JPH10335102A - Armor resin and electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water-resistant, washable armor resin and an electronic component exploiting the same capable of maintaining high mechanical strength, low cost, low internal stress, and good drying. SOLUTION: This armor resin consists of a first layer 6 and a second layer 7 and is structured in double layers. The first layer 6 has its open hole volume V(1)(cc/g) in 0.08<=V(1)<=0.13 and its distribution of open hole diameter Rp10%(1)(μm) in 2.40<=RP10%(1)<=3.50. The second layer 7 has its open hole volume V(2)(cc/g) in 0.05<=V(2)<=0.10 and its distribution of open hole diameter Rp10% (2)(μm) in 0.35 <=Rp10%(2)<=0.90.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an exterior resin and an electronic component.

[0002]

2. Description of the Related Art Conventionally, an electronic component with a lead terminal, for example, an electronic component with a lead terminal having a cavity inside, such as a ceramic oscillator, as disclosed in Japanese Patent Laid-Open No. 6-310973, has an external component. The housing is made of a resin material for the purpose of preventing mechanical impact from water and intrusion of water. This exterior resin was made of a mixture of a thermosetting resin and an inorganic filler, and was characterized by low cost, high mechanical strength, and low internal stress.

[0003]

However, in the conventional packaging method using a packaging resin, a gap (void) is easily generated between the thermosetting resin and the inorganic filler, resulting in a porous resin structure as a whole. .

[0004] After soldering an electronic component on which such an exterior resin is applied to a substrate by reflow, if the electronic component is immersed in a cleaning solution or hot water for flux cleaning, a negative pressure is generated in a cavity of the electronic component due to the rapid temperature drop. Is generated, and the cleaning liquid or the hot water is sucked through the gaps of the exterior resin and penetrates into the cavities, so that there is a problem that the electrical characteristics are deteriorated.

[0005] In order to avoid this problem, there is a method of eliminating voids by increasing the content of the thermosetting resin or reducing the particle size of the inorganic filler. There are problems that the stress increases and the drying property of the organic solvent decreases.

As another method, there is a method of coating a general exterior resin with a dense resin called a top coat. However, when the exterior resin and the top coat are simultaneously cured, the solvent in the exterior resin composition generates pinholes in the top coat. Therefore, there is a method of separately curing the exterior resin and the top coat. However, in this method, it is necessary to divide the process into two stages, resulting in an increase in cost. Further, the base portion of the lead terminal is hardly covered with the top coat, and water may enter from this portion.

An object of the present invention is to provide an exterior resin having sufficient washing resistance while maintaining high mechanical strength, low cost, low internal stress, and good drying properties, and an electronic component using the same. It is in.

[0008]

In order to solve the above-mentioned problems, the present invention has completed an exterior resin and an electronic component.

The exterior resin according to the first aspect of the present invention is an exterior resin for covering an electronic component element, wherein the exterior resin has a two-layer structure including a first layer and a second layer, and
The layer has an open pore volume V (1) (cc / g) of 0.08 ≦ V (1) ≦
0.13 and the pore size distribution Rp10% (1) (μ
m) is 2.40 ≦ Rp10% (1) ≦ 3.50.

The first invention of the present application is characterized by a two-layer structure including a porous inner layer resin (first layer) having the above characteristics and a dense surface layer resin (second layer). Due to this feature, it is possible to also have excellent water washing resistance while maintaining high mechanical strength, low cost, low internal stress, and good drying property.

When V (1) is smaller than 0.08 cc / g or when the pore size distribution Rp10% (1) is smaller than 2.40 cc / g, the effect of trapping water entering from the outside is lost. Water easily reaches the interior of the cavity. On the other hand, when V (1) exceeds 0.13 cc / g, or when the pore size distribution Rp10% (1) exceeds 3.50 cc / g, not only water from outside easily enters, but also The mechanical strength is also insufficient.

In the exterior resin of the present invention, the composition of the first layer preferably comprises an epoxy resin which is solid at room temperature, silica having an average particle diameter of substantially 30 μm, and an additive.

Further, in the exterior resin of the present invention, the second layer has an open pore volume V (2) (cc / g) of 0.05 ≦ V.
(2) ≦ 0.10 and pore size distribution Rp10% (2)
(Μm) is preferably 0.35 ≦ Rp10% (2) ≦ 0.90.

When V (2) exceeds 0.10 cc / g, or when Rp10% (2) exceeds 0.90 μm, water easily infiltrates, which is not preferable. On the other hand, V (2)
Is smaller than 0.05 cc / g, or when Rp10% (2) is smaller than 0.35 μm, water intrusion can be prevented, but the drying of the organic solvent is delayed, and poor appearance such as pinholes occurs. Is not preferred.

