JP2000022316A - Printed wiring board and electronic apparatus containing printed units - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a high-accuracy solder precoat by a convenient processing work to realize a high-accuracy electronic component mounting. SOLUTION: A solder resist 22 is deposited to regions on a wiring board body 201 for mounting an electronic component body 211, except component connecting pads 203, a plurality of openings 221 are provided at the solder resist 22 on ground connecting pads 202 of the circuit board body 201, and solder 23 is precoated on the ground connecting pads 202 and component connecting pads 203, except the solder resist 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed wiring board suitable for mounting on electronic equipment such as a personal computer (PC).

[0002]

2. Description of the Related Art Generally, a printed wiring board of this type is mounted with electronic components having connection leads arranged at a pitch of 0.3 mm or less, for example, a TCP (Tape Carrier Package), and a desired printed wiring unit is formed. The printed wiring unit is formed and housed in a device main body of an electronic device such as a PC.

FIGS. 8 and 9 show such a conventional printed wiring unit. A wiring board main body 1 of a printed wiring board is connected to a ground corresponding to a component main body 2a called a die of an electronic component 2. FIG. Pad 1a is formed, and component connection pad 1b is formed corresponding to ground connection pad 1a. The component connection pads are formed at a pitch of, for example, 0.3 mm or less, and are connected to a circuit pattern (not shown) of the wiring board body 1 to form a desired electronic circuit.

On the wiring board body 1 of the printed wiring board, a solder resist 3 is applied to a region other than the ground connection pad 1a and the component connection pad 1b, and then solder is applied on the ground connection pad 1a and the component connection pad 1b. 4 is pre-coated (see FIG. 8). The connection lead 2b of the component main body 2a is soldered to the component connection pad 1b. At this time, the electronic component 2 is
Formed on the back surface of the wiring board body 1 is bonded to a ground connection pad 1a of the wiring board body 1 using a conductive adhesive material called a die attach material (not shown in the drawing for convenience of the drawing).

In the printed wiring board, when the pitch of the component connection pads 1b is extremely narrow, it is difficult to perform solder connection using a well-known cream solder technique.
The solder resist 3 is applied to the area of the wiring board body 1 except for the ground connection pads 1a and the component connection pads 1b, and the solder 4 is pre-coated, so that the connection leads 2b of the electronic component 2 are connected to the components of the wiring board body 1. There is known a method of performing solder connection to the connection pad 1b.

However, if the printed wiring board is pre-coated with the solder 4, it is difficult to uniformly form the solder 4 pre-coated on the ground connection pad 1a (see FIG. 8). There is a problem that high-precision mounting on the wiring board main body 1 becomes difficult.

Therefore, as a method of pre-coating the solder 4 on the component connection pads 1b of the wiring board body 1, first, the solder 4 is pre-coated on the component connection pads 1b, and the ground connection pads 1a are subjected to gold flash processing. Then, a method of applying a gold plating layer or performing a pre-flux treatment is adopted.

However, in the above method, in addition to the pre-coating process of the solder 4, a gold flashing process or a pre-flashing process has to be performed. There is a problem that there is.

[0009]

As described above, in the conventional printed wiring board, when the solder precoating process is simplified, the mounting accuracy of electronic components is reduced, and it is possible to realize a high precision solder precoat. However, there is a problem that the precoating operation becomes very troublesome.

[0010] The present invention has been made in view of the above circumstances, and a printed wiring board capable of realizing high-precision solder precoating with a simple processing operation and mounting high-precision electronic components. The purpose is to provide. Another object of the present invention is to provide an electronic device having a built-in printed wiring unit capable of improving reliability.

[0011]

SUMMARY OF THE INVENTION The present invention provides a wiring board body having component connection pads formed corresponding to a ground connection pad to which a ground of an electronic component body is connected, and the component connection pad of the wiring board body. A solder resist having a plurality of openings formed on the ground connection pad, and the ground connection pad and the component connection pad except for the solder resist of the wiring board body. The printed wiring board was constituted by including the solder pre-coated thereon.

According to the above construction, the wiring board body is divided and pre-coated with solder at positions corresponding to the solder resist openings of the component connection pads and the ground connection pads, and the solder pre-coat on the ground connection pads is provided. By dividing the surface into small portions, the solder thickness dimension is formed substantially uniformly. Therefore, a simple solder precoating process is ensured, and when mounting the electronic component on the ground connection pad, the precision of the solder on the ground connection pad is not adversely affected, and the high precision of the soldering on the ground connection pad is prevented. Mounting is possible.

