JP2006210779A - Board assembly - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a board assembly in which a cost is not increased, an attachment operation is easy and a high reliability of a terminal joining part is obtained. <P>SOLUTION: A first printed wiring board (50F) having a first land (12a) and a plurality of holes (13) is integrated with a second printed wiring board (50R) having a second land (2a) and a plurality of chips (3), by electrically connecting the first land (12a) to the second land (2a). At least two of the plurality of holes (13) are fitted into two of the plurality of chips, and the side face (3h) or the corner (3a) of the side of the fitted chips is abutted on or almost abutted on an inner face of the opposing hole. A location of the first printed board for the second printed board is controlled in two directions (D1, D2) (S1, S2) which are mutually opposite directions along a surface of the first printed board. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a board assembly, and more particularly to a board assembly in which a printed board having a plurality of holes is attached to and integrated with a printed board on which a plurality of chip components are mounted.

Conventionally, in an electronic device, a printed circuit board (for example, a flexible printed circuit board) is attached to a member such as a rigid wiring board on which chip components and the like are mounted at high density, and the pattern between the two is electrically connected via a connection terminal. A structure to connect is often used.
As an example of a structure in which both members are assembled with good positional accuracy to form an assembly, there is a structure described in Patent Document 1.
This is a structure in which a flexible printed circuit board is attached to the main body of a device such as a camera. A locking pin for positioning is provided on the main body of the apparatus, a through hole is formed in the flexible printed circuit board, and the locking pin is inserted into the through hole. Thus, the positioning is performed.

As another example, in Patent Document 2, a member to be attached to which a flexible printed board is attached is a printed board, and a connection terminal of the attached member and a connection terminal of the flexible printed board are soldered together. The mounting stage is provided with a positioning pin having a substantially C-shaped cross section with a part thereof omitted, and the hole of the mounted member is engaged with this pin, and the C-shaped missing There is described a structure in which a corner portion of a flexible printed circuit board is brought into contact with a portion to position both members via this pin to form an assembly.
Japanese Patent Laid-Open No. 2-54986 Japanese Patent Laid-Open No. 5-183021

Meanwhile, there is a strong demand from the market for downsizing and cost reduction of electronic devices on which printed circuit boards are mounted. In order to meet this demand, it is necessary to make the printed circuit board and the mating member to which it is attached as small as possible.
In other words, the wiring density and the component mounting density are also increased.
In addition, it is necessary to simplify the manufacturing process and manufacturing equipment as much as possible to reduce the man-hours and costs.

However, in the conventional board assembly described in Patent Document 1, a locking pin for positioning must be provided on the attached member, which hinders space saving in the attached member and increases the cost. There was a problem.
In addition, the conventional substrate assembly described in Patent Document 2 has a problem that the cost is increased because a specially shaped pin is provided on the stage for mounting.
In addition, after positioning the board by engaging the two boards, it is necessary to remove the board from the pin (stage), which is not easy and requires extra man-hours and increases costs. It was.
Furthermore, at the time of removal, there is a case where a hole is caught on the pin and it is difficult to come off and a load is applied to the joint. Therefore, there is a possibility that bonding failure may occur at the terminal bonding portion, and there is a problem that high reliability is difficult to obtain.

  Therefore, the problem to be solved by the present invention is to provide a board assembly that does not increase the cost, is easy to mount, and provides high reliability of the terminal joint.

In order to solve the above problems, the present invention has the following configuration as means.
[1] That is, the substrate assembly of the present invention includes a first printed board (50F) having a first land (12a) and a plurality of holes (13), a second land (2a), and a plurality of A board assembly (50) comprising a second printed circuit board (50R) having a chip part (3) and an integrated connection by electrically connecting the first and second lands (12a, 2a). There,
Two of the plurality of chip components (3) are fitted in at least two of the plurality of holes (13), respectively, and the side surface (3h) or side of the fitted chip component (3) is formed. The corner (3a) of the portion and the inner surface of the hole (13) facing the corner (3a) are brought into contact or substantially in contact with each other, and the position of the first printed circuit board (50F) with respect to the second printed circuit board (50R) It is characterized by being restricted in two directions (D1, D2) (S1, S2) opposite to each other along the surface of the first printed circuit board (50F).
[2] The board assembly according to [1], wherein the first printed board (50F) or the second printed board (50R) is a flexible printed board.

  According to the present invention, in the board assembly in which the first printed board is assembled to the second printed board on which the chip component is mounted, the cost is not increased, the mounting operation is easy, and the terminal joint is highly reliable. The effect that is obtained.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to FIGS.
FIG. 1 is a plan view for explaining a first embodiment of a board assembly of the present invention and a printed board used therefor.
FIG. 2 is a plan view showing Embodiment 2 of the substrate assembly of the present invention.
FIG. 3 is a plan view showing Embodiment 3 of the substrate assembly of the present invention.
FIG. 4 is a view showing a main part in another embodiment of the substrate assembly of the present invention.

<Example 1>
The board assembly 50 according to the first embodiment includes a rigid board 50R on which chip components are mounted and a flexible printed board 50F, which will be described with reference to FIGS. 1C, 1A, and 1B.

