JPH0739114B2 - Manufacturing method of molded products with interior parts enclosed - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a molded product containing an interior product such as a film.

[0002]

2. Description of the Related Art With the recent miniaturization and thinning of electronic components, there has been a demand for a technique of accurately coating these electronic components with an outer coating as thin as possible. As an example, as shown in FIGS. 9 and 10, a thickness of 1.8 mm
When the printed board 50 is enclosed in a molded product 52 of a rubber sheet having a size of about 2.0 mm, for example, the upper surface portion 5 of the molded product 52 is
There is a method of manufacturing the molded products of 2a and the lower surface portion 52b , respectively, and fixing the molded products by sandwiching the printed circuit board 50 with an adhesive or the like, but the manufacturing process is complicated, and the external shape of the molded product 52 changes the printed circuit board. There is a problem that the printed board 50 is deteriorated due to invading water or the like because the 50 is peeled off or the watertightness (airtightness) is not sufficient. There is also a method in which a gap is formed in the inner length direction of the molded product 52, and the printed board 50 is inserted into the gap and fixed with an adhesive.
As with the above, not only are there problems with watertightness and adhesive strength, but actually the very thin core mold (gap for inserting the printed circuit board) is molded without deforming it in place, and the printed circuit board is fixedly molded. It is difficult to do.

Generally, a compression molding method, a transfer molding method and the like are known as methods for molding a molding material such as a thermosetting resin. In the compression molding method, a molding material is put between the upper and lower molds, the molding material is filled in the cavity while pressing both molds, and then heated and cured to mold.
Although this method can be carried out at a low manufacturing cost, the molding material partially leaks between the upper and lower molds to generate burrs on the molded product, and a post-treatment step such as removal work is required. The transfer molding method is a method in which a molding material is placed in a heated pot, pressurized with a plunger, and the molding material is poured into a mold cavity for molding, and is a method suitable for molding a precision molded product. is there. However, particularly when the molded product has a thin wall, it becomes difficult to accurately fill a predetermined amount of the molding material into the lower mold cavity, and there is a problem in that the shape of the molded product becomes uneven.

[0004]

DISCLOSURE OF THE INVENTION In producing a molded product containing an interior product, the present invention precisely and firmly encapsulates the interior product in a predetermined position of the molded product and ensures sufficient water tightness. A manufacturing method is provided.

[0005]

The first means of the present invention for solving the above-mentioned problems is to load the thermosetting molding material into the cavities of the first mold and the second mold, respectively, Before the curable molding material is cured, the interior parts are placed between the cavities of the first mold and the second mold, and then the first mold and the second mold are pressure-bonded to each other, The present invention is characterized in that the thermosetting molding material is integrated and cured. A second means of the present invention comprises a pot mold for pouring a thermosetting molding material into the cavities of the first mold and the second mold, and the first mold and the second mold of the pot mold are provided. In a state in which a release film having releasability with respect to the thermosetting molding material is formed on the corresponding surface of the mold, and the release film forming portion is in close contact with the first mold and the second mold. It is characterized in that a thermosetting molding material is poured into the mold cavity. A third means of the present invention is characterized in that the interior component is a film, and the cavities of the first mold and the second mold are cavities for molding the outer coating of the film. .

[0006]

EXAMPLES Next, an example of the present invention will be described in the case of manufacturing the molded product shown in FIGS. 9 and 10, specifically, a rubber watch band enclosing a printed circuit board. 1 to 3 show the manufacturing process of the present embodiment. In FIG. 1, 1 is a first mold, 2 is a pot mold, and 3 is a mold.
Is a plunger.

The first mold 1 is for molding the upper surface portion 52a of the molded product 52 shown in FIGS. The upper surface of the first mold 1 is formed smoothly, and the upper surface of the first mold 1 is almost centered as shown in FIG.
And a band-shaped cavity 1a as shown in FIG. 5 is formed. A recess 1b is formed at one end of the cavity 1a so as to correspond to the one-end thick portion 52c of the molded product 52. A recess 1c extending in the width direction is formed near one end of the first mold 1, and the block mold 4 is removably fitted in the recess 1c. A projecting piece 4a is formed at the center of the block mold 4, and the projecting piece 4a is located in the cavity recess 1b. The protrusion 4a forms a groove portion into which the support portion 51 (which serves as an energizing contact of the printed board 50) provided at the end portion of the printed board 50 is fitted. The first mold 1
And the upper surface of the block mold 4 are flush with each other.

The pot mold 2 is an upper mold with respect to the first mold 2, and has a molding material reservoir 2a formed on the upper part thereof, and the molding material reservoir 2a and the mold cavity 1a.
A small-diameter gate 2b communicating with each other is perforated. The bottom surface of the pot mold 2 is a smooth surface, and the release film 5 is formed on the bottom surface. Although the release film 5 of this embodiment has a fluorine resin sheet (Teflon: trade name) attached thereto, the film layer may be formed by a surface treatment means such as coating. The release film 5 may be formed on at least the surface of the bottom surface of the pot mold corresponding to the mold cavity 1a, and need not be formed on the entire bottom surface of the pot mold. The gate 2b is formed so as to be located at the center of the mold cavity 1a.

