JPH06164185A - Hybrid ic - Google Patents

Abstract

PURPOSE:To enable dip coating for a shield layer 6 of a hybrid IC and also give sufficient conductivity and intimate contactness to the shield layer. CONSTITUTION:A conductive paint to form a shield layer 6 is obtained by mixing 100 pts.wt. of metal copper powder of which surface 18 covered with 0.05 to 0.5 pt.wt. of titanate, 5 to 33 pts.wt. of resol type phenol resin, 0.5 to 8 pts.wt. of chelate layer forming agent and 0.1 to 2 pts.wt. of coupling agent. Next, a substrate 1 mounted with electronic components element 2, 3 is soaked to an insulating resin bath with a copper foil conductive material 7 for a ground lead terminal 4a to form a protective layer 5. Moreover, after bending the conductive material 7 toward inside, the substrate 1 is dipped in the conductive paint bath to form a shield layer 6. The ground lead terminal 4a and the shield layer 6 are electrically connected through the conductive material 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid IC in which an electronic component element on a substrate is sealed with a protective layer made of an insulating resin and a shield layer is formed thereon.

[0002]

2. Description of the Related Art A hybrid IC is used by mounting it on a printed wiring board, and its electronic component element is covered with a protective layer of an insulating resin to protect it from the external environment. A shield layer is formed to block the external influence of the electromagnetic wave emitted from the hybrid IC and the external influence on the hybrid IC.

To form the shield layer, there are means for providing an outer case of a metal case and means for applying a conductive substance as disclosed in Japanese Utility Model Laid-Open No. 61-75192. The former has a large shape and is expensive. On the other hand, the latter has the advantages that the entire hybrid IC can be downsized and the manufacturing cost is low.

However, although a conductive paint is usually used for the above-mentioned conductive material, conventionally, it is possible to obtain a sufficient shielding effect such as having sufficient conductivity while maintaining high adhesion with the copper foil. The reality is that nothing that can be done has been proposed.

In view of the above situation, it is an object of the present invention to make the shield layer have sufficient conductivity while maintaining the adhesion to the copper foil.

[0006]

In order to solve the above problems, according to the present invention, an electronic component element is mounted on a substrate, and a protective layer made of an insulating resin is formed on the electronic component element. A number of lead terminals are projected from the protective layer, and a shield layer of conductive paint having the composition of (A) to (D) below is formed on the protective layer, and the shield layer is the ground of the lead terminals. The structure is such that it is electrically connected only to the lead terminals.

Note (A) 100 parts by weight of metal copper powder surface-coated with 0.05 to 0.5 parts by weight of titanate, zirconate, stearic acid, stearate, or a mixture thereof (B) Resol-type phenol resin 5 to 33 parts by weight (C) chelate layer forming agent 0.5 to 8 parts by weight (D) coupling agent 0.1 to 2 parts by weight
.

The above-mentioned resol type phenol resin is preferably the following. The 2-1 substitution product, 2,4-2 substitution product, 2,4,6-3 substitution product, methylol group, dimethylene ether, each infrared transmittance of phenyl group is 1, m, n, a, b, When c,
Between each transmittance, (a) l / n = 0.8 to 1.2 (b) m / n = 0.8 to 1.2 (c) b / a = 0.8 to 1.2 ( D) A resole type phenolic resin in which the relationship of c / a = 1.2 to 1.5 is established.

The protective layer and the shield layer may be formed by dip coating in which the substrate on which the electronic component element is mounted is successively dipped in an insulating resin bath and a conductive paint bath.

The substrate material is an insulating material such as epoxy resin, phenol resin, glass fiber or ceramics.

The metallic copper powder may have any shape such as flakes, dendritic shapes, spherical shapes, and irregular shapes. Particle size is 10
It is preferably 0 μm or less, and particularly preferably 1 to 30 μm.
Particles having a particle size of less than 1 μm are easily oxidized and the conductivity of the resulting coating film (coating film) is lowered, which is not preferable.

Further, the metallic copper powder is finely dispersed in the resin mixture by surface-coating it with titanate, zirconate, stearic acid, stearate, or a mixture thereof (hereinafter referred to as a dispersibility-imparting agent). It is promoted, thereby stabilizing the quality of conductive paint and improving conductivity. The amount of the dispersibility-imparting agent added is 100
It is 0.05 to 0.5 parts by weight with respect to parts by weight. When the amount of the dispersibility-imparting agent added is less than 0.05 parts by weight, the conductivity of the coating film decreases, and when it exceeds 0.5 parts by weight, the solder heat resistance is unfavorable. The dispersibility-imparting agent may be added alone, or the solvent may be removed after being added as a solution. Incidentally, this surface treatment makes it unnecessary to add a dispersant.