The present invention also provides a wiring board in which a ground connection pad to which the ground of an electronic component body is connected is divided into a plurality of sub-portions, and component connection pads are formed corresponding to the sub-divided ground connection pads. A main body, a solder resist applied to a region of the wiring board main body excluding the ground connection pad and the component connection pad, and a solder resist on the ground connection pad and the component connection pad of the wiring board main body excluding the solder resist. The printed wiring board was constituted by including the pre-coated solder.

According to the above configuration, the wiring board body is precoated with solder on the component connection pads and the subdivided ground connection pads, and the solder precoat surface corresponding to the ground connection pads is subdivided. By doing
The thickness of the solder is formed substantially uniformly. Therefore, a simple solder precoating process is ensured, and when mounting the electronic component on the ground connection pad, the precision of the solder on the ground connection pad is not adversely affected, and the high precision of the soldering on the ground connection pad is prevented. Mounting is possible.

Further, according to the present invention, a component connection pad is formed on the wiring board body corresponding to the ground connection pad, and a solder resist is applied to a region excluding the component connection pad. Forming an opening of
A solder is pre-coated on the ground connection pads and the component connection pads excluding the solder resist, and the ground of the electronic component is connected to the ground connection pads of the wiring board body, and the component connection pads are An electronic device is configured including a printed wiring unit to which connection terminals of electronic components are connected and the electronic component is mounted, and a device main body in which the printed wiring unit is housed.

According to the above configuration, the wiring board body is divided and pre-coated with solder at positions corresponding to the openings of the solder resist of the component connection pads and the ground connection pads, and the solder on the ground connection pads is formed. Since the pre-coated surface is divided into small portions and the thickness of the solder is formed to be substantially uniform, it is possible to mount electronic components with high precision.
Therefore, a simple solder pre-coating process is ensured, and when mounting the electronic component on the ground connection pad, the reliability of the performance of the electronic device is not adversely affected by the mounting accuracy due to the solder on the ground connection pad. Can be improved.

Further, according to the present invention, a subdivided ground connection pad and a component connection pad are formed on a wiring board body, and a solder resist is applied to a region excluding the ground connection pad and the component connection pad. A solder is pre-coated on the ground connection pads and the component connection pads excluding the solder resist, and the ground of the electronic component is connected to the ground connection pads of the wiring board body, and the component connection pads are An electronic device comprising a printed wiring unit to which connection terminals of electronic components are connected and the electronic component is mounted, and a device main body in which the printed wiring unit is accommodated.

According to the above construction, the wiring board body is precoated with solder on the component connection pads and the subdivided ground connection pads, and the solder precoat surface corresponding to the ground connection pads is subdivided, Since the thickness of the solder is substantially uniform, the electronic component can be mounted with high accuracy. Therefore, a simple solder pre-coating process is ensured, and when mounting the electronic component on the ground connection pad, the reliability of the performance of the electronic device is not adversely affected by the mounting accuracy due to the solder on the ground connection pad. Can be improved.

[0019]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an electronic device incorporating a printed wiring unit according to an embodiment of the present invention. A device main body 10 includes a printed wiring board 20 having electronic components 21 mounted on a printed wiring board 20 which is a feature of the present invention. The unit 30 is built in.

In the printed wiring unit 30, as shown in FIGS. 2 and 3, an electronic component 21 is mounted on a printed wiring board 20 to form a desired electronic circuit. That is, the ground connection pad 20 is attached to the wiring board body 201 of the printed wiring board 20.
2 and component connection pads 203 are formed corresponding to grounds and connection leads 212 (not shown) formed on the back surface of the component main body 211 of the electronic component 21. The ground connection pad 202 and the component connection pad 203 are connected to a circuit pattern (not shown) of the wiring board body 201 to form a desired electronic circuit.

A solder resist 22 is applied to the wiring board body 201 in a region other than the component connection pads 203. In the solder resist 22, for example, a plurality of circular openings 221 (see FIG. 3) are formed at predetermined intervals corresponding to the ground connection pads 202. The number of the openings 221 is set to such an extent that a ground (not shown) of the electronic component 21 can be stably taken.

The solder 23 is pre-coated on one surface of the wiring board main body 201 where the ground connection pads 202 and the component connection pads 203 are formed. Here, the solder 23 is placed on the ground connection pad 202 corresponding to the opening 221 of the solder resist 22.
Are formed in a state of being divided into a plurality of parts corresponding to the openings 221, and the thickness thereof is formed substantially uniformly so as not to be affected by the mounting of the electronic component 21 thereafter.

