JPH01230289A - Electronic circuit unit - Google Patents

Abstract

PURPOSE:To increase mounting density, by mounting surface mounting type parts on one surface, molding and forming resin, mounting insertion mounting type parts by inserting them into through holes from above the resin, and mounting surface mounting type parts on the other surface. CONSTITUTION:Circuit patterns 16, 17 are formed on both surfaces of an insulating film 15. Through holes 18 are formed at positions where insertion mounting type parts are mounted. Solder resist 20, 21 is printed on both surfaces in the manner in which pat parts 19 are left at parts of mounting positions. Firstly, the surface mounting type parts 13A, 13B are mounted, and a resin substrate 12 is formed on the surface. In the substrate 12, lead inserting holes 24 are formed at positions corresponding with the through holes 18. This hole 24 sets a pin on a metal mold to mold and form the substrate 12. A surface mounting type parts 13C is mounted on the other surface of a circuit film 11. An insertion mounting type parts are mounted by inserting lead parts 14' of the insertion mounting type parts 14 into the lead inserting holes 24 and the through holes 18 from the substrate 12.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electronic circuit unit using a molded circuit board, and particularly to an electronic circuit unit in which electronic components can be mounted with high density.

[Conventional technology and its issues]

A molded circuit board is one in which a circuit film having an IN or two or more layers of circuit patterns is placed in a mold, and a resin is molded on one side of the circuit film to form a resin board that is integrated with the circuit film. .

This molded circuit board has the advantage that the shape of the resin board can be freely selected depending on the application, compared to ordinary glass/epoxy circuit boards. However, on the other hand, since one side of the circuit film is covered with a molded resin substrate, electronic components can only be mounted on one side, making it difficult to increase the packaging density of electronic components.

On the other hand, rapid progress in surface-mounted components and surface-mounting technology in recent years has enabled high-density mounting of electronic components and has greatly contributed to making electronic devices lighter, thinner, and smaller.

However, in high-frequency analog circuits and the like, the main circuits that make up the high-frequency section are often modularized into metal packages or the like for each function due to high-frequency characteristics, electromagnetic interference, etc., making surface mounting difficult. Moreover, the mounting positional relationship between the main functional modules and their peripheral components has many restrictions, as it is necessary to take into account signal flow, grounding, interference, etc. Furthermore, equipment adjustment circuits and power supplies with large current capacities are required. In circuits and the like, it is also required to mix lumped constant components such as electrolytic capacitors, adjustment coils, and relays, which are difficult to miniaturize and surface mount, together with small surface mount components.

Conventionally, component mounting in such electronic devices involves mounting functional modules and miniaturization on the front side of the printed circuit board.
Electronic components that are difficult to surface mount are mounted, and on the back side,
We try to mount small surface-mounted components whose heights are approximately the same. In other words, the mounting surface is divided according to the size of the components to improve the component mounting density.

However, in reality, it is extremely rare to be able to mount all surface mount components on the back side of a printed circuit board, considering signal flow, grounding, interference, etc. The reality is that many surface-mounted components must be mounted. For this reason, the surface side of the printed circuit board has a large height (different components are mixed together, resulting in a large dead space and a problem in that the component mounting density is reduced).

[Means for solving problems and their effects]

An object of the present invention is to provide a molded circuit board type electronic circuit unit that solves the above problems and has a high component mounting density and a large degree of freedom in wiring.

In order to achieve this object, the present invention mounts a surface mount type component on one side of a circuit film having circuit patterns on both sides, and fills the surface mount type component with a resin on the same side of the circuit film. A resin substrate is formed integrally with the circuit film by molding, and lead insertion holes are formed in the resin substrate to correspond to the through holes of the circuit film, and a surface mount type is formed on the other side of the circuit film. An electronic circuit unit is constructed by mounting the components and inserting the lead portions of the insertion mount components into the lead insertion holes and through holes from the resin substrate side to mount the insertion mount components. Claim 1).

