JP4411893B2 - Solid circuit board and imaging device - Google Patents

Description

  The present invention relates to a three-dimensional circuit board for mounting an image pickup element and an optical member such as a lens, which are constituent members of the image pickup apparatus, and an image pickup apparatus formed by mounting the image pickup element and the optical member on the three-dimensional circuit board. It is about.

  Conventionally, a small-sized imaging device using an imaging element has been put into practical use. This image pickup apparatus is formed by mounting an image pickup device and an optical member such as a lens for supplying information light to the image pickup device on a circuit board. For example, a monitor camera, a medical camera, an in-vehicle camera, a mobile phone Used as a telephone camera.

A three-dimensional circuit board formed in a three-dimensional manner is known as a circuit board for mounting an imaging element, an optical member, and the like (see, for example, Patent Document 1). By using such a three-dimensional circuit board, circuits can be arranged in a three-dimensional manner, and the imaging device can be miniaturized.
JP 2001-245186 A

  Pressure welding may be used for mounting the image sensor on the three-dimensional circuit board. Here, in the pressure welding, after positioning the semiconductor element so that the terminal formed on the surface of the semiconductor element such as the image pickup element and the pad formed on the surface of the circuit board are opposed to each other, the semiconductor element is directed to the circuit board. It is a joining method in which the semiconductor element and the circuit board are electrically connected by fixing them to the circuit board using resin or the like while pressing. Thus, since it is necessary to press an image pick-up element toward a 3D circuit board by considerable force in the case of press-contact joining, the said pressed part of a 3D circuit board may deform | transform (FIG. 12 (A)). ).

  In particular, the portion of the three-dimensional circuit board where the image sensor is mounted is cut away so as not to block the optical path of the information light or is formed to be thin with a thickness of 1 mm or less. It was easy.

  When the image pickup device is bonded using an underfill (adhesive such as an epoxy resin) or the like in this deformed state (FIG. 12B), the image pickup device and the optical member are joined in a shifted state. As a result, the optical performance of the image pickup apparatus is poor. Further, since the elastic stress remains on the three-dimensional circuit board, the image pickup device may be easily detached by applying a slight external force.

  The present invention has been made to solve such a conventional problem.

In order to solve the above problems, a first solving means of the present invention includes a substrate portion having an opening, and an optical member mounting portion provided on one surface of the substrate portion for mounting the optical member. The three-dimensional circuit board on which the imaging element is mounted across the opening on the other surface of the substrate portion is configured by providing a reinforcing member for reinforcing the substrate portion in a part of the substrate portion. And the position which includes the position where the reinforcing member for reinforcing the substrate portion is translated in the thickness direction of the substrate portion from the position of the electrode pad which is the connection portion for connecting the electrodes of the image pickup device. The reinforcing member is composed of a plurality of regions having different thicknesses, and the ratio of the thickness of the reinforcing member in each region is determined by the electrode pad provided on the surface of the region of the substrate portion to be reinforced by each region. The decision is to be proportional to the number.

  The second solving means of the present invention includes a three-dimensional circuit board configured by the first solving means, an imaging device attached to the substrate of the three-dimensional circuit board by pressure contact bonding, and a lens circuit body attached to the three-dimensional circuit board. An imaging device is provided.

According to the first solving means, when the imaging element is mounted across the opening on the three-dimensional circuit board, it is possible to prevent the substrate portion from being deformed by the reinforcing member, and thus the imaging element can be mounted with high dimensional accuracy. A three-dimensional circuit board with high mounting reliability can be provided. In addition, the reinforcing member can be arranged in a necessary thickness for each region to be reinforced, and the deformation of the substrate portion can be prevented with an appropriate amount of the reinforcing member.

  According to the second solving means, since the deformation of the substrate portion is prevented by the reinforcing member, the imaging element is mounted with high dimensional accuracy, and as a result, the reliability in which the imaging element and the optical member are mounted in a good positional relationship. An imaging device with high image quality can be provided.

