JPH06310841A - Printed-wiring board with pad part fit for mounting minipower package and mounting method thereof - Google Patents

Abstract

PURPOSE:To enable the surface mount of a minipower package and U type package, etc., to be favorably packaged by a method wherein the specific pads contained in pad parts are divided into the first and second parts while a bonded part in a specific width is provided between the first and second parts. CONSTITUTION:A specific number of pads 6 are provided on proper positons on the surface of a printed-wiring board 5 in a specific material and then the surface is coated and printed with a creamy solder 7 in a specific thickness. Next, a bond 8 in specific material is arranged on the position whereon a part 9 is to be mounted. Next, the part 9 is mounted on the pads 6 and then the rear part of the part 9 is fixed on the bond 8 to be put in a proper reflow furnace so that the part 9 may be soldered by the setting action of the bond 8 and the fusing action of the creamy solder 7. Through these procedures, the reliability upon the connection of solder parts can be enhanced thereby enabling the mounting step of a minipower package on the printed-wiring board to be easily executed without fail.

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 having a pad portion suitable for mounting a power type package component and a mounting method thereof, and more particularly to a pad for a power type package component to be connected / mounted. By devising the structure of the parts, it is possible to advantageously mount surface mount type mini power type packages and U type power type packages, etc., and it has a pad part suitable for mounting power type package parts The present invention relates to a printed wiring board and its mounting method.

[0002]

2. Description of the Related Art FIG. 4 is an exemplary view of a main portion of a printed wiring board having a pad portion suitable for mounting a power type package component which has been generally used conventionally. In FIG. 4 (A), a central pad extension 1A having a certain width is provided on the upper portion of the central pad 1 arranged in the center, and the left and right sides of the central pad 1 are substantially the same. A left pad 2 and a right pad 3 having shapes and dimensions are provided. Next, in FIG. 4B, the left pad 2 and the right pad 3 are provided, but the central pad is omitted. Then, a modified T-shaped central pad extension 1A is provided at an appropriate position. In such a conventional example, when performing a required mounting on a printed wiring board in which surface mounting components and insertion components coexist, [1] a step of applying a bond at an appropriate place on the substrate; [2] surface mounting components at required portions. Mounting step; [3] curing the applied bond based on a reflow operation; [4] inserting an insertion part into a required portion; [5] required portion based on a flow soldering operation Soldering process;
Will be applied in sequence.

When taking the above-mentioned steps, the following several difficulties are found. That is, [1] when the required surface mount components are fixed to the proper positions on the printed circuit board by using a bond, particularly when fixing a mini power type package component or a U type power package component, in the space where the bond is applied. Since there is no room,
The bond is applied on the pad (pattern) shown in FIG. However, when the flow soldering operation in some of the steps is performed, the solder plating on the pads may melt and the mounted components may drop. If the amount of the bond applied is increased to prevent such inconvenience, the bond flows out to the vicinity of the electrode of the mounted component, and it becomes impossible to perform desired soldering satisfactorily. [2] Further, when the above-mentioned flow soldering operation is executed, another surface mount component may be present at a position that interrupts the flow of the molten solder to the mini power package or the power package; May be improperly oriented; the target printed circuit board is not thick enough (eg, 0.
8 to 1.0 mm), the amount of solder used when connecting parts is reduced, or when warping is likely to occur,
Alternatively, the parts and the like may not be connected at all.

[0004]

The above-mentioned conventional example has some problems as follows. That is, [1] When a required surface mount component is fixed to a proper position of a printed circuit board by using a bond, there is no space for applying the bond, so that the pad (pattern) shown in FIG. Allowed to apply a bond. However, if such a treatment is performed, the solder plating on the pad may melt and the mounted component may drop during the flow soldering operation in some steps. In addition, if the coating amount of the bond is increased to prevent such a situation, the bond flows out to the vicinity of the electrode of the mounted component, and it becomes impossible to perform desired soldering satisfactorily. [2] Further, when the flow soldering operation is executed, another surface mount component exists at a position that interrupts the flow of the molten solder with respect to the mini power package or the power package, or the direction of the flow of the molten solder is changed. If it is not appropriate, or if the thickness of the target printed circuit board is insufficient and warpage is likely to occur, the amount of solder at the time of connection may decrease, or connection may not be possible at all.

