JP2933729B2 - Printed wiring board device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer printed circuit board having a through hole as a component mounting hole.

[0002]

2. Description of the Related Art Conventionally, a through-hole portion of a multilayer printed circuit board is constructed as shown in FIGS.

FIG. 2 is a sectional view of a conventional multilayer printed circuit board.
FIG. 3 is a plan view of the multilayer printed circuit board of FIG. 2, and FIGS.
1 is a glass epoxy substrate, 2 is a through hole, 3 is a hole wall of a through hole, 4 is a through hole land, 5 is an inner layer copper foil pattern, 6 is a radial connection pattern, and 7 ′.
Is a thermal land formed by removing the copper foil pattern around the through hole 3 into a slit shape. When a lead wire of a lead component is passed through the through hole 2 of such a multilayer printed board and soldering is performed, unless the thermal land 7 is provided, the copper foil pattern 5 of the inner layer is wide in a power supply pattern and a GND pattern. An area is required, so that the heat capacity is increased, and heat is easily released during soldering. However, as shown in FIG. 3, a thermal land 7 'is formed in a portion connecting the hole wall 3 of the through hole and the copper foil pattern 5 of the inner layer. So that the heat does not escape through the copper foil pattern 5 of the inner layer,
This prevents problems with poor soldering.

[0004]

However, in the above conventional example, the connection pattern 6 in the radial direction needs to have a sufficient length to prevent diffusion of heat during soldering. As a result, the shape of the thermal land 7 'becomes large, which has an adverse effect on the high-density wiring of the copper foil pattern 5 of the inner layer and the narrowing of the pitch between the through holes.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to prevent the diffusion of heat at the time of soldering components, and to reduce the high-density wiring of an inner copper foil pattern and the pitch between through holes. It is an object of the present invention to provide a printed wiring board device capable of performing the following.

[0006]

In order to achieve the above object, a printed wiring board device according to the present invention comprises a through hole.
In a multilayer printed circuit board with
Around the hole wall of the hole, this hole wall and the inner layer copper foil pattern
Radial connection pattern formed to connect with
Between the hole wall of the through hole and the copper foil pattern
Multiple sensors formed to reduce the thermal conductivity of the
And a plurality of thermal lands,
The inner peripheral shape is a substantially circular shape, and the outer peripheral shape is a substantially square shape
It is characterized by being formed as follows.

[0007]

According to the present invention, the diffusion of heat at the time of soldering of the through-hole portion is prevented, the pitch between the through-holes can be narrowed, and the high-density wiring of the copper foil pattern of the inner layer becomes possible. .

[0008]

FIG. 1 is a plan view of a multilayer printed circuit board according to an embodiment of the present invention. In FIG.
Is a hole wall of a through hole, 4 is a land of a through hole, 5 is a copper foil pattern of an inner layer, 6 is a connection pattern in a radial direction, 7
Are thermal lands formed by removing the copper foil pattern around the through hole 3 in a slit shape.

Next, in the above configuration, the connection pattern 6 in the radial direction is set to a sufficient length as in the conventional example,
Prevents diffusion of heat during soldering to through holes. However, the connection patterns in the radial direction, which connect these connection patterns in the radial direction with each other via the thermal land 7, are formed linearly, and as shown in FIG. And This allows
As for the prevention of heat diffusion, the area of the thermal land is reduced while maintaining the same effect as the conventional thermal land, and the copper pattern around the thermal land can be increased and the pitch between through holes can be reduced. Becomes

[0010] Such a structure is not only valid when the thermal land is formed on the copper foil pattern of the inner layer, but also exhibits the same effect when it is formed on the copper foil pattern on the surface. Things.

[0011]

As described above, according to the present invention , the hole wall of the through hole and the copper foil pattern of the inner layer are formed around the hole wall.
Connection pattern in the radial direction for connecting
Thermal conductivity between the hole wall of the through hole and the copper foil pattern
A plurality of thermal lands to reduce
And the inner peripheral shape of the plurality of thermal lands is substantially
By making the circular shape and the outer peripheral shape approximately square,
When soldering compared to conventional circular thermal lands
Of copper in the inner layer without impairing the effect of preventing heat diffusion
High density wiring of foil pattern and narrow pitch between through holes
Pitching can be realized.

[Brief description of the drawings]

FIG. 1 is a plan view of a multilayer printed circuit board according to an embodiment of the present invention.

FIG. 2 is a sectional view of a conventional multilayer printed circuit board.

FIG. 3 is a plan view of the multilayer printed circuit board of FIG. 2;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 glass epoxy substrate 2 through hole 3 through hole hole wall 4 through hole land 5 inner layer copper foil pattern 6 radial connection pattern 7, 7 'thermal land

Claims (1)

(57) [Claims] 1. A multilayer printed circuit board having a through hole as a component mounting hole, wherein the hole wall and the inner layer copper foil pad are formed around the hole wall of the through hole.
Radial connection pads formed to connect turns
Turn, hole wall of the through hole and the copper foil pattern
Multiple formed to reduce thermal conductivity between
And a thermal land, said plurality of thermal land, the inner peripheral shape approximately circular shape
A printed wiring board device characterized in that its shape and outer peripheral shape are formed to be substantially square .