JPH0590372U - Spring probe - Google Patents

Abstract

(57) [Summary] [Structure] The front end of the barrel 11 having a substantially cylindrical shape is press-molded to form the front opening 12 having a rectangular shape or the like. The prismatic measurement terminal portion 22 of the conductive plunger 21 is inserted into the front opening 12. The spring body 31 presses the plunger 21 to the front side. The terminal 41 is fixed with the rear opening 15 of the barrel 11 inserted. At all times,
The contact portion 26 of the plunger 21 and the contact portion 45a of the terminal 41 are separated and insulated. When the tip end 22a of the plunger 21 is pressed against the object to be measured, the plunger 21 retracts, and the contact portion 26 and the contact portion 45a come into contact with each other and become conductive. [Effect] The strength and continuity test of the object to be measured can be performed almost simultaneously. When the plunger 21 is pressed against the object to be measured, the plunger 21 does not easily come off, positioning is easy and reliable, and the accuracy of the continuity test can be improved. The front opening 12 that can reliably support the square plunger 21 can be easily formed. The diameter of the tip of the barrel 11 can be reduced.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a spring probe used for an electrical continuity test of electronic parts and the like.

[0002]

[Prior Art]

 Conventionally, for example, as disclosed in Japanese Utility Model Laid-Open No. 2-5072, as shown in FIG. 4, a barrel 1 having a cylindrical shape is provided, and is elastically supported by a spring body 2 from an opening at a front end of the barrel 1. There is known a spring probe in which a conductive measuring terminal (plunger) 3 having a substantially cylindrical shape is provided so as to be able to move forward and backward, and a conductive terminal 5 is provided so as to project from an opening at a rear end.

The spring probe is normally insulated from each other by the urging force of the spring body 2 in a state where the plunger 3 and the terminal 5 are separated from each other, but the tip 3a of the plunger 3 is to be measured. In the state of being pressed against an object, the plunger 3 moves backward against the urging force of the spring body 2 and comes into contact with the elastically supported tip 5a of the terminal 5 so as to be electrically connected to each other.

Therefore, after fitting a socket to the terminal 5 and connecting the lead wire led out from the socket to a measuring device or the like, the object to be measured such as a printed wiring in a test circuit or a terminal of an electronic component is measured. The tip 3a of the plunger 3 is pressed against the, the plunger 3 is retracted, the plunger 3 and the terminal 5 are brought into contact with each other, and the electrical continuity is ensured. A continuity test can be performed.

Further, in this spring probe, a constant weight can be applied to the object to be measured through the tip portion 3a of the plunger 3 by the urging force of the spring body 2. It is possible to perform a strength test of an object.

[0006]

[Problems to be solved by the device]

 However, in the above-described conventional spring probe, since the substantially cylindrical plunger 3 is used, when the tip portion 3a is pressed against the object to be measured, the tip portion 3a is rotated by the rotation of the plunger 3 or the like. However, there is a problem that the measured object is easily separated from the measured object, and the contact between the measured object and the plunger 3 becomes uncertain.

In this respect, it is possible to use a substantially prismatic plunger, but in order to support such a prismatic plunger, the opening at the front end of the barrel must be adjusted to the shape of this plunger. It needs to be processed. Conventionally, such an opening is formed by a processing method such as drilling or milling, but with such a processing method, the formation of a minute rectangular opening is a complicated work. Particularly today, many spring probes are arranged at high density, and the continuity test of each part of the DUT having a fine structure is conducted at the same time, so that the tip of the barrel can be made thinner. Although desired, it is difficult to reduce the outer diameter of the tip of the barrel that supports the square plunger to a small diameter of, for example, 3 mm or less depending on the conventional processing method. There is.

The present invention has been made in view of the above points, and the contact between the object to be measured and the plunger can be ensured, the accuracy of the continuity test can be improved, and the outer diameter of the tip portion of the barrel can be increased. It is an object of the present invention to provide a spring probe that can have a smaller diameter and can expand the measurement range.

