JPH04363877A - Check terminal structure - Google Patents

Abstract

PURPOSE:To provide a check terminal structure having a sufficiently large fixing strength of a soldered check terminal in which the mounting area of a circuit part is never narrowed in the check terminal structure loaded on a printed wiring board. CONSTITUTION:A conductive blind hole 30 continued to an inner layer 12 formed in the center part of a foot print 35 and a check terminal 40 having an emboss 43 protruded to the lower part of a bottom plate member 41 are provided. By inserting the emboss 43 into the conductive blind hole 30, the bottom plate member 41 is fixed onto the foot print 35. A solder 16 charged in the hole 30 is swollen in a rivet head form onto the upper part of the bottom plate member 41 to solder the check terminal 40 to a multilayer printed wiring board 1.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a check terminal structure mounted on a printed wiring board. Multilayer printed wiring boards with high-density surface mounting of circuit components are sometimes equipped with check terminals at important points on the multilayer printed wiring boards to measure electrical characteristics such as power supply voltage drop and ground potential. .

0002

2. Description of the Related Art FIG. 5 is a sectional view of a conventional example. In FIG. 5, 1 is a multilayer printed wiring board on which a large number of circuit components 2 are surface-mounted. The circuit component 2 is surface-mounted on the multilayer printed wiring board 1 by disposing a footprint 18 on the surface layer 11 and seating each lead terminal 3 on the corresponding footprint 18 and soldering.

A through hole 13 is provided in the multilayer printed wiring board 1 at a position where a check terminal is mounted, and this through hole 13 is connected to a desired inner layer 12. Note that rectangular lands 14 communicating with the through holes 13 are provided on both the front and back surfaces.

On the other hand, reference numeral 20 denotes a rectangular cylinder-shaped check terminal on which the hook of the probe is hooked and connected, and a pin 21 projecting downward is provided at the center of the bottom plate member 22. and,
After inserting the pin 21 into the through hole 13 and seating the bottom plate member on the land 14 of the surface layer 11, the through hole 13 and the pin 21 are soldered from the back side to attach the check terminal 20 to the multilayer printed wiring board 1. It is equipped.

As mentioned above, the pin 21 is inserted into the through hole 13.
Since the bonding strength to the multilayer printed wiring board 1 is strengthened by soldering to the multilayer printed wiring board 1, even if the check terminal 20 is pulled by the probe, the land 14 will not peel off or the check terminal 20 will not fall off. There is no.

[0006]

By the way, the printed wiring board on which the check terminal is mounted is a multilayer printed wiring board in which circuit components are mounted on both the front and back sides. Therefore, it is not possible to solder the check terminal by dipping the back side in a solder bath or the like. As a result, the check terminal must be soldered using a soldering iron or the like, resulting in a problem that the workability of mounting the check terminal is poor.

[0007] Furthermore, since a through hole is provided through the multilayer printed wiring board, there is a problem in that the mounting area for circuit components on the mounting surface opposite to the surface on which the check terminal is mounted becomes narrow.

The present invention was created in view of the above points, and provides a check terminal in which the soldered check terminal has a sufficiently high fixing strength and the mounting area of circuit components is not narrowed. The purpose is to provide structure.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a check terminal 40 with an embossing 43 protruding from the bottom of a bottom plate member 41, as illustrated in FIG.

On the other hand, a conductive blind hole 30 communicating with the inner layer 12 is provided in the multilayer printed wiring board 1 at the center of the footprint 35 . The embossing 43 is inserted into the conductive blind hole 30 and the bottom plate member 41 is seated on the footprint 35. and,
The check terminal 40 is soldered to the multilayer printed wiring board 1 by the solder 16 which is raised in the shape of a rivet on the upper part of the bottom plate member 41 by hardening the creamy solder 16A filled in the conductive blind hole 30.

Further, as illustrated in FIG. 3, a check terminal 50 having a pair of curved legs 52 is provided below the ring-shaped head 51. Then, the leg 52 is connected to the conductive blind hole 30.
The check terminal 50 is soldered to the multilayer printed wiring board 1 using the solder 16 that is raised in the shape of a riveted head at the bottom of the ring-shaped head 51. The configuration is as follows.

Alternatively, as illustrated in FIG. 4, a hole 62 is bored in the seating portion 61 of the selected lead terminal 60 of the circuit component 2 to be surface mounted on the multilayer printed wiring board 1. on the other hand,
A conductive blind hole 30 communicating with the inner layer 12 is provided in the center of the footprint 18 where the lead terminal 60 is seated.

Then, the lead terminal 60 is seated on the footprint 18 , the creamy solder filled in the conductive blind hole 30 is hardened, and the solder 16 swells in the shape of a riveted head at the top of the hole 62 . Footprint 18
The lead terminal 60 is also used as a check terminal.

