JP2576907B2 - Manufacturing method of circuit board device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit board device, and more particularly, to a circuit board having a structure in which a semiconductor element is electrically connected to a wiring conductor of the circuit board via a protruding electrode. The present invention relates to a device manufacturing method.

2. Description of the Related Art There is a circuit board device having a structure in which a semiconductor chip (flip chip) having solder bumps (protruding electrodes) is fixed to a wiring conductor on a circuit board via a solder bump. In this type of circuit board device, internal stress is repeatedly generated due to the thermal expansion during operation due to the difference in thermal expansion coefficient between the flip chip and the circuit board, but solder bumps are caused by thermal fatigue caused by this internal stress. A failure mode in which cracks occur is easily generated. As a measure to improve the thermal fatigue characteristics of solder bumps, it is known to improve the shape of the solder bumps. For example, JP-A-63-62333 discloses a method of forming a high columnar solder bump and forming a solder bump. A method for alleviating the thermal fatigue of the above has been disclosed. However, in order to form a high columnar bump, it is necessary to previously form a solder bump having a large cross-sectional area, which is disadvantageous in terms of miniaturization and high-density mounting of a flip chip. Further, it is not easy to form a high columnar solder bump into a predetermined shape.

Accordingly, it is an object of the present invention to solve the above-described problems and to provide a method for manufacturing a circuit board device that is resistant to thermal fatigue.

Means for Solving the Problems A method for manufacturing a circuit board device according to the present invention provides a circuit board (3) having a wiring conductor (12) formed on one main surface and a protruding electrode (13) on the wiring conductor (12). A substrate assembly (11) having a semiconductor element (4) electrically connected through the substrate;
Liquid protective resin forming material having a viscosity of 5,000 centipoise or less, containing a filler and a resin material having a thermal expansion coefficient smaller than that of the semiconductor element (4) and a solvent of 20% by weight or more based on the total weight. (6a, 7a); and forming a protective resin forming material (6a, 7a) in a region where one main surface of the semiconductor element (4) and one main surface of the circuit board (3) are separated and opposed to each other. ) And the protective resin forming material (6
forming a protective resin (6, 7) having a coefficient of thermal expansion larger than the coefficient of thermal expansion of the semiconductor element (4) and smaller than the coefficient of thermal expansion of the circuit board (3) based on a, 7a);
Forming a resin sealing body (10) to which the circuit board (3) is fixed and which seals the support plate (1) constituting the board assembly (11) and the protective resin (6, 7).

The material for forming a protective resin (6a, 7a) contains a filler composed of granular silica having an average particle diameter of 5 to 20 μm in an amount of 85.5 to 96.5% by weight based on the total weight of the filler and the resin material, and Desirably, it has a viscosity of 500 to 2500 centipoise.

According to the invention, the wiring conductor (12) is provided on one main surface.
A board assembly (11) having a circuit board (3) on which a semiconductor device (3) is formed and a semiconductor element (4) electrically connected to the wiring conductor (12) via a protruding electrode (13); 4) The first filler having a smaller coefficient of thermal expansion than the coefficient of thermal expansion, the first resin material, and 20% by weight based on the total weight.
A liquid first protective resin molding material (6a) containing the first solvent and having a viscosity of 5,000 centipoise or less; and a second material having a thermal expansion coefficient smaller than that of the semiconductor element (4). The liquid second protective resin forming material (7) containing the second solvent at a content smaller than the content of the first solvent in the filler, the second resin material, and the first protective resin molding material (6a).
a) preparing a first protective resin forming material (6a) in a region where one main surface of the semiconductor element (4) and one main surface of the circuit board (3) are separated from each other and opposed to each other; A step of filling, a step of evaporating at least a part of the first solvent to lower the fluidity of at least the first protective resin forming material (6a), and a step of converting the second protective resin forming material (7a) to a circuit board ( 3)
Supplying the first protective resin-forming material (6a) having at least reduced fluidity with the second protective resin-forming material (7a), and substantially removing the second solvent. Forming the second protective resin (7) based on the second protective resin forming material while evaporating all the resin, and sealing the resin with a thermal expansion coefficient larger than the thermal expansion coefficient of the second protective resin (7). And a step of further coating the second protective resin (7) with the stopper (10). In the step of evaporating at least a part of the first solvent and / or the step of forming the second protective resin (7), the first protective resin-forming material (6a) is substantially all of the first solvent. A first protective resin having a coefficient of thermal expansion that is smaller than the coefficient of thermal expansion of the circuit board (3) and the coefficient of thermal expansion of the second protective resin (7) and larger than the coefficient of thermal expansion of the semiconductor element (4); Form (6).

