JPH0476932A - Electronic component mount board using film base - Google Patents

Abstract

PURPOSE:To prevent the problem such as creases, cracks, or peeling from arising in a die even when the film base is repeatedly wound around a reel, for example by forming a die pad in a state that one of its diagonals is almost orthogonal to the longitudinal direction of the film base. CONSTITUTION:In an electronic component mount board 10, one diagonal 13 of a die pad 12 is almost orthogonal to the feed direction of film base 11. Therefore, when substrates 10 are wound one after another around a reel or around the substrate 10 or the base 11, a square-shaped die pad 12 is located on the reel or on the already wound substrate 10 or the base 11 in the order of one apex 12a, two diagonal apexes 12b, and the remaining apex 12a. This acts to disperse force received upon winding or the like so that the problem such as creases, cracks, or peeling can be prevented from arising in a die pad even when the base is repeatedly wound around a reel.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to an electronic component mounting board for mounting electronic components, and in particular an electronic component mounting board using a flexible film base material as an insulating base material. The present invention relates to a board for mounting components.

(Prior art) In order to continuously form large quantities of electronic component mounting boards for constructing watches, so-called IC carts, etc., the insulating base material is made of long lengths such as epoxy glass tape. It is constructed using a so-called film base material having flexibility, and as shown in FIG. 1 or 3, it is constructed continuously. The electronic component mounting board using such a film base material is prepared by cutting the film base material into individual pieces by cutting a predetermined portion of the film base material, etc., as shown in FIG. The base material is wound onto a reel (30) or
) while performing various operations such as conductor circuits, plating, and mounting electronic components.

In other words, in this type of electronic component mounting board, after electronic components are mounted and molded with sealing resin, the film base material that makes up the board is processed before being made into individual products. The reel (30) is wound and rewound many times. Such operations such as winding and bending have the following negative effects on the mounting portion for electronic components and conductor circuits located in the vicinity thereof. There are typically two types of mounting parts: an opening formed in the film base material itself, and one formed by a metal foil integrated on the film base material. Below, each case will be explained separately. .

When an opening formed in the film base material (11) itself is used as the mounting part, as shown in FIG. 3, this opening is formed as a square to match the square shape of the electronic component. The conductor circuit (11) formed on the film base (11) is placed inside this opening.
4), the inner leads (finger leads) are formed in a protruding state. This opening was generally constructed by sides parallel to the longitudinal direction (transportation direction) of the film base material (11) and sides perpendicular thereto.

A film base material (
When forming a conductor circuit (14) etc. on the 11) or mounting an electronic component (2) on the mounting part, as mentioned above, a reel such as the one shown in Fig. 4 is used. The film base material (11) is wound around (30) or unwound, but at this time stress tends to concentrate on the metal foil laminated on the opening before forming the inner lead. Distortion occurs in the foil above the square opening.Furthermore, even after the inner lead is formed, the stress concentrated on the opening causes distortion in the lead.

This distortion has an adverse effect on the mounting of the electronic component (20) in that the work cannot be carried out reliably. In particular, if the inner lead is bent and bent after forming the inner lead, the electronic component (20) to be mounted on the conductor circuit (14) formed on the film base material (11) may
) may change slightly, making implementation difficult.

On the other hand, in the case where a mounting part (12) made of metal foil is formed instead of an opening on the film base material (11), the negative side of the mounting part (12) is Generally, a mounting part (12) made of metal foil is also used, but when the film base material (11) is hung on the reel (30), The following inconveniences may occur. The metal foil that becomes the mounting part (12) can be plated using anchors formed on the back side of the film base material (11) itself, or it can be formed as a foil in advance and then integrated with a simple adhesive. In any case, when the film base material (11) is wound around the reel (30), creases or dents may occur in the metal foil that forms the mounting portion (12). be.

Examining the cause of creases and dents in this square metal foil, we found that the - pair of sides is parallel to the conveyance direction of the film base material (11), so stress concentration occurs on the - side. This is thought to be due to what happens.

The reason is that the film base material (11
), this force is applied evenly to any part of the metal foil constituting the mounting portion (12), and the film base material (11) itself has a bending force for winding. This is thought to be due to tension,
In particular, the negative side of the mounting part (12) is the film base material (11).
If it is parallel to the conveying direction of the film base material (11
This is because the above-mentioned folds are considered to be formed in a state perpendicular to the transport direction of the film base material (11) because the force received from the film base material (11) cannot be released. Therefore, the mounting portion (12) made of metal foil will have creases, and in some cases, the mounting portion (12) may partially peel off from the film base material (11). There is.