When the content of the resol-type phenol resin is less than 5 parts by weight, the metallic copper powder is not sufficiently bound, the resulting coating film becomes brittle, and the electrical conductivity also deteriorates. Further, if it exceeds 33 parts by weight, the conductivity decreases. It is preferably 9 to 20 parts by weight.

Further, the stoichiometry, the amount of the 2-1 substitution product is λ,
The amount of 2,4-2 substitution product is μ, the amount of 2,4,6-3 substitution product is ν, the amount of methylol group is α, the amount of dimethylene ether is β,
When the amount of phenyl group is γ, 1 / n and m / n of the above-mentioned constitution
Is large, it means that λ / ν and μ / ν are small. That is, the amount of 2-1 substitution product λ, 2,4-2
This means that the amount of 2,4,6-3 substitution product ν is larger than the substitution product amount μ. In addition, b / a, c /
A large a means that β / α and λ / α are small. That is, it means that the amount of methylol groups α is larger than the amount of dimethylene ether β and the amount of phenyl groups λ.

Generally, when the 2,4,6-3 substitution product amount ν increases, the crosslink density of the resol type phenol resin increases, so that the smaller λ / ν and μ / ν, that is, 1 / n. , M / n is larger, the conductivity of the coating film is better. However, on the contrary, the coating film tends to be hard and brittle, and the physical properties deteriorate. Further, if γ / α is large, the conductivity of the coating film is deteriorated.

Therefore, in the obtained conductive coating material, the resol type phenolic resin which has appropriate hardness of the coating film and has good conductivity has 1 / n, m / n,
b / a is 0.8-1.2, c / a is 1.2-
A value of 1.5 is suitable.

The chelate layer forming agent is at least one selected from aliphatic amines such as monoethanolamine, diethanolamine, triethanolamine, ethylenediamine, triethylenediamine and triethylenetetramine.
It is a seed. The chelate layer forming agent prevents oxidation of the metal copper powder and contributes to maintaining conductivity. The blending amount is 0.5 to 8 parts by weight with respect to 100 parts by weight of the metal copper powder. If the blending amount is less than 0.5 parts by weight, the conductivity of the coating film decreases,
On the contrary, when the amount exceeds 8 parts by weight, no further effect can be expected.

The coupling agent serves to improve the dispersibility of the copper metal powder in the binder and to improve the conductivity, and it can be used as a silane coupling agent, a titanium coupling agent, a zirconate coupling agent, or an aluminum coupling agent. At least one selected from the above. The blending amount is 0.1 part to 2 parts by weight with respect to the metal copper powder. 0.
If it is less than 1 part by weight, the effect cannot be expected, and if it exceeds 2 parts by weight, no further effect can be expected.

In the conductive paint, a usual organic solvent can be appropriately used in order to adjust the viscosity. For example, known solvents such as cellosolve acetate, carbitol, butyl carbitol, and butyl cellosolve acetate.

[0020]

As can be understood from the above description, the conductive coating material according to the present invention having such a structure has a high conductivity without causing deterioration of adhesion.

[0021]

EXAMPLE First, 100 parts by weight of a dendritic metal copper powder having a particle size of 5 to 10 μm and a specific surface area of 0.4 m ² / g or less and a hydrogen reduction weight loss of 0.25% or less was put into a stirrer to prepare a titanate. Was added little by little and stirred to coat the surface of the metal copper powder with titanate. After that, the metal copper powder was mixed with triethanolamine as a chelate layer forming agent and an infrared transmittance ratio (l / n: 1.03, m / n: 1.02, b
/ A: 0.96, c / a: 1.31) in the proportions shown in Table 1, butyl cellosolve is added as a solvent, and the mixture is kneaded in place with a triaxial roll for 20 minutes to give a viscosity of A conductive paint bath was obtained with a measuring machine VT-04 manufactured by Rion Co., Ltd. so as to be 20 to 40 P.

In place of butyl cellosolve, butyl carbitol, butyl carbitol acetate, butyl cellosolve acetate, methyl isobutyl ketone, toluene,
Known materials such as xylene can be used.

[0023]

[Table 1]

On the other hand, as shown in FIG. 1, electronic component elements such as various chip components 2 and resistors 3 are mounted or printed on an epoxy resin substrate 1 on which a copper foil circuit pattern is formed, and from the circuit. Required number of lead terminals 4 ... 4
a is projected.