(1) First embodiment:
(1-1) Structure of the three-dimensional circuit board:
First, the structure of the three-dimensional circuit board according to the first embodiment will be described with reference to FIGS. FIG. 1 is a perspective view of the three-dimensional circuit board according to the first embodiment, and FIG. 2 is a cross-sectional view of the three-dimensional circuit board.

  As shown in FIGS. 1 and 2, the three-dimensional circuit board 1 includes a substrate unit 2 for mounting the imaging element E and an optical member mounting unit 3 for mounting the optical member L. As will be described later, the substrate portion 2 and the optical member mounting portion 3 are integrally formed by injection molding of a resin material. In addition, the constituent material and the molding method of the substrate unit 2 and the optical member mounting unit 3 are not particularly limited to this, but the injection molding can mold a complicated shape with high accuracy and has excellent mass productivity. The resin material is advantageous in that it has good moldability and insulating properties.

  In the following description, the surface of the substrate unit 2 on which the optical member mounting portion 3 is provided is referred to as a first surface 2a, and the surface opposite to the first surface 2a is referred to as a second surface 2b.

  The board | substrate part 2 has the opening part 4 penetrated from the 1st surface 2a side to the 2nd surface 2b side. The opening 4 is an opening that allows the information light to pass from the first surface 2a side to the second surface 2b side in order to supply the information light whose optical path is adjusted by the optical member L to the imaging device E. The opening 4 has the side surface 4a in the direction of widening the opening 4 from the second surface 2b side to the first surface 2a side so as not to block the optical path of the information light condensed on the image sensor E. Inclined.

  Further, the circuit 5 is formed on the second surface 2 b side of the substrate portion 2, and a plurality of electrode pads 5 a are formed at the end portion located in the vicinity of the opening 4 of the circuit 5. The electrode pad 5a is a connection portion for connecting the electrodes of the image sensor E. And the electrode of the image pick-up element E is joined to the electrode pad 5a by pressure welding as mentioned later.

  Furthermore, the board | substrate part 2 is equipped with the reinforcement member 6 in a part of the thickness direction. The reinforcing member 6 is disposed at a position including a position translated from the position of the electrode pad 5 a of the substrate portion 2 in the thickness direction of the substrate portion 2. The reinforcing member 6 is formed of any one of metal, ceramic, or glass. Therefore, the reinforcing member 6 is made of a material having a higher elastic modulus (Young's modulus) than the material (resin) constituting the substrate unit 2, and the imaging element E is attached to the three-dimensional circuit board 1 as will be described later. It is possible to prevent deformation of the substrate portion 2 at the time, and by extension, the image pickup element E can be accurately mounted at a fixed position.

  Further, the reinforcing member 6 is made of a material having a thermal conductivity compared to the material (resin) constituting the substrate portion 2, and as described later, the temperature in the three-dimensional circuit board 1 is made uniform at the time of pressure welding, Generation | occurrence | production of a joining failure can be prevented, and an adhesive material can be hardened rapidly by removing the reinforcement member 6 and forcibly adding heat to a joining location.

  Examples of the constituent material of the reinforcing member 6 include phosphor bronze as a metal, alumina as a ceramic, and quartz glass as a glass. Further, since the Young's modulus of the resin that is the constituent material of the substrate portion 2 is about 5 GPa, it is desirable to use a material of 30 GPa or more as the constituent material of the reinforcing member 6.

  In addition, the constituent material of the reinforcing member 6 is not particularly limited to the above-described material, and by appropriately selecting a material having a higher elastic modulus (Young's modulus) than the constituent material of the substrate portion 2, the deformation of the substrate portion 2 can be selected. Further, by appropriately selecting a material having a higher thermal conductivity than that of the constituent material of the substrate portion, it is possible to prevent poor bonding and promote the curing of the adhesive.

  The optical member mounting portion 3 is formed in a cylindrical shape, and an optical member L such as a lens or an aperture is mounted inside the cylindrical shape.

(1-2) Manufacturing method of three-dimensional circuit board:
Next, a method for manufacturing the three-dimensional circuit board 1 will be described with reference to FIG. FIG. 3 is a diagram illustrating a manufacturing procedure of the three-dimensional circuit board 1.

