JP7045894B2 - Circuit board manufacturing method - Google Patents

Description

The present application relates to a method for manufacturing a circuit board including an optical module.

In order to improve the rotation accuracy of a general servo motor or the like, the encoder mounted on the servo motor has optical components (light emitting element and light receiving element) installed in a position detection unit on a circuit board. This position detection unit is configured so that the light emitted from the light emitting element is incident on the light receiving element via the disk forming the optical pattern, and when the disk rotates with the rotation of the shaft, the light is emitted by the optical pattern. Position detection is possible by transmitting and blocking. Therefore, if there is a foreign substance that blocks light on the optical path, there is a problem that the position detection characteristic is affected and the position detection accuracy is deteriorated, and stain resistance is required.

In the conventional technique, the optical component is mounted on the circuit board 6 by reflow soldering or individual soldering in a state where the light emitting surface of the light emitting element which is an optical component or the light receiving surface of the light receiving element is exposed. However, there is no description about measures against foreign matter adhesion to the light receiving surface or the light emitting surface of the optical component in the manufacturing process (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2016-3853

However, as described above, in the conventional technique, the light receiving surface or the light emitting surface is mounted on the circuit board 6 by reflow soldering or individual soldering with the light receiving surface or the light emitting surface of the optical component exposed. There was a problem that foreign matter such as dust or dirt adhered to the surface, resulting in a defective product. Further, although there is no description about measures against foreign matter adhering to the light receiving surface or the light emitting surface of the optical component in the manufacturing process, this measure is considered to be indispensable. In addition, it is expected that the man-hours for manufacturing (hereinafter, simply referred to as man-hours for the sake of simplicity) will increase due to this measure.

Furthermore, due to the above problem, work such as foreign matter inspection or foreign matter removal occurs in the post-process, which affects the productivity due to the increase in man-hours, which further adversely affects the productivity. Has a point.

Therefore, in order to solve the above problems, in order to reduce the adhesion of foreign matter, before the process such as reflow soldering or individual soldering where foreign matter is likely to adhere, foreign matter on the light receiving surface or light emitting surface In order to prevent adhesion, it is conceivable to provide a sticking step of sticking the cover, and then carry out the remaining steps.

This will be described in a little more detail below with reference to the figures.
FIG. 15 is an external perspective view showing an example of an optical module 1 provided with a light emitting element 2 and a light receiving element 3, which are optical components of a position detection unit provided in a general reflection type optical encoder. In this figure, the light emitting element 2 is mounted on the light emitting element storage portion 4a which is a part of the storage portion of the package 4 of the optical module 1, and the light receiving element 3 is a light receiving element storage which is a part of the storage portion of the package 4. It is mounted on the part 4b. Further, the light emitting element 2 is solder-bonded onto an electrode pattern (not shown) formed in the light emitting element storage portion 4a of the package 4, and the light receiving element 3 is formed in the light receiving element storage portion 4b of the package 4 (not shown). Not) Soldered onto the electrode pattern. Further, the electrodes of the light emitting element 2 and the light receiving element 3 are electrically connected to the electrode pattern (not shown) formed in the package 4 by the bonding wire 14, respectively.

The optical module 1 configured as described above is soldered and fixed on the rotating substrate 6 used for mounting the parts of the encoder, and the foreign matter generated during this soldering is the optical parts of the encoder. If it adheres to a certain light emitting element 2 or light receiving element 3, the position detection performance of the optical encoder deteriorates, and it is necessary to prevent this.
As a countermeasure, it is conceivable to cover the above-mentioned optical component with a tape-shaped cover before the component mounting process.

FIG. 16 is a diagram showing an example of a case where the upper surface of the package 4 of the optical module 1 is covered with the tape-shaped cover 105. The tape-shaped cover 105 is attached to the upper surface of the package 4 including the light emitting element accommodating portion 4a and the light receiving element accommodating portion 4b (not shown) so as to cover the entire upper surface thereof, for example, with an adhesive.