[0009]

[Means for Solving the Problems]

 According to the present invention, a cylindrical barrel having a front opening and a rear opening, a conductive terminal fixed to the barrel while the rear opening is inserted, and a tip portion of the front opening. A conductive plunger that is elastically supported by a biasing means and is capable of advancing and retracting in the barrel in a state of being inserted and protruding to the front side, and the rear end portion of the plunger is normally provided. Is separated from the front end of the terminal, and the rear end of the plunger is brought into contact with the front end of the terminal while the front end of the plunger is pressed rearward. The section is formed in a rectangular shape, and the front opening through which the tip portion is inserted is flattened by press molding in accordance with the shape of the tip portion.

[0010]

[Action]

 In the present invention, the strength test is performed by pressing the tip of the plunger against the DUT against the urging force of the urging unit and applying the load of the urging unit to the DUT. When the tip of the plunger is pressed further against the DUT, the plunger retracts further, the rear end of the plunger contacts the front end of the terminal, and both are electrically connected. In this state, energize to conduct a continuity test of the DUT. The square tip of the plunger ensures reliable contact between the tip and the DUT. Press molding facilitates the formation of a flat front opening capable of reliably supporting a plunger having a square tip.

[0011]

【Example】

 A configuration of an embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 11 is a barrel having a substantially cylindrical shape, and the barrel 11 has, for example, a diameter of 1. It is 9 mm thick and is made of nickel-plated brass. Front and rear openings 12 and 15 are formed at the front and rear ends, respectively.

As shown in FIGS. 2 and 3, in the vicinity of the front opening 12, the inside is formed thick, and the rear end of this thick portion serves as a locking step 16. .. In addition, the front end is made slightly thinner, and the through hole with a circular cross section is crimped by pressing from above and below to make it flat, and the cross section is adjusted according to the shape of the measuring terminal portion 22 of the plunger 21 described later. A front opening 12 having a rectangular or elliptical cross section is formed.

An annular locking collar 18 is provided on the outer peripheral surface near the front end of the barrel 11, and the barrel 11 of the spring probe is press-fitted and fixed in a mounting hole of a probe board (not shown). In this case, the rear side of the locking brim portion 18 contacts the surface of the probe board to lock the spring probe.

As shown in FIGS. 1 and 2, the plunger 21 is inserted into the barrel 11 through the rear opening 15. The plunger 21 is formed from a conductive metal such as copper-plated beryllium copper by machining or the like, and has an expanded cylindrical flange portion 25 formed in the axial middle portion. Further, the front side of the flange portion 25 is formed in a rectangular cross section to serve as a measurement terminal portion 22, and the tip portion 22a is also rectangular. The rear end portion of the plunger 21 serves as a contact portion 26 as a rear end portion.

The plunger 21 is inserted into the barrel 11 through the rear opening 15, and the measurement terminal 22 is slidably inserted through the front opening 12 and protrudes forward. The front end of the flange portion is in contact with and locked by the locking step portion 16 of the barrel 11.

Then, a relatively strong spring body 31 as an urging means is inserted into the barrel 11 through the rear opening 15 of the barrel 11, and the front end of the spring body 31 is located at the rear end of the flange portion 25 of the plunger 21. It abuts and is engaged, and pushes the plunger 21 forward.

Further, a cylindrical spacer 33 made of brass or the like is fitted into the barrel 11 through the rear opening 15 of the barrel 11, and the rear end of the spring body 31 is locked at the front end of the spacer 33. ..

Subsequently, an insulator 35 made of Duracon or the like having a substantially cylindrical shape and a stopper 36 are sequentially fitted into the barrel 11 through the rear opening 15 of the barrel 11. The insulator 35 and the stopper 36 may be integrally formed.

Further, a fitting hole 38 is formed in the axial center portion of the insulator 35 and the stopper 36, and an annular locking portion 35a is provided so as to project inward from the front end portion of the insulator 35. Has been done.

Then, a terminal 41 is fitted into the fitting hole 38 from the rear side.