  As shown in FIG. 3, first, the reinforcing member 6 is formed into a predetermined shape (FIG. 3A). When the reinforcing member 6 is made of metal, it may be formed by casting, cutting, etc., when it is made of ceramic, it may be formed by powder molding or the like, and when it is made of glass, it may be formed by melt pressing.

  Next, the reinforcing member 6 is placed on the first mold M1, and the cavity C is formed while fixing the reinforcing member 6 with the presser pins P provided on the second mold M2 (FIG. 3B). In this way, since the reinforcing member 6 is fixed by the presser pin P, the reinforcing member 6 can be molded in a state where it is arranged at the design position without moving the reinforcing member 6 when the resin material is injected and filled in the subsequent process.

  Next, a molding material is injection-filled into a cavity C formed between the first mold M1 and the second mold M2, and then cured (FIG. 3C). Since the three-dimensional circuit board 1 is formed by inserting the reinforcing member 6 in this manner, the joining state between the substrate portion 2 and the reinforcing member 6 can be ensured. Further, there is no need to provide a separate step for joining the reinforcing member 6, and the three-dimensional circuit board 1 can be manufactured efficiently and at low cost.

  Subsequently, the molded product is released from the mold, and the circuit 5 and the electrode pad 5a are formed on the second surface 2b of the substrate part 2 after release by plating, printing, or the like, thereby completing the three-dimensional circuit board 1 (FIG. 3). (D)).

(1-3) Structure of imaging device:
Next, an imaging apparatus using the above three-dimensional circuit board will be described with reference to FIG. FIG. 4 is a cross-sectional view illustrating the structure of the imaging device.

  As shown in FIG. 4, the imaging device 10 includes a three-dimensional circuit board 1, an imaging element E attached to the second surface 2 b side of the substrate part 2 of the three-dimensional circuit board 1, and an optical member attachment part of the three-dimensional circuit board 1. 3 and an optical member L attached to 3.

  Since the configuration of the three-dimensional circuit board 1 is as described above, the description thereof is omitted here.

  The image sensor E is a device that converts optical information (optical signal) from an image into an electric signal by an arrangement of pixels, and a known image sensor can be used. Specifically, for example, a CCD image sensor or a CMOS image sensor can be used. The image sensor E includes a light receiving unit for receiving optical information and a terminal which is a connection unit with an external circuit for sending an electrical signal converted from the optical information to an external circuit. The image sensor E is attached to the three-dimensional circuit board 1 with a terminal connected to the electrode pad 5 a so that the light receiving portion is positioned on the opening 4.

  The optical member L is a member for supplying information light to the image sensor E, and is, for example, a lens for condensing the information light, an aperture for blocking unnecessary light, or the like. In FIG. 4, the optical element L is comprised by the 1st lens L1, the aperture L2, and the 2nd lens L3. These optical members L are sequentially inserted into the cylinder of the optical member mounting portion 3 formed in a cylindrical shape and mounted on the three-dimensional circuit board 1.

  The imaging device 10 formed in this way is connected to a circuit Y formed on the surface of the flexible printed board X via solder Z, for example.

(1-4) Manufacturing method of imaging device:
Next, a manufacturing method of the imaging device will be described with reference to FIG. FIG. 5 is a diagram illustrating a manufacturing procedure of the imaging device.

  As shown in FIG. 5, first, the optical member mounting portion 3 of the three-dimensional circuit board 1 is pressed against and fixed to a work surface plate (not shown), and the imaging element E is placed on the second surface 2 b side of the substrate portion 2. Is arranged so that the terminal contacts the electrode pad 5a (FIG. 5A).

  Next, the image sensor E is pressed toward the substrate portion 2 (FIG. 5B). The pressing force at this time is determined so that the E electrode of the image sensor and the electrode pad 5a of the three-dimensional circuit board are brought into contact with each other surely and sufficiently. Usually, the number of terminals of the image sensor E (that is, the three-dimensional path) The number of electrode pads 5a of the plate 1). Specifically, a pressing force of 30 to 300 g is applied per electrode pad, and for example, a pressing force of 1200 to 12000 g is applied to the three-dimensional circuit board 1 having 40 electrode pads 5a.