After that, the optical module 1 having the tape-shaped cover 105 attached to the upper surface of the package 4 is soldered onto the circuit board 6 by reflow soldering or individual soldering (see FIG. 17). Here, the heat resistant temperature of the tape-shaped cover 105 needs to be equal to or higher than the melting point of the lead-free solder, and generally needs to be equal to or higher than 240 degrees.

By covering the entire upper surface of the package 4 with the tape-shaped cover 105 in this way, it is considered that foreign matter can be prevented from adhering to the light emitting element 2 or the light receiving element 3 which is an optical component of the encoder.

However, when the upper surface of the package 4 is covered with the tape-shaped cover 105 as described above and the mounted parts and the rotating board are soldered to a high temperature environment such as a reflow furnace, the tape-shaped cover 105 covers the upper surface. The sealed space formed by the soldering may expand and contract due to the influence of the high temperature of the surroundings, so that the tape-shaped cover 105 may be peeled off, and foreign matter may be mixed in from the peeled-off portion and adhere to the optical component.

The present application provides a method for manufacturing a circuit board that can improve productivity without the need for foreign matter inspection or foreign matter removal work in the post-process of component mounting by solving the above-mentioned problems. With the goal.

The method for manufacturing a circuit board disclosed in the present application is as follows.
A method for manufacturing a circuit board on which an optical module having an optical component for detecting the position of an encoder and a package for accommodating the optical component and a mounting component composed of an electronic circuit component other than the optical module are mounted.
A die-bonding process in which the optical component is housed in the package and then the optical component and the package are joined and fixed.
After the completion of the die-bonding step, a resin sealing step of sealing the optical component by injecting a silicone-based resin into the storage portion of the optical component, and a resin sealing step.
After the resin sealing step is completed, the surface of the package has no holes in a temperature environment of room temperature or lower, and a tape-shaped cover having ventilation holes forming holes in a high temperature environment of more than 200 ° C. is attached. Pasting process and
After the cover attaching step, a component mounting step of applying solder paste on the circuit board and mounting the mounting component including the package to which the tape-shaped cover is attached on the circuit board.
After the component mounting process, a soldering step of soldering and joining the mounted component and the circuit board,
After the soldering step, a cover removing step of removing the tape-shaped cover attached to the surface of the package from the package,
Is included.

The method for manufacturing a circuit board disclosed in the present application is as follows.
Before mounting the optical component on the circuit board, the tape-shaped cover covers and covers the light-receiving surface of the light-receiving element, which is the optical component, or the light-emitting surface of the light-emitting element, in an assembly process such as reflow soldering of the optical component. Since the risk of foreign matter adhering to the light receiving surface or the light emitting surface can be reduced, the yield can be improved, or the subsequent foreign matter inspection or foreign matter removal work becomes unnecessary, the number of steps in the manufacturing process can be reduced.

FIG. 5 is an external perspective view showing an example of an optical module constituting the position detection unit of the encoder according to the first embodiment. It is an exploded perspective view which shows the optical module which constitutes the position detection part of the encoder by Embodiment 1. FIG. It is a schematic diagram which shows the optical module and the circuit board which constitute the position detection part of the encoder by Embodiment 1. FIG. FIG. 5 is an external perspective view for explaining the arrangement of ventilation holes of the tape-shaped cover attached to the optical module according to the first embodiment. It is a flowchart explaining the manufacturing process of the circuit board for an encoder by Embodiment 1. FIG. It is sectional drawing explaining the die-bonding process of the circuit board for an encoder by Embodiment 1. FIG. It is sectional drawing explaining the wire bonding process of the circuit board for an encoder by Embodiment 1. FIG. It is sectional drawing explaining the resin sealing process of the circuit board for an encoder by Embodiment 1. FIG. It is sectional drawing explaining the cover sticking process of the circuit board for an encoder by Embodiment 1. FIG. It is sectional drawing explaining the component mounting process of the circuit board for an encoder by Embodiment 1. FIG. It is an external perspective view which shows an example of the optical module which constitutes the position detection part of the encoder by Embodiment 2. FIG. It is an external perspective view which shows an example of the optical module which constitutes the position detection part of the encoder by Embodiment 4. FIG. FIG. 5 is an external perspective view showing an example of an optical module constituting the position detection unit of the encoder according to the fifth embodiment. It is a figure for demonstrating the manufacturing method of the tape-shaped cover attached to the optical module constituting the position detection part of the encoder according to Embodiment 5. It is a perspective view which showed the main element of the optical module which constitutes the position detection part of the encoder for demonstrating the subject of this application. It is external perspective view when the optical module which constitutes the position detection part of the encoder for demonstrating the subject of this application is covered with the tape-shaped cover. It is a schematic diagram which shows the optical module and the circuit board of the encoder covered with the tape-like cover for demonstrating the subject of this application.

