JPH06350231A - In-molded item incorporating electronic component - Google Patents

Abstract

PURPOSE:To improve the smoothness of a plane by setting the coefficient of linear expansion of a resin layer lower at the inner layer part than at the surface layer part thereby suppressing the irregularities on the surface. CONSTITUTION:Thickness t2 of resin layer at the inner layer part R2 is set equal to that of an electronic component 4 and the thicknesses t1a, t1b at the surface layer parts R1a, R1b, are set equal to that of the resin layer at the parts above and below the electronic component 4. Total thickness of a long fiber reinforced resin layer R is equal to that of an in-molded item. On the other hand, the coefficient of linear expansion in the direction of thickness is highest(3X10<-4>/ deg.C) at the surface layers R1a, R1b, of the resin layer R, is equal to 1X10<-4>/ deg.C at the inner layer part R2 of the resin layer R, and is lowest (0.5X10<-4>/ deg.C) at the electronic component 4. This constitution suppresses the irregularities on the surface of the in-molded item to enhance the smoothness of plane. It is suitable employed when the smoothness of plane is required for the in-molded item, e.g. when the surface of in-molded item is subjected to transfer printing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-mold product having a built-in electronic component structure, and more specifically, a structure that combines electronic components such as ICs and exhibits one or more functions such as oscillation, reception, calculation, and storage. The present invention relates to an in-mold product with a built-in electronic component structure in which a product (hereinafter referred to as an electronic component constituent) is integrally molded and embedded in a long fiber reinforced resin layer.

[0002]

2. Description of the Related Art As a method for fixing electronic parts such as ICs in electric / electronic devices, bolts are used for nuts in bosses which are preformed on the inner surface of the housing of a device of a printed wiring board on which ICs are mounted. Fixing method (hereinafter referred to as bolt fixing method), a method of adhering the IC module to the inner surface of the housing of the device with an adhesive (hereinafter referred to as adhesive fixing method), forming a recess in the inner surface of the device housing in advance,
A method in which an IC module coated with an adhesive is mounted in the recess and heat-welded (hereinafter referred to as heat-welding fixing method) is used. As the housing material of the above-mentioned equipment, resins such as ABS resin and vinyl chloride resin, and glass fiber reinforced resin (F
RP) is commonly used.

However, the above fixing method has the following problems. That is, in the bolt fixing method, at least a space necessary for fixing the printed wiring board needs to be provided between the board and the housing, so that it is difficult to make the device compact. On the other hand, in the adhesive fixing method and the heat-welding fixing method, it is easy to make the device compact because the space required for fixing is small, but when the housing bends
Due to the difference in elastic modulus between parts such as IC and the housing material, stress acts in the vicinity of the fixed part (adhesive part or heat-welded part), and there is a problem that peeling of parts and cutting of IC lead wires are likely to occur. . Furthermore, in any of the above fixing methods, it is necessary to coat the module surface with a sealing resin in order to protect the IC and the IC lead wires from moisture such as moisture, corrosive gas, chemicals and the like. Further, at least the housing molding process and the mounting substrate fixing process are required, and the number of manufacturing processes is large.

Therefore, studies have been made to solve the above problems, and as a result, an electronic component component-containing in-mold product in which the electronic component component is integrally molded in a long fiber reinforced resin layer and incorporated therein. Has been proposed (Japanese Patent Application No. 3-
No. 345181). Such an in-molded product is manufactured by a method in which long-fiber-reinforced resin prepregs obtained by impregnating reinforced long fibers with a resin are laminated on both sides of an electronic component component and compression-molded by a mold. At this time, the long fiber reinforced resin prepreg is compressed and hardened while incorporating the electronic component component into a long fiber reinforced resin layer. This long fiber reinforced resin layer contains reinforced long fibers and resin. An example of the in-molded product is shown in FIG. In FIG. 3, 1 is a long fiber reinforced resin layer, 2 is a printed wiring board, 3 is an electronic component such as an IC, and the electronic component 3 is mounted on the substrate 2 to form an electronic component component.

According to the above-described in-mold product with built-in electronic component structure, the housing can be made smaller, so that the device can be easily made compact. Moreover, since it is hard to bend and excellent in strength, it is possible to peel off the component or to remove the IC lead wire. Cutting is less likely to occur, and furthermore, the electronic component component can be manufactured by in-molding it in the long fiber reinforced resin layer and integrally molding it into a housing shape, so the manufacturing process is greatly reduced.

