JP2003218510A - Component mounting board and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve printability of a pasty bonding material on a component mounting board where an IC chip and surface-mount components are mixedly mounted and to enable the component mounting board to be reduced in size and improved in mounted density. <P>SOLUTION: The component mounting board is composed of a board 9, an IC chip 2 mounted only on the one surface of the board 9, and surface-mount components 3 which are mounted only on the other surface of the board 9 through the intermediary of a pasty bonding material 5 such as cream solder or conductive paste supplied through a screen printing method. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit board in which ICs and surface mount components coexist, and in particular, electronic devices such as ICs and capacitors for driving display devices such as liquid crystal display panels, PDP display panels and organic ELs. The present invention relates to a circuit board on which components are mounted, mainly a film board.

[0002]

2. Description of the Related Art A conventional liquid crystal display device, as shown in FIG. 8, is connected to a liquid crystal display panel 1 and electrodes 1a of the liquid crystal display panel 1, and an IC chip 2 for driving the liquid crystal display panel, a chip resistor, and a chip capacitor. It is the one-sided film substrate 30 in which the surface-mounted components 3 such as are mixedly mounted on one side.

FIG. 9 shows a conventional film substrate mounting process. First, the IC chip 2 is mounted on the single-sided film substrate 30, and then the surface mount component 3 is mounted. Then, the electrode 30a of the single-sided film substrate 30 and the electrode of the display device 1a are bonded.

Explaining in detail with reference to FIG. 10, the IC chip 2 is mounted on the circuit pattern of the one-sided film substrate 30 (FIG. 10A). As a mounting means, a conductive material such as a conductive paste or a conductive sheet is supplied onto the circuit pattern to press and heat the IC chip, or an IC chip provided with a metal bump is pressed against the circuit pattern while ultrasonically vibrating. There is something to do.

Here, the IC chip is first mounted because the circuit pattern on the substrate is oxidized and the bonding surface of the IC chip is contaminated by the solder used for mounting the surface mount component, resulting in defective bonding. This is to prevent this.

Next, a bonding material for bonding the surface mount component 3 to the circuit pattern of the substrate 30 is supplied. As a supply means, a screen plate 32 having an opening corresponding to a printing pattern as shown in FIG. 10B and having an emboss 31 covering the IC chip 2 is arranged on the single-sided film substrate 30, The squeegee 7 moves on the screen plate 32 to which the bonding material 5 has been supplied to fill the opening 32a with the bonding material 5 for printing, or to apply and supply by the application nozzle 8 as shown in FIG. 10 (c). There is.

Then, the surface mount component 3 is mounted on the bonding material 5 as shown in FIG. 10 (d), and the reflow process is performed as shown in FIG. 10 (e) to melt the bonding material and the surface mount component and the circuit. Bond with the substrate.

[0008]

However, in the conventional case, since the IC chip 2 and the surface mount component 3 are mounted on the single-sided film substrate 30 on the same plane, the embossing covering the IC chip 2 as described above. Since it is necessary to purposely form 31 or to prepare an emboss according to the type of the substrate to be mounted, the production cost increases. Also IC
It is necessary to accurately align the chip 2 and the emboss 31 with each other, which causes a decrease in production tact.

Further, as shown in the figure, the embossing 31 has a structure in which a part of the embossing 31 projects from the surface of the screen printing plate 32, and the periphery of the embossing 31 portion of the screen printing plate 32 rises and is located around the embossing 31 during actual printing. Opening 3
2a cannot be completely filled with the bonding material, and contact with the substrate is incomplete on the substrate, which makes the transfer and printing of the bonding material unstable. Further, after printing, the plate separation operation between the screen plate 32 and the substrate becomes unstable. The print state is defective.
In order to solve this problem, it is conceivable that a sufficient distance is provided between the embossing 31 and the opening 32a.
With the miniaturization of electric devices such as car navigations and portable DVDs, and portable image devices, it is inconvenient to increase the size of the circuit board, because of the fact that miniaturization of circuit boards is also desired.

The present invention provides a component mounting board in which an IC chip and surface mounting components are mixed in order to solve such problems.
The purpose is to improve the printability of the paste-like bonding material, and to achieve miniaturization and high-density mounting.

[0011]

In order to achieve the above object, the present invention provides a substrate, an IC chip mounted only on one surface of the substrate, a cream solder, a conductive paste, or the like by a screen printing method. A component mounting board comprising a surface mounting component which is supplied with a paste-like bonding material and is mounted only on the other surface of the substrate.