As shown in FIG. 1A, the rigid substrate 50R is composed of a rigid base 1 on which a pattern 2 is formed. For example, epoxy can be used as the material of the substrate 1.
A part of the pattern 2 is a soldering land 2a exposed on the surface, and the other part is covered with an insulating layer 1a. The land portion 2a is formed in a rectangular shape whose longitudinal direction is the vertical direction of the figure.
A plurality of chip components 3 are mounted in the vicinity of the land 2a. In this example, two lands 2a and two chip components 3 are provided.

As shown in FIG. 1B, the flexible printed circuit board 50F is made of a polyimide base 11 having a pattern 12 and having flexibility. The thickness of this base 11 is 50-200 micrometers as an example.
A part of the pattern 12 is a connection soldering land portion 12a exposed on the surface (the side opposite to the paper surface of FIG. 1B), and the other portion is covered with an insulating layer 11a.
The two land portions 12a are provided at intervals corresponding to the two land portions 2a of the rigid substrate 50R.
The base 11 has two elongated round holes 13 which are fitting holes for the chip component 3. The oblong hole 13 is formed so that the width Wf thereof is substantially the same as the interval Wr between the opposing sides of the chip component 3 of the rigid substrate 50R, and the two are engaged with each other without play. It is provided corresponding to.

In order to engage the two without any play, the side surface 3h of the chip part 3 and the inner surface of the oblong hole 13 opposed thereto are brought into contact with each other, or a substantially contacted state having a slight gap is made. The dimensions are set.
The relative positional relationship between the oblong hole 13 and the land portion 12a is the same as the relative positional relationship between the chip component 3 and the land portion 2a of the rigid substrate 50R. The land portion 2a and the land portion 12a are formed such that a part of the land portion 2a and the land portion 12a overlap each other when the chip component 3 of the rigid substrate 50R is fitted into the elongated circular hole 13 of the flexible printed circuit board 50F. Yes.
By this fitting, the position of the flexible printed board 50F is accurately regulated with respect to the rigid board 50R in the D1 direction which is the vertical direction in FIG. 1 and the D2 direction opposite thereto. Similarly, the position is also restricted in the S1 direction which is the left-right direction in FIG. 1 and the S2 direction opposite to this.

As shown in FIG. 1C, the board assembly 50 fits the chip component 3 of the rigid board 50F into the elongated round hole 13 of the flexible printed board 50F, and then the land portions 12a of the boards 50F and 50R. , 2a is heated and melted to join the two at the joint 14 (shaded portion in the figure) where the two overlap each other, whereby the pattern 2 of the flexible printed board F and the pattern 12 of the rigid board 50R are joined together. It is formed by electrical connection.
The two substrates 50R and 50F may be pressed by a pressing jig (not shown) so that the two substrates 50R and 50F are in close contact with each other at the time of heat bonding, and both the substrates are bonded with a double-sided tape (not shown) interposed therebetween. You may make it do.

The variation in position due to the mounting accuracy of the chip component 3 is normally suppressed within ± 0.15 mm.
Therefore, if the size of the land portions 2a and 12a is about 1 mm square, it is possible to eliminate the influence of mounting variations of chip components.

<Example 2>
In the first embodiment described above, the longitudinal direction of the elongated round hole 13 of the flexible printed board 50F is drilled in a direction orthogonal to the longitudinal direction of the land portions 2a and 12a (vertical direction in FIG. 1). You may drill so that the longitudinal direction of the hole 13 may correspond with the longitudinal direction of land part 2a, 12a.
At that time, the longitudinal direction of the chip component may be matched.
A substrate assembly 50A configured in this manner is shown in FIG.

When the elongated round hole 13 and the chip part 3 are fitted, the backlash in the width Wf direction of the elongated round hole 13 is less than that in the longitudinal direction, so that the shift in the short direction of the land portions 2a and 12a to be joined is reduced. be able to.
That is, by this fitting, the position of the flexible printed board 50F is accurately regulated with respect to the rigid board 50R in the S1 direction which is the left and right direction in FIG. 2 and the S2 direction opposite thereto. Similarly, the position is also restricted in the D1 direction which is the vertical direction in FIG. 2 and the D2 direction opposite to this.
Therefore, both the land portions 2a and 12a are reliably soldered at the joint portion 14 and the reliability is improved.
Therefore, this example is particularly suitable when a high-density pattern layout is performed by narrowing the interval d between the land portions.

<Example 3>
Next, a substrate assembly 50B including two sets G1 and G2 in which the longitudinal directions of the elongated hole 13 and the chip part 3 are orthogonal to each other is shown in FIG.
In this case, in addition to the vertical direction of FIG. 3, the play in the left-right direction is reduced, and the positional deviation of the land portions 2a, 12a can be further reduced.
That is, by this fitting, the position of the flexible printed board 50F is accurately regulated with respect to the rigid board 50R in the D1 direction which is the vertical direction in FIG. 3 and the D2 direction opposite thereto. Similarly, the position is also regulated with high accuracy in the S1 direction which is the left-right direction in FIG. 3 and the S2 direction opposite thereto.
Therefore, the two land portions 2a and 12a are more reliably soldered at the joint portion 14 and the reliability is further improved.
Therefore, this example is particularly suitable for realizing an ultra-high-density pattern layout by reducing the area of the land portion itself.