Further, a keyboard 11 is provided on the main body 10, and the keyboard 11 is electrically connected to a circuit module 30 in the main body 10.
The device body 10 includes a liquid crystal display (LC).
D) 12 is assembled so as to be rotatable in the direction of the arrow. In the above configuration, the printed wiring board 20 is electrically connected to the ground connection pad 202 of the wiring board main body 201 by using a conductive adhesive (not shown) of the ground (not shown) of the component main body 211 of the electronic component 21. Adhesively connected. At the same time, the connection lead 212 of the electronic component 21 is
01 is connected to the component connection pad 203 by soldering. At this time, the electronic component 21 is mounted on the ground connection pad 202 with high mounting accuracy without being affected by the solder 23 divided and arranged on the ground connection pad 202 of the wiring board body 201.

As described above, the printed wiring board 20 is formed by applying the solder resist 22 to a region other than the component connection pads 203 of the wiring board main body 201 on which the electronic component main body 211 is mounted, and Connection pad 202
A plurality of openings 221 are provided in the upper solder resist 22, and the solder 23 is pre-coated on the ground connection pads 202 and the component connection pads 203 excluding the solder resist 22.

According to this, the solder 23 is placed at a position corresponding to the opening 221 of the solder resist 22 of the component connection pad 203 and the ground connection pad 202 of the wiring board body 201.
Is divided and pre-coated, so that the solder 23 on the ground connection pad 202 is divided into small pieces and pre-coated, so that the solder thickness dimension can be made uniform.
Therefore, a simple solder pre-coating process is ensured, and the ground connection pad 202 of the electronic component 21 is formed by the solder 23 pre-coated on the ground connection pad 202.
The mounting of the electronic component 21 with high accuracy is realized without being adversely affected by the mounting accuracy on the top.

Further, the electronic device is composed of a wiring board main body 201.
A component connection pad 203 is formed corresponding to the ground connection pad 202, and a solder resist 22 is applied to a region excluding the component connection pad 203, and the ground connection pad 2 is formed.
2, a plurality of openings 221 are formed in the solder resist 22 on the ground connection pad 202, and the solder connection 23 is pre-coated on the ground connection pad 202 and the component connection pad 203 excluding the solder resist 22.
2 and the ground of the electronic component 21
The connection lead 212 of the electronic component 21 is connected to the component connection pad 203, and the printed wiring unit 30 on which the electronic component 21 is mounted is housed and arranged in the device body 10.

According to this, the solder 2 is placed at a position corresponding to the opening 221 of the solder resist 22 on the component connection pad 203 and the ground connection pad 202 of the wiring board body 201.
3 is divided and pre-coated, the solder pre-coated surface on the ground connection pad 202 is divided into small portions, and the thickness of the solder is formed substantially uniform, so that the electronic component 21 can be mounted with high accuracy. . Therefore, a simple solder pre-coating process is ensured, and when the electronic component 21 is mounted on the ground connection pad 202, the mounting accuracy of the solder 23 on the ground connection pad 202 is not adversely affected. The mounting of the component 21 is realized, and the reliability in the performance of the electronic device can be improved.

It should be noted that the present invention is not limited to the above embodiment, and it is also possible to configure the printed wiring units 31 and 32 as shown in FIGS. 4 and 5, and FIGS. 6 and 7. . However, here, in FIG. 4 to FIG.
2 and 3 are denoted by the same reference numerals, and description thereof is omitted.

FIGS. 4 and 5 show that a plurality of slit-shaped openings 222 are formed at predetermined intervals in the solder resist 22 on the ground connection pads 202 of the wiring board body 201, and the inside of the slit-shaped openings 22 is formed. Ground connection pad 202
Since the solder 23 is pre-coated thereon, an effective effect is expected as in the above embodiment.

The opening 2 in the solder resist 22
22 (221) is not limited to the above-described hole shape, and may be formed using other shapes.

6 and 7, the ground connection pad 202 is exposed without forming the solder resist 22 on the ground connection pad 202 of the wiring board body 201. Then, for example, a circular hole 204 is formed in the ground connection pad 202, the ground connection pad 202 is divided into a plurality of pieces, and the solder 23 is formed on the ground connection pad 202 and the component connection pad 203 excluding the solder resist 22. Is pre-coated. As a result, the solder 23 on the ground connection pad 202 is pre-coated on each of the subdivided upper portions, and the solder pre-coated surface is divided into small portions. As a result, the solder 2 on the ground connection pad 202
Reference numeral 3 indicates that the thickness of the solder is formed substantially uniformly, and similarly, the electronic component 21 can be mounted with high accuracy.