With this configuration, the surface mount component and the IC chip are not mixed in the same surface of the substrate, and the IC chip and the surface mount component can be individually mounted, so that the printability of the paste-like bonding material is improved. It is possible to manufacture a component mounting board in which small and high density IC chips and surface mounting components are mixed.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The first embodiment of the present invention is a second embodiment.
Supply paste-like bonding material such as cream solder or conductive paste on one side of the board by screen printing method,
A step of mounting only surface mount components, a step of mounting only an IC chip on one surface of the first board, and a step of connecting the other surfaces of the first board and the second board with a joining member. And a step of supplying a paste-like bonding material to the substrate by screen printing to mount the surface mount component and a step of mounting the IC chip on the substrate separately and independently. This is useful for achieving stability of printability during screen printing, and particularly for realizing high-density mounting in which an IC chip and surface mount components are mixed.

According to a second embodiment of the present invention, a step of mounting only an IC chip on one surface of a first substrate, a step of mounting only surface mount components on one surface of a second substrate, and the first A method of manufacturing a component mounting board, which comprises a step of connecting the other surface of the board and the other surface of the second board with a joining member, wherein the step of mounting the surface mount component and the step of mounting the IC chip on the board are performed separately. It can be carried out independently, and by bonding with a bonding member, high-density mounting in which IC chips and surface mount components are mixed is realized.

In the third embodiment of the present invention, the substrate is mounted on the printing jig while the IC chip portion of the substrate on which the IC chip is mounted is accommodated in the recess formed in the printing jig, and the IC is mounted on the printing jig. A screen mask having an opening that serves as a print pattern is arranged on the surface of the substrate opposite to the surface on which the chip is mounted, and the squeegee slides on the screen mask to print the bonding material on the substrate through the opening. ,afterwards,
A method for manufacturing a component mounting board in which a surface mounting component is mounted via a bonding material, the step of mounting a surface mounting component without using the bonding member according to Embodiments 1 and 2, and mounting an IC chip on the substrate. These steps can be carried out individually, and high-density mounting in which IC chips and surface mount components are mixed is realized. Further, since no bonding member is used, it is possible to create a component mounting board in which a good quality surface mounting board and an IC chip are mixed without depending on the positioning of the boards and the bonding strength.

In the fourth embodiment of the present invention, only the first substrate on which only the IC chip is mounted on one side and the paste bonding material such as cream solder or conductive paste by the screen printing method are supplied to supply only the surface mount component. A fifth embodiment of the present invention is a component mounting board provided with a second board to be mounted on one surface, and a joining member for connecting the other surfaces of the first board and the second board. A multilayer film substrate, an IC chip mounted on only one surface of the multilayer film substrate, and a paste bonding material such as cream solder or conductive paste by a screen printing method to supply only to the other surface of the multilayer film substrate. It is a component mounting board including surface mounted components to be mounted, and it is possible to provide a component mounting board in which a high quality surface mounting board and an IC chip are mixed.

In the sixth embodiment of the present invention, in addition, the surface mount component is mounted on the component mounting substrate at a position where the IC chip of the substrate is opposed to each other, thereby further stabilizing the printability.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, in the embodiments, the same configurations will be described with the same reference numerals.

In the present embodiment, the display device is a liquid crystal display panel, a PDP display panel or an organic EL, and the IC chip and the surface mount parts are electronic parts such as an IC for driving the display device and a capacitor. Is.

The surface mount component is a component mounted on a film substrate by using a paste-like bonding material such as cream solder or conductive paste, and specifically, a chip component such as a chip capacitor and a chip resistor, a QFP (Quad).
Flat Package), BGA (Ball Gr)
id Alley), CSP (Chip SizePa
package).

The paste-like bonding material is cream solder or conductive paste.

FIG. 1 shows a component mounting board 20 according to an embodiment of the present invention.

The first substrate 4 is mounted with only the IC chip 2, and the second substrate 6 is mounted with only the surface mount component 3. The joining member 14 joins the first substrate 4 and the second substrate 6.

The manufacturing process of the component mounting board of this embodiment will be described with reference to FIG.

The IC chip 2 is mounted on the circuit pattern of the film substrate 4 which is the first substrate (FIG. 2A).

As a mounting means, a conductive material such as a conductive paste or a conductive sheet is supplied on the circuit pattern, and I
There are those which press and heat the C chip 2 and those which press the IC chip 2 provided with the metal bumps while ultrasonically vibrating the circuit pattern.