In particular, the more the film base material (11) is wound around the reel (30), the more the above phenomenon becomes more noticeable.

Therefore, the inventors of the present invention have proposed that the mounting portion (12) made of an opening in the film base material (11) itself or a metal foil integrated on the film base material (11),
) is wound on the reel (30), this mounting part (12
) The present invention was completed as a result of various studies on what should be done to prevent adverse effects such as creases from appearing on the paper.

(Problems to be Solved by the Invention) The present invention has been made based on the above circumstances, and the problem to be solved is to wind a film base material (11) around a reel (30). This is an adverse effect such as creases caused by

The purpose of the present invention is to provide a film base material (
A simple configuration of an electronic component mounting board (10) that can prevent problems such as creases, cracks, or peeling from occurring in the mounting part even when the electronic component mounting board (11) is repeatedly wound around a reel (30). It is provided by.

(Means for Solving the Problems) In order to solve the above problems, the means taken by the present invention are as follows:
To explain with the reference numerals used in the examples, ``a long and flexible film base material (11) is continuously formed to take out a large number of pieces, and the film base material (11 ) or film base material (11
) In an electronic component mounting board (lO) having a rectangular mounting portion (12) made of metal foil integrated on top of the electronic component (20), the mounting portion (12) is placed along its diagonal line ( 13) is an electronic component mounting substrate (10)J characterized in that it is formed in a state substantially orthogonal to the longitudinal direction of the film base material (11).

(Operation of the Invention) The operation of the electronic component mounting board (10) according to the present invention configured as described above will be explained with reference to FIGS. 1 and 2.

First, as shown in FIG. 1, the electronic component mounting board (10) according to the present invention is formed as a series of many parts before being cut out into individual parts. be. In other words, this electronic component mounting board (1
The film base material (11) constituting the film base material (11) is long so that a large number of electronic component mounting substrates (lO) can be constructed.
) itself has flexibility so that it can support a large number of electronic component mounting boards (lO) in a continuous state and wind and unwind it onto a reel (30) as shown in Figure 4. It is something. Therefore, for each electronic component mounting board (10),
By means of a conveying device having a reel (30) schematically shown in FIG. 4, it is possible to continuously convey the material while winding it around the reel (30).

In addition, when looking at one electronic component mounting board (lO) individually, as shown in Figures 1 and 2, the mounting part (lO) is
Since one diagonal line (13) of 2) is approximately perpendicular to the conveying direction of the film base material (11), this electronic component mounting board (lO) is on the reel (30) or has already been placed on the reel (30). When the electronic component mounting board (10) or the film base material (11) is wound on the reel (30), the square mounting part (12) has one top part (12a). ) The two diagonal tops (12b) and the remaining one top (12a) are located on the reel 30) or on the electronic component mounting board (10) or film base material (11) that has already been wound. I'm going to go.

In other words, in the case of the conventional mounting section (12), the front two tops (12a) are placed on the electronic component mounting board (10) or the film base material (11), and then the back two tops (12a) are placed on the electronic component mounting board (10) or the film base material (11).
) are positioned twice at the same time, but in the electronic component mounting board (10) according to the present invention, they are positioned three times.

In other words, whether it is a square opening formed in the film substrate (11) itself or a square metal foil integrated onto the film substrate (11), the film substrate (11) is loaded with Even if a different part (12) is formed, the top part (12a) or diagonal top part (12b) of this mounting part (12) is such that one diagonal line (13) of the mounting part (12) is a film base. Since the film is arranged in a state substantially perpendicular to the conveying direction of the material (11), the force applied during winding etc. acts to be dispersed toward the film base material (11). As a result, if the mounting part (12) is open, the inner lead will not be distorted, and if the mounting part (12) is made of metal foil, the mounting part (12) will not break. It will not peel off.

In particular, when the mounting portion (12) is an opening formed in the film base material (11), the stress that would otherwise be concentrated on the top portion (12a) located on the left or right side of FIG. They end up being dispersed within the film base material (11) by the edges of the film base material (11) that constitute the two sandwiched sides. Then, almost simultaneously, the two diagonal apexes (1
2b) is placed on the reel (30) or the film base material (11), the bending force applied to the mounting portion (12) will momentarily concentrate on each top portion (12a); After passing the apex (12a), each force transfers to the next apex (12a).
Since it is again dispersed to the film base material (11) side by the two sides sandwiching a), no distortion is caused in the inner lead corresponding to each top (12a) or diagonal top (12b) in any case. be.

