JP2010226010A - Electronic circuit unit, and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the occurrence of a failure due to outflow of solder (solder burst) in thermal curing while sufficiently securing mounting strength of a cover to a circuit board using an adhesive. <P>SOLUTION: The electronic circuit unit 10 includes: a circuit board 12; electronic components 14-20 mounted on a mounting surface 12a thereof; and a shield cover 22 installed on the mounting surface 12a in a state covering the electronic components 14-20. The shield cover 22 is stuck to the electronic components 14, 16 by an adhesive member 24 filled on the back face, and fixed to the circuit board 12 only by the adhesive force thereof. The adhesive member 24 adheres to the upper surfaces and side surfaces of the electronic components 14, 16 but adheres to neither the bottom surface nor the circuit board 12. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electronic circuit unit, and more particularly to an electronic circuit unit including a metal cover.

  For example, some electronic circuit units in which high-frequency electronic components are mounted on a circuit board have a metal shield cover that covers the electronic components. The shield cover is usually fixed to the circuit board using solder. In this state, the shield cover protects the electronic components and at the same time functions as a noise countermeasure by being grounded to the circuit on the board. In order for such a shield cover to perform its function sufficiently, it needs to be securely fixed to the circuit board both electrically and mechanically.

  For this reason, conventionally, as a method for fixing the shield cover to the circuit board, the prior art is known in which the shield cover is soldered to the circuit board and the shield cover is bonded to the upper surface of the package of the electronic component via a conductive adhesive. (For example, refer to Patent Document 1). According to this prior art, since the shield cover can be fixed using the adhesive force of the adhesive in addition to the soldering, it is considered that the shield cover can be firmly fixed as much.

  As another method, there is a prior art in which an adhesive is applied on a circuit board in an increased amount so as to cover the entire electronic component, instead of applying the adhesive only on the upper surface of the electronic component (for example, Patent Documents). 2). According to this prior art, it is considered that the adhesive force is further increased by the amount of the adhesive increased, and the shield cover can be firmly fixed by that amount.

JP 2006-165470 A JP 2007-67002 A

  The method of the prior art (Patent Document 1) mentioned above is for adhering only a limited range of the upper surface of the package, and the adhesive force is relatively weak, but it is still a space where the shield cover can be soldered on the circuit board. If there is enough, it is considered effective. However, in recent years, with the high density mounting on the circuit board, there is no room in the space where the shield cover can be soldered. For this reason, when sufficient strength for soldering the cover itself cannot be secured, there is a problem that the strength is insufficient only by bonding the upper surface of the package.

  In this respect, the technique of the prior art (Patent Document 2) listed later has little worry about insufficient strength because a large amount of adhesive is used. However, if the entire electronic component is covered with an adhesive as in the latter prior art (see, for example, FIG. 2 of Patent Document 2), it is not negligible that another problem arises.

  Specifically, if the soldering part of the electronic component is covered with an adhesive (resin), when the solder melts in the process of thermosetting the adhesive, the moisture content evaporates and the residual flux vaporizes. A phenomenon (solder explosion) in which solder flows out from minute gaps in the adhesive (resin) is likely to occur. Such a phenomenon causes poor soldering of electronic components and solder bridges elsewhere, thereby reducing the reliability of the product.

  Therefore, an object of the present invention is to provide a technique capable of preventing the occurrence of defects due to the outflow of solder (solder explosion) while sufficiently securing the cover mounting strength to the circuit board.

In order to solve the above problems, the present invention employs the following solutions.
That is, the electronic circuit unit of the present invention (which may be an electronic circuit module or a high-frequency module) is manufactured from a circuit board, an electronic component mounted with the bottom surface facing the mounting surface of the circuit board, and a metal plate, A cover that is placed on the mounting surface of the circuit board in a state of covering the electronic component, and an electronic component that adheres to the outer surface except the bottom surface, and the cover and the electronic component are bonded to each other without adhering to the circuit board. It is the structure provided with the adhesive member to do.