Hereinafter, embodiments of the present application will be described with reference to the drawings.
Embodiment 1.
FIG. 1 shows an optical module 1 covered with a tape-shaped cover 5 having a vent hole 7 to be used in a soldering process during a manufacturing process of a circuit board including an optical module as a mounting component according to the first embodiment. It is a figure which shows an example.
In this example, an external perspective view shows a configuration in which an optical module 1 constituting an optical component for detecting the position of an encoder is covered with a tape-shaped cover 5 having ventilation holes 7.
Further, FIG. 2 is an exploded perspective view showing the tape-shaped cover 5 having the ventilation holes 7 in FIG. 1 and the optical module 1 in an exploded manner.
As shown in FIG. 1 or 2, the optical module 1 includes a package 4 in which a light emitting element 2 and a light receiving element 3 are separately mounted. Further, the light emitting element 2 is housed in the light emitting element storage part 4a in the storage part of the package 4, and the light receiving element 3 is housed in the light receiving element storage part 4b in the storage part of the package 4. A tape-shaped cover 5 having a ventilation hole 7 for covering the optical module 1 is attached to the upper surface (also referred to as a surface; the same applies hereinafter) of the package 4 of the optical module 1.
Here, the light emitting element 2 is solder-bonded onto an electrode pattern (not shown) formed in the light emitting element accommodating portion 4a, and the light receiving element 3 is an electrode formed in the light receiving element accommodating portion 4b (not shown). Soldered onto the pattern.
The electrodes of the light emitting element 2 and the light receiving element 3 are electrically connected to an electrode pattern (not shown) formed in the package 4, respectively, by a bonding wire.
The tape-shaped cover 5 having the ventilation holes 7 is attached to the upper surface of the package 4 with an adhesive or the like so as to cover the entire surfaces of the light emitting element accommodating portion 4a and the light receiving element accommodating portion 4b.

FIG. 3 is a schematic view in which the optical module 1 according to the first embodiment is mounted on a circuit board 6 for an encoder by soldering or the like. Here, a tape-shaped cover 5 having ventilation holes is attached to the upper surface of the package 4 on which the light emitting element 2 and the light receiving element 3 which are the optical components of the optical module 1 are mounted. Then, the optical module 1 to which the tape-shaped cover 5 having the ventilation holes is attached is soldered onto the circuit board 6 by reflow soldering or individual soldering.

Due to this soldering process, the heat resistant temperature of the tape-shaped cover 5 having the vents must be 240 degrees or higher, which is the temperature above the melting point of the lead-free solder, as in the case of the tape-shaped cover 105 without the vents. Must be.

In this soldering process, as described in the section of the subject, when the upper surface of the package 4 is covered with the tape-shaped cover 105 having no ventilation holes, the tape-shaped cover is put into a high temperature environment such as a reflow furnace. The sealed space formed by covering with 105 expands and contracts due to the influence of the high temperature of the surroundings, so that the tape-shaped cover 105 may peel off, and foreign matter may enter from the peeled part and adhere to the optical component. be. Therefore, in the present application, as the cover for covering the optical component, the tape-shaped cover 5 provided with the vent holes 7 is used instead of the tape-shaped cover 105 without the vent holes.
In particular, in the tape-shaped cover 5 having the vent holes 7 used here, the vent holes are located in the light emitting element accommodating portion 4a and the light receiving element accommodating portion 4b as shown by the frame shown by the dotted line in FIG. There is one place corresponding to each.