[0006]

However, in the conventional in-mold product with a built-in electronic component component, the linear expansion coefficient (hereinafter referred to as α) of the long fiber reinforced resin layer is larger than α of the electronic component component. Since the two differ in α in the thickness direction of the in-molded product, there are the following problems caused by this. That is, when the in-mold product is manufactured, the compression molding is performed by the mold as described above. However, when the in-mold product is taken out from the mold and cooled after the molding, the in-mold product is different due to the difference (α). There is a difference in the shrinkage amount in the thickness direction of the in-molded product between the electronic component component built-in portion and the electronic component component non-embedded portion. Therefore, unevenness appears on the surface of the in-molded product, and depending on the degree of the unevenness, it may not be possible to satisfy the planar smoothness required when applying transfer printing or the like to the surface of the in-molded product. Here, the electronic component component built-in portion refers to a portion including the electronic component component and the long fiber reinforced resin layers above and below the component. The electronic component component non-embedded portion means a portion in which the electronic component component is not embedded, which is a portion other than the electronic component component embedded portion, that is, the in-molded product is made of only the long fiber reinforced resin over the entire thickness. It corresponds to the part.

The present invention has been made by paying attention to such a situation, and an object thereof is to solve the problems of the conventional in-mold product with a built-in electronic component component and to have less unevenness on the surface. It is intended to provide an in-mold product with a built-in electronic component structure that is excellent in flatness.

[0008]

In order to achieve the above object, the in-molded electronic component component-embedded product according to the present invention has the following configuration. That is, the in-molded product according to claim 1 is an in-molded product with a built-in electronic component component, which is obtained by integrally molding an electronic component component in a long fiber reinforced resin layer, wherein the inner layer portion of the resin layer is This is an in-mold product with a built-in electronic component structure, wherein the linear expansion coefficient is smaller than the linear expansion coefficient of the surface layer portion.

The in-molded article according to claim 2 is an in-molded article with a built-in electronic component component, which is obtained by integrally molding an electronic component component in a long fiber reinforced resin layer.
An in-mold product with a built-in electronic component component, wherein the linear expansion coefficient of the inner layer portion located on the left and right of the electronic component component in the resin layer is smaller than the linear expansion coefficient of the surface layer portion other than the inner layer portion. Is.

The in-molded product according to claim 3 is the in-molded product with a built-in electronic component structure according to claim 1 or 2, wherein the resin layer of the inner layer portion has a thickness equal to the thickness of the electronic component structure. Further, the in-molded product according to claim 4 is the in-molded product with a built-in electronic component component according to claim 1, 2 or 3, wherein the linear expansion coefficient of the inner layer portion is equal to the linear expansion coefficient of the electronic component component. is there.

[0011]

In the in-molded product with a built-in electronic component component according to the present invention, the in-molded product according to claim 1 is formed by integrally molding the electronic component component in the long fiber reinforced resin layer as described above. In an in-mold product with a built-in electronic component structure, the linear expansion coefficient (α) of the inner layer portion in the resin layer
Is smaller than α of the surface layer portion, the difference between the average value of α in the in-molded product thickness direction in the electronic component component built-in portion and that in the electronic component component non-embedded portion is the case of the conventional molded product. Smaller than. Therefore, in this in-molded product, after the compression molding by the mold performed at the time of manufacturing, the in-molded product thickness direction in the electronic component component built-in part when the in-molded product is taken out of the mold and cooled The difference between the amount of shrinkage and that of the part without built-in electronic components is
It is smaller than in the case of the conventional molded product, and unevenness does not easily appear on the surface of the in-molded product. Therefore, the in-mold product with a built-in electronic component structure according to claim 1 has few irregularities on the surface and is excellent in flatness.

Further, in the in-molded product according to claim 2, the linear expansion coefficient (α) of the inner layer portions located on the left and right of the electronic component component in the long fiber reinforced resin layer is a surface layer portion other than the inner layer portion. Is smaller than .alpha. Of .alpha., The difference between the average value of .alpha. Therefore, the same operation as in the case of the in-mold product according to claim 1 is performed, and thus the in-mold product with a built-in electronic component structure according to claim 2 is also excellent in flatness.

When the thickness of the resin layer of the inner layer portion is equal to the thickness of the electronic component component, the amount of shrinkage in the thickness direction of the in-mold component in the electronic component component built-in portion during cooling of the in-mold component and the electronic component configuration. The difference from that of the non-object built-in portion is the difference between the shrinkage amount of the resin layer of the inner layer portion and the shrinkage amount of the electronic component component. Therefore, the α of the resin layer of the inner layer is the α of the electronic component
By approaching to, the difference in shrinkage amount can be surely made to be a low level, and the flatness can be improved.