The surface mount component 3 is mounted on the circuit pattern of the film substrate 5 which is the second substrate (FIG. 2B).
~ (C)). As a mounting means, a bonding material 5 such as a conductive paste or cream solder is supplied on the circuit pattern, the component 3 is mounted on the bonding material 5, and the bonding material 5 is heated and melted by a reflow device or the like to bond the parts. Specifically, Fig. 2
As described in (b), the screen mask 10 having openings to be a print pattern is arranged on the film substrate 5, and the squeegee 7 is placed on the screen mask 10 to which the bonding material is supplied.
Slides and supplies the bonding material 5 onto the film substrate 5 through the opening. Then, the component 3 is mounted on the bonding material 5 by the suction nozzle, and the bonding material 5 is heated and melted and solidified in the reflow furnace to bond the component 3 onto the film substrate.

Next, the first substrate 4 and the second substrate 6 are integrated into an IC.
The surfaces on which the chip 2 and the component 3 are not mounted face each other and are bonded by the bonding material 14 to form the composite substrate 16 (FIG. 2D).

Finally, the display device 1 and the composite substrate 16 are joined (FIG. 2 (e)).

As described above, in this embodiment, by mounting only the IC chip on the first substrate and mounting only the surface mount component on the second substrate, the IC chip and the surface mount component are mounted on one side as in the conventional case. It is possible to prevent the cost increase and the productivity decrease such as the purpose of forming the emboss on the screen plate and the positioning of the emboss.

Further, the screen printing can be performed stably and the quality can be improved.

(Embodiment 2) FIG. 3 shows a component mounting board 21 according to an embodiment of the present invention. I is mounted only on one surface 9a of the multilayer film board 9.
It comprises a C chip 2 and a surface mount component 3 mounted only on the other surface 9b of the multilayer film substrate 9.
In this embodiment, as the multilayer film substrate 9, two copper foils are formed on the upper and lower surfaces of the base film with an adhesive agent, and are covered with a cover film that serves as an insulating layer except for the circuit pattern surface. They are joined together through through holes.

The manufacturing process of the component mounting board of this embodiment will be described with reference to FIG.

As shown in FIG. 4A, the IC chip 2 is mounted on the circuit pattern of the multilayer film substrate 9. As the mounting means, a conductive material such as a conductive paste or a conductive sheet is supplied onto the circuit pattern to press and heat the IC chip 2, or the IC chip 2 provided with metal bumps is ultrasonically vibrated in the circuit pattern. While there are things to press.

Next, as shown in FIG. 4B, the IC chip 2
The multilayer film substrate 9 on which is mounted is placed on the printing jig 12 in which the concave portion 16 capable of accommodating the IC chip 2 is formed. Here, with the IC chip 2 housed in the recess 16, it is positioned and fixed to the printing jig 12 by a fixing means such as a film tape 11.

Next, a screen mask 10 having an opening serving as a printing pattern is arranged on the multilayer film substrate 9 opposite to the surface on which the IC chip 2 is mounted, and a paste-like bonding material 5 such as a conductive paste or cream solder. The squeegee 7 slides on the screen mask 10 which has been supplied, and the bonding material 5 is supplied onto the multilayer film substrate 9 through the opening. Then, the surface mount component 3 is mounted on the paste bonding material 5 by the suction nozzle, and the paste bonding material 5 is heated and melted and solidified in the reflow furnace to bond the surface mount component 3 onto the film substrate.

According to the above embodiment, by storing the IC chip in the concave portion, the printing state can be stabilized, and the step of joining the two film substrates as in the first embodiment is unnecessary.

In the present embodiment, a multi-layer film substrate is used for explanation, but a single-layer substrate also has the same effect.

Further, by disposing the elastic body 13 such as rubber or sponge in the recess 16 and supporting the IC chip,
The load applied to the IC chip during printing is reduced and the IC chip is protected.

In the first and second embodiments, as shown in FIG. 5, by mounting the surface mount component at a position opposite to the IC chip via the film substrate, the IC chip portion is against the pressure of the squeegee during printing. By supporting and interposing, the printability on the surface mount parts is stabilized.

By mounting a plurality of IC chips or surface mount components on both sides of the substrate, higher density mounting can be achieved and the mounting area can be reduced.

(Embodiment 3) In this embodiment, as shown in FIG. 6, component mounting boards 20 and 21 are joined to a display device 1, and as shown in the figure, the surface mount component 3 is a display device 1. By bending the component mounting boards 20 and 21 so as to face with, the product can be downsized.

Further, when the above-mentioned bent component mounting board is assembled into another board, it is possible to prevent a defect such as a contact with a surface mounting part existing on the other board or a short circuit between joints.

Thus, the surface (image surface) 1 of the display device 1
a and the IC chip 2 side of the component mounting boards 20 and 21 are arranged in the same direction, the back surface 1b of the display device and the component mounting boards 20 and 21 are bonded to each other, and the component mounting boards 20 and 21 are connected to the display device. By bending at a non-bonded position and arranging the surface mount component 3 at a position facing the back surface of the display device, it is possible to reduce the size of the product and to prevent a short circuit when the component mount boards 20 and 21 are incorporated in the product. Can be prevented.