By using the tape-shaped cover 5 having the vent holes, the gas generated in a high temperature environment such as a reflow furnace in the soldering process of joining the mounted component and the circuit board with solder, or the tape-shaped cover without the vent holes. The sealed space formed by 105 can be exhausted, the cover can be prevented from peeling off, and foreign matter can be prevented from being mixed in from the peeled-off portion of the cover and adhering to the optical component.

The ventilation holes 7 are arranged so as to avoid positions directly above the light emitting element 2 and the light receiving element 3 as much as possible. By arranging in this way, it is possible to reduce the risk of foreign matter adhering to the light emitting surface or the light receiving surface of the element. In the present embodiment, the ventilation holes 7 are formed in a circular shape, but the shape is not limited to this shape, and may be an elliptical shape or a shape other than a circular shape such as a rectangle.

As described above, when soldering the optical module 1 onto the circuit board 6 (particularly when joining by reflow soldering), by using a tape-shaped cover 5 having a vent hole, the light emitting element accommodating portion 4a is used. In addition, it is possible to protect the entire surface of the light receiving element storage portion 4b and prevent foreign matter from adhering to the light emitting surface of the light emitting element 2 or the light receiving surface of the light receiving element 3 by soldering after mounting the components. Yield improvement, foreign matter inspection, and foreign matter removal work can be abolished, and productivity can be improved by this.

The method of manufacturing the circuit board 6 including the optical module 1 having the above configuration will be described below in order.
FIG. 5 is a flowchart showing an example of a manufacturing process related to manufacturing a circuit board 6 having an optical module 1.

In the die bonding step of step 1 (S1), as shown in FIG. 6, the light emitting element 2 and the light receiving element 3 are placed on the electrode pattern 12 for mounting the element formed on the package 4, respectively, via the die bonding material 13. To be installed. After that, the light emitting element 2 and the light receiving element 3 are bonded to the package by heat treatment.

In the wire bonding step of step 2 (S2), as shown in FIG. 7, the light emitting element 2 and the light receiving element 3 are electrically connected to the electrode pattern 12 of the package 4 via the bonding wire 14.

Next, in the resin sealing step of step 3 (S3), as shown in FIG. 8, a silicone-based resin is injected into the light emitting element accommodating portion 4a, the light receiving element accommodating portion 4b, or both. Then, this resin is cured by heat treatment, and the light emitting element 2 and the light receiving element 3 are sealed by the cured resin (hereinafter referred to as a sealing resin) 8. This resin sealing step is not essential and can be omitted. In the first embodiment, it is assumed that both the case where the resin sealing step of step 3 (S3) is included (in this case, the optical module 1a) and the case where the resin sealing step is not included (in this case, the optical module 1) are included. .. The details of the case where the resin sealing step of step 3 (S3) is included will be described in a little more detail in another embodiment shown below.

Subsequently, in the cover attaching step of attaching the tape-shaped cover in step 4 (S4), as shown in FIG. 9, the tape-shaped cover 5 is attached to the upper end surface of the package 4 by the tape attaching device.

In the component mounting process of the next step 5 (S5), as shown in FIG. 10, the solder paste 15 is printed on the circuit board 6 by the solder printing device, and the optical module 1 and other mounted components are mounted on the mounter (automatic mounting machine). ) Is mounted on the circuit board 6.

In the reflow soldering step of step 6 (S6), the circuit board 6 is put into a reflow furnace, and each mounted component and the circuit board 6 are soldered and joined. During the flow of this process, the light emitting surface of the light emitting element 2 or the light receiving surface of the light receiving element 3 is protected by the tape-shaped cover 5, so that the light receiving surface of the element is easily attached to foreign matter such as dust or dirt. Alternatively, it is possible to prevent foreign matter from adhering to the light emitting surface, and it is possible to improve the yield. Further, foreign matter inspection or foreign matter removal work after the reflow process becomes unnecessary, productivity is improved, and manufacturing cost can be reduced.

In the tape-shaped cover peeling step of step 7 (S7), the tape-shaped cover 5 is removed from the optical module 1.