In this way, not only surface-mounted components can be mounted on both sides of the circuit film, but also insertion-mounted components can be mounted, making it possible to significantly increase the density of component mounting on the molded circuit board.

Note that the circuit film may have three or more layers of circuit patterns as long as it has circuit patterns on both sides. Furthermore, the resin board may be molded so that the surface mount type component mounted on one side of the circuit film is completely embedded, or it may be molded so that the head of the surface mount type component is exposed. good.

In addition, the resin board is divided into multiple parts and formed on one circuit film, and adjacent resin boards are connected by the circuit film.
If the circuit film is made bendable at the connecting portion (claim 2), components can be mounted in a flat state and a three-dimensional structure can be created after the components are mounted, which simplifies component mounting and makes the electronic circuit unit smaller. It is effective for

Furthermore, in order to further increase component mounting density and wiring flexibility, the present invention mounts surface mount type components on one side of a first circuit film having circuit patterns on both sides, and A resin substrate is formed integrally with the circuit film by molding a resin so as to fill the surface mount type component, and a second circuit having circuit patterns on both sides is formed on the opposite side of the resin substrate from the circuit film. An electronic circuit unit is constructed by pasting the films, connecting the circuit patterns of both circuit films with a conductive member penetrating the resin substrate, and mounting components on at least one of the outer surfaces of both circuit films. Claim 3
), or a first circuit film with circuit patterns on both sides and surface mount components mounted on one side, and a second circuit film with circuit patterns on both sides and surface mount components mounted on one side. A second circuit film is placed facing each other with the component mounting surface facing inside, a resin is molded between them to form a resin substrate integrated with both circuit films, and the circuit pattern of both circuit films is passed through the resin substrate. The electronic circuit unit is configured by providing electrical continuity using a conductive member and further mounting components on at least one of the outer surfaces of both circuit films (claim 4).

With this configuration, when mounting large components on the front side and small surface mount type components on the back side, if it is necessary to mount the small surface mount type components on the front side together with the large components, it is possible to It can be mounted embedded in the resin board, which means that it can be mounted not only on the front and back sides of the circuit board, but also on the front and back sides of the circuit board.
Since components can also be mounted inside, the density of component mounting increases. Further, by connecting the circuit patterns of the first and second circuit films with a conductive member penetrating the resin substrate, the wiring becomes three-dimensional and the degree of freedom of the wiring increases.

〔Example〕

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

FIG. 1 shows an electronic circuit unit according to an embodiment of the present invention. In the figure, 11 is a circuit film, 12 is a resin substrate, 13A to 13C are surface mount type components, and 14 is an insertion mount type component.

The circuit film 11 has a structure as shown in FIG.

That is, the circuit pattern 16 is formed on both sides of the insulating film 15.
17, a through hole 18 is formed at the position where the insertion mounting type component is to be mounted, and a solder resist 20/2 is formed on both sides, leaving a pad portion 19 at the component mounting position.
1 is printed. As the insulating film 15, a film made of polyimide, polyetherimide, polyester, etc. is used.

Further, although the circuit patterns 16 and 17 are usually formed by pattern etching of copper foil, they may also be formed by printing conductive paste.

On one side of this circuit film 11, surface mount type components 13A and 13B are mounted as shown in FIG.

22 is the soldering part.

Further, a resin substrate 12 is formed on the surface on which the surface-mounted components 13A and 13B are mounted, as shown in FIG. 4.

The resin substrate 12 is formed by placing the circuit film 11 in the state shown in Figure 3 in a mold and molding a thermosetting resin or a thermosetting resin.The molding is performed by transfer molding. If this is done, it can be done at a relatively low temperature and pressure, and the resin substrate 12 will have less warpage and sink marks. Lead insertion holes 24 are formed in the resin substrate 12 at positions corresponding to the through holes 18 of the circuit film 11. This lead insertion hole 24 can be easily formed by placing a pin in a mold for molding the resin substrate 12. By forming the resin substrate 12, a molded circuit board 25 in which the surface-mounted components 13A and 13B are embedded in the resin substrate 12 is obtained. Note that the circuit film 11 and the resin bases vi, 12 are integrated with an adhesive (not shown) applied to the circuit film 11.

