JP2002232125A - Printed wiring board and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printed wiring board where a land at the soldering surface side of a through-hole is squared for high-density packaging and wiring, when inserting and soldering the component lead of lead frame components, and to provide a technology regarding the manufacturing method of the printed- wiring board. SOLUTION: As shown in Figure 1, the printed-wiring board related to the aspect comprises the through-hole 1 for fitting the lead frame components on a printed-wiring board surface 7 and a pattern 5, and the through-hole 1 has a land 2 in a square shape 4 at the side of a soldering surface.

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, and more particularly to a printed wiring board for mounting a lead frame component which cannot be automatically mounted by reflow, and a method of manufacturing the same.

[0002]

2. Description of the Related Art In the production of a conventional printed wiring board,
Lead frame components that cannot be automatically mounted by reflow are soldered by a soldering iron in a post-reflow process.

[0003] As an example of a printed wiring board according to the prior art, Japanese Patent Application Laid-Open No. 2000-208908 (Soldering method, printed wiring board and mounted parts suitable therefor)
Has been published.

[0004] The printed wiring board described in this publication is
In order to increase the amount of solder attached, a metal component is mounted on the land of the through hole as an auxiliary member by a surface mount component mounting machine.

FIG. 5 is a diagram showing an example of a conventional printed circuit board surface on the solder surface side.

In the drawing, a through hole 101 and a large circular land 102 are formed on a solder surface side C of a printed wiring board surface 107.
And the pattern 105.

[0007]

However, the prior art has the following problems.

[0008] Through hole 101 for high-density mounting and wiring
Adopts a landless through-hole with almost no land, so that the number of lands is small, the contact with the soldering iron is insufficient, the heating amount is small, and the inside of the through-hole 101 cannot be sufficiently heated. However, it was difficult to supply a sufficient amount of solder because the land area to which the solder was attached was small.

In addition, it is necessary to mount a metal component as an auxiliary member on the land of the through hole 101, which increases the number of processes.
There was a problem of cost increase.

Further, a predetermined area is required on the printed wiring board surface 107 in order to mount the metal parts. However, if the land area is increased while maintaining a circular shape as in the prior art, the adjacent patterns are formed as shown in FIG. 105 and circular land size 102
And NG location D occurs. As a result, there is a problem that high-density mounting and wiring cannot be realized.

The present invention has been made in view of such a problem, and an object of the present invention is to enable high-density mounting and wiring when inserting and soldering component leads of a lead frame component. Another object of the present invention is to provide a technique relating to a printed wiring board in which a land on the solder surface side of a through hole is made square and a method for manufacturing the same.

[0012]

The gist of the present invention is to provide a printed wiring board on which a lead frame component can be mounted, wherein a land is provided on a solder side of a printed circuit board surface for mounting the lead frame component. Wherein the land has a substantially planar shape having a side that is substantially straight at an end of the land facing a pattern arranged on the printed circuit board surface, and the land is The printed wiring board is characterized in that the sides are arranged so as to be substantially parallel to the extending direction of the pattern.
The gist of the present invention according to claim 2 is that, in the land, the pattern and the side opposite to the pattern keep a predetermined interval, so that the end of the land that forms a substantially circular shape with the pattern is the land. The printed wiring board according to claim 1, wherein a land area larger than a substantially circular land requiring an interval can be maintained. According to a third aspect of the present invention, there is provided the printed wiring board according to the first or second aspect, wherein the land is a polygon having the side. The gist of the present invention described in claim 4 resides in the printed wiring board according to any one of claims 1 to 3, wherein the land is a quadrangle having the side. According to a fifth aspect of the present invention, there is provided the printed wiring board according to the first or second aspect, wherein the land is a semicircle having the side. The gist of the present invention according to claim 6 is a method of manufacturing a printed wiring board on which a lead frame component can be mounted, wherein a first step of inserting a component lead of the lead frame component into a through-hole, A soldering iron is applied to a land where a portion facing the pattern on the solder surface side has a substantially straight side, and a land arranged so that the extending direction of the pattern is substantially parallel to the side is heated. Then, a second step of melting the solder, attaching the component leads to the lands, and pouring the solder into the through holes, and a third step of performing a connection check on the attached portion and confirming a defective portion are included. A method for manufacturing a printed wiring board, comprising: The gist of the present invention described in claim 7 is that, when a defective portion is confirmed in the third step, the second step is performed again. Be in the way.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a diagram showing an example of a printed wiring board surface 7 in the printed wiring board according to the present embodiment.

As shown in FIG. 1, the printed wiring board according to the present embodiment includes a through hole 1 for mounting a lead frame component on a printed wiring board surface 7 and a pattern 5, and the through hole 1 Lands 2 having a square shape 4 on the solder surface side.

The land 2 in FIG. 1 has a square shape 4 on the solder surface side A and a circular shape 3 on the component surface side described later.
In the figure, a soldering iron 6 is shown.

FIG. 2 is a diagram showing an example of a cross section of the through hole 1 in FIG.

A component lead 8 is inserted into the through hole 1, and the through hole 1 has a circular land 9 on the component side B.
A rectangular land 10 is provided on the solder surface side A. The wiring of the adjacent pattern 5 is displayed in the figure.

As described above, the shape of the land 2 on the solder surface side A of the through hole 1 is square 4 (square).
Can be arranged so that the side 41 of the pattern 5 is substantially parallel to the extending direction of the pattern 5. Thus, the land area can be increased while maintaining the interval between the adjacent wiring patterns 5. A similar arrangement can be made even when the one adjacent to the through hole 1 is another through hole or is solid.