  In the third embodiment, as long as the long round hole 13 and the chip component 3 fitted to the long hole 13 are combined, it is sufficient to have at least two sets G1 and G2 whose longitudinal directions are substantially orthogonal. It goes without saying that the longitudinal direction of G1 and G2 and the longitudinal direction of the land portions 2a and 12a do not have to coincide with each other.

In each of the above-described embodiments, the hole 13 into which the chip component 3 is fitted is an elongated hole, and the opposite side 3h of the chip component 3 is used as a positioning reference. However, as shown in FIG. Not only the round hole but also the round hole 13a may be used, and the corners 3a at the four corners of the side of the chip component 3 may be used as a positioning reference.
Further, the size of the fitting hole 13 may be set so that the chip part 3 is press-fitted. In this case, a radial slit (cut) SL that facilitates press-fitting may be formed around the fitting hole 13 (see FIG. 1C).
In the case of press-fitting, temporary fixing can be reliably performed without bonding the flexible printed circuit board 50F and the rigid circuit board 50R, so that pressing and bonding at the time of heat bonding are not required.

According to each embodiment described above, it is not necessary to provide a pin or the like for positioning, so that the cost is not increased and the space to be attached (rigid board in the above-described embodiments) can be saved.
In addition, the chip component has an advantage that the external dimensions are standardized with respect to other electronic components, the variation in the size is small, and the variation in the position after mounting can be suppressed small. Since each embodiment uses such a chip component for positioning of the flexible substrate, its positioning accuracy is very good.
Further, since there is no need to provide positioning pins or the like on the stage during assembly (attachment), there is no increase in cost of the assembly equipment.
In addition, once the chip component is fitted into the fitting hole, the two substrates are not separated thereafter. Therefore, the operation is very easy and the cost is not increased. In addition, since no load due to separation is applied to the solder joint, no poor bonding of the land joint occurs, and extremely high reliability is obtained.

The embodiment of the present invention is not limited to the configuration and procedure described above, and it goes without saying that modifications may be made without departing from the scope of the present invention.
The hole into which the chip component is fitted is not limited to an oblong hole or a round hole, and the shape of the hole is not limited.
Further, the number of chip parts used for fitting for positioning is not limited to two, and may be three or more. Needless to say, the larger the number, the more backlash is absorbed and the variation in the relative positions of the two substrates decreases.
Further, the number of land portions to be soldered is not limited to two and may not be adjacent to each other.

The substrate constituting the substrate assembly is not limited to a flexible substrate and may be a rigid substrate. Moreover, the member is not limited to a planar substrate, and may be a member on which a chip component is mounted by printing a wiring pattern on the surface of a three-dimensional resin molded product, for example.
A chip component used for fitting for positioning may be a dummy chip that does not constitute a circuit and is mounted on a substrate for positioning.
In this case, it can be mounted on the substrate in the same process as other chip components, and there is no need to newly increase the process.
Of course, it is most desirable that the chip component used for the fitting is a chip component constituting a circuit formed on the mounted substrate.

  Moreover, the printed circuit board integrated by solder bonding is not limited to one that is directly solder-bonded between lands. For example, an electronic component may be mounted so as to straddle both, and a terminal of the electronic component and each land may be soldered.

It is a top view explaining Example 1 of the board assembly of the present invention, and a printed circuit board used therefor. It is a top view which shows Example 2 of the board | substrate assembly of this invention. It is a top view which shows Example 3 of the board | substrate assembly of this invention. It is a figure which shows the principal part in the other Example of the board | substrate assembly of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base 1a Insulating layer 2 Pattern 2a Land part 3 Chip part 3a (Reference) corner 3h (Reference) side 11 Base 11a Insulating layer 12 Pattern 12a Land part 13 Long round hole (fitting hole)
13a Round hole (fitting hole)
14 Junction 50, 50A, 50B Board assembly 50F Flexible printed circuit board (first board)
50R rigid board (second board)
G1, G2 assembly Wf (long round hole) width Wr (chip part) side spacing

Claims (2)

A first printed circuit board having a first land and a plurality of holes;
A board assembly comprising a second printed circuit board having a second land and a plurality of chip parts, wherein the first and second lands are electrically connected and integrated.
Two of the plurality of chip parts are respectively fitted to at least two of the plurality of holes,
The corners of the side surface or the side portion of the fitted chip component and the inner surface of the hole facing the chip component are brought into contact or substantially in contact with each other, and the position of the first printed circuit board with respect to the second printed circuit board is set to the first printed circuit board. A substrate assembly characterized by being regulated in two directions opposite to each other along the surface of the printed circuit board.   The board assembly according to claim 1, wherein the first printed board or the second printed board is a flexible printed board.

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