Further, on the other side of the circuit film 11, a surface mount type component 13c is mounted as shown in FIG. The insertion mounting type component 14 is mounted by inserting it into the through hole 18. 26 is the part for soldering them.

The electronic circuit unit shown in Figure 1 was made as described above. Note that the resin substrate 12 can be made into a three-dimensional shape, and the circuit film 11 can also be made into a three-dimensional shape to match the resin substrate 12 by setting it on the uneven surface of the mold. In addition, the mounting type component 14 is inserted into the surface of the resin board 12.
It is also possible to form a positioning recess.

Figure 5 shows another embodiment of the present invention. Although the electronic components to be mounted are not shown (in other words, the state of the molded circuit board in Figure 4), this electronic circuit unit is made of a single sheet. Five resin substrates 12A to 12B are separately formed on one side of the circuit film 11 by molding. Therefore, the adjacent resin substrate 12B
and 12A, . . . , 12E and 12D are the circuit films 11
The circuit film 11 can be bent at the connected portion.

With this structure, components can be mounted in a flat state, and the circuit film 11 can be bent to form a three-dimensional structure after component mounting, which facilitates component mounting and miniaturizes the electronic circuit unit. It is valid.

Conventionally, as shown in Figure 6, an electronic circuit unit in which hybrid ICs 28A to 28D and other electronic components 29 are mounted on a circuit board 27 has been used. In addition to the connection points for various electronic components inside C, each vibe lift IC28A
Since the electronic circuit unit of the present invention can be mounted in high density, for example, the surrounding resin substrate 12A in FIG. If electronic components corresponding to the hybrid ICs 28A to 28D are mounted on the circuit films 11 on the circuit films 12D to 12D, and other electronic components are mounted on the circuit films 11 on the central resin substrate 12E, the conventional biref l- It becomes possible to eliminate connection points between the ICs 28A to 28D and the circuit board 27.

FIG. 7 shows still another embodiment of the electronic circuit unit according to the present invention, in which 31 is a first circuit film;
32 is a resin substrate, 33 is an adhesive, 34 is a second circuit film, 35 is a connection bump, 36 is a functional module, 37
A, 37B, and 37C are surface-mounted components.

The first circuit film 31 has a structure as shown in FIG. 8(a), and has circuit patterns 42 and 4 on both sides of the insulating film 41.
3, through-holes 44 are formed at locations where the circuit patterns 42 and 43 on both sides are electrically connected, and a solder resist 45 is printed on the outer surface.

Circuit pattern 4 on the inner surface side of this first circuit film 31
2, a surface mount type component 37A is mounted thereon.

The installed state will be as shown in Figure 8 (1)).

Furthermore, a resin substrate 32 is integrally formed on the inner surface side of the first circuit film 31 so as to embed the surface mount type component 37A. The resin substrate 32 is made by setting the first circuit film 31 (in the form of 8 peaks in the figure) on which the surface-mounted component 37A is mounted in a mold, and molding a thermoplastic resin or thermosetting resin. The resin substrate 3 is formed by molding, and the state after molding is as shown in Figure 8(C).
A hole 46 for inserting a lead of an insertion-mount type component and a hole 47 for accommodating a connection bump 35 are formed in the molding part 2 during molding.

Further, a second circuit film 34 is attached to the surface of the resin substrate 32 opposite to the first circuit film 31 via an adhesive 33. Before pasting the second circuit film 34, a connecting bump 35 is installed in the hole 47. The connection bump 35 is, for example, a copper ball having a diameter approximately the same as the thickness of the resin substrate 32, and the surface thereof is plated with solder.

The second circuit film 34 has a structure as shown in FIG. 8(d), and has circuit patterns 52 and 5 on both sides of the insulating film 51.
3, a through hole 54 is formed at the location where the circuit patterns 52 and 53 on both sides are electrically connected, and a hole 55 is formed at the location where the lead part of the insertion mount type component is inserted. A solder resist 56 is printed on the surface. The second circuit film 34 is attached to the resin substrate 32
The state shown in Figure 8(e) is when it is pasted on.

As described above, the composite circuit board 57 containing the surface-mounted component 37A is constructed, and this composite circuit board 57 includes the following:
The functional module 36 and surface mount type components 37B and 37C are mounted using conventional means.

The circuit patterns 42 and 52 on the inner surfaces of the first and second circuit films 31 and 34 are surface-mounted components 37B and 37C.
The solder on the surface of the connection bump 35 is melted by the heat generated when the connection bump 35 is mounted, so that the connection bump 35 is soldered and becomes electrically conductive.

In this way, the electronic circuit unit shown in FIG. 7 has three layers of surface-mounted components, and further includes insertion-mounted components such as functional modules.

FIG. 9 shows another embodiment of the present invention. In this electronic circuit unit, the resin substrate 32 is not planar but has a three-dimensional shape with bent portions. Since the resin substrate 32 is formed by molding, its shape can be freely selected. The rest of the configuration is the same as that of the embodiment shown in FIG. 7, so the same parts are given the same reference numerals and the explanation will be omitted.

FIG. 10 shows still another embodiment of the present invention. This electronic circuit unit 7 has first and second circuit films 31 and 34.
The circuit patterns 42 and 52 on the inner surface are electrically connected via an electronic component 58 such as a chip resistor instead of a connecting bump. The other configurations are the same as the embodiment shown in FIG.

FIG. 11 shows still another embodiment of the present invention. In this electronic circuit unit, circuit patterns 42 and 43 on both sides of a first circuit film 31 are connected by spot welding,
Circuit patterns 52 and 5 on both sides of the second circuit film 34
3 is similarly connected by spot welding. Further, the circuit patterns 42 and 43 of the first circuit film 31 and the circuit patterns 52 and 53 of the second circuit film 34 are connected by a through hole 59. Through hole 59
is formed by applying copper plating to the inner surface of the hole formed in the resin substrate 32, with the composite circuit board 57 containing the surface-mounted component 37A formed therein. Further, on the outside of the first circuit film 31, an LSI 60 of a QFP package is mounted. ? j[Although the combined circuit board 57 is upside down compared to FIG. 7, the other configurations are the same as the embodiment shown in FIG.

FIG. 12 shows still another embodiment of the present invention. In this electronic circuit unit, a surface-mounted component 37D is mounted not only on the inner surface of the first circuit film 31 but also on the inner surface of the second circuit film 34. and this surface mount type component 37D,
The surface mount type component 37A mounted on the inner surface of the first circuit film 31 is also embedded in the resin substrate 32.

In order to form the composite circuit board 57 having such a structure, the first circuit film 31 on which the surface-mounted component 37A is mounted is formed.
and a second circuit film 34 on which a surface mount type component 37D is also mounted, are placed facing each other in a mold with the component mounting side inside, and a resin is molded between them to integrate them with both circuit films 31 and 34. What is necessary is to form the resin substrate 32 of
Further, in order to establish continuity between the two circuit films 31 and 34, for example, a connection bump 61, which is a copper stud plated with solder, is soldered to the inner circuit pattern 32 of the first circuit film 31, and the resin board 32 is connected to the circuit pattern 32 of the first circuit film 31. After forming, the connecting bump 61 may be soldered to the inner circuit pattern 52 of the second circuit film 33. Of course, conduction can also be achieved through a through hole as shown in FIG. 11. Note that mounting the surface mount type components 37B and 37C on the outer surfaces of the first and second circuit films 31 and 34, respectively, and inserting and mounting the functional module 36 are the same as in the previous embodiment.

In the electronic circuit unit having such a configuration, the component mounting surface is further increased compared to the case shown in FIG. 7, so that the component mounting density can be further increased.

〔Effect of the invention〕

As explained above, according to the invention of claims 1 and 2,
Since electronic components can be mounted on both sides of the circuit film in an electronic circuit unit using a molded circuit board, the component mounting density of the electronic circuit unit using a molded circuit board can be greatly improved.