The present invention has been made in order to solve the above-mentioned problems, and has sufficient room for arranging a required bond, and enables more reliable soldering. Another object of the present invention is to provide a printed wiring board having a pad portion suitable for mounting a power type package component and a mounting method thereof.

[0006]

A printed wiring board according to the present invention is a printed wiring board having a pad portion suitable for mounting a power type package component, and a predetermined wiring portion included in the pad portion. The pad comprises a first part (1) and a second part
(1A) and a bond application part (4) of a predetermined width is provided between the two. Further, a method of mounting a component on a printed wiring board according to the present invention is a method of mounting a component on a printed wiring board provided with a pad portion suitable for mounting a power type package component, in which cream solder is provided on an upper surface of the pad portion. Steps of applying / printing, placing a bond on a site where a component is to be mounted, mounting a component on a required site, and performing a reflow process on the printed wiring board on which the above operation has been performed. It is characterized by including.

[0007]

According to the printed wiring board having the pad portion suitable for mounting the power type package component and the mounting method thereof according to the present invention, the structure of the pad portion for the power type package component to be connected / mounted should be devised. By doing so, it is possible to mount surface-mount type mini power type packages, U type power type packages, etc. with advantage, and easily and surely mount the power type package components on the printed wiring board. The advantage of being done is brought.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic explanatory view of the essential part of an embodiment of a printed wiring board having a pad portion suitable for mounting a power type package component according to the present invention. First, in FIG. 1 (A), a central pad extension 1A which is widened to some extent is provided above the central pad 1 arranged in the center, and the central pad 1 and the central pad extension 1A are provided. A bond application part 4 having a predetermined width is provided between them. A resist of an appropriate material is applied to the surface including the bond applying portion 4, and therefore, the adhesive strength to the parts is sufficiently maintained and the undesired dropping can be prevented. . Further, when components are mounted, the bond in the bond application section 4 spreads, but the bond is prevented from protruding to the pad due to the presence of a step with the pad having a predetermined thickness. . Further, as will be described later with reference to FIG. 3, cream solder is applied / printed on the pad prior to mounting the components, and the amount of solder for connecting the components is insufficient or the solder is insufficient. Does not exist. In FIG. 1A, although not particularly limited to this, when the distance from the top of the central pad extension 1A to the top of the central pad 1 is h, the central pad extension is The height of 1A itself is (3/4) h, and the height (or its width) of the bond application part 4 is (1/4) h. A left pad 2 and a right pad 3 having substantially the same shape and size are provided on the left and right of the central pad 1. Next, in FIG. 1B, a bond application part 4 having a further enlarged width is provided between the central pad 1 and the central pad extension part 1A. Although not particularly limited to this in FIG. 1B, when the distance from the top of the center pad extension 1A to the top of the center pad 1 is h, the center pad extension is The height of 1A itself is (1/4) h, and the height (or its width) of the bond application portion 4 is (3/4) h. The shape of the central pad extension 1A here is rectangular. A left pad 2 and a right pad 3 having substantially the same shape and size are provided on the left and right of the central pad 1. Further, in FIG. 1C, a central pad extension portion 1A which is widened to some extent is provided on an upper portion of the central pad 1 arranged at the center.
A bond applicator 4 having a predetermined width is provided between the central pad extension 1A and the central pad extension 1A. In FIG. 1C, which is more preferable, the distance from the top of the central pad extension 1A to the top of the central pad 1 is h.
Then, the height of the central pad extension portion 1A itself is (1/2) h, and the height (or width) of the bond application portion 4 is also (1/2) h. ing. A left pad 2 and a right pad 3 having substantially the same shape and size are provided on the left and right of the central pad 1. It should be noted that these parts (A) to (C) of FIG. 1 are advantageously applied to the mini power package. Further, in FIG. 1D, the left pad 2 and the right pad 3 are provided, but the central pad is omitted. Then, a modified T-shaped central pad extension 1A is provided at an appropriate position. A bond applicator 4 having a predetermined width is provided between the left pad 2 and the right pad 3. Note that FIG. 1D is advantageously applied to the U-type power package.

