JPH05327170A - Mounting of component and printed-wiring board for terminal connection conversion use - Google Patents

Abstract

PURPOSE:To improve a working efficiency in the case where surface mounting components, which are different from each other in the arrangement of terminals, are mounted and to lessen a possibility of the generation of an electrical fault, such as noise, by a method wherein first pads are reflow-soldered to the pads of a printed-wiring board, while the second surface mounting component of the components is soldered to second pads. CONSTITUTION:A creamy solder 44 is fed to each pad 12a forming a group of pads on a printed-wiring board 16 and pads 34a on the lower surface of a printed-wiring board 30 are superposed on the pads 12a. A heater chip 48 of a reflow soldering device 46 is pressed from over pads 36a on the surface of the board 30 and the pads 34a are reflow-soldered to the pads 12a. After the printed-wiring board 30 for terminal connection conversion use is soldered on the board 16, an IC 20 is mounted on the surface of the board 30. That is, after a creamy solder 50 is fed to the pads 36a on the upper surface of the board 30, terminals 20a of the IC 20 are placed on each pad 36a, the chip 48 is pressed and the terminals 20a are reflow-soldered to the pads 36a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for mounting surface mount components having different terminal arrangements on a printed wiring board and a printed wiring board for terminal connection conversion used for implementing this method.

[0002]

2. Description of the Related Art Even though they are surface mount components such as ICs having almost the same function, the terminal arrangement may differ depending on the manufacturer. When there are parts having different terminal arrangements as described above, there arises a problem that a printed wiring board made to mount parts of a certain manufacturer cannot mount parts of another manufacturer.

Therefore, conventionally, when components having the same terminal arrangement pitch are used, after manually cutting a part of the circuit pattern of the printed wiring board, components having different terminal arrangements are mounted on the printed wiring board. After that, the pads to which the terminals of the parts were soldered were connected to the separated circuit patterns by jumper wires.

FIG. 6 is an explanatory view of a step of mounting a surface mounting IC on a printed wiring board having a suitable terminal arrangement, and FIG. 7 is an explanatory view of a step of mounting a surface mounting IC having a different terminal arrangement on this printed wiring board. Is.

In FIG. 6, reference numeral 10 is an IC as a first surface mounting component, which is, for example, a mini flat type.
Reference numeral 12 denotes a pad group (first pad group) of the printed wiring board made for this IC 10. That is, the pad group 12 is formed of a large number of pads 12a corresponding to the terminals 10a of the IC 10. Each pad 12a is connected to an appropriate printed wiring circuit pattern 14.

The IC 10 has its terminals 10a aligned with the corresponding pads 12a as shown in FIG.
Soldering is performed as shown in FIG. For example, after supplying cream solder to each pad 12a, the terminals 10
It is soldered by a known reflow soldering method in which a is temporarily fixed to this cream solder and the whole is put in a reflow furnace to melt the cream solder. FIG. 6C is a side sectional view of this soldered state, and in this figure, 16 shows a printed wiring board.

The pad group 12 of the printed wiring board 16
A second surface mount component IC2 having a different terminal arrangement
When mounting 0 (see FIG. 7B), first,
As shown in (A), a predetermined printed wiring circuit pattern 1
A cut 22 is manually inserted in 4 using a cutter or the like. Then, after the IC 20 is soldered to the pad group 12 by a reflow soldering method or the like, a predetermined terminal 22a is connected to a circuit pattern (not shown) by using a jumper wire 24 by a manual soldering method.

[0008]

2. Description of the Related Art As described above, it is necessary to manually make a cut 22 in the circuit pattern 14 of the printed wiring board 16 or solder the jumper wire 24. there were.

Since the jumper wire 24 is routed over the other circuit pattern 14, crosstalk between signals may occur depending on the length and route of the jumper wire 24, especially in the case of a high frequency circuit. There was a risk of electrical disturbance such as noise.

Further, the terminal 2 of the IC 20 which is the second component
There is also a problem that the conventional method cannot be used when the pitches and the numbers of 2a are different.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and when mounting surface-mounted components having different terminal arrangements, work efficiency is improved, and electrical trouble such as noise may occur. It is a first object of the present invention to provide a component mounting method that reduces the number of components and that enables components with different terminal pitches and numbers to be mounted. A second object is to provide a printed wiring board for terminal connection conversion used for mounting this method.