The first material for forming a protective resin (6a) comprises a first filler made of granular silica having an average particle diameter of 5 to 20 μm, which is 85.5 to 85.5% based on the total weight of the first filler and the first resin material. 96.5% by weight and having a viscosity of 500 to 2500 centipoise when filled, wherein the second filler is a particulate silica having an average particle size greater than the average particle size of the particulate silica of the first filler and / or Alternatively, the first filler desirably contains a particulate silica having a content smaller than that of the particulate silica.

According to the invention of claim 1 of the present application, the protective resin forming material (6a, 7a) containing a solvent of 20% by weight or more and having a viscosity of 5,000 centipoise or less includes the semiconductor element (4) and the circuit board (6). 3) satisfactorily flows into a region opposed to and fills this region. The protective resin forming material (6a, 7a) contains a filler having a smaller coefficient of thermal expansion than that of the semiconductor element (4), and the protective resin (6, 7) formed by the protective resin forming material (6a, 7a). Has a value intermediate between the linear expansion coefficient of the semiconductor element (4) and the thermal expansion coefficient of the circuit board (3). Further, the protective resin (6, 7) has a porous structure in which pores generated by evaporation of the solvent remain. Therefore, the protective resin (6, 7) effectively relieves the thermal stress of the protruding electrode (13) generated due to the difference in thermal expansion coefficient between the semiconductor element (4) and the circuit board (3). The invention described in claim 2 is desirable to realize this.

According to the invention as set forth in claim 3 of the present application, in addition to the above-mentioned functions, the first protective resin (6) has a good porous structure in which pores generated by evaporation of the solvent are dispersed. Thus, the thermal stress on the protruding electrode (13) is effectively reduced. Also, since the solvent content of the second protective resin forming material (7a) is lower than that of the first protective resin forming material (6a), the second protective resin (7) is formed of the first protective resin (7a). The porosity is smaller than that of the first protective resin (6), and the effect of preventing intrusion of harmful substances is larger than that of the first protective resin (6). Further, since the thermal expansion coefficient of the protective layer composed of the first protective resin (6) -the second protective resin (7) -the resin sealing body (10) increases stepwise, the thermal stress at each boundary portion is increased. Is effectively alleviated. The invention described in claim 4 is desirable for realizing this.

Embodiment Hereinafter, a method of manufacturing a power hybrid IC having a circuit board to which a flip chip is fixed will be described as an embodiment of the present invention.

Power hybrid IC manufactured by this embodiment
As shown in FIG. 1, a support plate (1), external leads (2), a circuit board (3), a flip chip (4), a power semiconductor chip (5), a first protective resin (6), It comprises a second protective resin (7), a third protective resin (8), a thin lead wire (9), and a resin sealing body (10). In order to manufacture this power hybrid IC, first, a support plate (1) having a power semiconductor chip (5) and a circuit board (3) fixed to one main surface thereof via solder and an adhesive, respectively; Support plate (1) and external lead (2) arranged on one end side
A substrate assembly (11) is prepared. The circuit board (3) is made of an Al ₂ O ₃ (alumina) ceramic substrate (linear expansion coefficient: 6.8 × 10 ⁻⁶ / ° C.). On one main surface of the circuit board (3), a wiring conductor (1
2) and thick film resistors (not shown) are formed. In this specification, the electrode portion and the wiring portion are collectively referred to as a wiring conductor. The flip chip (4) disposed on one main surface of the circuit board (3) is a silicon semiconductor chip (linear expansion coefficient: 3.0 × 10 ^-6 /
° C). An electrode and a solder bump (13) are formed on one main surface of the flip chip (4). Although the solder bump (13) is formed by forming a hemispherical solder layer on a multilayer metal layer, its detailed illustration is omitted in FIG. The solder bumps (13) of the flip chip (4) are
2), and arranged such that one main surface of the flip chip (4) faces one main surface of the circuit board (3). The flip chip (4) is fixed to the circuit board (3) by a known solder reflow method. The distance between one main surface of the flip chip (4) and one main surface of the circuit board (3) is about 100 μm. In addition, between the power semiconductor chip (5) or the external lead (2) and the wiring conductor (12) of the circuit board (3) are electrically connected by a thin lead wire (9) formed by a known wire bonding method. Have been.