FIG. 2 is a schematic explanatory view of the essential part of another printed wiring board having a pad portion suitable for mounting the power type package component according to the present invention. First, in FIG. 2A, the slimmed corridor portion 1B is provided above the central pad 1 arranged in the center,
A central pad extension 1A, which is widened to some extent, is provided. The left pad 2 and the right pad 3 are provided adjacent to the central pad 1, respectively. 2A is advantageously applied to the mini power package. In addition, in FIG. 2B, a central pad extension 1A, which is widened to some extent, is provided above the central pad 1 arranged in the center. It should be noted that, instead of the corridor portion 1B in FIG. 2A, a slim protruding portion 1C is provided halfway. The left pad 2 and the right pad 3 are provided adjacent to the central pad 1, respectively. 2B is advantageously applied to the U-type power package. Next, FIG. 2 (C) shows something similar to the case of FIG. 1 (D). And
In FIG. 2C, the left pad 2 and the right pad 3 are provided, but the central pad is omitted, and a modified T-shaped central pad extension 1A is provided at a proper position, and the bottom portion thereof is provided. In the vicinity (though not limited to this), a bond application portion having a circular shape is provided. FIG. 2C is also advantageously applied to the U-type power package. In FIG. 2D following this, a similar one to the case of FIG. 1D is shown. And
Also in FIG. 2D, the left pad 2 and the right pad 3 are provided, but the central pad is omitted, and a modified T-shaped central pad extension 1A is provided at a proper position and the bottom portion thereof is provided. The vicinity (not limited to this) is cut into a square approximation and a predetermined bond application part is provided. 2D is also advantageously applied to the U-type power package. 2E, a central pad extension 1A which is widened to some extent is provided on the upper portion of the central pad 1 arranged in the center, and the central pad 1 is provided on the left and right sides of the central pad extension 1A. , A left pad 2 and a right pad 3 having substantially the same shape and size are provided. A circular bond application portion is provided (although not limited to this) in the vicinity of the bottom portion on the side of the central pad extension portion 1A. The above-mentioned shape of the bond application part may be any desired shape such as a circle or a square.

FIG. 3 is an explanatory diagram relating to a component mounting method in the embodiment of the present invention. First, in FIG. 3A, a required number of pads 6 are provided at appropriate places on the printed wiring board 5 of a desired material. Next, in FIG. 3B, the cream solder 7 having a required thickness is formed on the upper surface of the pad 6.
Is applied and printed, and a bond 8 made of a desired material is placed on a site where the component is to be mounted. Subsequently, in FIG. 3C, a component 9 (here, a mini power type package component) is mounted on the pad 6, and a lower portion of the component 9 is fixed by a bond 8. A suitable reflow furnace (not shown) is in a state as shown in FIG. 3 (C).
Then, soldering is performed by the hardening action of the bond 8 and the melting action of the cream solder 7.

[0011]

As described in detail above, according to the printed wiring board having the pad portion suitable for mounting the power type package component and the mounting method thereof according to the present invention, the power to be connected / mounted By devising the structure of the pad section for the die package parts, it becomes possible to advantageously mount the surface mount type mini power type package, U type power type package, etc., and the mounted parts in the process of mounting. The number of out-of-stock items decreased,
The connection reliability of the soldering portion is improved, and the effect that the power type package component is easily and surely mounted on the printed wiring board can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of a main portion of an embodiment of a printed wiring board having a pad portion suitable for mounting a power type package component according to the present invention.

FIG. 2 is a schematic explanatory view of a main portion of another embodiment of a printed wiring board having a pad portion suitable for mounting a power type package component according to the present invention.

FIG. 3 is an explanatory diagram related to a component mounting method according to the embodiment of the present invention.

FIG. 4 is an exemplary view of a main part of a printed wiring board including a pad portion suitable for mounting a power type package component that has been generally used in the past.

[Explanation of symbols]

1 --- central pad; 1A --- central pad extension;
-Left pad; 3--Right pad; 4--Bond application part.

Claims (2)

[Claims] 1. A printed wiring board having a pad portion suitable for mounting a power type package component, wherein predetermined pads included in the pad portion are provided in a first portion and a second portion. A printed wiring board having a pad portion suitable for mounting a power type package component, characterized in that it is divided, and a bond coating portion having a predetermined width is provided between the two. 2. A method of mounting a component on a printed wiring board having a pad portion suitable for mounting a power type package component, wherein cream solder is applied and printed on the upper surface of the pad portion, and the component is mounted. The steps of arranging a bond at an appropriate site, mounting a component at a desired site, and performing a reflow process on the printed wiring board subjected to the above operation are included. How to implement.