The hole 204 for dividing the ground connection pad 202 into a plurality of pieces is not limited to the above-described circular shape, but can be further divided into a plurality of pieces using holes of various shapes.

Each of the printed wiring units 30 shown in FIGS. 4 to 7 is housed in the device main body 10 (see FIG. 1) to constitute an electronic device such as a personal computer. According to this, the printed wiring board 2 of the electronic component 21 having the same high accuracy
0, and the reliability of the performance of the electronic device can be improved as much as possible. Therefore, it is needless to say that the present invention is not limited to the above-described embodiment, and that various modifications can be made without departing from the scope of the present invention.

[0034]

As described above in detail, according to the present invention, a printed wiring board capable of mounting a high-precision electronic component by realizing a high-precision solder precoat with a simple processing operation. Can be provided. Further, the present invention can provide an electronic device having a built-in printed wiring unit capable of improving reliability.

[Brief description of the drawings]

FIG. 1 is an exemplary view showing a main part of an electronic device including a printed wiring unit according to an embodiment of the present invention;

FIG. 2 is a sectional view showing a main part of the printed wiring unit according to the embodiment of the present invention;

FIG. 3 is a plan view showing a main part of the printed wiring board according to the embodiment of the present invention;

FIG. 4 is a sectional view showing a printed wiring unit according to another embodiment of the present invention.

FIG. 5 is a plan view showing a printed wiring board according to another embodiment of the present invention.

FIG. 6 is a sectional view showing a printed wiring unit according to another embodiment of the present invention.

FIG. 7 is a plan view showing a printed wiring board according to another embodiment of the present invention.

FIG. 8 is a cross-sectional view showing a conventional printed wiring unit.

FIG. 9 is a plan view showing a conventional printed wiring board.

[Explanation of symbols]

 10… The device itself. 11 ... keyboard. 12 LCD. 20 ... printed wiring board. 201 ... wiring board body. 202… Ground connection pad. 203 ... Component connection pad. 204 ... holes. 21 Electronic parts. 211 ... The component body. 212 Connection lead. 22 ... Solder resist. 221, 222 ... opening. 23 ... solder. 30 ... printed wiring unit.

Claims (5)

[Claims] 1. A wiring board body in which component connection pads are formed corresponding to a ground connection pad to which a ground of an electronic component body is connected, and a wiring board body is attached to a region excluding the component connection pads. A solder resist provided with a plurality of openings on the ground connection pad, and a solder pre-coated on the ground connection pad and the component connection pad except for the solder resist of the wiring board body. Printed wiring board equipped. 2. A wiring board main body in which a ground connection pad to which a ground of an electronic component main body is connected is divided into a plurality of parts, and a component connection pad is formed corresponding to the subdivided ground connection pad. A solder resist applied to a region of the wiring board body other than the ground connection pads and the component connection pads; and a solder pre-coated on the ground connection pads and the component connection pads of the wiring board body excluding the solder resist. A printed wiring board comprising: 3. A component connection pad is formed on the wiring board body corresponding to the ground connection pad, a solder resist is applied to a region excluding the component connection pad, and a plurality of openings are formed on the ground connection pad. Forming and pre-coating solder on the ground connection pads and the component connection pads except for the solder resist, and connecting the ground of the electronic component to the ground connection pads of the wiring board main body, and connecting the component connection pads to the component connection pads An electronic device comprising: a printed wiring unit to which a connection terminal of the electronic component is connected and the electronic component mounted thereon; and a device main body in which the printed wiring unit is housed. 4. A method of forming a subdivided ground connection pad and a component connection pad on a wiring board body, applying a solder resist to an area excluding the ground connection pad and the component connection pad, and removing the solder resist. A solder is pre-coated on the ground connection pad and the component connection pad, and the ground of the electronic component is connected to the ground connection pad of the wiring board body, and the connection terminal of the electronic component is connected to the component connection pad. An electronic device comprising: a printed wiring unit connected to the electronic component and mounted thereon; and a device main body in which the printed wiring unit is housed. 5. The electronic device according to claim 3, wherein the electronic component has a ground formed on a mounting surface side of the component main body.