In the lens bonding step of step 8 (S8), the circuit board 6 mounted on the encoder by adhering a condensing lens for condensing the light emitted from the light emitting element 2 to the upper part of the light emitting element 2 via an adhesive. Is assembled.

Embodiment 2.
Next, a method of manufacturing a circuit board using the optical module 1 covered with another tape-shaped cover 5a according to the second embodiment will be described.
FIG. 11 shows an external perspective view of the optical module 1 provided with the tape-shaped cover 5a different from that of the first embodiment. The difference from the first embodiment is that, as shown in FIG. 11, the tape-shaped cover 5a is smaller than the surface area value determined by the size of each side of the outer frame of the package 4 (adjacent two on the outermost periphery of the upper surface of the package 4). The point is that it is composed of a value that is smaller than the value when the surface area is multiplied by the size of the sides) and a size that can be accommodated in the package 4 (however, it is larger than the frame size on the outside of the storage portion). Other than this, the contents are the same as those described in the first embodiment.

In the first embodiment, after the configured optical module 1 is joined to the circuit board 6 by soldering, the appearance state of the soldering is usually inspected by an appearance inspection device. If the tape-shaped cover 5 protrudes from the outer frame of the package 4 at the time of the inspection, the protruding portion of the tape-shaped cover 5 covers the soldered portion on the package when visually recognized from the upper surface. As a result, in the inspection from the upper surface, the soldered portion on the package cannot be directly seen, which may affect the inspection of the appearance condition.

Therefore, in the second embodiment, the tape-shaped cover 5a to be attached is fitted in the package 4. This makes it possible to visually recognize the soldered portion from the upper surface, and it is possible to inspect the appearance state of the soldering.
In consideration of the influence on the proximity parts, by housing the tape-shaped cover 5a in the package 4, the distance from the proximity parts can be shortened, the mounting density of the circuit board 6 can be improved, and the encoder itself can be used. Miniaturization is also possible.

By arranging the ventilation holes 7 so as to avoid directly above the light emitting element 2 and the light receiving element 3, it is possible to reduce the risk of foreign matter adhering to the light emitting surface of the light emitting element or the light receiving surface of the light receiving element. In the present embodiment, the ventilation holes 7 are formed in a circular shape, but may be elliptical or rectangular.

Embodiment 3.
Next, a method of manufacturing a circuit board using an optical module 1a different from that of the second embodiment including the tape-shaped cover 5a will be described.
Regarding the cross section of the optical module 1a having the silicone-based sealing resin 8 according to the third embodiment, in FIG. 9, the length of the tape-shaped cover 5 is set to be smaller than the length of the bottom of the package 4, and the tape-shaped cover 5a is set. Corresponds to the case of. It is different from the second embodiment in that the storage portion of the package of the optical module 1 is filled with the silicone-based sealing resin 8 to form the optical module 1a. In this case, the optical module 1a includes a package 4 on which the light emitting element 2 and the light receiving element 3 are mounted, and the light emitting element accommodating portion 4a and the light receiving element accommodating portion 4b are filled with a silicone-based sealing resin 8. ing. Further, a tape-shaped cover 5a having a ventilation hole 7 is attached to the optical module 1a on the upper surface of the package.

The light emitting element 2 and the light receiving element 3 are solder-bonded to an electrode pattern 12 (not shown) formed in the light emitting element accommodating portion 4a and the light receiving element accommodating portion 4b of the package 4, respectively.
The electrodes of the light emitting element 2 and the light receiving element 3 are electrically connected to the electrode pads formed in the package by bonding wires.
After that, a silicone-based resin is injected into the light-emitting element storage portion 4a and the light-receiving element storage portion 4b, and after the silicone-based resin is cured in a high- temperature environment , the tape-shaped cover 5a having the ventilation holes 7 is the optical module 1a. It is pasted on the top surface of.