Next, as shown in FIG. 2 (a), a first protective resin forming material (6a) is applied onto the circuit board (3) so as to contact the side surface of the flip chip (4). The first protective resin forming material (6a) is a filler made of 90% by weight of granular silica, a polyimide resin material as an organic binder, and diethylene glycol dimethyl ether as a volatile solvent [viscosity 0.981CP at 25 ° C. Centipoise) solvent]. The granular silica has an average particle size of about 12.5 μm and 3.5 × 10 smaller than the flip chip (4).
^It has a linear expansion coefficient of ^-7 / ° C. Silica is a common name for silicon oxide. The volatile solvent is contained in an amount of 30% by weight based on the total weight of the first protective resin forming material (6a). The first protective resin forming material (6a) is excellent in fluidity because it contains a large amount of volatile solvent and granular silica having a small average particle size, and as shown in FIG. 2 (b), the flip chip (4) and the circuit board It flows satisfactorily over the entire region formed between (3) and (3), and this region can be filled with the first protective resin molding material (6a) without gaps.

Subsequently, the substrate assembly (11) is kept at room temperature for about one hour to remove volatile solvent in the first protective resin forming material (6a) by 50 hours.
%. Thereby, the fluidity of the first protective resin forming material (6a) decreases.

Furthermore, as shown in FIG. 2 (c), a second protective resin forming material (6a) and a second main surface of the circuit board (3) are coated on the entirety of the main surface of the circuit board (3) so as to cover the flip chip (4). Apply the protective resin forming material (7a). Second protective resin forming material (7
a) has fluidity similarly to the first protective resin forming material (6a) and contains granular silica, a polyimide resin material, and diethylene glycol dimethyl ether as a volatile solvent. However, the content of the particulate silica, the average particle size, and the content of the volatile solvent are different from those of the first protective resin forming material (6a). That is, the second protective resin forming material (7
In (a), the content of the particulate silica is 80% by weight based on the weight of the particulate silica and the polyimide resin material, which is smaller than that of the first protective resin forming material (6a). The average particle size of the granular silica is 31.5 μm, and the first protective resin forming material (6
a) Greater than. The content of the volatile solvent in the second protective resin forming material (7a) is 25% by weight based on the total weight thereof,
It is smaller than the first protective resin forming material 6a). Therefore, when the solvent does not evaporate, the second protective resin forming material (7a) has a higher viscosity and lower fluidity than the first protective resin forming material (6a).

Next, a heat treatment is performed at room temperature for 5 hours, at 40 ° C. for 4 hours, and at 150 ° C. for 3 hours to substantially remove volatile solvents contained in the first and second protective resin forming materials (6a) and (7a). All are volatilized. Accordingly, a first protective resin (6) is formed by the first protective resin forming material (6a), and a second protective resin (7) is formed by the second protective resin forming material (7a). . When the solvent volatilizes from the first protective resin forming material (6a), only the solid portion composed of the particulate silica and the polyimide resin material remains, so that the volume of the first protective resin (6) is reduced to the first protective resin forming material. It decreases compared to (6a). However, the first protective resin (6) has a "pumice-like structure" in which a large amount of particulate silica particles are bonded by a polyimide resin material, and a large number of pores are uniformly formed by volatilization of a solvent.
It becomes a porous structure that can be called. Therefore, the area between the flip chip (4) and the circuit board (3) can be filled with the first protective resin (6) without gaps. Second
The protective resin (7) also has a porous structure similarly to the first protective resin (6), but has a smaller porosity than the first protective resin (6) due to the smaller amount of the volatile solvent.

Next, the power semiconductor chip (5) is covered with a third protective resin (8) made of a polyimide resin. Unlike the first and second protective resins (6) and (7), the third protective resin (8) does not contain granular silica. The third protective resin (8) may be provided simultaneously with the formation of the first and second protective resins (6) and (7) or in a previous step.

Thereafter, a resin sealing body (10) for covering the entire surface of the support plate (1) and the ends of the external leads (2) is formed by well-known transfer molding. The resin sealing body (10) is made of a thermosetting epoxy resin and has a linear expansion coefficient of 20 × 10
^-6 / ° C. The resin sealing body (10) covers the second and third protective resins (7) and (8). In addition, lead wire (9)
Of these, the portion not covered with the second and third protective resins (7) and (8) is covered with a resin sealing body (10).