  At this time, the three-dimensional circuit board 1 is applied with such a large pressing force as described above, and the vicinity of the electrode pad 5a of the substrate portion 2 tends to be deformed, but the deformation is prevented by the reinforcing member 6.

  Next, in the pressed state, a thermosetting adhesive T is filled between the substrate portion 2 of the three-dimensional circuit board 1 and the image sensor E, and then heat is applied to cure the adhesive T (FIG. 5). (C)). Here, as described above, since the reinforcing member 6 has better heat conduction than the substrate portion 2, by heating the portion 6 a exposed to the outside of the reinforcing member 6, the vicinity of the adhesive filling portion can be efficiently heated. It is possible to cure the adhesive T efficiently.

  Next, the second lens L3, the aperture L2, and the first lens L1 are sequentially inserted and mounted on the optical member mounting portion 3 of the three-dimensional circuit board 1 to complete the imaging device 10 (FIG. 5D).

  In the imaging apparatus 10 manufactured in this way, the deformation of the substrate portion 2 is prevented by the reinforcing member 6, so that the imaging element E is mounted with high dimensional accuracy, and as a result, the imaging element E and the optical member L have a good positional relationship. So that the imaging device can be made highly reliable.

(2) Second embodiment:
(2-1) Structure of the three-dimensional circuit board:
The structure of the three-dimensional circuit board according to the second embodiment will be described with reference to FIGS. FIG. 6 is a plan view of a molded circuit board according to the second embodiment, and FIG. 7 is a cross-sectional view of the molded circuit board.

  As illustrated in FIGS. 6 and 7, the three-dimensional circuit board 1 ′ according to the second embodiment is configured such that the reinforcing member 6 according to the first embodiment further functions as an electrode pad and a circuit. Except for this point, the 3D circuit board 1 ′ according to the second embodiment is basically the same as the 3D circuit board 1 according to the first embodiment, and the same components are denoted by the same reference numerals. The description in is omitted.

  The substrate portion 2 is configured to include a plurality of reinforcing members 6 '. Each reinforcing member 6 ′ is exposed on the second surface 2 b of the substrate portion 2 around the opening 4, and the exposed portion serves as an electrode pad. Further, each reinforcing member 6 'functions as a circuit line and plays a role as a circuit as a whole.

  Note that the electrode pad and the circuit may be configured only by the reinforcing member 6 ′, but in addition to this, the circuit 5 and the electrode pad 5a are formed on the second surface 2b of the substrate portion 2 as in the first embodiment. You may do it.

(2-2) Manufacturing method of three-dimensional circuit board:
Next, the manufacturing method of 3D circuit board 1 'is demonstrated.

  The method of manufacturing the three-dimensional circuit board 1 'is basically the same as the method of manufacturing the three-dimensional circuit board 1 according to the first embodiment, and differs only in that a plurality of reinforcing members 6' are inserted and molded. That is, a mold having a presser pin for fixing each reinforcing member 6 ′ is used, and a cavity is formed in a state where each reinforcing member 6 ′ is fixed with these presser pins, and a resin material is injected and filled in the cavity. Then, the three-dimensional circuit board 1 ′ is formed.

(2-3) Imaging device:
The imaging device 10 ′ using the 3D circuit board 1 ′ is basically the same as the configuration and manufacturing method of the imaging device 10 according to the first embodiment, except that the configuration of the 3D circuit board 1 ′ is different in the above points. is there.

  If the circuit is formed on the surface of the substrate portion 2 in addition to the reinforcing member 6 ′ to form the three-dimensional circuit board 1 ′, the circuit can be multilayered, thereby reducing the size of the imaging device 10 ′. Can be achieved.

(3) Third embodiment (3-1) Three-dimensional circuit board:
The structure of the three-dimensional circuit board according to the third embodiment will be described with reference to FIG. FIG. 8 is a plan view of the three-dimensional circuit board according to the third embodiment.