Further, according to the inventions of claims 3 and 4, components can be mounted not only on both sides of the circuit board but also inside the circuit board.
For example, when mounting large and small components on separate mounting surfaces, if it becomes necessary to mount a small component on the large component side, it is possible to mount it by embedding it in the resin board. , the component mounting density can be further increased.

In addition, since the circuit patterns of the first and second circuit films are electrically connected by a conductive member that penetrates the resin substrate, the wiring becomes three-dimensional and the degree of freedom in component placement is large, making it ideal for configuring high-frequency analog circuits, etc. Extremely effective.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the main parts of an electronic circuit unit according to an embodiment of the present invention, FIGS. 2 to 4 are sectional views showing the manufacturing process of the electronic circuit unit of FIG. I, and FIG. A perspective view showing a schematic configuration of an electronic circuit unit according to another embodiment of the present invention, FIG. 6 is a perspective view showing an example of a conventional electronic circuit unit, and FIG. Cross-sectional view of the electronic circuit unit, 1 m -8 (al ~ (el is a cross-sectional view showing the manufacturing process of the unit, Figures 9 to 12)
2A and 2B are cross-sectional views showing still other embodiments of the present invention. 11: Circuit film, 12: Resin board, 13A/13B
・13C; Surface mount type component, 14: Insertion mount type component, 1
5: Insulating film, 16/17: Circuit pattern, 18 Varnish through hole, 19: Bad part, 20/21: Solder resist, 24: Lead insertion hole, 25: Molded circuit board, 31: First circuit film, 32 :Resin substrate, 33
: Adhesive, 34: Second circuit film, 35: Connection bump, 36: @Noh module, 37A to 37D: Surface mount type component, 41: Insulating film, 42/43: Circuit pattern, 51: Insulating film, 52・53; Circuit pattern, 57: Composite circuit board, 59 Varnish through hole, 60:
LSI, 61F connection bump. Figure-1 Figure-2 Figure-4 Figure-5 Figure-6

Claims (4)

[Claims] 1. A surface mount type component is mounted on one side of a circuit film having a circuit pattern on both sides, and a resin is molded so as to bury the surface mount type component on the same side of the circuit film, so that the surface mount type component is integrated with the circuit film. A resin substrate is formed, lead insertion holes are formed in the resin substrate corresponding to the through holes of the circuit film, and a surface mount type component is mounted on the other side of the circuit film, and an insertion mount type component is mounted on the other side of the circuit film. An electronic circuit unit characterized in that an insertion mounting type component is mounted by inserting the lead portion of the above into the lead insertion hole and the through hole from the resin substrate side. 2. 2. The electronic circuit unit according to claim 1, wherein the resin substrate is formed in a plurality of parts on one circuit film, and adjacent resin substrates are connected by the circuit film so that the circuit film can be bent at the connected portion. What has become. 3. A surface mount type component is mounted on one side of a first circuit film having a circuit pattern on both sides, and a resin is molded so as to bury the surface mount type component on the same side of the circuit film, thereby producing the circuit film. A second circuit film having circuit patterns on both sides is pasted on the opposite side of the resin substrate to the circuit film, and the circuit patterns of both circuit films are passed through the resin substrate. What is claimed is: 1. An electronic circuit unit that is electrically connected by a conductive member and further includes components mounted on at least one of the outer surfaces of both circuit films. 4. A first circuit film that has a circuit pattern on both sides and has a surface mount type component mounted on one side, and a second circuit that also has a circuit pattern on both sides and has a surface mount type component mounted on one side. The circuit films are placed facing each other with the component mounting surfaces facing inside, and a resin is molded between them to form a resin substrate integrated with both circuit films, and the circuit pattern of both circuit films is formed by a conductive member penetrating the resin substrate. conduction,
Furthermore, an electronic circuit unit characterized in that components are mounted on at least one of the outer surfaces of both circuit films.