The plunger 3 has the molding material reservoir 2a.
Has a push-out portion 3a to be fitted into the molding material reservoir portion 2a at a predetermined pressure, and the thermosetting molding material 20 from the gate 2b to the first mold cavity 1a. It is designed to be poured out.

In FIG. 2, numeral 10 is a second mold for molding the lower surface portion 52b of the above-mentioned molded product 52, which is the pot mold 1.
1 and a plunger 12. The upper surface of the second mold 10 is formed to be smooth, and a band-shaped cavity 10a as shown in FIGS. 6 and 7 is formed in a substantially central portion.

A pot mold 11 which is an upper mold of the second mold 10.
The configurations of the plunger 12 are the same as those of the pot mold 2 and the plunger 3, respectively. That is, the pot mold 11
A molding material reservoir 11a is formed on the upper surface of the mold, and a small-diameter gate 11b is formed to connect the molding material reservoir 11a and the second mold cavity 10a. The bottom surface of the pot mold 11 is a smooth surface, and the release film 13 similar to the above is formed on the bottom surface. Further, the push-out portion 12a of the plunger 12 is adapted to be fitted into the molding material reservoir portion 11a with a predetermined pressure.

In the molding apparatus shown in FIG. 1, the first mold 1 is used.
Thus, the upper surface portion 52a of the molded product 52 is molded. That is,
The molding material reservoir 2a of the pot mold 2 is loaded with a predetermined amount of thermosetting molding material (tablet) 20 according to the volume of the first mold cavity 1a, and is pressurized by the plunger 3. The pot mold 2 and the first mold 1 are heated to a predetermined temperature, and at the same time when the plunger 3 is pressed down, the pot mold 2 presses the first mold 1 and the unvulcanized state in the molding material reservoir 2a. The thermosetting molding material 20 is poured into the first mold cavity 1a through the gate 2b, and the thermosetting molding material 20 is loaded in the cavity 1a. At this time,
Since the release film 5 is formed on the bottom surface of the pot mold 2, the thermosetting molding material 20 is uniformly spread in the cavity 1a.

Similarly, the second mold 10 shown in FIG.
Thus, the lower surface portion 52b of the molded product 52 is molded. That is,
The thermosetting molding material 20 in the molding material reservoir 11a of the pot mold 11 is pressed into the cavity 10a of the second mold 10 by the plunger 12 and loaded through the gate 11b.

Next, when the thermosetting molding material 20 in the first mold cavity 1a and the second mold cavity 10a is not completely cured and is in an unvulcanized state, each pot mold 2, 11 is separated from the first mold 1 and the second mold 10. At this time, since the release films 5 and 13 are formed on the bottom surfaces of the pot dies 2 and 11, the thermosetting molding material 20 is used.
Does not adhere to its bottom surface.

After that, as shown in FIG. 3, the cavity 10a of the second mold 10 faces downward and is arranged above the first mold 1, and the block mold 4 of the first mold 1 is removed to remove the first mold. The printed circuit board 50 shown in FIGS. 9 and 10 is placed on the upper surface of the thermosetting molding material 20 of the mold cavity 1a. In this state, the first mold 1 and the second mold 10 are closed, and the thermosetting materials 20 and 20 of both molds are pressure-bonded to each other,
While heating 0 at a predetermined temperature, the thermosetting molding material 20,
Integrate 20.

At this time, since the thermosetting molding materials 20 and 20 are in an unvulcanized state, the printed circuit board 50 adheres due to its adhesive action. When the thermosetting molding materials 20, 20 are integrated and cured, they are water-tightly sealed and fixed inside the molded product 52. Further, when the thermosetting molding materials 20 and 20 of both mold cavities 1a and 10a have the same thickness, the printed board 50 is enclosed in the center of the molded product 52 in the thickness direction.

The printed board 50 is attached to the first mold cavity 1
When it is placed on the thermosetting molding material 20 of 0 a, the protruding piece portion 4 a of the block mold 4 is attached to one end of the thermosetting molding material 20.
Since the groove portion 20a is formed by
The printed circuit board 50 can be positioned only by inserting the printed circuit board support portion 51 into 0a.

FIG. 8 shows another embodiment of the present invention, in which the pot mold 3 is provided between the first mold 1 and the second mold 10.
0 is arranged and the thermosetting molding material 20 is poured out from the pot mold 30 into the cavities 1a, 10a of both molds 1, 10. The pot mold 30 has a reservoir 30a of the thermosetting molding material 20 formed therein,
Small-diameter gates 30b and 30c are perforated in the upper and lower portions so as to communicate with the reservoir 30a. This gate 30b,
30c communicates with the center of the first mold cavity 1a and the second mold cavity 10a, respectively. The upper surface and the lower surface of the pot mold 30 are smooth surfaces, and the release films 31 and 32 similar to those described above are formed.

The first mold 1 and the second mold 10 are pot molds 3.
The first mold 1 is brought into close contact with the lower surface of the pot mold 30 and the second mold 10 is brought into close contact with the upper surface of the pot mold 30 by being pressed down with 0 interposed therebetween. In this state, the thermosetting molding material 20 loaded in the thermosetting molding material reservoir 30a of the pot die 30 is pressed by a plunger (not shown) to form the gates 30b, 3b.
It is injected into the first mold cavity 1a and the second mold cavity 10a through 0c.