In the exterior resin of the present invention, it is preferable that the composition of the second layer comprises an epoxy resin which is solid at room temperature, silica having an average particle diameter of substantially 6 μm, and an additive.

Further, in the exterior resin of the present invention, the epoxy resin of the first layer is in a range of 9 to 13% by weight of a total of 100% by weight of the first layer, and Is preferably in the range of 80 to 84% by weight of the total 100% by weight of the first layer.

When the compounding amount of the epoxy resin is less than 9% by weight (when the compounding amount of silica exceeds 84% by weight),
It is not preferable because the mechanical strength decreases. On the other hand, when the compounding amount of the epoxy resin exceeds 13% by weight (when the compounding amount of silica is less than 80% by weight), the stress cannot be increased, the drying property of the organic solvent can be reduced, or water cannot be trapped. This is not preferred for that reason.

In the exterior resin of the present invention, the epoxy resin of the second layer is in a range of 12 to 14% by weight of the total of 100% by weight of the second layer, and Is preferably in the range of 79 to 81% by weight of the total of 100% by weight of the second layer.

When the amount of the epoxy resin is less than 12% by weight (when the amount of silica exceeds 81% by weight), it is not preferable because the mechanical strength is reduced and water easily penetrates. . On the other hand, when the compounding amount of the epoxy resin exceeds 14% by weight (when the compounding amount of silica is less than 79% by weight), the drying property of the organic solvent decreases, which is not preferable.

Further, the electronic component of the present invention comprises an electronic component element and an exterior resin for covering the electronic component element,
The exterior resin is characterized in that it is an exterior resin having a two-layer structure according to any of the above.

An exterior resin composition can be obtained by adding an appropriate amount of an organic solvent to the components of the first and second layers and mixing them. The two types of exterior resin compositions were successively applied and simultaneously cured to provide high mechanical strength, low internal stress, and low cost. Exterior can be applied. Further, by having excellent resistance to water washing, it is possible to wash with water after mounting on a substrate.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Porous inner layer resin (first layer)
Is used to trap water that has entered from the outside and not to reach the inside of the cavity. The composition and the amount of the first layer are not particularly limited as long as they have the above characteristics. It is not something to be done.

The required degree of porousness (pore diameter distribution) is not uniquely determined, and depends on the density of the second layer. However, the open pore volume V (1) (cc / g) is not less than 0.1. 0
8 ≦ V (1) ≦ 0.13, and the pore size distribution Rp10% (1) (μm) is 2.40 ≦ Rp10% (1) ≦ 3.5.
It is said that a range of 0 is preferable.

Here, the open pore volume V (cc / g) is the volume of open pores per 1 g of a sample, and corresponds to the amount (volume) of mercury intrusion measured by the mercury intrusion method.
The mercury intrusion method is the most widely used method for obtaining the pore size distribution, and is a method of injecting mercury into a sample and obtaining the pore amount and the pore size from the relationship between the pressure and the amount of the injected mercury. Since the internal pores into which mercury cannot enter cannot be measured, it is referred to as open pore volume.

The pore size distribution Rp10% (μm) refers to an open pore distribution measured by a mercury intrusion method, which corresponds to a pore size of 10% from the larger pore size (mercury is the pore size To invade from a big place).

The additives are added as needed, and include, for example, a thixotropic agent and a coloring pigment.

The silica having a substantially average particle diameter of 30 μm is
It does not indicate only the average particle diameter of 30 μm, but means about 30 μm of the average particle diameter including before and after. The same applies to silica having an average particle diameter of 6 μm.

The dense surface layer resin (second layer) is used to suppress the intrusion of water from the outside, and if it has the above-mentioned characteristics, the composition constituting the second layer And the amount thereof are not particularly limited.

The degree of denseness (pore size distribution) is not also defined unambiguously, and depends on the porosity of the first layer to be combined, but the open pore volume V (2) (cc / cc)
g) is in the range of 0.05 ≦ V (2) ≦ 0.10, and the pore size distribution Rp10% (2) (μm) is 0.35 ≦ Rp10
It is said that a range of% (2) ≦ 0.90 is preferable.

Next, the present invention will be described more specifically based on examples, but the present invention is not limited to only these examples.

[0031]

FIG. 1 is a sectional view of a ceramic oscillator according to an embodiment of the present invention. The ceramic oscillator 1 includes an external terminal cup 3a formed integrally with the piezoelectric element 2 and an external terminal lead (not shown) connected to the circuit board.
4a, a two-layered exterior resin 6 and 7 composed of a first layer and a second layer, and a cavity 5 formed around the entire piezoelectric element 2.