Power hybrid manufactured by the above embodiment
In the IC, the first chip having a coefficient of thermal expansion intermediate between these coefficients of thermal expansion between the flip chip (4) and the circuit board (3).
The protective resin (6) can be formed. That is, the first
Since the average particle size and content of the granular silica contained in the protective resin (6) are about 12.5 μm and 90% by weight, respectively, the linear expansion coefficient of the first protective resin (6) is 5 × 10 ^−6. / ℃
Becomes Therefore, when the flip chip (4) is energized, the stress generated in the solder bump (13) due to the difference in thermal expansion coefficient between the flip chip (4) and the circuit board (3) is reduced by the first protective resin (6). It can be effectively relaxed. Further, the first protective resin forming material (6a) for forming the first protective resin (6) is excellent in fluidity and can be formed in a short time in a region between the flip chip (4) and the circuit board (3). It can be filled well.

As shown in FIG. 3, when the mixing ratio of the particulate silica in the first protective resin (6) is smaller than 85.5% by weight, the thermal expansion coefficient of the first protective resin (6) is excessively increased. If the coefficient of thermal expansion of the first protective resin (6) exceeds the circuit board (3) (linear expansion coefficient: 6.8 × 10 ⁻⁶ / ° C.), a satisfactory stress relaxation effect cannot be obtained. When the mixing ratio of the particulate silica is more than 96.5% by weight, the thermal expansion coefficient of the first protective resin (6) is excessively reduced, and the flip chip (4) (linear expansion coefficient 3.0 × 10
^-6 / ° C), a good stress relaxation effect cannot be obtained. Further, even when the mixing ratio of the particulate silica is within the above range, when the average particle size of the particulate silica is larger than 20 μm, the thermal expansion coefficient of the first protective resin (6) becomes larger than that of the circuit board (3). With the first protective resin (6)
Of the film decreases. FIG. 3 shows the thermal expansion coefficient and the film elastic modulus of the protective resin when the particle size of the particulate silica is 31.5 μm for comparison. Even if the silica content is 90% by weight, which is the same as that of the first protective resin (6), when the average particle size is as large as 31.5 μm, the thermal expansion coefficient becomes larger than that of the circuit board (3), and the filler for stress relaxation is used. Will not function well. In addition, the film elastic modulus is reduced, and the effect of suppressing the application of mechanical stress due to the warpage of the circuit board (3) to the solder bumps (13) is also reduced. On the other hand, when the average particle size of the granular silica is smaller than 5 μm, the coefficient of thermal expansion is easily reduced, and a large film elastic modulus is obtained. However, the first protective resin forming material (6a) has a thixot (thixot) property.
(ropy) occurs, the viscosity on the body becomes large, and it is difficult to satisfactorily pour it into the lower surface of the flip chip (4). In this embodiment, the first protective resin forming material (6a)
After the solvent contained in the first resin is volatilized to lower the fluidity of the first protective resin forming material (6a), the second protective resin forming material (7a) is coated. Therefore, a large number of pores generated by the volatilization of the solvent can be formed in a state of being uniformly dispersed throughout the entire area of the first protective resin (6).

On the other hand, according to an experiment conducted by the present inventors, the first protective resin forming material (6a) was converted into the second protective resin forming material (6a) without substantially evaporating the solvent contained in the first protective resin forming material (6a). When covered with the forming material (7a), a large number of pores are formed in the first protective resin (6) in a partially concentrated manner without being uniformly formed,
It has been found that a gap is formed between the first protective resin (6) and the flip chip (4). If a gap is formed between the chip and the flip chip (4), the stress relaxing effect is reduced, and the protective effect on the chip surface is impaired.
This embodiment solves this problem. In the present embodiment, the second protective resin forming material (7a) is formed based on the present invention.
The volatile solvent content of the first protective resin forming material (6a)
Smaller than. Therefore, the second protective resin (7) has a smaller porosity and a higher rigidity than the first protective resin (6), so that the circuit board (3) and the flip chip (4) can be better protected. . Further, the content of the particulate silica in the second protective resin (7) is smaller than that of the first protective resin (6), and the average particle size is larger than that of the particulate silica of the first protective resin (6). . As a result, the thermal expansion coefficient of the second protective resin (7) is larger than that of the first protective resin (6). However, since the thermal expansion coefficient of the second protective resin (7) is smaller than that of the resin sealing body (10), the first protective resin (6)-
The thermal expansion coefficient increases stepwise in the protective layer composed of the second protective resin (7) and the resin sealing body (10). For this reason,
It is possible to effectively reduce the thermal stress at each boundary portion. In particular, it is effective in preventing breakage of the fine lead wire (9) at the interface between the second protective resin (7) and the resin sealing body (10).