  The three-dimensional circuit board 1 ″ according to the third embodiment is different from the first embodiment in that a reinforcing member 6 ″ having a plurality of regions having different thicknesses is used, and other configurations and manufacturing methods are basically the first. Since it is the same as that of embodiment, the same component uses the same code | symbol, and abbreviate | omits description.

  As shown in FIG. 8, the reinforcing member 6 ″ is divided into four regions S1 to S4 corresponding to the respective sides of the three-dimensional circuit board 1 ″, and the thickness of the reinforcing member 6 ″ in each region S1 to S4 is as follows. The regions S1 to S4 are determined in accordance with the number of electrode pads 5a formed in the regions R1 to R4 of the substrate portion 2 to be reinforced.

  Next, an example of a method for determining the thickness of each of the regions S1 to S4 of the reinforcing member 6 ″ will be specifically described. As shown in FIG. 8, the substrate portion 2 to be reinforced by the region S1 of the reinforcing member 6 ″. In the region R1, five electrode pads 5a are formed. Similarly, the region R2 to be reinforced by the region S2, the region R3 to be reinforced by the region S3, and the region R4 to be reinforced by the region S4 have 7 electrode pads 5a, respectively. 6 pieces, 7 pieces are formed. When the image pickup element E is attached to the three-dimensional circuit board 1 ″ by pressure welding, a pressing force corresponding to the number of the electrode pads 5a is applied, and each of the regions R1 to R4 has a respective region R1 to R4. Thus, a pressing force proportional to the number of electrode pads 5a formed is applied. Therefore, the reinforcing member 6 "is opposed to the pressing force applied in proportion to the number of electrode pads 5a in each of the regions R1 to R4. And the ratio of the thicknesses of the regions S1 to S4 may be determined as S1: S2: S3: S4 = 5: 7: 6: 7.

  Here, the area | region of the board | substrate part 2 which each area | region of the reinforcement member 6 "should reinforce means the area | region of the board | substrate part 2 which can suppress a deformation | transformation by each area | region of the reinforcement member 6". Specifically, for example, a region obtained by translating each region of the reinforcing member 6 ″ in the thickness direction of the substrate portion 2 can be set as a region of the substrate portion 2 to be reinforced by the region of the reinforcing member 6 ″. .

  In the three-dimensional circuit board 1 ″ shown in FIG. 8, the reinforcing member 6 ″ is divided into four regions S1 to S4 corresponding to the respective sides of the three-dimensional circuit board 1 ″. However, the dividing method is not limited to this. For example, the three-dimensional circuit board 1 ″ may be divided into a plurality of regions without being bound by each side.

  Further, in the three-dimensional circuit board 1 ″ shown in FIG. 8, the integrally formed reinforcing member 6 ″ is divided into a plurality of (four) regions, but the reinforcing member 6 ″ may be formed separately for each region. good.

(3-3) Imaging device:
The imaging device 10 ″ using the 3D circuit board 1 ″ is basically the same as the configuration and manufacturing method of the imaging device 10 according to the first embodiment, except that the configuration of the 3D circuit board 1 ″ is different in the above points. is there.

  And imaging device 10 '' concerning a 3rd embodiment is constituted by a plurality of fields S1-S4 from which thickness differs, and thickness in each field S1-S4 is substrate part 2 which each field S1-S4 should reinforce. Since the reinforcing member 6 ″ is determined based on the number of electrode pads 5a provided on the surfaces of the regions R1 to R4, the reinforcing member 6 ″ is disposed in a thickness necessary for each region to be reinforced. Therefore, it is possible to obtain a high-accuracy, small, and light-weight imaging device that prevents deformation of the substrate portion 2 with an appropriate amount of the reinforcing member 6 ″.

(4) Other embodiments:
In the above embodiment, the reinforcing member 6 is extended to the outside of the position where the optical member mounting portion 3 of the substrate portion 2 is connected. However, the present invention is not limited to this. For example, as shown in FIG. The reinforcing member 6 may be disposed only inside the position where the optical member mounting portion 3 is connected.