With the above configuration, the land 2 can be easily heated by the soldering iron 6 without damaging the high-density mounting / wiring. As a result, heat is easily transferred into the through-hole 1 and the amount of solder attached to the land 2 is increased, sufficient solder is attached to the through-hole 1 and soldering strength is increased, and sufficient reliability of the product is achieved. Can be secured.

FIG. 3 is a flowchart showing an example of the flow in the method of manufacturing a printed wiring board according to the present embodiment.

First, the component lead 8 is inserted into the through hole 1 (component insertion) (step A1).

Next, soldering is performed (step A2).
At the time of soldering, the soldering iron 6 is applied to the component leads 8 and the rectangular lands 10 and heated to melt the solder, adhere to the lands 2 and flow into the through holes 1.

Next, the adhered portion is cooled (step A).
3).

A connection check is performed for the attached portion (connection check) (step A4).

If the connection is good (OK in the figure), the process ends.

In step A4, the connection is poor (in the figure,
In the case of (NG), the defective portion is confirmed (NG portion correction) (step A5), and the process returns to step A2.

FIG. 4 is a diagram showing another example of the printed wiring board surface 7 in the printed wiring board according to the present embodiment.

As shown in FIG. 4, on the printed wiring board surface 7, the rectangular land 21 of the through hole 1 into which the component lead 8 can be inserted has a pentagon shape having the side 41 of the land 2 of FIG. . This square land 2
1 may be a polygon (n-gon) or semicircle having a side similar to the side 41 shown in FIG.

The lands 2 and the sides 4 of the rectangular lands 21
By keeping the predetermined interval between 1 and pattern 5 approximately parallel,
To increase the land area of the land 2 having the substantially straight side 41 and the land area of the square land 21 with respect to the substantially circular land in which the end of the substantially circular land of the related art and the pattern 5 are arranged at the same interval. Can be.

The printed wiring board according to the embodiment and the method of manufacturing the same are configured as described above, and thus have the following effects.

The first effect is that a solderable through-hole 1 which can maintain reliability with respect to product quality without damaging high-density mounting / wiring can be formed.

The reason is that by making the land 2 on the solder surface side A of the through hole 1 into a square 4, the area of the land 2 can be increased without moving the adjacent pattern land solid copper foil, etc. This is because sufficient heating and solder supply can be performed.

The area of the land 2 can be finely increased by making the land 2 have a polygonal or semicircular shape.

In the present embodiment, the present invention is not limited to this, and can be applied to a technique relating to a printed wiring board and a method for manufacturing the same, which are suitable for applying the present invention.

Further, the number, position, shape, etc. of the above-mentioned constituent members are not limited to the above-mentioned embodiment, but can be set to a suitable number, position, shape, etc. for carrying out the present invention.

In each of the drawings, the same components are denoted by the same reference numerals.

[0038]

Since the present invention is configured as described above, the following effects can be obtained.

By making the land on the solder surface side of the through hole square, the land area can be increased without moving the adjacent pattern, land, solid copper foil, etc.
Sufficient heating and solder supply. As a result, a solderable through-hole capable of maintaining reliability with respect to product quality can be formed without impairing high-density mounting / wiring.

The land area can be finely increased by making the land polygonal or semicircular in accordance with the shape of the wiring pattern.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a printed wiring board surface in a printed wiring board according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a cross section of the through hole of FIG. 1;

FIG. 3 is a flowchart illustrating an example of a flow in a method of manufacturing a printed wiring board according to an embodiment of the present invention.

FIG. 4 is a diagram showing another example of the surface of the printed wiring board in the printed wiring board according to the embodiment of the present invention.

FIG. 5 is a diagram illustrating an example of a soldering surface side of a printed wiring board surface in a conventional technique.

[Explanation of symbols]

 A Solder side B Part side C Solder side D NG location 1 Through hole 2 Land 3 Circular 4 Square 5 Pattern 6 Soldering iron 7 Printed wiring board surface 8 Component lead 9 Circular land 10 Square land 21 Square land 41 Side Reference Signs List 101 through hole 102 large circular land 105 pattern 107 printed wiring board surface

Claims (7)

[Claims] 1. A printed wiring board on which a lead frame component can be mounted, comprising: a through hole having a land on a solder surface side of a printed circuit board surface for mounting the lead frame component; The end of the land opposed to the pattern arranged on the upper side has a substantially planar shape having sides that are substantially straight, and the lands are such that the sides are substantially parallel to the extending direction of the pattern. A printed wiring board to be arranged. 2. The land according to claim 1, wherein the pattern has a predetermined interval between the pattern and the side facing the pattern.
2. The printed wiring board according to claim 1, wherein the pattern and the end of the substantially circular land can maintain a land area larger than that of the substantially circular land requiring the space. 3. 3. The printed wiring board according to claim 1, wherein the land is a polygon having the side. 4. The printed wiring board according to claim 1, wherein the land is a rectangle having the side. 5. The printed wiring board according to claim 1, wherein the land is a semicircle having the side. 6. A method of manufacturing a printed wiring board on which a lead frame component can be mounted, comprising: a first step of inserting a component lead of the lead frame component into a through hole; Opposing portions have sides that are substantially straight, and a soldering iron is applied to a land that is arranged so that the extending direction of the pattern and the sides are substantially parallel to each other, and the solder is melted. ,
A printing method comprising: a second step of attaching the component leads to the lands and pouring the solder into the through holes; and a third step of performing a connection check on the attached portion and confirming a defective portion. Manufacturing method of wiring board. 7. The method for manufacturing a printed wiring board according to claim 6, wherein in the third step, when a defective portion is confirmed, the second step is performed again.