On the other hand, when α of the inner layer portion is equal to α of the electronic component component, the shrinkage amount of the inner layer portion in the thickness direction of the in-molded component is equal to that of the electronic component component. Therefore, by bringing the thickness of the resin layer of the inner layer portion closer to the thickness of the electronic component component, the shrinkage amount in the thickness direction of the in-mold component in the electronic component component built-in portion during cooling of the in-mold component and the electronic component can be reliably performed. The difference from that of the non-built-in portion can be set to a low level, and the planar smoothness can be improved. As can be seen from the above points, it is more preferable that the resin layer of the inner layer portion and the electronic component component have the same thickness and α.

The in-mold product with a built-in electronic component structure according to the present invention can be manufactured as follows. First,
A long-fiber-reinforced resin molding material having a known α value after compression molding and different α values is formed into a sheet to prepare a plurality of sheets. Next, these materials are laminated on both sides of the electronic component component so that the one with a small α value and the one with a large α value are placed on the side closer to the electronic component component, and then the mold is formed. By compression molding. For example, by impregnating a reinforced long fiber with a thermosetting resin, the α value after molding is a normal level (relatively large), and the long fiber reinforced thermosetting resin prepregs 6a, 6b with a small thickness and Long fiber reinforced thermosetting resin prepreg 7 with small α value and thick thickness
After manufacturing a, 7b, 7c, 7d, as shown in FIG. 4, these prepregs are arranged on the side closer to the electronic component component 4 with the prepregs 7a, 7b, 7c, 7d, and on the far side from the prepregs 6a, 6b. And stack them on both sides of the electronic component component 4,
This is set in a mold and then compressed by a lower mold 8 and an upper mold 5 at a predetermined temperature and a predetermined surface pressure to be molded, and then a molded product (in-molded product) is taken out from the mold and cooled. To do. Here, the long fiber reinforced resin molding material such as prepreg having a small α value after molding is added with various additives such as fused silica in the material or in the thermosetting resin when the material is prepared. It can be obtained by adjusting the addition amount.

[0016]

EXAMPLE An in-mold product with a built-in electronic component structure according to an example of the present invention was manufactured by a method similar to the method illustrated in FIG. A side sectional view of this in-molded product is shown in FIG. In FIG. 1, 4 is an electronic component constituent, R is a long fiber reinforced resin layer, R1a and R1b are surface layers of the resin layer R, R2 is an inner layer portion of the resin layer R, and A is a built-in electronic component constituent. Reference numeral B denotes a portion in which the electronic component component is not built-in.
Here, the thickness t ₂ of the resin layer of the inner layer portion R2 is the electronic component component 4
Thickness (2.5 mm) of the surface layer R1a and R1b
_1a and _t1b are set to be equal to the thickness (0.25 mm each) of the upper and lower resin layers of the electronic component component 4. The total thickness of the long fiber reinforced resin layer R is equal to the thickness (3 mm) of the in-molded product. The entire resin layer (t ₂ :: 2.5 mm portion) or a part thereof (t ₂ : 2.5 mm or less portion) of the resin layer of the inner layer portion R2 is located on the left and right sides of the electronic component component according to claim 2. It corresponds to an example of the inner layer portion. On the other hand, the linear expansion coefficient α in the thickness direction of each portion is the largest in the surface layer portions R1a and R1b of the resin layer R and is 3 × 10 ⁻⁴ /
C., 1 × 10 ⁻⁴ / ° C. in the inner layer portion R2 of the resin layer R, and 0.5 × 10 ⁻⁴ / ° C., which is the smallest in the electronic component component 4. The linear expansion coefficient α of the inner layer portion R2 was adjusted by adding 67% of fused silica to the material (prepreg) for forming the resin layer when the material was prepared.

As can be seen from these facts, the in-molded electronic component component-embedded product according to the above embodiment is an electronic component component formed by integrally molding the electronic component component 4 in the long fiber reinforced resin layer R. In the product-embedded in-mold product, the linear expansion coefficient α of the inner layer portion R2 of the resin layer R is smaller than the linear expansion coefficient α of the surface layer portions R1a and R1b, and the thickness of the resin layer of the inner layer portion R2. Is equivalent to the thickness of the electronic component component 4. That is, it corresponds to an example of an in-mold product with a built-in electronic component structure.