Modifications The above embodiment of the present invention can be variously modified as follows.

(1) It is desirable that the porosity of the second protective resin (7), which covers the entire surface of the circuit board (3), is smaller than that of the first protective resin (6). Therefore, the content of the volatile solvent in the second protective resin forming material (7a) should be smaller than that of the first protective resin forming material (6a) by 3% by weight or more, preferably 5% by weight or more. .

(2) The first protective resin forming material (6a) contains a volatile solvent in an amount of 20% by weight or more, preferably 25% by weight or more based on the total weight so that the first protective resin forming material (6a) flows into the lower surface of the flip chip (4) well. Is good. However, in order not to form a gap between the flip chip (4) and the first protective resin (6),
Further, the porosity is preferably 40% by weight or less, and more preferably 35% by weight or less, so as to obtain a porosity within an acceptable range as a protective resin.

(3) The viscosity at the time of filling the first protective resin forming material (6a) is adjusted to 200 to 5,000 centipoise by adjusting the amount of the solvent or the like so as to flow into the lower surface of the flip chip well. Practically, it is more preferable that the viscosity is 500 to 2500 centipoise.

(4) The content of the particulate silica of the second protective resin (7) may be the same as that of the first protective resin (6). However, as described above, it is desirable that the thermal expansion coefficient in the protective layer composed of the first protective resin (6) -the second protective resin (7) -the resin sealing body (10) increases stepwise. The content of the particulate silica in the second protective resin (7) is 2% by weight or more, preferably 5% by weight than that of the first protective resin (6).
It is desirable to make it smaller. When the same content of the particulate silica is used, the average particle diameter of the particulate silica of the second protective resin (7) is 5 μm or more, preferably 10 μm or more than that of the first protective resin (6). It is better to increase the thermal expansion coefficient.

(5) The content of the particulate silica in the first protective resin (6) is set at 85.5 so that the value of the coefficient of thermal expansion is intermediate between the coefficients of thermal expansion of the circuit board (3) and the flip chip (4). % By weight to 96.5% by weight. In this range, when the content of the particulate silica decreases, the coefficient of thermal expansion increases. Conversely, when the content of the particulate silica increases, the film elastic modulus decreases. Therefore, a more desirable range is from 87.5% by weight to 92.5%.
% By weight.

(6) The average particle size of the particulate silica of the first protective resin (6) is preferably 5 to 25 μm, and more preferably 7 to 20 μm, in which the thermal expansion coefficient, the film elastic modulus and the thixotropy are all suitable.

(7) As the first resin material and the second resin material, a polyimide resin or a polyamide resin is most preferable, but a phenol resin or the like can provide a certain effect.

(8) The volatile solvent of the first protective resin forming material (6a) is covered with the second protective resin forming material (7a) so that the pores are dispersed and formed in the first protective resin (6). 30% before you
As described above, desirably, volatility is reduced by 40% or more to reduce fluidity. However, no significant change is observed in the distribution of pores even when volatilized by 90% or more. Therefore, it is preferable to set it to 90% or less from the viewpoint of productivity.

(9) The formation of the first protective resin (6) using the first protective resin forming material (6a) is performed using the second protective resin forming material (7a) from the state shown in FIG. 2 (c). It is reasonable to carry out simultaneously with the formation of (7). However, even if the first protective resin (6) is formed by the first protective resin forming material (6a) from the state of FIG. 2 (b) before coating with the second protective resin forming material (7a). Good.

(10) The protruding electrode may be provided on the circuit board side,
It may be provided on both the semiconductor element and the circuit board.