When the optical module 1a shown in the present embodiment is bonded to the circuit board 6 by reflow soldering, gas is generated from the sealing resin 8 due to the high temperature in the reflow furnace. Due to this generated gas, the pressure in the light emitting element accommodating portion 4a and the light receiving element accommodating portion 4b increases, and the tape-shaped cover 5a may be peeled off. Therefore, by using the tape-shaped cover 5a provided with the ventilation holes 7, the generated gas can be exhausted, the tape-shaped cover 5a can be prevented from peeling off, and the light emitting surface of the light emitting element 2 or the light receiving light of the light receiving element 3 can be prevented. It is possible to reduce the risk of foreign matter adhering to the surface.

In the present embodiment, both the light emitting element accommodating portion 4a and the light receiving element accommodating portion 4b are filled with the sealing resin 8, but only one of them may be filled with the sealing resin 8.

Embodiment 4.
Next, a method of manufacturing a circuit board using the optical module 1 provided with the tape-shaped cover 5b will be described with reference to the drawings.
FIG. 12 shows an external perspective view of the optical module 1 provided with the tape-shaped cover 5b having the notch portion 9 according to the fourth embodiment. By attaching the tape-shaped cover 5b having the notch portion 9 to the upper surface of the optical module 1, the notch portion 9 of the tape-shaped cover 5b, the light emitting element accommodating portion 4a, and the light receiving element accommodating portion 4b provide ventilation holes. 7 can be configured. The ventilation hole 7 composed of the notch portion 9, the light emitting element accommodating portion 4a, and the light receiving element accommodating portion 4b enables exhaust of air in the storage space of each of the above elements or exhaust of gas generated from the sealing resin 8. , The tape-shaped cover 5b can be prevented from peeling off, and the risk of foreign matter adhesion can be reduced.

Here, the tape-shaped cover 5b is generally manufactured by die-cutting with a die. When the ventilation holes are formed in the tape-shaped cover 5b during this processing, there are two or more unnecessary parts after the die cutting process, so that the load of removing the unnecessary parts increases. By forming the cutout portion as in the present embodiment, it is possible to make the unnecessary portion generated after the die cutting process continuous, and it is possible to easily perform the work of removing the unnecessary portion.

Embodiment 5.
Next, a method of manufacturing a circuit board using the optical module 1 provided with the tape-shaped cover 5c will be described with reference to the drawings. In the fifth embodiment, the shape of the ventilation holes of the tape-shaped cover is a slit shape, which is different from each of the above-described embodiments. FIG. 13 shows an external view of the tape-shaped cover 5c having the slit-shaped ventilation holes 10 of the present embodiment.
When the tape-shaped cover 5c is attached to the upper surface of the optical module 1, the slit-shaped ventilation hole 10 is located so that the slit-shaped ventilation hole 10 is located in the region of the light emitting element storage portion 4a and the light receiving element storage portion 4b. Is provided. Further, the slit-shaped ventilation holes 10 are not arranged directly above the light emitting element 2 and the light receiving element 3.

With the tape-shaped cover 5c of the present embodiment attached to the upper surface of the optical module 1, the optical module 1 is mounted on the circuit board 6 and joined by reflow soldering.

As described above, in the present embodiment, by forming the ventilation holes into a slit shape, the air in the light emitting element accommodating portion 4a and the light receiving element accommodating portion 4b expands under the high temperature environment in the reflow furnace. The slit-shaped ventilation hole 10 is widened, the air in the element accommodating portion can be exhausted, and the tape-shaped cover 5 can be prevented from peeling off in the reflow furnace. That is, the ventilation holes of the tape-shaped cover 5c of the present embodiment have no holes in a temperature environment of room temperature or lower, and are the ventilation holes that form holes for the first time in a high temperature environment of more than 200 ° C. in a reflow furnace. It is characteristic that there is. In this case, the size of the ventilation holes in a high temperature environment exceeding 200 ° C. is set to 0.05 mm or less on the short side and 2 mm or less on the long side when the slit shape is rectangular.

Therefore, in a room temperature environment outside the reflow furnace, the pressure inside the element housing is reduced, and the slit-shaped ventilation holes 10 are closed, so that the risk of foreign matter entering the element storage can be reduced.