[0012]

According to the present invention, this first object is
In a component mounting method for mounting a second surface mounting component having a different terminal arrangement on a printed wiring board having a pad group for mounting the surface mounting component, a first group corresponding to the pad group of the printed wiring board. And a second pad group for mounting the second surface mount component are formed on each surface, and a printed wiring for terminal connection conversion in which the corresponding pads of the first and second pad groups are connected to each other. A board is prepared, and the printed wiring board for terminal connection conversion is positioned between the pad group of the printed wiring board and the pad group of the printed wiring board and is interposed between the printed wiring board and the second surface mount component.
Is soldered to the pad of the printed wiring board while the second surface mount component is soldered to the second pad.

The terminal connection conversion printed wiring board substrate is used as a heat-resistant file, and after reflow soldering to the printed wiring board with a heater chip, the second mounting portion is further reflow soldered. Is desirable.

A second object is to form a first pad group formed on one surface of the substrate and having a terminal arrangement symmetrical with the terminal arrangement of the first surface mount component, and formed on the other surface of the substrate. A printed wiring circuit for mutually connecting a second pad group having a terminal arrangement of a second surface mounting component having a terminal arrangement different from that of the first surface mounting component and corresponding pads of the two pad groups to each other. And a printed wiring board for terminal connection conversion. The substrate used here is preferably a resin film such as polyimide having high heat resistance.

[0015]

1 is a view showing the front surface of an embodiment of the present invention, FIG. 2 is a view showing the back surface thereof, and FIG. 3 is a view showing the conversion path of its terminal arrangement.

In FIGS. 1 and 2, reference numeral 30 is a printed wiring board for terminal connection conversion according to the present invention, which has a substrate 32 made of a polyimide resin film. On the back surface of the substrate 32, as shown in FIG. 2, a first pad group 34 including pads 34a which are plane-symmetrical to the terminal arrangement of the IC 10 which is the first component is formed. Further, as shown in FIG. 1, a second pad group 36 including pads 36a corresponding to the terminals 20a of the IC 20 which is the second component is formed on the surface of the substrate 32.

Each pad 34 of the first pad group 34 on the back surface
a is a corresponding pad 36 of the second pad group 36 on the surface.
They are connected to each other by a printed wiring circuit 38. The printed wiring circuit 38 includes circuit patterns 40 and 42 and through holes A to F formed on the front and back of the substrate 32.

The numeral 1 attached to the outside of the frame of the substrate 32 in FIGS.
The numbers 14 to 14 represent terminal numbers, and in this embodiment, the terminal connections are converted as shown in FIG. For example, the pad 34a of the terminal 2 on the back surface is connected to the pad 36a of the terminal 3 on the front surface through the through hole A. These circuit patterns 4
0 and 42 are formed together with the pads 34a and 36a by a known printed circuit board manufacturing method.

This printed wiring board 30 is used as shown in FIG. First, the printed wiring board 1 shown in FIG.
The cream solder 44 is supplied to each pad 12a forming the pad group 12 of No. 6 and the pad 34a on the lower surface (back surface) of the printed wiring board 30 is overlaid (FIG. 4A). Then, the heater chip 48 of the reflow soldering device 46 is pressed from above the pad 36a on the surface for reflow soldering (FIG. 4 (B)). The heater chip 48 controls the heating temperature by controlling the current flowing therethrough.

After soldering the terminal connection conversion printed wiring board 30 to the printed wiring board 16 in this manner, I
C20 (see FIG. 7) is mounted on the surface of the printed wiring board 30. That is, after supplying the cream solder 50 to the pads 36a on the upper surface (front surface) (FIG. 4C), the terminals 20a of the IC 20 are placed on the respective pads 36a, and the heater chip 48 is placed.
Press for reflow soldering (FIG. 4 (D)). As a result, the connection of the pad 12a is converted into 36a by way of the wiring board 30, and the second component IC20 can be mounted in place of the IC10 which is the first component for the pad group 12 of the printed wiring board 16. .. Therefore, it is not necessary to process the cut 22 or connect the jumper wire 24 to the circuit pattern 14 of the printed wiring board 16.

The printed wiring board 30 used here is shown in FIG.
As shown in FIG. 5, a large number of circuit patterns and pads of the wiring board 30 are formed on the film 52 by a known printed wiring board manufacturing method, and can be cut out and used when used. The film 52 has wiring boards 30 with different specifications.
A may be formed in advance and used properly according to the terminal arrangement of the components used. For example, pads 34a and 36a are provided so as to correspond to ICs having different terminal pitches and numbers.
Alternatively, the circuit 38 (FIGS. 1 and 2) may be formed.

The substrate 32 to be used is preferably made of a material having high heat resistance and high heat conductivity in order to transfer the heat of the heater chip 48 pressed from the upper surface to the lower surface, and a polyimide resin film is preferable. However, in the present invention, a ceramic thin plate having good heat conductivity may be used. Substrate 3
2 and parts are printed wiring boards 16 and 3 using a reflow furnace
It is also possible to reflow solder to 0, in which case the substrate 32 does not necessarily have to be thin.

Further, the cream solder 44 used for soldering the lower surface of the printed wiring board 30 may have a higher melting point than the cream solder 50 used for soldering the upper surface. In this case, there is no possibility that the cream solder between the printed wiring boards 30 and 16 melts during reflow soldering of the IC 20.

[0024]

As described above, according to the invention of claim (1), a printed wiring board for terminal arrangement conversion is prepared, and the first pad group formed on one surface of the printed wiring board is located in the puls group of the printed wiring board. The second surface mount component is soldered to the second pad group on the other side while being reflow-soldered together. Therefore, cuts or jumpers can be made in the circuit pattern of the printed wiring board. -Since there is no need to solder wires, work efficiency is improved when mounting parts with different terminal arrangements.

Further, since a jumper wire is unnecessary, there is no possibility of electrical trouble such as noise. Further, the invention can be applied even when the pitch and the number of terminals on the front and back sides are different, and the range of mountable components is expanded.

A substrate of the printed wiring board for terminal connection conversion is made of a heat-resistant resin film, and a heat is applied from above the substrate.
If this terminal connection conversion printed wiring board is reflow-soldered to the printed wiring board by heating with a tip, the work efficiency is improved and the soldering reliability is also increased (claim 2). According to the inventions of claims 3 and 4, a printed wiring board for terminal connection used for carrying out this method can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing a surface of an embodiment of the present invention.

FIG. 2 is a view showing the back side as well.

FIG. 3 is a diagram showing the terminal arrangement conversion path.

FIG. 4 is a diagram showing a usage example of this embodiment.

FIG. 5 is a diagram showing an example of a manufacturing method of this embodiment.

FIG. 6 is a diagram for explaining a mounting process of an IC having the same terminal arrangement.

FIG. 7 is a diagram illustrating a conventional mounting process of an IC having a different terminal arrangement.

[Explanation of symbols]

 10 IC as First Surface-Mounted Component 20 IC as Second Surface-Mounted Component 30 Printed Wiring Board for Terminal Connection Conversion According to the Present Invention 32 Substrate 34 First Pad Group 36 Second Pad Group 38 Printed Circuit

Claims (4)

[Claims] 1. A component mounting method for mounting a second surface mount component having a different terminal arrangement on a printed wiring board having a pad group for mounting a first surface mount component, comprising: A first pad group corresponding to the pad group and a second pad group for mounting the second surface mount component are formed on each surface, and the corresponding pads of the first and second pad groups are connected to each other. A printed wiring board for terminal connection conversion is prepared, and the printed wiring board for terminal connection conversion is aligned between the first pad group and the pad group of the printed wiring board to be connected to the second surface mount component. And the first pad is reflow soldered to the pad of the printed wiring board while the second surface mount component is soldered to the second pad. .. 2. The printed wiring board for terminal connection has a substrate made of a heat-resistant resin film, and when the first pad group is reflow-soldered to the pad group of the printed wiring board, the second pad of the substrate is used. The surface on the group side is heated by a heater chip, and then the second surface mount component is attached to the second surface.
The component mounting method according to claim 1, wherein reflow soldering is performed on the pad group. 3. A first pad group formed on one surface of the substrate and having a terminal arrangement that is plane-symmetrical to the terminal arrangement of the first surface-mounted component, and the first pad group formed on the other surface of the substrate. A second pad group having a terminal arrangement of a second surface mounting component having a terminal arrangement different from that of the surface mounting component; and a printed wiring circuit interconnecting corresponding pads of the two pad groups to each other. A characteristic printed wiring board for terminal connection conversion. 4. The printed wiring board for terminal connection conversion according to claim 3, wherein the substrate is formed of a heat resistant resin film.