JPH0736067U - Contact of probe used for board abnormality detection device - Google Patents

Abstract

(57) [Abstract] [Purpose] In the contact of the probe used for the electronic device board abnormal point detection device, if the flux debris remaining on the land and other dust are attached, it will come into contact if used for a long time. May cause defects. It is an object of the present invention to provide a contact which can prevent adhesion of flux fragments and dust and prevent contact failure. [Structure] It is composed of a needle-shaped contact 12 and a cover 21 having a hole having a structure in which the entire contact is closely adhered and covered when not in contact, and is insulative and elastic.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 It relates to the contact of a probe that detects a signal in the test of a circuit mounted on an electronic device.

[0002]

[Prior art]

 The conventional technique will be described with reference to FIG. In order to confirm the operation of the circuit network mounted on the electronic equipment and diagnose the failure, the contact 12 of the probe 11 is brought into contact with the land 19 of the board 13 on which the electronic component is mounted, and the voltage of the signal is detected. It may be displayed as a waveform on the screen, or digitally processed to pursue the defective part. As shown in FIG. 4 (A), the land 19 of the board 13 physically and chemically connects the lead 18 of the electronic component 17 and the copper foil pattern 14 to each other. It is a fixed portion, and in addition to that, the plating treatment of the solder 15 may be performed on the copper foil pattern 14.

When performing this work, a material that is a flux is used in order to smoothly perform soldering, but after the work, the flux film 16 remains with the solder 15 being covered. Although the flux film 16 was cleaned and removed, the flon-based cleaning solvent has been completely abolished in recent years, and the flux cleaning may be stopped, and the flux film 16 may remain. At the time of the test in such a state, the needle-shaped contact 12 at the tip of the probe 11 is pierced through the flux film 16 and pressed against the solder 15 to be brought into contact therewith to obtain an electrical connection. This state is shown in FIG.

[0004]

[Problems to be solved by the device]

 When it is used for a long time under such a condition, (1) Fragments of the flux film 16 and other insulating dust adhere to the tip of the needle-shaped contact 16. (2) The needle-shaped contact 16 undergoes a chemical change due to heat at the time of contact to form an insulating oxide film on the contact surface. For this reason, the contact resistance increases, and the signal voltage value may not be accurately detected, which is a problem.

The present invention was devised in order to solve the above-mentioned problems of the prior art, and it is a contact that can prevent dust and the like from adhering and maintain a low contact resistance even when used for a long time. The purpose is to provide.

[0006]

[Means for Solving the Problems]

 (Claim 1) The contact is made of a conductive metal material and has a needle shape. The cover uses an insulative elastic body, and has a hole with a structure that covers the entire contact when it is not in contact. (Claim 2) The contact is made of a conductive metal material and has a structure in which a plurality of needle-shaped contacts are annularly arranged from the tip of the probe 11. (Claim 3) The cover is made of an elastic material having an insulating property, has columnar holes corresponding to a plurality of needle-shaped contacts, and has a structure in which the entire contact is closely adhered and covered when not in contact.

[0007]

[Action]

 (Claim 1) By making the contact shape needle-shaped, it has a function of smashing the flux film 16 and making sure contact with the solder 15 therebelow. The insulating property of the cover 21 prevents a short circuit even if the land 19 at the test location comes into contact with another land 19 or a pattern. Next, when the material of the cover 21 is made elastic, the needle-like contact 12 is sealed inside the cover 21 when not in contact, but when pressed against the land 19, the cover 21 is deformed vertically (crushed). And the tip of the needle-shaped contact 12 is projected to the outside of the cover 21 to make contact with the solder 15.

Next, when the probe 11 is separated from the land 19, the shape of the cover 21 begins to return to its original shape. However, by providing a structure in which the cover 21 is in close contact with the outer periphery of the needle-shaped contact 12, the fragments and dust of the flux film 16 are removed. Are removed from the contact surface. This action keeps the contact surface clean every time. Further, when the shape of the cover 21 is restored to the original shape, the entire needle-shaped contact 12 is closely adhered to the cover 21 and is covered therewith, so that the contact surface has a function of alleviating a chemical change that progresses due to contact with air. .

(Claims 2 and 3) Providing a plurality of needle-shaped contacts from the tip of the probe 11 serves to strengthen the contact with the solder 15. Depending on the land 19, the lead 18 of the electronic component 17 may protrude, and if the lead 18 is in contact with the lead 18 and the contact point is poor, it may slip off the lead 18 and not contact the solder 15. obtain. In such a case, if there are a plurality of contacts 12, even if one contact 12 fails to contact, the remaining contacts 12 have an opportunity to contact the solder 15. When there are a plurality of contacts 12, the shape of the cover (the hole enclosing the contact) changes correspondingly, but the action is the same as that described in (Claim 1).