The terminal 41 has a substantially cylindrical conductive tube body 43 having a closed rear end, and a relatively weak spring body 44 is inserted into the tube body 43. A plunger 45 protruding from the opening at the front end of the tube body 43 is inserted. Further, the front end portion of the plunger 45 is a contact portion 45a, and the rear end portion is integrally formed with a substantially cylindrical expanded diameter portion 45b. The expanded diameter portion 45b is slidably fitted inside the tube body 43, and the rear end portion of the expanded diameter portion 45b is elastically pressed forward by the spring body 44. A front end portion of the expanded diameter portion 45b is locked by a locking portion 43a that is caulked to have a small diameter at an opening portion of the front end of the tube body 43.

Then, this terminal 41 is fitted into the fitting hole 38 of the insulator 35 and the stopper 36, and the locking portion 43a at the front end of the tubular body 43 is locked to the annular locking portion 35a of the insulating body 35. In this state, the contact portion 26 at the rear end portion of the plunger 21 and the contact portion 45a at the front end portion of the plunger 45 face each other with a predetermined gap a therebetween, and the rear portion of the tube body 43 is opened at the rear portion of the barrel 11. It is designed to protrude from the part 15. Further, the protruding portion of the tubular body 43 serves as a terminal portion 48 to which a socket or the like from which the lead wire is drawn is fitted and connected.

Then, the insulator 35 and the stopper 36 are locked by the annular recess 51 and the plurality of locking recesses 52 formed on the peripheral surface of the rear portion of the barrel 11, and these insulators 35 and the stopper 36 are used. The rear end of the spring body 31 is locked, and the terminal 41 is fixed to the barrel 11.

Next, the operation of this embodiment will be described.

First, a probe board (not shown) having mounting holes formed at a plurality of positions according to the position of the object to be measured such as a square hole connector is prepared. Then, the rear portion of the barrel 11 of the spring probe described above is press-fitted into each of the mounting holes and locked by the locking flange portion 18, so that each spring probe is disposed. Further, the lead wire connected to a measuring device (not shown) is connected to the terminal portion 48 of the terminal 41 through a socket.

When the probe board is held apart from the object to be measured and the tip 22a of the measuring terminal portion 22 of the plunger 21 is not pressed against the object to be measured, the urging force of the spring body 31 is increased. The plunger 21 is pressed by the front side, and the contact portion 26 at the rear end portion of the plunger 21 and the contact portion 45a at the front end portion of the plunger 45 of the terminal 41 are opposed to and separated from each other with a predetermined gap a therebetween. Therefore, the plunger 21 and the terminal 41 are insulated from each other.

Next, the probe board is brought close to the object to be measured, and the tip portions 22a of the plungers 21 of the spring probes are simultaneously pushed into the object to be measured. The plunger 21 compresses the spring body 31 by the flange portion 25 and retracts against the biasing force.

In this state, a load of several tens of grams to 3000 grams is applied to the tip portion 22a of the plunger 21, and the strength test of the measured object can be performed.

When the tip portion 22a of the plunger 21 is further pressed against the object to be measured, the plunger 21 further retracts, and the contact portions 26 and 45a of the plunger 21 and the terminal 41 facing each other come into contact with each other. At this time, the plunger 45 of the terminal 41 is also elastically biased forward by the spring body 44 and can slide backward along the axis, so that both plungers 21, 45 contact the contact portions 26, 45a. It is possible to obtain a reliable electrical connection between the plunger 21 and the terminal 41 by sliding the rear end integrally in a state in which the plunger 21 and the terminal 41 are in close contact with each other. At this time, the axial load applied to the terminal 41 is supported by the insulator 35 and the stopper 36 locked by the annular recess 51 and the locking recess 52 of the barrel 11.

Therefore, by conducting a test current in the test circuit in a state where electrical continuity is ensured in this way, a continuity test of the object to be measured can be performed.