  According to the electronic circuit unit of the present invention, since the cover is bonded in a state where the adhesive member is adhered to the outer surface except the bottom surface of the electronic component, a larger bonding area can be secured. At this time, the adhesive member adheres to the outer surface of the electronic component and also to the back surface of the cover. The outer surface excluding the bottom surface of the electronic component corresponds to the upper surface and the side surface of the electronic component mounted on the circuit board when viewed from the circuit board. Therefore, compared to the case where only one surface (for example, the upper surface) of the electronic component is bonded to the cover, not only the bonding area is increased, but also the bonding member is attached in a three-dimensional manner so as to wrap the outer surface of the electronic component. Even when the cover is peeled off from the circuit board, the adhesive force of the adhesive member acts in a distributed manner on the upper and side surfaces of the electronic component, so that a stronger adhesive force can be exhibited. .

  Further, since the attachment strength of the cover can be ensured with only the adhesive member, it is not necessary to solder the cover separately, and the manufacturing process corresponding to that can be simplified. Also, since the soldering area of the cover on the circuit board can be omitted, the entire electronic circuit unit can be reduced in size, and the mounting density of electronic components can be improved by taking advantage of the soldering area that has become unnecessary. You can also.

  Furthermore, in the present invention, since the cover is bonded to the circuit board without adhering the adhesive member, the adhesive member does not cover the soldered portion (for example, solder bump) of the electronic component on the circuit board. For this reason, the solder explosion phenomenon does not occur in the process of thermally curing the adhesive member, and the occurrence of soldering defects can be reliably prevented.

  More specifically, the electronic component is an aspect in which it is soldered to the circuit board at least on the bottom surface. At this time, the adhesive member is preferably attached to a position that does not cover the soldered portion of the electronic component.

  In many cases, electronic components suitable for high-density mounting are soldered to a circuit board by reflow through, for example, solder bumps provided on the bottom surface. Even in such a form, according to the electronic module of the present invention, since the adhesive member does not reach the bottom surface of the electronic component, the solder bump is not covered with the adhesive member. In addition, in surface mount type chip parts, etc., even if the soldering part is protruding sideways from the bottom surface of the electronic component, because the adhesive member is attached to a position that does not cover the soldering part, Thereby, the solder explosion phenomenon at the time of thermosetting can be surely prevented.

  The electronic circuit unit of the present invention includes a conductive portion formed on the mounting surface of the circuit board and a contact portion formed on the periphery of the cover and in contact with the conductive portion in a state of being installed on the mounting surface of the circuit board. Further, it may be provided. In this case, the contact portion of the cover is preferably crimped to the conductive portion by the adhesive force of the adhesive member. The conductive portion may be connected to the ground (GND) of the electric circuit formed on the circuit board, for example.

  According to said structure, a cover can be electrically connected (crimped) with respect to the electroconductive part of a circuit board by adhere | attaching a cover with an adhesive member. For this reason, it is not necessary to solder the cover to the conductive part separately, and the area required for soldering can be reduced accordingly. Therefore, the entire electronic circuit unit can be reduced in size, and the reduced space can be utilized. The mounting density of electronic components can also be improved.

  Further, the electronic circuit unit of the present invention is formed in the cover and protrudes from the periphery of the electronic circuit unit toward the circuit board, and is provided in the thickness direction of the circuit board, and a hole portion in which a conductive layer (film) is formed on the inner wall. And may further be provided. In this case, it is preferable that the leg portion of the cover is press-fitted into the hole portion in a state where the cover is installed on the mounting surface of the circuit board, and is pressed against the conductive layer by the adhesive force of the adhesive member. The conductive layer may be connected to the ground (GND) of the electric circuit formed on the circuit board, for example.

  According to said structure, the leg part press-fitted in the hole (conductive layer) can be electrically connected (crimped) by adhere | attaching a cover with an adhesive member. For this reason, it is not necessary to solder the leg portion of the cover separately in the hole portion, and the manufacturing process can be simplified accordingly.

  The present invention also provides a circuit board, an electronic component mounted with the bottom surface facing the circuit board mounting surface, and a metal cover installed on the circuit board mounting surface so as to cover the electronic component. A method of manufacturing an electronic circuit unit having the above is provided. The manufacturing method of the present invention includes the following steps.

[Step 1]
In step 1, an electronic component is mounted on a circuit board. In addition to the wiring patterns and solder lands forming the electric circuit being formed in advance on the circuit board, inner layer patterns, through holes, vias, and the like may be formed. In any case, in step 1, the electronic component is mounted by, for example, reflow soldering.

