JPH09283548A - Electronic circuit board and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the angle of setting of a coating nozzle and the positional accuracy of the nozzle and to contrive speedup by simplifying the operation by a method wherein a through hole, which communicates from one surface to the component mounting surface, is bored in the circuit board in accordance with the mounting position of an electronic component and an annular wall is formed on the component mounting surface in such a way as to encircle an opening formed in the through hole. SOLUTION: A circuit board 1 is set facing its surface mounted with a bare IC to its lower side and a coating nozzle 5 is vertically pressed on a through hole 8 to extrude a sealing resin 4 through the nozzle 5 utilizing an air pressure to inject the resin 4 in the hole 8. Thereby, the injected resin 4 passes through the hole 8, reaches the IC 2 and continues to penetrate into the gap between the IC 2 and the board 1, the action of a capillary phenomenon is also generated and the gap is filled with the resin 4. Moreover, the resin 4 is stopped by an annular wall 7 being formed on the periphery of the IC 2 and it is also eliminated that the resin 4 unnecessarily flows and extends.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic circuit board and its manufacturing method.

[0002]

2. Description of the Related Art In recent years, with the miniaturization and weight reduction of various electric products such as video, video cameras and audio equipment, and various electric products required for electronic control devices, high-density mounting of electronic circuit boards has been progressing. Along with this, the integrated circuit used is also shifting from mounting the packaged integrated circuit to directly mounting the bare IC.

Conventionally, as shown in FIG. 6 and FIG. 7, a bare IC 2 which requires mounting a bare IC 2 and a chip component 3 on a circuit board 1 and sealing with a sealing resin 4 is as follows.
The circuit board 1 is set with the component mounting surface A on which the bare IC 2 is attached facing upward, and the coating nozzle 5 is set at an angle in an oblique direction to a position aiming at a gap between the bare IC 2 and the circuit board 1. While maintaining the position, the sealing resin 4 is pushed out by using air pressure while traveling around the bare IC 2, and the sealing resin 4 is injected into the gap between the bare IC 2 and the circuit board 1 as shown in FIG. There is.

Further, FIG. 9 shows a case of the circuit board 1 in which the concave portion 6 is formed at the mounting position of the bare IC 2, and in this case as well, as in FIGS. Sealing resin 4 while traveling around bare IC 2 at an angle
Is extruded, and the sealing resin 4 is poured into the gap between the recess 6 and the resin while pouring it over time.

The bare IC 2 is constructed by attaching bumps 2b to a semiconductor chip 2a as shown in FIG. 6, and since the semiconductor chip surface is exposed on the upper surface C of the bare IC 2, this portion is sealed. It is protected by sealing with resin 4.

[0006]

However, in any of the conventional methods for manufacturing an electronic circuit board as described above, a sealing facility capable of high-level adjustment and setting of the angle and position of the coating nozzle 5 and running is provided in any case. It is necessary and requires man-hours for traveling around the bare IC2.

Further, in the traveling operation of the coating nozzle 5 at an oblique angle, the tall chip component 3a around the bare IC 2 becomes an obstacle. For this reason, there is a problem that the mounting position of the tall chip component 3a needs to be arranged apart from the bare IC2.

In the case shown in FIG. 8, the sealing resin 4
Has a problem that the flow spreads over a predetermined range around the bare IC2. The present invention provides an electronic circuit board that reduces the setting angle and position accuracy of the coating nozzle 5, speeds up by simplifying the coating operation, and eliminates the height constraint of IC peripheral arrangement components, and a manufacturing method thereof. To aim.

[0009]

An electronic circuit board of the present invention is an electronic circuit board on which an electronic component that needs to be resin-sealed is mounted, and which corresponds to the mounting position of the electronic component. From this surface, a through hole communicating with the component mounting surface is bored, and an annular wall is formed on the component mounting surface so as to surround the opening of the through hole.

According to the present invention, by mounting the electronic component and filling the sealing resin from the through hole, the setting angle and position accuracy of the coating nozzle can be reduced, and the coating operation can be simplified to increase the speed. It is possible to eliminate the height restriction of the parts arranged around the IC.

