200B through the gap 607. The height T3 of the gap 607 is equal to several tens of microns. In contrast, the depth T4 of the through hole 212 is equal to the sum of the thickness of the copper pattern of the outer layer and the thickness of the insulating layer, and is several tens of microns to several hundred microns. The depth T3 is smaller than the depth T4 (T3<T4). Therefore, the resin leaked through the gap 607 accumulates in the through hole 212. In this way, when the through hole 212 is set for the predetermined wiring bonding terminal 203, it is possible to avoid the resin leaked through the gap 607 during the molding process of the frame 400 from adhering to the wiring bonding terminal 203.

[0078] Incidentally, since the wiring bonding terminals 203 are provided on the printed circuit board 200B at several hundred to several thousand points, if through holes 212 are provided for all the wiring bonding terminals 203, the following first and second problems will occur. The first problem is that if holes 212 are provided for all the wiring bonding terminals 203 using a laser or a drill, the manufacturing cycle time of the printed circuit board 200B will be increased. This increases the manufacturing cost. The second problem is that if many through holes 212 are provided near the wiring bonding terminals 203, the strength of the printed circuit board 200B will be reduced. In particular, the manufacturing process of the sensor assembly 100 in the present embodiment includes a process for applying pressure and heat to the printed circuit board 200B from the outside (such as molding of the frame 400), mounting (pasting) of the image sensor 300, and wiring bonding. Therefore, the reduction in the strength of the printed circuit board 200B may lead to fatal defects such as poor molding of the frame 400 and peeling of the wiring bonding.

[0079] The printed circuit board 200B is provided with a configuration that solves the first and second problems described above. Fig.12 This structure will be described. Fig.12 It is shown along Fig.10 1 is a cross-sectional view taken along line CC of the printed circuit board 200B showing a state where the metal mold 600 is mounted on the printed circuit board 200B.

[0080] The upper metal mold 601 of the metal mold 600 has a gap 608 with respect to the printed circuit board 200B in a region where the through hole 212 for the wiring bonding terminal 203 is not formed. Then, the height T5 of the gap 608 is greater than Fig.11The height T3 of the shown gap 607 is small (T5 < T3). Since the molten resin injected into the cavity of the mold 600 has a certain viscosity, when gaps with different heights are formed between the printed circuit board 200 and the upper mold 601, the resin preferentially leaks through the larger gap. That is, the resin preferentially leaks through the gap 607 rather than the gap 608.

[0081] As described above, since the through hole 212 is provided between the gap 607 and the wiring bonding terminal 203, the resin leaking into the printed circuit board 200B accumulates in the through hole 212 and is blocked, which prevents the resin from adhering to the wiring bonding terminal 203. A small amount of resin leaks into the printed circuit board 200B through the gap 608. However, when parameters such as the relative heights of the gaps 608 and 607, the depth of the through hole 212, and the distances from the wiring bonding terminal 203 to the gaps 608 and 607 are appropriately set, the resin leaking into the printed circuit board 200B through the gap 608 is prevented from reaching the wiring bonding terminal 203.

[0082] Next, the sensor assembly according to the fourth embodiment will be described. Fig.13 is shown in the same manner as Figure 7 a diagram showing a state in which the mold 600 is mounted on the printed circuit board 200C constituting the sensor assembly according to the fourth embodiment. It should be noted that, Fig.13 in the same manner as Figure 7 the same manner shows Figure 5 the region corresponding to the region B in

[0083] The upper mold 601 of the mold 600 has a gap 607 with respect to the printed circuit board 200C. The thermosetting resin poured into the cavity of the mold 600 to form the frame 400 leaks into the printed circuit board 200C through the gap 607. A groove 213 for mounting to the inner layer of the substrate is provided between the gap 607 and the wiring bonding terminal 203. The chip 214 is mounted in the groove 213.