Further, in the state where the probe board is brought close to the object to be measured as described above, when the electronic parts or the terminals of the electronic parts as the object to be measured are not attached, the tip 22a of the plunger 21 is Does not come into contact with the object to be measured, or the amount of movement is short even if it comes into contact, and the contact portions 26 and 45a of both plungers 21 and 45 are held in a separated state. As a result, the plunger 21 and the terminal 41 are held. And are kept insulated. Therefore, it is possible to test whether or not electronic parts are present.

According to the spring probe of this embodiment, the strength of the object to be measured such as an electronic component, the presence or absence of the component, and the continuity test can be performed almost at the same time, so that the number of measurements can be reduced. ..

Further, since the tip of the measuring terminal portion 22 of the plunger 21 is formed into a square shape, the plunger 21 does not easily come off when it is pressed against the object to be measured, and positioning is easy and reliable. The continuity test accuracy can be improved.

Further, the front opening 12 at the front end of the barrel 11 is flattened by crimping a through hole having a circular cross section by press working from above and below according to the shape of the measurement terminal portion 22 of the plunger 21. Since the cross-section is rectangular or elliptical, the front opening 12 that can securely support the square plunger 21 without rotating can be easily formed, and the outer diameter of the tip of the barrel 11 can be increased. Can be reduced to, for example, 1.0 mm or less. Therefore, it is possible to densely arrange the springs on the probe board, etc., and it is possible to simultaneously conduct the continuity test of the DUT with a finer structure, thus expanding the measurement range.

Then, as the object to be measured, a rectangular hole connector having a corner length of 0.65 mm × 1.1 mm is used. With the spring probe of the present invention, the tip end of the measuring terminal portion 22 of the plunger 21 is used. According to the continuity test experiment conducted by inserting the portion 22a having a size of 0.65 mm × 1.1 mm into this square hole connector, good continuity results were obtained after 100 continuity tests.

On the other hand, when a continuity test was performed 100 times with a cylindrical spring probe with a diameter of 0.63 mm at the tip of the plunger, the cylindrical plunger was used as the object to be measured. The number of times that a good continuity result was obtained was 50 times because of the fact that it rotated and came off when pressed.

This experiment proved that more reliable contact can be obtained and the accuracy of the continuity test can be improved.

[0039]

[Effect of the device]

 According to the spring probe of the present invention, since the tip of the plunger is square, it is difficult for the plunger to come off when it is pressed against the object to be measured, and positioning is easy and reliable, especially for rectangular connectors. The continuity test accuracy can be improved. In addition, the front opening of the barrel has, for example, a through hole having a circular cross section that is flattened by pressing from above and below and is formed into a rectangular or elliptical cross section, so that a square plunger can be reliably supported. The front opening can be easily formed, and the outer diameter of the barrel tip can be made smaller. Therefore, for example, spring probes can be densely arranged on a probe board or the like, and it becomes possible to simultaneously conduct a continuity test of an object to be measured having a finer structure, thereby expanding the measurement range.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view showing an embodiment of a spring probe of the present invention.

FIG. 2 is a partially enlarged sectional view of the same.

FIG. 3 is an end view seen from the front side of the same as above.

FIG. 4 is a partially cutaway side view showing a conventional spring probe. 11 Barrel 12 Front opening 15 Rear opening 21 Plunger 22a Tip 26 Contact part as rear end 31 Spring body as biasing means 41 Terminal 43a Front end

Claims (1)

[Scope of utility model registration request] 1. A cylindrical barrel having a front opening and a rear opening, a conductive terminal fixed to the barrel with the rear opening inserted, and a front end having the front opening. And a conductive plunger that is elastically supported by the biasing means and is provided in the barrel so as to be able to move forward and backward in a state where the plunger is inserted into the front end of the plunger. Is a spring probe in which the front end of the plunger is separated from the front end of the terminal, and the rear end of the plunger contacts the front end of the terminal while the front end of the plunger is pressed backward. Is formed in a square shape, and the front opening through which the tip portion is inserted is flattened by press molding so as to conform to the shape of the tip portion. Breakfast.