[Step 2]
In step 2, a predetermined amount of adhesive is applied to the back surface of the cover that covers the electronic component with the back surface facing upward. The prescribed amount here can be determined in advance based on, for example, the shape and size of the electronic components mounted on the circuit board, the total number, and the like. That is, the adhesive applied here wraps around and adheres to the outer surface of the electronic component in subsequent steps, but does not wrap around the bottom surface of the electronic component or adhere to the circuit board. It is assumed that the volume (specified amount) has been calculated.

[Step 3]
In step 3, the cover is placed relative to the mounting surface of the circuit board with the back of the cover facing upward, so that only the outer surface excluding the bottom surface of the electronic component is applied to the adhesive applied to the back of the cover. To attach. In this way, by properly controlling the specified amount in Step 2 above, it is ensured that the adhesive member wraps around the bottom surface of the electronic component or adheres to the circuit board in Step 3. Can be prevented.

[Step 4]
In step 4, the adhesive is cured by heating with the cover positioned below the circuit board. At this time, since the adhesive is applied in the state of a fluid such as a thermosetting resin, for example, by keeping the cover down until it is cured as described above, it is possible to reliably prevent the fluid from falling. Can do. The adhesive becomes the above-described adhesive member in the completed state of the electronic circuit unit when thermally cured.

  By manufacturing the electronic circuit unit through the above steps 1 to 4, the electronic circuit unit of the present invention described above can be obtained. Further, since it is not necessary to solder the cover in the subsequent manufacturing process, the number of manufacturing steps can be reduced as a whole, and the production efficiency of the electronic circuit unit can be improved.

  In the method for manufacturing an electronic circuit unit of the present invention, in the step of applying the adhesive to the back surface of the cover (step 3), a substantially box shape in which a part of the side surface is opened by pressing a metal plate in advance. A burr-shaped portion is provided in advance along the open edge of the side surface by positioning the back surface in the stamping direction of the press working, and the adhesive applied by this burr-shaped portion is allowed to flow out. Shall be blocked.

  For example, even if the side surface of the cover is partially open due to design reasons, in the process of applying the adhesive by providing a burr-like portion by pre-pressing as described above, Since the outflow can be surely prevented, the workability is improved and the finished quality of the product can be improved.

  According to the electronic circuit unit and the manufacturing method thereof of the present invention, since the cover can be securely fixed to the circuit board by the adhesive member (adhesive), the area for soldering on the circuit board can be reduced. The whole can be reduced in size and the mounting density on the circuit board can be improved.

  Further, by omitting the soldering of the cover, it is possible to reduce the assembly reflow process, simplify the manufacturing process, and increase the production efficiency. Further, by eliminating the assembly reflow process that has been required so far, it is possible to eliminate the influence of the thermal stress generated during that time (for example, the influence on the soldering strength).

  Furthermore, since the adhesive member (cured resin) is filled inside the cover in a completed state, the rigidity of the entire unit (cover) can be improved accordingly.

It is a disassembled perspective view which shows roughly the whole structure of the electronic circuit unit of 1st Embodiment. It is a perspective view which shows the completion state of an electronic circuit unit. It is a longitudinal cross-sectional view of the electronic circuit unit which follows the III-III line | wire in FIG. It is a longitudinal cross-sectional view of the electronic circuit unit which follows the IV-IV line in FIG. It is the continuous figure which showed each process of the manufacturing method in order. It is a disassembled perspective view which shows roughly the whole structure of the electronic circuit unit of 2nd Embodiment. It is a longitudinal cross-sectional view of the shield cover (especially top plate) in alignment with the VII-VII line in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is an exploded perspective view schematically showing the overall configuration of the electronic circuit unit 10 of the first embodiment. The electronic circuit unit 10 is, for example, a high-frequency unit (module) having a high-frequency band wireless communication function (wireless LAN, Bluetooth: registered trademark). Such an electronic circuit unit 10 is, for example, a portable information terminal or a notebook personal computer. Etc. are built in.