  In the above embodiment, the reinforcing member 6 is inserted and molded. However, the present invention is not limited to this, and the reinforcing member 6 may be bonded to the substrate portion 2 by bonding or the like as shown in FIG.

  Further, in the above embodiment, one surface of the reinforcing member 6 is disposed so as to be exposed to the outside of the substrate portion 2, but only the portion that becomes the electrode pad of the reinforcing member 6 is disposed on the substrate portion 2 as shown in FIG. 11. The reinforcing member 6 may be formed by exposing it to the surface of the substrate and placing other portions inside the substrate portion 2. According to this, since portions other than the electrode pad of the reinforcing member 6 are sealed in the substrate portion 2, it is advantageous in terms of moisture resistance.

  Furthermore, the present invention is not limited to the above-described embodiments, and various modifications or changes can be made within the scope of the invention described in the claims.

It is a perspective view of the three-dimensional circuit board concerning a 1st embodiment. It is sectional drawing of the three-dimensional circuit board which concerns on 1st Embodiment. It is a figure which shows the manufacture procedure of the three-dimensional circuit board which concerns on 1st Embodiment. It is sectional drawing which shows the structure of the imaging device which concerns on 1st Embodiment. It is a figure which shows the manufacture procedure of the imaging device which concerns on 1st Embodiment. It is a top view of the three-dimensional circuit board which concerns on 2nd Embodiment. It is sectional drawing of the three-dimensional circuit board which concerns on 2nd Embodiment. It is a top view of the three-dimensional circuit board which concerns on 3rd Embodiment. It is a top view of the three-dimensional circuit board which concerns on other embodiment. It is a top view of the three-dimensional circuit board which concerns on another other embodiment. It is a top view of the three-dimensional circuit board which concerns on another other embodiment. It is a figure explaining the conventional 3D circuit board.

Explanation of symbols

1, 1 ', 1 "Three-dimensional circuit board 2 Substrate part 3 Optical member mounting part 4 Opening part 5 Circuit 5a Electrode pad 6, 6', 6" Reinforcing member 10 Imaging device E Imaging element L Optical member

Claims (7)

A substrate portion having an opening and an optical member mounting portion provided on one surface of the substrate portion for mounting the optical member, and the image sensor is mounted across the opening on the other surface of the substrate portion A three-dimensional circuit board,
A reinforcing member for reinforcing the substrate portion is a part of the substrate portion that is translated from the position of the electrode pad, which is a connection portion for connecting the electrodes of the image sensor, in the thickness direction of the substrate portion. An electrode provided on the surface of the region of the substrate portion to be reinforced by each region, wherein the reinforcing member is composed of a plurality of regions having different thicknesses, and the ratio of the thickness of the reinforcing member in each region is provided. A three-dimensional circuit board characterized by being determined so as to be proportional to the number of pads . The three-dimensional circuit board according to claim 1,
A three-dimensional circuit board, wherein the reinforcing member is made of metal, ceramic, or glass. The three-dimensional circuit board according to claim 2,
A three-dimensional circuit board, wherein the reinforcing member is formed by exposing at least a part of the reinforcing member to the surface of the substrate portion. In the three-dimensional circuit board as described in any one of Claims 1 thru | or 3,
The board part and the optical member mounting part are integrally formed by injection molding, and the reinforcing member is inserted into the board part at the time of injection molding. In the three-dimensional circuit board as described in any one of Claims 1 thru | or 4,
A three-dimensional circuit board, wherein the reinforcing member is formed as at least a part including a circuit electrode pad. The three-dimensional circuit board according to claim 5,
A three-dimensional circuit board, wherein the reinforcing member is formed by exposing only the electrode pad to the surface of the substrate portion. The three-dimensional circuit board according to any one of claims 1 to 6 ,
An imaging device mounted on the substrate portion of the three-dimensional circuit board by pressure welding;
An optical member mounted on the optical member mounting portion of the three-dimensional circuit board;
An imaging apparatus comprising:

Images