In the present embodiment, the slit-shaped ventilation holes 10 are provided at one location each for the light emitting element storage portion 4a and the light receiving element storage portion 4b, but the slit-shaped ventilation holes 10 are provided at two or more locations. , The configuration may be provided.

A method for manufacturing a tape-shaped cover having the above configuration will be described below with the tape-shaped cover 5c as a representative.

In the present embodiment, the base material of the tape-shaped cover 5c is mainly composed of a heat-resistant resin using a polyimide resin as an example.
It is created by punching out only the base material of the tape-shaped cover 5c bonded on the mount 11 with a mold. During the die cutting process, the die blade is set to cut off to the thickness of the tape base material. At the time of die-cutting, the slit-shaped ventilation holes 10 described above are formed by die-cutting at the same time. The die-cut tape is wound around a reel core and stored in a reel shape.

Further, as shown in FIG. 14, when forming the slit-shaped ventilation hole 10 described above, the angle of the slit is formed parallel to the reel unwinding direction. By forming the set angle of the slit-shaped ventilation hole 10 parallel to the reel unwinding direction, the tape-shaped cover 5c is torn from the slit-shaped ventilation hole 10 when the tape-shaped cover 5c is peeled off from the mount. It is possible to reduce the risk.

In the present embodiment, the tape-shaped cover 5c is made of a heat-resistant tape, but the material of the cover may be a metal or resin cover. By installing the metal and resin covers on the upper end surface of the optical module 1, there is a risk of foreign matter adhering to the light emitting surface of the light emitting element 2 or the light receiving surface of the light receiving element 3, as in the case of the present embodiment described above. It is possible to reduce the yield and improve the yield.

In the present application, each embodiment can be combined, and each embodiment can be appropriately modified or omitted. For example, in the fourth and fifth embodiments, the surface area of the tape-shaped cover attached to the package is described on the assumption that the surface area is smaller than the surface area of the surface of the package. Like the shape cover, it may be attached so as to cover the entire surface of the package, that is, it may have an area larger than the surface area of the surface of the package.

1, 1a optical module, 2 light emitting element, 3 light receiving element, 4 package, 4a light emitting element storage part, 4b light receiving element storage part, 5, 5a, 5b, 5c tape-shaped cover (with ventilation holes), 6 circuit board, 7 Vents, 8 encapsulation resin, 9 notches, 10 slit-shaped vents, 11 mounts, 12 electrode patterns, 13 die bonding materials, 14 bonding wires, 15 solder paste, 105 tape-like covers (without vents)

Claims (5)

A method for manufacturing a circuit board on which an optical module having an optical component for detecting the position of an encoder and a package for accommodating the optical component and a mounting component composed of an electronic circuit component other than the optical module are mounted.
A die-bonding process in which the optical component is housed in the package and then the optical component and the package are joined and fixed.
After the completion of the die-bonding step, a resin sealing step of sealing the optical component by injecting a silicone-based resin into the storage portion of the optical component, and a resin sealing step.
After the resin sealing step is completed, the surface of the package has no holes in a temperature environment of room temperature or lower, and a tape-shaped cover having ventilation holes forming holes in a high temperature environment of more than 200 ° C. is attached. Pasting process and
After the cover attaching step, a component mounting step of applying solder paste on the circuit board and mounting the mounting component including the package to which the tape-shaped cover is attached on the circuit board.
After the component mounting process, a soldering step of soldering and joining the mounted component and the circuit board,
After the soldering step, a cover removing step of removing the tape-shaped cover attached to the surface of the package from the package,
A method for manufacturing a circuit board, which comprises. The method for manufacturing a circuit board according to claim 1, wherein the tape-shaped cover is attached so as to cover the entire surface of the package, and the soldering joint is performed by reflow soldering or individual soldering. The method for manufacturing a circuit board according to claim 1 , wherein in the cover attaching step, the surface area of the tape-shaped cover attached to the package is smaller than the surface area of the surface of the package. The method for manufacturing a circuit board according to claim 1, wherein the tape-shaped cover has a notch. The method for manufacturing a circuit board according to claim 1, wherein the shape of the ventilation holes is a slit shape.

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