[Circuit board]
The electronic circuit unit 10 has a circuit board 12, and an electric circuit (not shown) is formed on the circuit board 12. For this reason, a wiring pattern (not shown) is provided on the mounting surface 12 a of the circuit board 12. The circuit board 12 may have a multilayer structure. In that case, a wiring pattern is also provided on the inner layer of the circuit board 12.

[Electronic parts]
A plurality of electronic components 14, 16, 18, 20, etc. are mounted on the mounting surface 12 a of the circuit board 12. Here, only a limited number of electronic components 14 to 20 are shown in order to prevent complication of the drawing, but other electronic components are also mounted on the mounting surface 12a, and these are to some extent. It is arranged in a dense state.

  Examples of the electronic components 14 to 20 to be mounted include passive elements such as a high-frequency chip or FET array packaged with an integrated circuit, a chip resistor, a chip coil, or a chip capacitor. Good. Among these, the relatively large electronic components 14 and 16 are, for example, surface mount type package components, and the outer shape thereof is a flat rectangular parallelepiped shape. These electronic components 14 and 16 are mounted on the circuit board 12 via solder bumps provided in advance on the bottom surface (not shown in FIG. 1), for example. The electronic components 14 and 16 are components that occupy a large area on the mounting surface 12a among components to be mounted and have a relatively upper back (mounting height) on the mounting surface 12a.

[Hole]
For example, a through hole 12b or an insertion hole 12c is formed at a corner position (corner position) of the circuit board 12, respectively. These through holes 12b and insertion holes 12c are provided so as to penetrate the circuit board 12 in the thickness direction. In addition, a conductive layer (no reference numeral) is formed on the inner wall surface of the through hole 12b by, for example, a conductive paste or conductive plating. The conductive layer is connected to a ground (GND) of an electric circuit (not shown), for example.

[Conductive part]
The circuit board 12 has, for example, a rectangular shape in plan view, and two conductive patterns 12d are formed on the mounting surface 12a along both side edges corresponding to a pair of long side portions. These conductive patterns 12d are connected to a ground (GND) of an electric circuit (not shown), for example.

[Shield cover]
The electronic circuit unit 10 has a shield cover 22. The shield cover 22 is disposed so as to cover the electronic components 14 to 20 (including other electronic components) on the mounting surface 12a in a completed state of the electronic circuit unit 10, and the electronic components 14 to 20 are mechanically and electrically connected. To protect.

  The shield cover 22 is formed by pressing a metal plate. The shape of the shield cover 22 is a substantially half-box shape with the lower end surface entirely opened in the state shown in FIG. Specifically, the shield cover 22 has a top plate 22a facing the mounting surface 12a, and four side plates 22b and 22c respectively connected to the four edges of the top plate 22a. The side plates 22b and 22c are bent at the respective edges of the top plate 22a and extend toward the mounting surface 12a.

〔leg〕
The shield cover 22 is formed with four leg portions 22d integrally with a pair of opposing side plates 22c. Although only two on the near side are shown in FIG. 1, two leg portions 22d are also formed at the same position on the side plate 22c located on the back side in FIG. These leg portions 22d are respectively placed corresponding to the four corners of the circuit board 12, and these leg portions 22d protrude from both side edges of the side plate 22c toward the circuit board 12 (downward in FIG. 1). As shown by the one-dot chain line in FIG. 1, with the shield cover 22 attached to the circuit board 12, the four leg portions 22d are inserted into the corresponding through holes 12b or insertion holes 12c, respectively. Has become.

[Press fit of legs]
FIG. 2 is a perspective view showing a completed state of the electronic circuit unit 10. As described above, with the shield cover 22 installed on the circuit board 12, the four leg portions 22d are inserted into the corresponding through holes 12b or insertion holes 12c. At this time, the inner diameters of the through hole 12b and the insertion hole 12c are substantially equal to the width of the leg portion 22d, and therefore the leg portion 22d is press-fitted into the corresponding through hole 12b or the insertion hole 12c. 2 shows only the two on the front side, but the two leg portions 22d are also press-fitted into the corresponding through holes 12b or insertion holes 12c on the back side. At this time, in the through hole 12b, the leg portion 22d is crimped to the conductive layer, whereby the conductive layer and the shield cover 22 are electrically connected (crimped).