The piezoelectric element 2 has a vibrating electrode 2a provided substantially at the center of one main surface thereof, and a terminal electrode 2c which is electrically connected to the vibrating electrode 2a at one end. A vibration electrode 2b facing the vibration electrode 2a is provided substantially at the center of the other main surface, and a terminal electrode 2d that is electrically connected to the vibration electrode 2b is provided at a position not facing the terminal electrode 2c. The cups 3a, 4a of the external terminals are connected to the terminal electrodes 2c, 2c of the piezoelectric element 2.
d is connected by soldering or the like.

The cavity 5 formed around the piezoelectric element 2
This is to secure a space in which the vibrating portion including the vibrating electrode of the piezoelectric element 2 vibrates.

Hereinafter, the composition of the exterior resins 6 and 7 will be described. Table 1 shows the exterior resin (first layer 6,
The composition (% by weight) and bending strength (MPa) of the second layer 7) are shown.

[0035]

[Table 1]

The epoxy resin used was Epicoat # 1007 (Mitsubishi Yuka). The silica used was Hughes Rex (trade name, manufactured by Tatsumori).

Then, an appropriate amount of a diluting solvent was added to the above components and mixed with a planetary mixer to prepare an exterior resin composition.

Table 2 shows the results obtained by the mercury intrusion method.
The open pore volume V of sample No. 1 to sample No. 10 (cc /
g) and the pore size distribution Rp10% (μm).

[0039]

[Table 2]

Next, Table 3 shows the evaluation results of the washing resistance to water.

[0041]

[Table 3]

The water-resistant washing property is as follows. After heating the hollow parts provided with the respective exterior resin samples to 160 ° C., they are immersed in a cleaning solution heated to 60 ° C., and after 20 minutes, the parts are taken out and decomposed, It was confirmed that water had entered the water.

In each of Examples 1 to 7, the number of NGs was 0, and it can be seen that the water cleaning resistance was very good.

On the other hand, in Comparative Examples 1 to 8, the number of NGs was 2
/ 20 to 20/20, indicating poor water-washing resistance.

[0045]

By using the exterior resin of the present invention, it is possible to provide excellent properties such as high mechanical strength and low internal stress, and to provide excellent washing resistance to water. Therefore, it is possible to use a conventional low-cost exterior resin for the exterior of an electronic component that is required to be resistant to washing with water.

[Brief description of the drawings]

FIG. 1 is a sectional view of a ceramic resonator according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ceramic oscillator 2 Piezoelectric element 2a, 2b Vibration electrode 2c, 2d Terminal electrode 3a, 4a Cup part of external terminal 5 Cavity 6 First layer of exterior resin 7 Second layer of exterior resin

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01L 23/31 H01L 23/30 R H03H 9/17 (72) Inventor Manabu Sumida 2-26-10 Tenjin, Nagaokakyo-shi, Kyoto Murata Manufacturing Co., Ltd. (72) Inventor Muneyuki Oshiro 2-26-10 Tenjin, Nagaokakyo-shi, Kyoto Prefecture Murata Manufacturing Co., Ltd.

Claims (7)

[Claims] 1. An exterior resin for covering an electronic component element, wherein the exterior resin has a two-layer structure including a first layer and a second layer, and the first layer has an open pore volume V (1). (Cc
/ G) is 0.08 ≦ V (1) ≦ 0.13, and the pore size distribution Rp10% (1) (μm) is 2.40 ≦ Rp10% (1).
≦ 3.50, an exterior resin. 2. The exterior resin according to claim 1, wherein the composition of the first layer comprises an epoxy resin solid at room temperature, silica having an average particle size of substantially 30 μm, and an additive. . 3. The second layer has an open pore volume V (2) (cc /
g) is 0.05 ≦ V (2) ≦ 0.10, and the pore size distribution Rp10% (2) (μm) is 0.35 ≦ Rp10% (2) ≦
The exterior resin according to claim 1 or 2, wherein the exterior resin is 0.90. 4. The composition according to claim 1, wherein the composition of the second layer comprises an epoxy resin solid at room temperature, silica having an average particle size of substantially 6 μm, and an additive. The exterior resin according to any one of the above. 5. The method according to claim 1, wherein the first layer of epoxy resin comprises
The silica of the first layer is in the range of 80 to 84% by weight of the total 100% by weight of the first layer. The exterior resin according to any one of claims 1 to 4, characterized in that: 6. The second layer of epoxy resin comprises
The silica of the second layer is in the range of 79 to 81% by weight of the total 100% by weight of the second layer, and the silica of the second layer is in the range of 12 to 14% by weight of the total 100% by weight of the layer. The exterior resin according to any one of claims 1 to 5, characterized in that: 7. An electronic component comprising an electronic component element and an exterior resin for covering the electronic component element, wherein the exterior resin has a two-layer structure according to any one of claims 1 to 6. An electronic component characterized by being an exterior resin.