On the other hand, an in-mold product with a built-in electronic component structure was manufactured as a comparative example. The in-molded article according to this comparative example is an in-molded article with a built-in electronic component, which is formed by integrally molding the electronic component component 4 in the long fiber reinforced resin layer R as shown in FIG. The resin layer R has a uniform composition and a uniform linear expansion coefficient α (α of the surface layer portion).
And α of the inner layer are equivalent). The coefficient of linear expansion α of the resin layer R in the thickness direction is equivalent to α (3 × 10 ⁻⁴ / ° C.) of the surface layer portions R1a and R1b of the in-mold product according to the embodiment of the present invention, and the electronic component structure The α of the object 4 is 0.5 × 10 ^-4 / ° C.

The thickness of the above-mentioned in-molded product was measured and the surface condition was observed. The in-mold product according to the comparative example is
The maximum thickness difference (hereinafter referred to as smoothness) between the electronic component component built-in part and the electronic component component non-built-in part was 100 μm, and unevenness appeared on the surface, resulting in poor planar smoothness. On the other hand, the in-molded products according to the examples of the present invention had a smoothness of 20 μm, had few irregularities on the surface, and had excellent planar smoothness.

By the way, when transfer printing or the like is applied to the surface of an in-molded product, the required flatness of the surface of the in-molded product is said to be about 10 μm or less in smoothness. The smoothness of the in-mold product according to the example is large and insufficient. In this case, in order to satisfy the required smoothness, the linear expansion coefficient α in the inner layer portion R2 of the resin layer R is approximately 0.
It may be 8 × 10 ⁻⁴ / ° C. or less, and for that purpose, as described above, the kind and the amount of the additive in the material for forming the inner layer portion R2 may be adjusted when the material is formed.

[0021]

EFFECT OF THE INVENTION The in-molded electronic component component built-in product according to the present invention has the above-described structure and operates, and the problems of the conventionally proposed in-molded electronic component component built-in product. The surface of the in-molded product has less unevenness and has excellent flatness smoothness. Therefore, when flatness is required for the in-molded product such as when transfer printing is performed on the surface of the in-molded product. It has an effect that it can be preferably used. Further, similar to the above-mentioned conventionally proposed in-mold product with built-in electronic component composition, compared to the conventional electronic component fixing method, it can be easily made compact, is not easily bent, and is excellent in strength and strong. At the same time, it has the effect that it is possible to significantly reduce

[Brief description of drawings]

FIG. 1 is a side sectional view showing a main part of an in-mold product with a built-in electronic component structure according to an embodiment of the present invention.

FIG. 2 is a side cross-sectional view showing a main part of an in-mold product with a built-in electronic component structure according to a comparative example.

FIG. 3 is a side sectional view showing a main part of a conventionally proposed in-mold product with a built-in electronic component structure.

FIG. 4 is a side sectional view showing an example of a manufacturing situation of an in-molded product with a built-in electronic component structure according to the present invention.

[Explanation of symbols]

1--long fiber reinforced resin layer, 2--printed wiring board, 3--electronic component, 4--electronic component composition, 5--upper mold, 6a, 6b--long fiber reinforced resin prepreg, 7a, 7b, 7c, 7d--long fiber reinforced resin prepreg, 8--lower mold, A--electronic component constituent built-in portion, B--electronic component non-embedded portion, R--long fiber reinforced resin layer, R1a, R1b--surface layer, R2--inner layer.

Claims (4)

[Claims] 1. An in-mold product with a built-in electronic component structure obtained by integrally molding an electronic component structure in a long fiber reinforced resin layer, wherein the linear expansion coefficient of the inner layer portion of the resin layer is that of the surface layer portion. An in-mold product with a built-in electronic component structure, which is smaller than the linear expansion coefficient. 2. An in-mold product with a built-in electronic component structure, which is obtained by integrally molding an electronic component structure in a long fiber reinforced resin layer, wherein inner layers located on the left and right of the electronic component structure in the resin layer. An in-mold product with a built-in electronic component structure, wherein a linear expansion coefficient of a part is smaller than a linear expansion coefficient of a surface layer part other than the inner layer part. 3. The in-molded electronic component product according to claim 1, wherein the resin layer of the inner layer portion has a thickness equal to that of the electronic component composition. 4. The in-mold product with a built-in electronic component structure according to claim 1, 2 or 3, wherein the linear expansion coefficient of the inner layer portion is equal to the linear expansion coefficient of the electronic component structure.