[Side plate crimping]
In addition, in a state where the shield cover 22 is installed on the circuit board 12, the lower ends of the four side plates 22b and 22c are in contact with the mounting surface 12a. At this time, the pair of side plates 22b (contact portions) positioned in the longitudinal direction is positioned immediately above the conductive pattern 12d, and is in a state of being crimped to the conductive pattern 12d. In this state, the conductive pattern 12d and the shield cover 22 are electrically connected (crimped).

  In the electronic circuit unit 10 of the present embodiment (first embodiment), the above-described press-fitting of the leg portion 22d and the pressure bonding of the side plate 22b are realized by the adhesive force of an adhesive member not shown in FIGS. Yes. Hereinafter, this point will be described together with the internal structure of the electronic circuit unit 10.

  FIG. 3 is a longitudinal sectional view of the electronic circuit unit 10 taken along the line III-III in FIG. 4 is a longitudinal sectional view of the electronic circuit unit 10 taken along line IV-IV in FIG. 3 and 4, the dimensions of each part are exaggerated in order to facilitate understanding of the internal structure of the electronic circuit unit 10 and the positional relationship between the parts.

(Adhesive member)
An adhesive member 24 is filled on the back surface of the shield cover 22, that is, the back surface of the top plate 22a. 3 or 4, the adhesive member 24 extends over substantially the entire back surface, and the adhesive member 24 has a certain thickness (layer thickness) when viewed in the vertical direction. The adhesive member 24 is, for example, a thermosetting resin (polyimide resin) cured by heat treatment, and the shield cover 22 is firmly bonded to the electronic components 14 and 16 in this state.

[Adhesive member adhesion range]
Here, as shown in FIGS. 3 and 4, the adhesive member 24 is attached to the electronic components 14, 16 on the top and side surfaces, but not on the bottom surface. Further, although the adhesive member 24 is attached to the back surface of the shield cover 22 and the outer surfaces of the electronic components 14 and 16, it does not adhere to the circuit board 12.

  In particular, in the present embodiment, the electronic components 14 and 16 are soldered on the bottom surface by the solder bumps 14a and 16a, respectively, but the adhesive member 24 is in a position that does not cover the solder bumps 14a and 16a (soldering portions). Only attached. The electronic components 18 and 20 which are chip mounted products are soldered mainly by solders 18a and 20a (cream solder) on the bottom surface (partial side surfaces), respectively. , 20a (soldering part) is attached only to a position not covering.

  The adhesive member 24 fixes the shield cover 22 to the circuit board 12 through the electronic components 14 and 16 by bonding the shield cover 22 to the electronic components 14 and 16. For this reason, the shield cover 22 is not particularly soldered on the mounting surface 12a.

  As shown in FIG. 3, in this embodiment, the leg 22d is pressure-bonded to the conductive layer in the through hole 12b as described above using only the adhesive force of the adhesive member 24, and FIG. As shown, the side plate 22b is pressure-bonded to the conductive pattern 12d on the mounting surface 12a. In addition, by using the thermosetting resin as the adhesive member 24 as described above, the shield cover 22 can be strongly pressed against the circuit board 12 by utilizing the shrinkage during the heat treatment.

〔Production method〕
Next, the manufacturing method of said electronic circuit unit 10 is demonstrated.
FIG. 5 is a continuous diagram showing the steps of the manufacturing method in order. Hereinafter, it demonstrates in order of each process.

[Mounting process]
5A: On the mounting surface 12a of the circuit board 12 in which the conductive pattern 12d, the through hole 12b, and the insertion hole 12c are previously formed together with the above-described electric circuit, electronic components 14 to 20 (other electronic components are also included). Implement). The electronic components 14 to 20 are mounted by soldering by reflow using the solder bumps 14a and 16a as described above or by soldering by reflow using cream solder (solders 18a and 20a). can do. Reflow is performed in the same mounting process.

[Coating process]
In FIG. 5, (B): An adhesive 24a, which is a base of the adhesive member 24, is applied to the back surface of the shield cover 22 press-molded in advance from a metal plate as described above with the back surface thereof facing upward. At this time, the adhesive 24 a can be applied using, for example, the filling nozzle 26. Further, the amount of the adhesive 24a applied is such that when the circuit board 12 is combined with the shield cover 22 in the subsequent steps, the adhesive 24a does not wrap around and adhere to the bottom surfaces of the electronic components 14 to 20, and It is assumed that it is calculated in advance as an appropriate amount (specified amount) that does not adhere to the substrate 12.