[0010]

【Example】

 An embodiment of claim 1 will be described with reference to FIG. As shown in FIG. 1A, a needle-shaped contact 12 is fixed to the tip of the probe 11 and connected to the input circuit inside the probe 11. Next, a cover 21 which is slightly longer than the length of the needle-shaped contact 12 is formed, and a hole is made slightly smaller than the outer circumference of the needle-shaped contact 12. When the needle-shaped contact 12 is further inserted, the contact 12 is in close contact with the entire contact 12, the tip of the contact 12 is covered, and the tip of the contact 12 is narrowed so that it cannot be seen from the outside. This is adhered to the tip of the probe 11 using an adhesive material. As the material of the cover, an insulating and elastic material such as natural rubber is used.

Next, a state in which the land 19 is actually pressed against and brought into contact with this is shown in FIG. 1B and described. When the contact 12 is pressed against the land 19, first, the cover 21 is deformed by applying upward pressure. Then, the tip of the contact 12 protrudes from the cover 21, pushes and breaks the flux film 16 and contacts the solder 15. In this state, the contact 12 and the solder 15 are electrically connected and the signal voltage is transmitted to the input circuit.

When the test is over and the land 19 is removed, the pressure disappears and the cover 21 starts to return to its original shape. The tip of the contact 12 begins to return to the inside of the cover 21 in order, but since the tip of the cover 21 is thin and thin, the fragments of the flux film 16 adhering to the contact 12 and other dust are removed. When the deformation of the cover 21 is completely eliminated and the original shape is restored, the contact 12 returns to the state in which the contact 12 is in close contact with the entire cover again. By repeating this operation, the deposits on the contact 12 are always removed.

Here, the material of the cover 21 is obtained by (probe pressing force) = (elastic force) + (force required to hold the contact), so that the cover 21 has an elastic coefficient satisfying this. Just choose the material. The shape of the cover 21 may be a columnar shape such as the covers 21a, 21b, 21c shown in FIG. 2 or a polygonal columnar shape.

Next, embodiments of claims 2 and 3 will be described with reference to FIG. As shown in FIG. 3A, a plurality of needle-shaped contacts 12 are fixed to the tip of the probe 11 and connected to the input circuit inside the probe 11. The arrangement state at the tip of the probe 11 is not particularly limited, but it is preferable to arrange it in a ring shape. The cover also has holes corresponding to these needle-shaped contacts. The size of the hole and the degree of adhesion with the contact are the same as those described in FIG. Further, the action is similar, but one difference is that the chance of contact with the land 19 is further strengthened. The shape of the cover 21 may be a cylindrical shape or a polygonal cylindrical shape as shown in 21d, 21e, 21f, etc., and the hole is formed in the peripheral portion in an annular shape.

[0015]

[Effect of device]

 Since the present invention is configured as described above, it has the following effects. Since the contact 12 is repeatedly projected and buried for each contact, the contact surface is cleaned by the cover. That is, the adhered flux fragments and dust can be removed each time, and the growth of the insulating film that is formed by chemical change can be prevented. Moreover, since the entire contact is intimately covered with the cover when not in contact, it is possible to mitigate the chemical change that progresses when exposed to air. From the above, it was possible to provide a contact capable of preventing the adhesion of dust and the like even when used for a long time, maintaining the contact resistance at a low level, and detecting a voltage signal without problems.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a first embodiment.

FIG. 2 is a diagram showing the shapes of a contact and a cover in the first embodiment.

FIG. 3 is a diagram showing the shapes of a contact and a cover in the second embodiment.

FIG. 4 is a diagram showing a conventional technique.

[Explanation of symbols]

11 probe 12 contact 13 board 14 copper foil pattern 15 solder 16 flux film 17 electronic component 18 lead 19 land 21, 21a, 21b, 21c, 21d, 21e, 21
f cover

Claims (3)

[Scope of utility model registration request] 1. A contact of a probe 11 for detecting a voltage of a signal from a test point of an electronic circuit network, a needle-like conductive contact (12) which is in contact with the test point and makes an electrical connection. A contact for a probe used in a board abnormality location detecting device, comprising: a cover (21) having a hole structure that closely covers and encloses the contact when not in contact, and has an insulating property and elasticity. 2. The needle-like contact (1) according to claim 1.
In 2), instead of one needle-shaped contact, a plurality of conductive contacts made of needle-shaped contacts. 3. The cover (21) according to claim 1, instead of a cover that covers one needle-shaped contact, corresponding to the plurality of needle-shaped contacts according to claim 2, one by one. An insulating and elastic cover that has a hole structure that closely adheres to and wraps around.