Next, when the thermosetting molding material 20 is in an unvulcanized state, the first mold 1 and the second mold 10 are opened, and the pot mold 30 is moved from between the molds 1 and 10. Then, the block mold 4 of the first mold 1 is removed. After that, the printed board 50 is placed on the thermosetting molding material 20 loaded in the first mold cavity 1a, and the molds 1 and 10 are closed to integrally combine the thermosetting molding materials of the cavities 1a and 10a. It hardens and hardens. In this case as well, it goes without saying that the first mold 1, the second mold and the pot mold 30 are heated to a predetermined temperature.

The thermosetting molding material 20 is specifically a thermosetting rubber such as silicone rubber or a thermosetting resin such as epoxy resin, phenol resin, silicone resin or the like.
The printed circuit board 50 is a polyimide film having a thickness of 0.1 mm, and a circuit such as an antenna circuit is printed on the surface thereof. Molded product 52 molded in this embodiment
Of the flat part has a thickness of 1.8 mm to 2.0 mm, and the depth of the mold cavities 1a and 10a for molding one surface is 0.9 mm to 1.0 mm. The portion 1b is formed deeper than this. Further, the heating temperature of the pot mold of this embodiment is 100 degrees or less, and the heating temperatures of the first mold and the second mold are 160 degrees to 170 degrees. When the interior part lacks affinity for the thermosetting molding material 20 in the unvulcanized state, an adhesive having an affinity for the thermosetting molding material is applied to the surface of the interior part, or a necessary surface is applied. You may give a process.

In the above embodiment, the molded product of the watch band is described as an example, but a flexible printed circuit board in which electronic components are incorporated may be enclosed in another band-shaped molded product. Further, as another application example, it is also suitable when a small piece is accurately and watertightly sealed in a molded product. The shape of the molded product of the present invention is arbitrary, and the configuration of the mold or the like is changed according to the shape of the molded product. Further, the enclosed position of the interior product in the thickness direction of the molded product can be enclosed at any position by mutually changing the depths of the upper and lower mold cavities. Further, although the first mold and the second mold of this embodiment are configured to open and close in the vertical direction, they may be configured to open and close in the horizontal direction. In addition, the configurations of the illustrated mold, pot mold, plunger and the like are for convenience of explaining the present invention, and can be arbitrarily changed as necessary.

[0023]

According to the present invention described above, in encapsulating the interior parts in the molded product, the thermosetting molding resin loaded in the cavities of the first mold and the second mold is cured before being cured. Since the interior part is arranged between the molds and both molds are pressure-bonded to each other, the interior part adheres to the thermosetting molding material due to the adhesiveness of the thermosetting molding resin. Therefore, when the thermosetting molding material is cured to form a molded article, the interior article is accurately sealed at a predetermined position inside the molded article, and sufficient watertightness is ensured.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a molding method by a first mold showing an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing a molding method with a second mold showing an embodiment of the present invention.

FIG. 3 is a schematic cross-sectional view for explaining an embodiment of the present invention.

FIG. 4 is a schematic plan view of the first mold of the present invention.

5 is a schematic cross-sectional view taken along the line AA of FIG.

FIG. 6 is a schematic plan view of a second mold of the present invention.

7 is a schematic cross-sectional view taken along the line BB of FIG.

FIG. 8 is a schematic sectional view for explaining another embodiment of the present invention.

FIG. 9 is a schematic plan view of a molded product molded in the example of the present invention.

10 is a schematic cross-sectional view taken along the line CC of FIG.

[Explanation of symbols]

 1 1st metal mold 1a 1st metal mold cavity 2 pot metal mold 2a gate 3 plunger 4 block metal mold 5 release film 10 2nd metal mold 10a 2nd metal mold cavity 11 pot metal mold 11b gate 12 plunger 13 Release Film 20 Thermosetting Molding Material 30 Pot Mold 30b Gate 30c Gate 31 Release Film 32 Release Film

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Claims (3)

[Claims] 1. After the thermosetting molding material is loaded into the cavities of the first mold and the second mold, respectively, and before the thermosetting molding material is cured, the cavity of the first mold and the second mold are molded. The interior is placed between the mold cavities, then the first mold and the second mold are pressed together, and the thermosetting molding materials in both cavities are integrated and cured. Of manufacturing the molded product. 2. A pot mold for pouring a thermosetting molding material is provided in a cavity of the first mold and the second mold, and the correspondence between the first mold and the second mold of the pot mold. A mold-releasing film having a mold-releasing property with respect to the thermosetting molding material is formed on the surface, and the mold-releasing film forming part is adhered to the first mold and the second mold, and the thermosetting molding is performed. The method for producing a molded product enclosing an interior product according to claim 1, wherein the material is poured into the mold cavity. 3. The interior component is a film, and the cavities of the first mold and the second mold are cavities for molding an outer coating of the film. A method for manufacturing a molded product that encloses the interior product of.