[Adhesion process]
In FIG. 5, (C): The shield cover 22 is placed relative to the mounting surface 12a of the circuit board 12 with the shield cover 22 in a state where the adhesive 24a is applied facing down (the back is facing upward). . Here, “relative” means that the shield cover 22 may be raised while the circuit board 12 is stationary, or the circuit board 12 may be lowered while the shield cover 22 is stationary, It means that both may be brought close to each other. In any case, the shield cover 22 can be correctly positioned with respect to the circuit board 12 by correctly inserting the leg portions 22d of the shield cover 22 into the corresponding through holes 12b or insertion holes 12c.

  In FIG. 5, (D): At this time, as described above, the relatively tall electronic components 14 and 16 sink into the filling layer of the adhesive 24a, and the adhesive 24a adheres to the outer surfaces (upper surface and side surfaces). . However, since the application amount of the adhesive 24a is correctly calculated in advance as described above, even if the shield cover 22 is relatively installed on the circuit board 12 to the end, the adhesive 24a is used for the electronic components 14 to 20. It does not stick to the bottom surface and does not adhere to the circuit board 12 either. Thereby, the soldering portions (solder bumps 14a and 16a, solders 18a and 20a) of the electronic components 14 to 20 are not covered with the adhesive 24a during the manufacturing process.

[Thermosetting process]
In FIG. 5, (D): When the shield cover 22 is completely installed on the circuit board 12, heat treatment is performed while the shield cover 22 is kept down, and the adhesive 24a is thermally cured. During this time, since the soldered portions (solder bumps 14a and 16a, solders 18a and 20a) of the electronic components 14 to 20 are all exposed, the above-described solder explosion phenomenon does not occur.

  By executing the above steps, the adhesive 24 a is thermally cured to become the adhesive member 24, and the shield cover 22 is fixed to the circuit board 12 through the electronic components 14 and 18. Therefore, since it is not necessary to solder the shield cover 22 again after this, a post-process such as assembly reflow can be omitted. Thereby, while simplifying the whole manufacturing process, the productivity can be improved.

  Further, since reheating by assembly reflow is not performed after the shield cover 22 is bonded, no thermal stress occurs during that time. On the contrary, the completed electronic circuit unit 10 is sealed by filling the adhesive member 24. There is an advantage in that the overall rigidity including 22 is improved.

  Further, since it is not necessary to secure an area for soldering the shield cover 22, there is no need to project the circuit board 12 outward from the side plates 22b, 22c of the shield cover 22, and the entire unit can be downsized accordingly. In addition, by allocating the corresponding area to the mounting area of the electronic component, higher density mounting is possible.

[Second Embodiment]
Next, FIG. 6 is an exploded perspective view schematically showing the overall configuration of the electronic circuit unit 30 of the second embodiment. The electronic circuit unit 30 of the second embodiment is different from the first embodiment mainly in that an opening 22e is provided in a part of the side plate 22b of the shield cover 22. Since other configurations are the same as those of the first embodiment, the same reference numerals are attached to the drawings, and redundant description is omitted.

  Also in the second embodiment, the shield cover 22 can be securely fixed by bonding with the adhesive member 24, and the shield cover 22 can be electrically connected to the conductive layers of the conductive pattern 12d and the through hole 12b. Connection (crimping) can be performed reliably.

[Burr-shaped part]
FIG. 7 is a longitudinal sectional view of the shield cover 22 (particularly the top plate 22a) along the line VII-VII in FIG. Here, the form of the open edge (side edge of the top plate 22a) on the side surface of the shield cover 22 is particularly shown enlarged.

[Press direction]
7A: As described above, the shield cover 22 is made of a metal plate by a pre-pressing process. At this time, the pressing direction (punching direction) of the metal plate is as shown in FIG. It is the direction of the arrow shown, that is, the direction from the top surface of the shield cover 22 toward the back surface. In other words, when the metal plate is pressed, the back surface of the shield cover 22 is formed in the pressing direction.