The substrate 1 is dipped in an epoxy resin bath with the conductive material 7 made of copper foil added to the base 4a 'of the ground lead terminal 4a to form a protective layer 5 having a required thickness. At the time of the immersion, the lead terminals 4 ... 4a are soaked up to the exposed portions (connection portions) of the lead terminals, that is, leaving the connection portions.
…… Make sure that the space is filled and covered with resin. This is to prevent short-circuiting between the shield layer 6 and the lead terminals 4, which will be described later.

Subsequently, the protruding portion of the conductive material 7 is attached to the protective layer 5.
The substrate 1 bent to the side (inside) and in that state is immersed in the conductive paint bath to form a shield layer 6 having a required thickness. The immersion depth should not reach the edge of the protective layer 5 on the side of the lead terminals 4 and 4a. At this time, the shield layer 6 is also formed on the conductive material 7, and the ground lead terminal 4 a and the shield layer 6 are electrically connected via the conductive material 7.

The superiority of the conductive paint b of this example can be understood by the following test.

That is, as shown in FIG. 2, copper foil electrodes 10 and 10 are formed on a glass epoxy substrate 11, and the copper foil electrodes 10 and 10 are coated with the same resin as the protective layer 5, and then, on top of that, Table 1
Each of the conductive paints b) is printed using an 80-mesh Tetoron screen to form a pattern with a width of 5 mm and a length of 60 mm, which is pre-dried at 100 ° C for 10 minutes and then at 160 ° C for 30 minutes.
It was heated for a minute and cured. Next, the resistance value between the electrodes 10 and 10 was measured by the 4-terminal method to obtain the resistance value per unit area. The results are shown in the lower column of Table 1.

Also, each conductive paint b in Table 1 was printed on a metal plate of the same type as the ground lead terminal 4 using an 80 mesh Tetron screen, and after temporary drying at 100 ° C. for 10 minutes, heating at 160 ° C. for 30 minutes. Then, the obtained coating film is JI
Tested using the SK5400 cross-cut tape method and visually inspected the number of cross-cuts left without being completely peeled off. 0/100 if all squares were peeled, 100/100 if all squares remained The adhesion was evaluated, and the results are shown in the lower column of Table 1.

As is clear from this result, Examples 1 to 1
In No. 4, the conductive coating material b according to the present invention is appropriately combined in a specific composition, and high conductivity is obtained without causing deterioration of adhesion.

On the other hand, in Comparative Example 1, the amount of the resol-type phenol resin is too large, and in Comparative Example 2, the amount of the chelate layer forming agent is small, so that the conductivity is poor. In Comparative Example 3, since the resol type phenol resin is small, the adhesion is poor. In Comparative Example 4, since no coupling agent was added,
There is a problem with conductivity.

[0032]

Since the present invention is constructed as described above,
Hybrid I of shield layer with excellent conductivity and adhesion
C can be obtained.

[Brief description of drawings]

1 is a front view of one embodiment, and b is a sectional view taken along line XX of FIG.

FIG. 2 is a perspective view of a resistance test piece.

[Explanation of symbols]

 1 substrate 2 chip parts 3 resistance 4 lead terminal 4a ground lead terminal 5 protective layer 6 shield layer 7 copper foil conductive material 10 copper foil electrode 11 glass epoxy substrate b conductive paint (coating film)

Claims (2)

[Claims] 1. An electronic component element is mounted on a substrate, a protective layer made of an insulating resin is coated on the electronic component element, and a required number of lead terminals are projected from the protective layer.
A hybrid IC, characterized in that a conductive paint shield layer comprising the following blends (A) to (D) is formed, and the shield layer is electrically connected only to the ground lead terminal of the lead terminals. . Note (A) 100 parts by weight of metal copper powder surface-coated with 0.05 to 0.5 parts by weight of titanate, zirconate, stearic acid, stearate, or a mixture thereof (B).
Resol type phenol resin 5 to 33 parts by weight (C) Chelate layer forming agent 0.5 to 8 parts by weight (D) Coupling agent 0.1 to 2 parts by weight 2. The hybrid IC according to claim 1, wherein the resol type phenolic resin is as follows. The 2-1 substitution product, 2,4-2 substitution product, 2,4,6-3 substitution product, methylol group, dimethylene ether, each infrared transmittance of phenyl group is 1, m, n, a, b, When c,
Between each transmittance, (a) l / n = 0.8 to 1.2 (b) m / n = 0.8 to 1.2 (c) b / a = 0.8 to 1.2 ( D) A resole type phenolic resin in which the relationship of c / a = 1.2 to 1.5 is established.