[0084] The chip 214 is an electrical component or an electronic component such as a resistor or a capacitor, and is mounted in the groove 213 by using a mounting technique. The mounting technique is a technique for forming a space in which a desired mounting component can be mounted in the inner layer of the mounting substrate, and the component is mounted in this space. By using the mounting technique to mount the component to the inner layer substrate of the substrate (hereinafter referred to as "inner layer mounting substrate"), the thickness of the substrate including the component can be thinned. This enables the sensor assembly 100 to be miniaturized. In addition, for a surface mounting substrate in which components are mounted on the substrate surface, signal lines need to be led out from the inside of the substrate to the substrate surface in order to guide the signals in the substrate to the components on the substrate surface. In contrast, since the inner layer mounting substrate enables wiring (connection) to be performed inside the substrate and does not require signal lines to be led out from the inside of the substrate to the substrate surface, the signal quality is improved by shortening the wiring length.

[0085] The space in the inner layer of the substrate is formed by a method of forming a groove by drilling after manufacturing the substrate or by laminating an insulating layer and a conductor layer having a notch corresponding to the shape of the component. The groove on the surface of the printed circuit board 200C can be formed by drilling or laminating the insulating layer and the conductor layer having a notch.

[0086] Fig.13 The state in which the upper mold 601 and the lower mold 602 are mounted on the printed circuit board 200C as in the third embodiment is shown. The upper mold 601 of the mold 600 has a gap 607 with respect to the printed circuit board 200C. The thermosetting resin poured into the cavity of the mold 600 to form the frame 400 leaks into the printed circuit board 200C through the gap 607.

[0087] In the printed circuit board 200C, the height T7 of the chip 214 is smaller than the depth T6 of the groove 213 (T7 < T6). The resin leaking through the gap 607 enters the groove 213. In addition, a part of the resin leaking through the gap 607 may flow onto the chip 214. The chip 214 has metal terminals 214a for mounting to the printed circuit board 200C.

[0088] As described above, the thermosetting resin for the frame 400 is an anaerobic resin, and its curing is accelerated when it comes into contact with metal. Therefore, the resin entering the groove 213 comes into contact with the metal terminal portion 214a and accelerates the curing. This prevents the leaked resin from reaching the wiring bonding terminal 203.

[0089] It should be noted that in this embodiment, the height T7 of the chip 214 is smaller than the depth T6 of the groove 213. Thus, the effect of thinning the substrate thickness obtained by the mounting technology is fully utilized. At the same time, in the case where the necessity of thinning the substrate thickness is low, the height T7 of the chip 214 can be greater than the depth T6 of the groove 213. In this case, the resin leaked through the gap 607 also flows into the groove 213 and is blocked by the chip 214, and the curing is accelerated by the contact metal terminal 214a. The same effect as the second embodiment is obtained.

[0090] It should be noted that, as in the third embodiment, the wiring bonding terminals 203 are arranged on the printed circuit board 200B at several hundred to several thousand points. Therefore, if a groove 213 is provided for each wiring bonding terminal 203 and a chip 214 is installed in each groove 213, the manufacturing cycle of the printed circuit board 200C will be increased and the strength will be reduced. Therefore, a position where the resin leaks preferentially is formed in the same manner as in the third embodiment, which forms gaps 607 and 608 with different heights between the metal mold 600 and the printed circuit board 200B. The leaked resin is absorbed by forming the groove 213 at the position where the resin leaks preferentially and by installing the chip 214 in the groove 213. This reduces (positions) the setting position of the groove 213 and the chip 214, avoiding an increase in the manufacturing cycle time and a reduction in strength.

[0091] Although the present invention has been described in detail based on appropriate embodiments, the present invention is not limited to these specific embodiments and includes various configurations that do not depart from the scope of the present invention. In addition, the above-mentioned embodiments show examples of the present invention, and the embodiments can be appropriately combined.