In addition, when the mounting part (12) is a metal foil formed on the film base material (11), the top of this mounting part (12) (
12a) or the diagonal apex (12b) is dispersed to the mounting part (12) and the film base material (11) side, so that the mounting part (12) may be folded or the mounting part may be bent. Part (12) is the film base material (1
1) There is no possibility of partial peeling.

(Example) Next, an electronic component mounting board (10) according to the present invention will be described according to an example shown in the drawings.

FIG. 1 shows an electronic component mounting board (10) according to the present invention.
The electronic component mounting substrate (10) is shown in a state before it is made into individual pieces, and these electronic component mounting substrates (10) are continuously formed from a long and flexible film base material (11). It is something. On this film base material (11), there are a plurality of pads (15) formed by pasted metal foil or plating.
), and each of these pads (15) is electrically integrated with a conductive circuit (14) or a plating lead. Then, the film base material (
11), as shown by the dotted line in FIG. 1, a substantially rectangular opening is formed in which the electronic component (20) is inserted and mounted on the pad (15), and the electronic component (20) is exposed through this opening. The pad (15) is used as the mounting portion (12).

As mentioned above, the mounting part (12) in this example is a substantially rectangular opening formed in the film base material (11). It may be made of metal foil or plating.

In that case, it is formed independently with a blind lead at the position indicated by the dotted line in FIG.

The reason why the conductor circuit (14), pad (15), or mounting part (12) is connected with a plating lead is because it is necessary when applying various types of plating to the surfaces of these pads (15), etc. This lead is cut when each electronic component mounting board (10) is separated individually, and as a result, the electronic component mounting board (10)
After completion, each pad (15) etc. is made electrically independent.

Since each mounting portion (12) is approximately square in shape, two diagonal lines (13) can be considered, and one of these diagonal lines (13) is defined as shown in FIG. As shown in FIG. 2, the film base material (11) is placed in a state substantially perpendicular to the transport direction. The substantially orthogonal state means that when the diagonal tops (12b) located at both ends of the corresponding diagonal (13) are wound around the reel (30), the film base material (11) is in a substantially orthogonal state.
) or on the already wound film base material (11), and for that purpose, this diagonal line (13) with respect to the line orthogonal to the transport direction of the film base material (11) It is sufficient that the inclination angle is within a range of about 0 to 5 degrees.

In this embodiment, since each pad (15) is also formed as a square shape, each pad (15) is
The above-mentioned problem with the mounting part (12) may also occur in 5), but each of these pads (15) is smaller than the mounting part (12), and one diagonal line of each pad (15) is smaller than the mounting part (12). Since the pads (12) are in a nearly parallel state, problems such as peeling and bending do not occur in each of these pads (15). In order to completely avoid this problem, the shape of each pad (15) should be similar to the mounting part (12), so that one of its diagonals is completely parallel to the diagonal (13) of the mounting part (12). All you have to do is make it so that

(Effects of the Invention) As detailed above, in the present invention, as exemplified in the above embodiment, "a long and flexible film base material (11) is used to produce a large number of pieces. The openings formed in the film substrate (11) or the film substrate (11) are continuously formed.
) In an electronic component mounting board (10) having a rectangular mounting portion (12) made of metal foil integrated on top of the electronic component (20), the mounting portion (12) is placed along its diagonal line ( 13) is formed in a state substantially perpendicular to the longitudinal direction of the film base material (11).
Provided is a substrate for mounting electronic components (10) with a simple configuration that can prevent problems such as creases, cracks, or peeling from occurring in the mounting portion even when the electronic component is repeatedly wound around a reel (30). It is possible.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a state in which a large number of electronic component mounting boards according to the present invention are arranged in series, FIG. 2 is a partially enlarged plan view for explaining the action of the mounting portion on the electronic component mounting board, and FIG. 3 4 is a plan view showing a conventional electronic component mounting board, and FIG. 4 is a partially enlarged front view showing a device for winding and transporting a film base material. Explanation of symbols 10...Substrate for mounting electronic components, 11...Film base material, 12...Mounting part, 12a...Top part, 12b...
・Diagonal top, 13... Diagonal, 14... Conductor circuit, 15... Pad, 20... Electronic component, 30...
reel. that's all

Claims (1)

[Scope of Claims] A long and flexible film base material is used to continuously form a large number of pieces, and an opening formed in the film base material or integrally formed on the film base material. In a board for mounting electronic components, which has a rectangular mounting section for mounting an electronic component, the mounting section is made of metal foil, and one of the diagonals of the mounting section is substantially perpendicular to the longitudinal direction of the film base material. 1. A substrate for mounting electronic components, characterized in that it is formed in a state in which: