JPH08330689A - Printed wiring board - Google Patents

Abstract

(57) [Summary] [Object] The present invention is to realize a printed wiring board that can facilitate the mounting position alignment of a surface mounting type electronic component with respect to the printed wiring board. [Structure] In a printed wiring board configured to mount a surface mount type electronic component, on a mounting surface of the printed wiring board on which the electronic component is mounted, a graduation for aligning is formed in correspondence with the outer shape of the electronic component. By providing at least two reference position marks, the operator can easily confirm the amount of displacement and the direction of displacement of the electronic component.

Description

Detailed Description of the Invention

[0001]

[Table of Contents] The present invention will be described in the following order. Field of Industrial Application Conventional Technology (FIG. 4) Problem to be Solved by the Invention (FIG. 5) Means for Solving the Problem (FIGS. 1 to 3) Action (FIGS. 1 to 3) Example (FIG. 1) ~ Fig. 3) Effect of the invention

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed wiring board, and is suitable for application to, for example, a printed wiring board on which electronic components for surface mounting are mounted.

[0003]

2. Description of the Related Art Conventionally, as a device for mounting an electronic component on a printed wiring board, a mounting device having a built-in numerical control mechanism (hereinafter referred to as a mounter) has been used. When mounting electronic parts using this mounter, in the numerical control mechanism provided inside the mounter,
By setting the X-axis and the Y-axis on the mounting surface of the printed wiring board with the corners of the printed wiring board as the origin, and expressing the desired position for mounting the electronic component as coordinate values composed of the X and Y coordinates. The electronic component is mounted at a desired position based on the coordinate value.

By the way, in practice, the mounter and the printed wiring board each have a physical error (offset).
Therefore, after mounting the electronic component once, the relative displacement amount is measured based on the alignment state of the electrode of the electronic component and the board land of the mounting surface of the printed wiring board, and this is turned off. It was necessary to correct the position by inputting it as set data into the numerical control mechanism.

At that time, in order for the operator to confirm the positional relationship between the electrode of the electronic component and the land on the mounting surface of the printed wiring board, a magnifying glass (hereinafter, referred to as a scale) with a scale is drawn.
This is called a magnifying glass with a scale) and the like, and the relative positional deviation amount is measured by reading these alignment states.

For example, as shown in FIG. 4 (A), when a QFP (quad flat package) 1 is used as an electronic component, a plurality of leads 3 drawn out from each edge of the package 2 of the QFP 1 are The mounting surface 4A of the printed wiring board 4 is aligned with the plurality of lands 5 arranged in a predetermined pattern, and then mounted. In this state, as shown in FIG. 4B, the leads 3 of the QFP 1 and the mounting surface 4 of the printed wiring board 4 corresponding thereto
Align the lands 5 of A with the magnifying glass 6 with scale.
The operator can easily measure the positional deviation by representing the positional deviation amount with reference to the scale 6A.

[0007]

However, such a position shift measuring method can be applied to an electronic component such as a QFP in which an electrode terminal is provided outside a package for sealing a semiconductor element. It may be difficult to apply to an electronic component in which an electrode terminal is provided on the bottom surface of the package.

For example, in a BGA (ball grid array) in which a predetermined number of metal bumps are arranged in a grid pattern as electrode terminals for external connection on the back surface of the package (that is, the bonding surface with the printed wiring board), the BGA is used. When the ball electrodes formed on each electrode terminal part of the circuit board are aligned relative to the external printed wiring board, the ball electrodes that serve as the measurement reference cannot be confirmed from the outside, so the misalignment is measured. There was a problem that it was difficult to do.

As one method for solving this problem, for example, when QFP1 is used as an electronic component as shown in FIG. 5, a predetermined position corresponding to the outer shape of the package 2 of the QFP1 on the mounting surface 4A of the printed wiring board 4 is provided. Alignment mark made of silk of a predetermined shape (hereinafter,
This is referred to as a reference position mark) 7 (7A to 7D) to print a QF based on the reference position mark 7.
A method of measuring the positional deviation of P1 has been considered.

However, in the printed wiring board 4,
Since the step of printing the silk forming the reference position mark 7 and the step of manufacturing the land 5 are performed separately from each other, there is a possibility that the accuracy of the reference position mark 7 and the land 5 may not be maintained. There is a problem in that the positional deviation amount between the package 2 and the reference position mark 7 also includes an accuracy error that occurs when the printed wiring board 4 is manufactured.

Further, even if the printed wiring board 4 can be manufactured so that the precision error of the reference position mark 7 and the land 5 which occurs at the time of manufacturing the printed wiring board 4 can be zero, as in the conventional case, the QFP1 can be manufactured. There is a problem that the alignment state of the package 2 and the reference position mark 7 is read using a magnifying glass with a scale, and the complexity of measuring the relative positional deviation amount is unavoidable.

The present invention has been made in consideration of the above points, and it is an object of the present invention to propose a printed wiring board capable of facilitating the mounting position alignment of a surface mounting type electronic component with respect to the printed wiring board.

[0013]

In order to solve the above problems, according to the present invention, a reference for alignment, which is a scale, is provided on a mounting surface of a printed wiring board on which electronic components are mounted, corresponding to the outer shape of the electronic components. Provide at least two position marks.

[0014]

The amount of misalignment of the electronic component is provided by providing at least two reference position marks for alignment, which are scales, on the mounting surface of the printed wiring board on which the electronic component is mounted, corresponding to the outer shape of the electronic component. Also, the operator can easily confirm the displacement direction.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

In FIG. 1, reference numeral 10 denotes a printed wiring board, and lands (not shown) are arranged in a predetermined pattern on a mounting surface 10A of the printed wiring board 10.
The BGA 11 is mounted on the mounting surface 10A with each ball electrode terminal (not shown) of the BGA 11 aligned with the corresponding land.

The mounting surface 10A of the printed wiring board 10
In the predetermined position corresponding to the outer shape of the package of the BGA 11 in the above, unlike the conventional reference position mark 7 (FIG. 5),
Reference position mark 12 of a predetermined shape made of the same material as the land
(12A to 12D) are formed, and the operator sets B based on the reference position mark 12 (12A to 12D).
The position shift amount and the position shift direction of the GA 11 are confirmed.

In forming the reference position mark 12, the printed wiring board 10 made of, for example, a copper clad wiring board.
When using, the reference position mark 12 is formed by using the same mask as the mask for forming the land arrangement pattern.
By forming the, the reference position mark 12 can be formed of copper similarly to the land.

Here, as shown in FIG. 2, the reference position mark 12 (12A to 12D) is substantially E-shaped as a whole,
Perpendicular to the long side 12L (12AL to 12DL),
A plurality of short side portions 12S (12AS to 12DS) as scales are formed at predetermined intervals, and the plurality of short side portions 12S (12S
AS-12DS), the central short side portion is formed to be slightly longer than the other short side portions.

When the BGA 11 has a square plane as shown in FIG. 1, the mounting surface 10 of the printed wiring board 10 is
A direction indicated by an arrow x and a direction indicated by an arrow y are set as an X axis and a Y axis, respectively, and the reference position marks 12B and 12D are respectively set so that their long side portions 12BL and 12DL are parallel to the X axis. The reference position marks 12A and 12C are formed near the corners of the BGA 11, and the long side portions 12AL and 12CL are formed near the corners of the BGA 11 so that they are parallel to the Y axis.

In this case, the BGA 11 has the reference position mark 1
When the center of each of the short sides 12BS and 12DS of 2B and 12D is set as the origin, the reference position marks 12B and 12D are shifted from the origin by -1 in the X-axis direction.
When the center of each of the short sides 12BS and 12DS is set as the origin, the printed circuit board 10 is mounted on the mounting surface 10A in the state of being deviated by plus one scale in the Y-axis direction from the origin.

Specifically, the long side 1 of the reference position mark 12
The thickness of 2L and the short side 12S are each 0.2 [mm],
If the distance between the short side portions 12S of the reference position mark 12, that is, one scale is 0.3 [mm], it is measured that the BGA 11 is displaced by 0.5 [mm] in the X-axis direction and 0.5 [mm] in the Y-axis direction. To be done.

In the above structure, the printed wiring board 1
At least two reference position marks 12 having graduations at predetermined intervals are formed at predetermined positions corresponding to the outer shape of the package of the BGA 11 on the mounting surface 10A of 0. At that time, by arranging the scales of the reference position marks 12 in the directions along the edges of the BGA 11, the operator can easily confirm the displacement amount and the displacement direction of the BGA 11 based on the reference position marks 12. be able to.

Since the reference position mark 12 is made of the same material as the land, it is possible to reduce the accuracy error of the reference position mark 12 and the land that occurs when the printed wiring board 10 is manufactured. At that time, when the reference position mark 12 is formed of the same material as the land, the reference position mark 12 is formed by using the same mask as the mask for forming the land arrangement pattern. The position mark 12 can be formed in the same process as the process of forming the land array pattern.

According to the above configuration, the printed wiring board 1
Reference position mark 1 having graduations at predetermined intervals arranged in the direction along the edge of BGA 11 at predetermined positions corresponding to the outer shape of the package of BGA 11 on mounting surface 10A of 0.
By forming at least two or more 2's, the operator can easily confirm the amount of displacement and the direction of displacement of the BGA 11 based on these reference position marks 12, and thus the BGA 11 with respect to the printed wiring board 10 can be confirmed. The mounting alignment of can be facilitated.

In the above embodiment, a plurality of substantially E-shaped reference position marks 12 (12A to 12D) are formed near the corners of the BGA 11 so as to be parallel to the X axis or the Y axis. However, the present invention is not limited to this, and the operator uses the reference position mark 20 (20A, 20B) as shown in FIG.
The position deviation amount and the position deviation direction of 1 may be confirmed.

In this case, the reference position mark 20 (20A,
20B) is formed in a substantially cross shape as a whole, is made of the same material as that of the land, and has vertical and horizontal lines that are orthogonal to each other and are graduated. Further, on the printed wiring board 10, a direction indicated by an arrow x and an arrow y
When the directions indicated by are set as the X axis and the Y axis, respectively, the vertical lines and the horizontal lines of the reference position marks 20A and 20B are formed so as to be parallel to the X axis or the Y axis, respectively.

Here, the reference position marks 20A and 20B
Since it is possible to display the positional deviation amounts of the BGA 11 in the X-axis direction and the Y-axis direction respectively, it is not necessary to form them in the vicinity of all the corners of the BGA 11, and they may be formed in the vicinity of two diagonal corners of the BGA 11. As described above, in the reference position mark 20 as well, by arranging the scales of the reference position mark 20 with the X axis and the Y axis as references,
The operator can easily confirm the amount of displacement and the direction of displacement of the GA 11.

Incidentally, the reference position mark may have various shapes and scales other than the reference position marks 12 and 20. In short, the reference position mark may be the mounting surface 10A of the printed wiring board 10. Various types can be applied as long as the operator can confirm the displacement amount and displacement direction of the BGA 11 based on the reference position mark when the BGA 11 is formed at a predetermined position corresponding to the outer shape of the package of the BGA 11. .

In the above embodiment, the BGA11
The printed wiring board 1 shows a case where the plane of is a square.
The X axis and the Y axis are set on the mounting surface 10A of 0, and the reference position marks 12, 20 are set with the X axis and the Y axis as references, respectively.
However, the present invention is not limited to this and, for example, when the plane of the BGA is a polygon other than a square and a rectangle, the mounting surface 10A has an X mark.
The scales of the reference position marks may be arranged in the direction along each edge of the polygonal BGA without setting the axis and the Y axis.

[0031]

As described above, according to the present invention, in a printed wiring board on which a surface mount type electronic component is mounted, the outer shape of the electronic component is mounted on the mounting surface of the printed wiring board on which the electronic component is mounted. By providing at least two reference position marks for alignment, which correspond to the above, the operator can easily confirm the amount of displacement and the direction of displacement of the electronic component. As a result, the printed wiring board On the other hand, the mounting position of the surface mount type electronic component can be easily adjusted.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of the configuration of a printed wiring board according to the present invention.

FIG. 2 is a plan view showing a configuration of a reference position mark shown in FIG.

FIG. 3 is a plan view showing the configuration of a printed wiring board according to another embodiment.

FIG. 4 is a plan view showing a configuration of a conventional printed wiring board.

5 is a plan view showing a configuration of a reference position mark shown in FIG.

[Explanation of symbols]

4, 10 ... Printed wiring board, 5 ... Land, 7, 1
2, 20 ... Reference position mark, 11 ... BGA.

Claims (4)

[Claims] 1. A printed wiring board adapted to mount a surface mount type electronic component, wherein a mounting surface on which the electronic component is mounted corresponds to an outer shape of the electronic component and is used as a scale for alignment. A printed wiring board having at least two reference position marks. 2. The printed wiring board according to claim 1, wherein the reference position mark is made of the same material as the wiring pattern formed on the mounting surface. 3. The printed wiring board according to claim 1, wherein the scales of the reference position marks are arranged in a direction along an edge of the electronic component. 4. The printed wiring board according to claim 1, wherein the reference position mark is provided corresponding to two diagonal corners of the electronic component on the mounting surface.