[0092] For example, the sensor assembly relating to the embodiment of the present invention is applicable not only to a digital single-lens reflex camera but also to other imaging devices such as a mirrorless single-lens reflex camera and a compact camera, and to various electronic devices equipped with an imaging function. In addition, the sensor assembly of the present invention may include the groove 209 as a characteristic configuration of the printed circuit board 200 and the plating bar connection portion 206a as a characteristic configuration of the printed circuit board 200A. This more surely prevents the resin leaked during the insert molding of the frame 400 from adhering to the wiring joint terminal 203.

[0093] Other Implementations

[0094] While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the claims is to be accorded the broadest interpretation so as to encompass all such modifications, equivalent structures, and functions.

[0095] This application claims priority from Japanese Patent Application No. 2019-159620 filed on September 2, 2019, Japanese Patent Application No. 2020-103090 filed on June 15, 2020, and Japanese Patent Application No. 2020-122340 filed on July 16, 2020, the entire contents of which are incorporated herein by reference.

Claims

1. A sensor assembly, comprising: Image sensor; A mounting substrate on which the image sensor is mounted; a frame, which is arranged on the mounting substrate in a manner of surrounding the image sensor; as well as a cover mounted on the frame in a manner covering the image sensor, Wherein, the mounting substrate comprises: A terminal electrically connected to the image sensor, It is characterized in that The mounting substrate further includes a groove provided at a predetermined depth between a region where the frame is provided and the terminal; and The groove is a recessed portion that is not a through hole into which the resin constituting the frame can flow.

2. The sensor assembly according to claim 1, wherein: The frame is made of thermosetting anaerobic resin.

3. The sensor assembly according to claim 1 or 2, wherein: A gold plating layer is formed on the surface of the terminal.

4. The sensor assembly according to claim 1 or 2, wherein: A chip is installed in the slot.

5. A mounting substrate capable of mounting an image sensor, the mounting substrate comprising: a terminal capable of being electrically connected to the image sensor, It is characterized in that The mounting substrate further includes a groove provided at a predetermined depth between the terminal and a region where a frame is provided to surround the image sensor, and The groove is a recessed portion that is not a through hole into which the resin constituting the frame can flow.

6. The mounting substrate according to claim 5, wherein: A chip is installed in the slot.

7. A method for manufacturing a sensor component, characterized in that: The manufacturing method comprises: Performing electrolytic plating treatment on a terminal provided in a mounting substrate, a conductive portion extending from the terminal to the outside of the mounting substrate, and a connecting portion formed outside the terminal and connecting the conductive portion and the terminal; forming a groove in the mounting substrate by removing the connection portion; and While the mounting substrate having the groove formed therein is clamped by a metal mold, a frame is formed of resin on the mounting substrate outside the groove by insert molding.

8. A method for manufacturing a sensor component, characterized in that: The manufacturing method comprises: Performing electrolytic plating treatment on a terminal provided in a mounting substrate, a conductive portion extending from the terminal to the outside of the mounting substrate, and a connecting portion formed outside the terminal and connecting the conductive portion and the terminal; forming a groove on the mounting substrate by removing at least a portion of the conductive portion by etching to insulate the terminal from the connecting portion; and While the mounting substrate is clamped by a metal mold, a frame is formed of an anaerobic thermosetting resin outside the connection portion on the mounting substrate by insert molding, and the terminal and the connection portion are insulated from each other in the mounting substrate.

9. A method for manufacturing a sensor component, characterized in that: The manufacturing method comprises: forming a groove outside a terminal disposed in the mounting substrate; installing a chip in the slot; and While the mounting substrate with the chip mounted in the groove is clamped by a metal mold, a frame is formed of resin on the mounting substrate outside the groove by insert molding.

10. The method for manufacturing a sensor assembly according to any one of claims 7, 8 and 9, wherein: The metal mold has a holding portion that holds the mounting substrate, and A cross-sectional area of ​​a gap formed between the metal mold and the mounting substrate at the holding portion is smaller than a cross-sectional area of ​​the groove in the same cross section.

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