[0014]

[Function] Regardless of the structure, in the present invention, the check terminal seated on the footprint electrically connected to the conductive blind hole is soldered to the conductive blind hole by solder raised in the shape of a rivet head. Therefore, the fixing strength of the check terminal is sufficiently large.

Therefore, the check terminal (
The solder connection between the check terminal (or lead terminal) and the footprint is reliable, even if the check terminal (or lead terminal) may be pulled.

On the other hand, since the multilayer printed wiring board has conductive blind holes instead of through holes, the mounting area on the mounting surface opposite to the surface on which the check terminal is mounted does not become narrow. That is, circuit components can be mounted with high density on the mounting surface on the back side of the multilayer printed wiring board.

Furthermore, since the check terminal can be soldered at the same time when circuit components are reflow soldered, workability for mounting the check terminal is good.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained in detail below with reference to the drawings. Note that the same reference numerals indicate the same objects throughout the figures.

FIG. 1 is a diagram showing the principle of the present invention, and (A)
(B) is a cross-sectional view before soldering, and (B) is a cross-sectional view after soldering. FIG. 2 is a perspective view of an embodiment of the invention, FIG. 3 is a sectional view of another embodiment of the invention, and FIG. 4 is a sectional view of still another embodiment of the invention.

In FIG. 1, reference numeral 1 denotes a multilayer printed wiring board on which a large number of circuit components are surface-mounted on both the front and back sides. The multilayer printed wiring board 1 is provided with a rectangular footprint 35 at a desired position on the surface layer 11 on which the check terminal is mounted, and a conductive blind hole whose bottom surface coincides with the inner layer 12 is provided in the center of the footprint 35. 30 are provided.

An inner wall conductor 31 is formed on the inner wall surface of the conductive blind hole 30 by plating or the like. Therefore, the footprint 35 and the inner layer 12 are electrically connected via the inner wall conductor 31.

On the other hand, reference numeral 40 denotes an L-shaped check terminal made of a highly conductive metal (for example, a copper alloy) having a hole in the vertical member for hooking and connecting the hook 91 of the probe 90. An emboss 43 is made to protrude from the lower part.

In order to mount the above-mentioned check terminal 40 on the multilayer printed wiring board 1, at the same time as screen printing creamy solder on the footprint of the circuit component (not shown), as shown in FIG. So, check terminal 4
A creamy solder 16A is printed and applied onto the footprint 35 on which the conductive blind hole 30 is filled with the creamy solder 16A.

When the embossing 43 is inserted into the conductive blind hole 30 filled with the creamy solder 16A as described above and the bottom plate member 41 is seated on the footprint 35, the creamy solder 16A fills the hollow hole 42 of the embossing 43. It passes through and rises in the shape of a rivet on the upper surface of the bottom plate member 41.

In this state, the multilayer printed wiring board 1 is heated to reflow the cream solder 16A, and then cooled.
As shown in (B), the solder 16 is attached to the bottom plate member 41.
Let it harden with a raised tack-head shape on the top.

Since the check terminals 40 are soldered as described above, the fixing strength of the check terminals 40 to the multilayer printed wiring board 1 is sufficiently high. Therefore, even if the hook 91 is hooked into the hole of the vertical member of the check terminal 40 and the probe 90 is connected to the check terminal 40, and a tensile force is applied to the check terminal 40, the soldering between the check terminal 40 and the footprint 35 will not occur. The printed wiring board 1 will not be damaged or the footprint 35 will not be peeled off from the multilayer printed wiring board 1.

Reference numeral 40-1 shown in FIG. 2 is a check terminal in which an emboss is provided at the lower part of the bottom plate member 41 and the upper part of the bottom plate member 41 is shaped like a gate. By having such a shape, the bottom plate member 41 and the footprint 3
The effect of further increasing the strength of soldering with 5,
This has the advantage that it becomes easier to engage the hook of the probe.

In FIG. 3, reference numeral 50 denotes a check terminal having a ring-shaped head 51 formed by bending a wire such as brass, and a pair of curved elastic legs 52 provided below the ring-shaped head 51. be.

The above-described check terminal 50 is obtained by pushing the leg 52 into the conductive blind hole 30 filled with creamy solder.
While the tip of the leg 52 is locked to the inner wall conductor 31 due to its elasticity, the creamy solder is reflowed, and the check terminal 50 is attached to the solder 16 raised in the shape of a rivet at the bottom of the ring-shaped head 51. It is soldered to a multilayer printed wiring board 1.