  Through such a pre-pressing process, a minute burr 22f is formed on the open edge (side edge of the top plate 22a) on the side surface of the shield cover 22. Such a burr-like portion 22f slightly curves the open edge on the side surface of the shield cover 22 toward the back surface.

[Operation during the coating process]
In FIG. 7 (B): By providing the burr-like portion 22f by the pre-pressing process, in the step of applying the adhesive 24a with the back surface of the shield cover 22 facing upward, it has spread to the open edge. The outflow of the adhesive 24a is stopped (blocked) by the burr-like portion 22f. In addition, by providing the burr-like portion 22f, the outflow of the adhesive 24a is similarly prevented in the subsequent adhesion process and thermosetting process ((C) and (D) in FIG. 5). As a result, inadvertent outflow of the adhesive 24a during the manufacturing process can be prevented, and the finished quality in the completed state can be maintained.

  In the first and second embodiments described above, the shield cover 22 is rectangular, but the shield cover 22 may have other shapes (polygonal shape, irregular shape).

  Further, the arrangement of the through holes 12b and the conductive patterns 12d mentioned in the first and second embodiments is merely an example, and other arrangements may be adopted, and the size, the number of arrangements, etc. may be changed as appropriate. Is possible.

  Further, the electronic circuit unit is not limited to the high frequency circuit, and may have other electronic circuits.

10, 30 Electronic circuit unit 12 Circuit board 12a Mounting surface 12b Through hole 12c Insertion hole 12d Conductive pattern 14, 16, 18, 20 Electronic component 14a, 16a Solder bump 18a, 20a Solder 22 Shield cover 22a Top plate 22b, 22c Side plate 22d Leg part 22e Opening part 22f Burr-like part 24 Adhesive member 24a Adhesive

Claims (6)

A circuit board;
An electronic component mounted with the bottom surface facing the mounting surface of the circuit board;
A cover made of a metal plate and installed on the mounting surface of the circuit board in a state of covering the electronic component;
An electronic circuit unit comprising: an adhesive member that adheres to an outer surface of the electronic component other than a bottom surface thereof and adheres the cover and the electronic component to each other without adhering to the circuit board. The electronic circuit unit according to claim 1,
The electronic component is
Soldered to the circuit board at least on its bottom surface,
The adhesive member is
An electronic circuit unit, wherein the electronic circuit unit is attached to a position not covering a soldered portion of the electronic component. The electronic circuit unit according to claim 1 or 2,
A conductive portion formed on the mounting surface of the circuit board;
A contact portion formed on the periphery of the cover and in contact with the conductive portion in a state of being installed on the mounting surface of the circuit board;
The electronic circuit unit according to claim 1, wherein the contact portion of the cover is crimped to the conductive portion by an adhesive force of the adhesive member. The electronic circuit unit according to claim 1,
Legs formed on the cover and projecting from the peripheral edge toward the circuit board;
A hole portion provided in the thickness direction of the circuit board and having a conductive layer formed on the inner wall;
The cover leg is press-fitted into the hole while the cover is placed on the mounting surface of the circuit board, and is crimped to the conductive layer by the adhesive force of the adhesive member. Electronic circuit unit. A circuit board; an electronic component mounted with the bottom surface facing the mounting surface of the circuit board; and a metal cover installed on the mounting surface of the circuit board so as to cover the electronic component. An electronic circuit unit manufacturing method comprising:
Mounting the electronic component on the circuit board;
Applying a specified amount of adhesive to the back surface of the cover covering the electronic component with the back surface facing upward;
By placing the cover relative to the mounting surface of the circuit board with the back surface of the cover facing upward, only the outer surface except the bottom surface of the electronic component is applied to the adhesive applied to the back surface of the cover. A step of attaching
Heating the adhesive with the cover positioned below the circuit board, and curing the adhesive. In the manufacturing method of the electronic circuit unit according to claim 5,
In the step of applying the adhesive to the back surface of the cover,
The cover is molded in a substantially box shape with a part of the side surface opened by pressing the metal plate in advance, and the back side is positioned in the punching direction of the press processing in advance to the open edge of the side surface. A burr-like portion is provided along the burr-like portion, and the outflow of the adhesive applied by the burr-like portion is prevented.

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