In the present embodiment, the component mounting board 20,
Although the reference numeral 21 is used by bending, the surface mount component 3 may be directly arranged so as to face the back surface of the display device 1 as shown in FIG. 7. In the present embodiment, as shown in FIG. 7B, both ends of the component mounting boards 20 and 21 are connected to both ends of the display device 1, and a gap is formed on the back surface of the display device 1 so that the surface mounting component 3 faces. It has and arranges it. Further, a method of relaxing the contact between the surface mount component 3 and the display device 1 by using a cushioning material or a spacer may be used.

[0046]

As described above, according to the present invention, a substrate, an IC chip mounted only on one surface of the substrate, and a paste-like bonding material such as cream solder or conductive paste by a screen printing method are used. The surface mount component is supplied and mounted only on the other surface of the board. With this configuration, the surface mount component and the IC chip do not coexist in the same surface of the board, and the IC chip and the surface mount are not mixed. Since the components can be individually mounted, it is possible to improve the printability of the paste-like bonding material and manufacture a component mounting board in which small-sized and high-density IC chips and surface-mounted components are mixed.

[Brief description of drawings]

FIG. 1A is a plan view of a component mounting board according to an embodiment of the present invention, and FIG. 1B is a side sectional view of the embodiment.

FIG. 2 is a diagram showing a method of manufacturing the component mounting board and the display device according to the embodiment.

FIG. 3 is a sectional view of a component mounting board according to a second embodiment.

FIG. 4 is a diagram showing a method of manufacturing a component mounting board according to the second embodiment.

FIG. 5 is a diagram showing a mounting state of an IC chip and surface mount components according to the first and second embodiments.

FIG. 6 is a diagram showing a display device in which component mounting boards are joined.

7A is a plan view of a display device to which component mounting boards according to an embodiment of the present invention are joined, FIG. 7B is a side sectional view of the embodiment, and FIG. 7C is a front sectional view of the embodiment.

FIG. 8A is a plan view of a display device in which a conventional component mounting board is joined, and FIG. 8B is a side sectional view of the same.

FIG. 9 is a diagram showing a conventional method of manufacturing a component mounting board.

FIG. 10 is a diagram showing a conventional method of manufacturing a component mounting board.

[Explanation of symbols]

1 Display device (liquid crystal display panel) 2 IC chip 3 Surface mount components 4 First substrate 5 Bonding material 6 Second substrate 7 Squeegee 8 coating nozzles 9 Multilayer substrate (multilayer film substrate) 10 screen version 11 film tape 12 jigs 13 Elastic body 14 Joining member 15 recess 16 composite substrate 20 Component mounting board 21 Component mounting board

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Dai Yamauchi             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F-term (reference) 5E319 BB05 CD29 GG20

Claims (6)

[Claims] 1. A step of supplying paste bonding material such as cream solder or conductive paste to one surface of a second substrate by a screen printing method to mount only surface mount components, and an IC chip on one surface of the first substrate. A method of manufacturing a component mounting board, which includes a step of mounting only a board and a step of connecting the other surfaces of the first board and the second board with a bonding member. 2. A step of mounting only an IC chip on one surface of a first board, a step of mounting only surface mount components on one surface of a second board, and the step of mounting the first board and the second board. A method for manufacturing a component mounting board, comprising the step of connecting the other surfaces to each other with a joining member. 3. The surface of the substrate on which the IC chip is mounted is placed in the recess formed in the printing jig, and the substrate is placed on the printing jig, which is opposite to the surface on which the IC chip is mounted. A screen mask having an opening to be a printed pattern is arranged on the substrate surface on the side, the squeegee slides on the screen mask to print the bonding material on the substrate through the opening, and then through the bonding material. A method for manufacturing a component mounting board on which surface mounting components are mounted. 4. A first substrate on which only an IC chip is mounted on one side, and a second substrate on which only a surface mount component is mounted on one side by supplying a paste bonding material such as cream solder or conductive paste by a screen printing method. And a joining member that connects the other surfaces of the first substrate and the second substrate to each other. 5. A multi-layer film substrate, an IC chip mounted only on one surface of the multi-layer film substrate, and a paste bonding material such as cream solder or conductive paste is supplied by a screen printing method to supply the multi-layer film substrate. A component mounting board consisting of surface mounting components mounted only on the other surface. 6. A component mounting board, the IC of the board
The component mounting board according to claim 4 or 5, wherein surface mounting components are mounted at opposite positions of the chip.