In the method of manufacturing an electronic circuit board according to the present invention, an electronic component requiring resin sealing is attached to the component mounting surface of the electronic circuit substrate, and the surface of the electronic circuit substrate opposite to the component mounting surface is mounted. From the above, a sealing resin is injected through a through hole formed in the electronic circuit board, and the electronic component is sealed with the injected sealing resin.

According to the present invention, the setting angle and position accuracy of the coating nozzle can be reduced, the coating operation can be simplified to increase the speed, and the height restriction of IC peripheral arrangement components can be eliminated.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention is an electronic circuit board on which an electronic component that needs to be resin-sealed is mounted, and which corresponds to the mounting position of the electronic component. A through hole communicating from one surface to the component mounting surface is bored, and an annular wall is formed on the component mounting surface so as to surround the opening of the through hole.A coating nozzle is pressed against the through hole to seal. Inject resin. The injected sealing resin is blocked by the annular wall and does not spread over a predetermined range.

According to a second aspect of the present invention, in the first aspect, the annular wall is formed so as to surround the mounted electronic component. According to a third aspect of the present invention, there is provided an electronic circuit board on which an electronic component that needs to be resin-sealed is mounted. A recess for accommodating an electronic component is formed, and a through hole communicating with the recess is formed from the other surface. A coating nozzle is pressed into the through hole to inject a sealing resin. The injected sealing resin is blocked by the recesses and does not spread beyond the predetermined range.

According to a fourth aspect of the present invention, there is provided a method of manufacturing an electronic circuit board, wherein an electronic component requiring resin sealing is attached to a component mounting surface of the electronic circuit board, and the electronic component is mounted on the component mounting surface of the electronic circuit board. Is characterized by injecting a sealing resin from the opposite surface through a through hole formed in an electronic circuit board and sealing the electronic component with the injected sealing resin. Angle / position accuracy is reduced, speeding up is achieved by simplifying the coating operation, and height restrictions on parts around the IC can be eliminated.

According to a fifth aspect of the present invention, in the fourth aspect, the sealing resin is injected from the through hole while pressing the support block against the electronic component so as to oppose the injection pressure of the sealing resin. The stress acting on the electronic component when the sealing resin is injected can be reduced.

According to a sixth aspect of the present invention, in the fourth aspect, the sealing resin is pushed through the through hole while pressing the supporting block against the electronic component so as to counter the stress at the time of injecting the sealing resin. Along with injecting, the sealing resin is injected from the through hole while heating the supporting block, and it is possible to reduce the stress acting on the electronic component when injecting the encapsulating resin. A quick cure can be achieved.

Hereinafter, each embodiment of the present invention will be described with reference to FIGS.
It will be described based on. (Embodiment 1) (a), (b) and (c) of FIG. 1 show (Embodiment 1).

As shown in FIG. 1A, at the mounting position of the copper-clad laminated printed circuit board 1 on which the bare IC 2 is mounted,
An annular wall 7 is formed on the component mounting surface A so as to surround the mounted bare IC 2, and a through hole 8 having a hole diameter of 0.3 mmφ is formed at the center of the mounting position. The annular wall 7 has a distance of 0.2 mm from the end of the IC mounting area and a thickness of 0.
The resist print pattern was 1 mm wide and 0.2 mm wide.

A bare IC 2 is mounted on the circuit board 1 as shown in FIG. 1B, and then the surface on which the bare IC 2 is mounted is faced down as shown in FIG. Was set, the coating nozzle 5 was vertically pressed against the through hole 8 and the sealing resin 4 was pushed out from the coating nozzle 5 using air pressure and injected. The dimensions of the coating nozzle 5 were an outer diameter of 0.6 mmφ and an inner diameter of 0.4 mmφ, and the pressing pressure was 600 g. The sealing resin 4 is an epoxy resin, and its viscosity is 5000 poise.

As a result, the injected sealing resin 4 reaches the bare IC 2 through the through hole 8 and enters the gap between the bare IC 2 and the circuit board 1 and also has a capillary action, which fills the gap. And the sealing resin 4 is the bare IC 2
It stayed at the annular wall 7 formed around the circumference, and the flow did not unnecessarily spread. It was confirmed that the filled sealing resin 4 had no bubbles and was cured to obtain a good sealing state.

Further, since the sealing resin 4 is injected from the side opposite to the component mounting surface A of the circuit board 1, the setting accuracy of the injection angle and position of the coating nozzle 5 can be reduced, and the traveling operation of the coating nozzle 5 can be reduced. Is no longer necessary, and the height restriction of the components arranged around the bare IC 2 can be eliminated.

(Second Embodiment) FIG. 2 shows a second embodiment.
Is shown. In the (Embodiment 1), as shown in FIG. 1C, the back surface D of the bare IC 2 was not in contact when the sealing resin was injected. While the block 9 is being pressed against the back surface D of the bare IC 2, the sealing resin 4 is injected from the through hole 8 to the bare IC 2 due to the bending of the circuit board 1 that may occur when the coating nozzle 5 is pressed. Relieves stress and improves reliability.

(Third Embodiment) FIG. 3 shows a third embodiment.
Is shown. In (Embodiment 2), the support block 9 was not specially heated, but in this (Embodiment 3), the heater 10 and the thermocouple 11 are embedded in the support block 9, and the thermocouple 11 is detected. The energization of the heater 10 is controlled by the temperature controller 12 so that the temperature approaches the set temperature. Here, the set temperature is set to 60 to 80 ° C.

With this structure, when the sealing resin 4 is injected into the gap between the bare IC 2 and the circuit board 1, the viscosity of the heated sealing resin 4 is lowered, and the time for filling the gap is shortened. did it.

(Embodiment 4) FIG. 4 shows (Embodiment 4).
Is shown. In each of the above embodiments, the through hole 8 is the sealing resin 4
Was provided only for the purpose of injecting, but in this (Embodiment 4), instead of the through hole 8, the surface conductor 1 of the circuit board 1 is replaced.
A through hole 8a (having a hole diameter of 0.3 mmφ) in which a conductor 13 that connects the a and the back surface conductor 1b is formed is provided. Poured and cured.

With this structure, the conductor 1
By also serving as the through hole 8a of No. 3, it is advantageous in terms of manufacturing cost and integration degree of the circuit board 1. (Embodiment 5) FIG. 5 shows (Embodiment 5). In this embodiment, the recess 6 is previously provided at the mounting position of the bare IC 2.
Is formed, and a through hole 8 is formed in the center of the recess 6. In this case, even if the annular wall 7 is not provided, the injected sealing resin 4 accumulates in the concave portion 6 and does not flow and spread around.

Further, as shown in FIG. 2 or 3, the support block 9 is used when the sealing resin 4 is injected, or the through hole 8 for forming the conductor 13 as shown in FIG. It is the same even if it is provided instead of.

In the case of (Embodiment 1) (Embodiment 2) (Embodiment 3) (Embodiment 4) of the above-mentioned embodiments, the component mounting surface A of the circuit board 1 is Although the annular wall 7 formed by the resist printing pattern is provided, this can also be configured by using an epoxy release material such as a silicone material. In this case, specifically, the thickness is 0.03 mm and the width is 0.13 mm.
The epoxy release material printing pattern of mm may be used.

[0030]

As described above, according to the electronic circuit board of the present invention, a through hole communicating from one surface to the component mounting surface is provided corresponding to the mounting position of the electronic component, and the component mounting surface is formed. To form an annular wall so as to surround the opening of the through hole, or to form an annular wall, a concave portion for accommodating an electronic component is formed on the component mounting surface corresponding to the mounting position, and the concave portion is formed. Since a through hole communicating with the component is formed, it is possible to inject the sealing resin from the side opposite to the component mounting surface through the through hole to seal the electronic component, and the injection angle and position of the coating nozzle can be improved. There is no need to adjust settings and drive with precision.

As a result, the sealing equipment can be simplified and the manufacturing cost of the electronic circuit board can be reduced. Further, since there is no step in which the coating nozzle travels around the electronic component and injects it, the number of manufacturing steps can be shortened and the manufacturing cost can be reduced. Since there are no restrictions on the layout of tall chip components, higher density design is possible.

Further, since the sealing resin does not flow and spread to the peripheral parts of the electronic circuit, the quality and reliability of the electronic circuit board can be improved. According to the method for manufacturing an electronic circuit board of the present invention, an electronic component that requires resin sealing is attached to the component mounting surface of the electronic circuit board, and the electronic circuit board is electronically mounted from the surface opposite to the component mounting surface. The sealing resin is injected through the through hole formed in the circuit board, and the electronic component is sealed with the injected sealing resin, so the sealing resin is applied from the surface opposite to the component mounting surface. Can be injected,
Moreover, it is possible to inject more quickly than before.

Further, when the support resin block is pressed against the electronic component and the through hole is formed in the sealing resin, the stress acting on the electronic component during the injection can be reduced, and the reliability is improved.

Further, when the support block is injected while being heated, the viscosity of the sealing resin is lowered and the sealing resin easily enters the gap, and the injection time can be shortened.

[Brief description of drawings]

FIG. 1 is a process diagram showing a manufacturing method according to a first embodiment.

FIG. 2 is a cross-sectional view in a step of injecting a sealing resin showing a manufacturing method according to a second embodiment.

FIG. 3 is a sectional view in a step of injecting a sealing resin showing a manufacturing method according to a third embodiment.

FIG. 4 is a sectional view of an electronic circuit board finished by the manufacturing method according to the fourth embodiment.

FIG. 5 is a sectional view in a step of injecting a sealing resin showing a manufacturing method according to a fifth embodiment.

FIG. 6 is a cross-sectional view during injection of a sealing resin in a conventional manufacturing process of an electronic circuit board.

FIG. 7 is a perspective view during injection of a sealing resin in the process of manufacturing a conventional electronic circuit board.

FIG. 8 is a sectional view of a finished shape of a conventional electronic circuit board.

FIG. 9 is a sectional view of a finished shape of a conventional electronic circuit board.

[Explanation of symbols]

 1 Circuit Board 2 Bare IC [Electronic Component] 4 Sealing Resin A Component Mounting Surface 5 Coating Nozzle 6 Recess 7 Annular Wall 8 Through Hole 9 Support Block 10 Heater 13 Conductor

Claims (6)

[Claims] 1. An electronic circuit board on which an electronic component requiring resin sealing is mounted, and a through hole communicating from one surface to the component mounting surface is formed at a position corresponding to the mounting position of the electronic component. The electronic circuit board is provided with an annular wall on the component mounting surface so as to surround the opening of the through hole. 2. The electronic circuit board according to claim 1, wherein the annular wall is formed so as to surround the mounted electronic component. 3. An electronic circuit board on which an electronic component that needs to be resin-sealed is mounted, and a recess for accommodating the electronic component corresponding to a mounting position on a component mounting surface on which the electronic component is mounted. And an electronic circuit board having a through hole which is formed from the other surface and communicates with the recess from the other surface. 4. An electronic component requiring resin sealing is attached to a component mounting surface of an electronic circuit board, and a penetrating hole formed in the electronic circuit board from a surface opposite to the component mounting surface of the electronic circuit board. A method for manufacturing an electronic circuit board, comprising injecting a sealing resin through a hole and sealing the electronic component with the injected sealing resin. 5. The method for manufacturing an electronic circuit board according to claim 4, wherein the sealing resin is injected from the through hole while pressing the supporting block against the electronic component so as to oppose the injection pressure of the sealing resin. 6. The sealing resin is injected from the through hole while pressing the supporting block against the electronic component so as to counter the stress when the sealing resin is injected, and the sealing resin is injected while heating the supporting block. The method of manufacturing an electronic circuit board according to claim 4, wherein the injection is performed through a through hole.