It goes without saying that such a check terminal 50 has a sufficiently high adhesion strength to the multilayer printed wiring board 1. Further, there are advantages in that the check terminal 50 has a simple structure, is low cost, and can be easily miniaturized.

FIG. 4 shows an example in which the lead terminal 60 of the circuit component 2 is also used as a check terminal. In FIG. 4, a circuit component 2 to be surface mounted on a multilayer printed wiring board 1,
The seating portion 61 of the selected lead terminal 60 is extended longer, and a hole 62 is bored in the seating portion 61.

On the other hand, a conductive blind hole 3 communicating with the inner layer 12 is provided in the center of the footprint 18 where the lead terminal 60 is seated.
0 is set. Then, when the creamy solder is screen printed on all the footprints 18 of the circuit component 2, the conductive blind hole 30 is simultaneously filled with the creamy solder.

The lead terminal 60 is seated on the footprint 18, and creamy solder is passed through the hole 62 and placed on the seating portion 61.
Pour it onto the top. In this state, the creamy solder is reflowed and hardened, and the lead terminal 60 is soldered to the footprint 18 by the solder 16 that rises in the shape of a rivet at the top of the hole 62.

As described above, since the solder 16 bulges in the shape of a rivet and solders the lead terminal 60, the soldering strength is sufficiently strong. Therefore, even if the probe is hooked onto this lead terminal 60 and connected, the lead terminal 60
The soldered portion between the and footprint 18 will not be damaged, or the footprint 18 will not be peeled off from the multilayer printed wiring board 1.

By using the lead terminal as a check terminal in this way, there is no need to specially mount a check terminal on the multilayer printed wiring board 1, which has the effect of lowering costs.

[0036]

Effects of the Invention As explained above, the present invention provides the inner layer 12
A conductive blind hole is provided in the center of the footprint leading to the
This is a check terminal structure in which a check terminal is soldered to this footprint, and the adhesion strength of the check terminal is sufficiently large so that even if a tensile force is applied to the check terminal, there is no difference between the check terminal and the footprint. This has an excellent effect in that the soldered part is not damaged or the footprint is not peeled off from the multilayer printed wiring board.

Furthermore, the mounting area on the mounting surface opposite to the surface on which the check terminal is mounted does not become narrow, and circuit components can be mounted with high density on the mounting surface on the back side of the multilayer printed wiring board. It has the effect of being able to.

Furthermore, since the check terminals can be soldered at the same time when circuit components are reflow soldered, the workability of mounting the check terminals is good. on the other hand,
By adopting a structure in which a ring-shaped head is provided with legs, or by using a lead terminal of a circuit component as a check terminal, the cost of the check terminal can be reduced.

[Brief explanation of drawings]

[Figure 1] Diagram showing the principle of the present invention, (A) is a cross-sectional view before soldering (B) is a cross-sectional view after soldering

[Fig. 2] Perspective view of an embodiment of the present invention

[Figure 3] Cross-sectional view of another embodiment of the present invention

[Figure 4]
A sectional view of still another embodiment of the present invention

[Figure 5] Cross-sectional view of conventional example

[Explanation of symbols]

Claims (3)

[Claims] 1. A conductive blind hole (30) communicating with the inner layer (12) formed in the central part of the footprint (35);
A check terminal (40) with an emboss (43) protruding from the bottom of the bottom plate member (41) is provided, and the conductive blind hole (3
0), the bottom plate member (41) is seated on the footprint (35), and the solder (16) filled in the conductive blind hole (30) is inserted into the bottom plate. A check terminal structure characterized in that the check terminal (40) is raised in the shape of a rivet head on the upper part of the member (41) and is soldered to the multilayer printed wiring board (1). 2. A conductive blind hole (30) communicating with the inner layer (12) formed in the central part of the footprint (35);
A pair of curved legs (5) are provided below the ring-shaped head (51).
a check terminal (50) having a check terminal (50) having a
2) is inserted into the conductive blind hole (30), and the solder (16) filled in the conductive blind hole (30) is inserted into the ring-shaped head (
A check terminal structure characterized in that the check terminal (50) is raised in the shape of a rivet head at the bottom of the check terminal (51) and is soldered to the multilayer printed wiring board (1). 3. A conductive blind hole (30) formed in the central part of the footprint (18) and communicating with the inner layer (12);
a circuit component (2) in which a hole (62) is bored in a seating part (61) of a lead terminal (60), the lead terminal (60) is seated on the footprint (18), and the conductive blind The solder (16) filled in the hole (30) is attached to the seating portion (6).
The circuit component (2) is raised in the shape of a rivet on the top surface of 1).
A check terminal structure characterized in that the lead terminal (60) is surface mounted on a multilayer printed wiring board (1) and the lead terminal (60) is also used as a check terminal.