Effects of the Invention As described above, according to the present invention, it is possible to manufacture a circuit board device which can reduce stress and fatigue on a protruding electrode due to thermal expansion and the like, and can withstand high reliability and use under severe environmental conditions. Can be.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a circuit board device manufactured by the method of the present invention, FIG. 2 shows each step of the manufacturing method of the present invention, and FIG. FIG. 2B is a cross-sectional view illustrating a state where the first protective resin forming material is sufficiently filled over the entire area formed between the flip chip and the circuit board. FIG. 2 (c) shows the second main surface on one main surface of the circuit board.
Sectional view showing a state where a material for forming a protective resin is applied, and FIG.
The figure is a graph showing the relationship between the content of the silica filler and the film elastic modulus and the coefficient of thermal expansion. (1) Support plate (3) Circuit board (4) Flip chip (6) First protective resin (6a)
A first protective resin forming material, (7) a second protective resin,
(7a) ... second protective resin forming material, (10) ... resin sealing body, (11) ... board assembly, (12) ... wiring conductor,
(13) ... solder bumps,

Claims (4)

(57) [Claims] 1. A circuit board (3) having a wiring conductor (12) formed on one main surface and a semiconductor element (3) electrically connected to said wiring conductor (12) via a protruding electrode (13). 4) a substrate assembly (11) comprising: a filler having a coefficient of thermal expansion smaller than the coefficient of thermal expansion of the semiconductor element (4); a resin material; and at least 20% by weight of a solvent with respect to the total weight. , 50
A step of preparing a liquid protective resin forming material (6a, 7a) having a viscosity of not more than 00 centipoise, wherein one main surface of the semiconductor element (4) and one main surface of the circuit board (3) are A step of filling the protective resin forming material (6a, 7a) into the region facing away from the substrate; and, based on the protective resin forming material (6a, 7a), having a larger thermal expansion coefficient than the semiconductor element (4) and Forming a protective resin (6, 7) having a coefficient of thermal expansion smaller than the coefficient of thermal expansion of the circuit board (3); and fixing the circuit board (3) and fixing the board assembly (1).
The support plate (1) and the protective resin (6,
7) A step of forming a resin sealing body (10) for sealing the circuit board. 2. The material for forming a protective resin (6a, 7a) is 5 to
The filler consisting of granular silica having an average particle diameter of 20 μm is 85.5 to the total weight of the filler and the resin material
The method according to claim 1, wherein the content is 96.5% by weight and the filling has a viscosity of 500 to 2500 centipoise. 3. A circuit board (3) having a wiring conductor (12) formed on one main surface and a semiconductor element (3) electrically connected to said wiring conductor (12) via a protruding electrode (13). 4) a first filler, a first resin material having a smaller coefficient of thermal expansion than the coefficient of thermal expansion of the semiconductor element (4), and a weight of 20% with respect to the total weight. % Of a first solvent, and a liquid first protective resin forming material (6a) having a viscosity of 5,000 centipoise or less; a first material having a thermal expansion coefficient smaller than that of the semiconductor element (4); Liquid second protective resin containing a second solvent at a content smaller than the content of the first solvent in the filler (2), the second resin material, and the first protective resin forming material (6a). A step of preparing a forming material (7a); and one main surface of the semiconductor element (4) and the circuit board ( A) filling the first protective resin forming material (6a) into a region facing one main surface of the first protective resin, and evaporating at least a part of the first solvent to form at least the first solvent. A step of reducing the fluidity of the protective resin forming material (6a); and supplying the second protective resin forming material (7a) to one main surface of the circuit board (3), and Covering the first protective resin forming material (6a) with the second protective resin forming material (7a); evaporating substantially all of the second solvent and forming the second protective resin forming material on the second protective resin forming material; Forming a second protective resin (7) based on the second protective resin (7); and forming the second protective resin (7) by a resin sealing body (10) having a coefficient of thermal expansion larger than that of the second protective resin (7). A step of further coating a resin (7). The material for forming a protective resin (6a) is obtained by evaporating at least a part of the first solvent.
And in the step of forming the second protective resin (7), substantially all of the first solvent evaporates and the coefficient of thermal expansion of the circuit board (3) and the second protective resin (7)
Forming a first protective resin (6) having a thermal expansion coefficient smaller than that of the semiconductor element (4) and larger than that of the semiconductor element (4). 4. The first protective resin molding material (6a) comprises:
The first filler comprising granular silica having an average particle size of about 20 μm to 85.5 to 96.5% by weight based on the total weight of the first filler and the first resin material; When having a viscosity of 500 to 2500 centipoise, the second
Is a particulate silica having an average particle size larger than the average particle size of the particulate silica of the first filler and / or a particulate silica having a content smaller than the content of the particulate silica of the first filler. The method for manufacturing a circuit board device according to claim 3, comprising: