DE8330915U1 - Component for a contacting device - Google Patents

Description

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Fine metal Company with limited liability

7033 Herrenberg

10

C £ component for a contacting device

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The invention relates to a component according to the » Preamble of claim 1. Contacting devices of this type are known (vB KRUGSK "Test equipment for electrical testing of line ^;

ter plates for ears " , yearbook of the Deutsche Gesell- j

schaft für Chronometrie, Volume 30, 1979, pp. 269-276). |

Such contacting devices are used to test Circuit boards or other electronic components |

the electronics industry to make newly manufactured conductors- γ

plates or the like before or after their assembly on '

Check that it is free of errors quickly and easily or J

to be able to measure by placing the test item on several |

or in general, mostly with a large number of digits - |

timely by contact members of the contacting device f

is scanned electrically «The test centers are there

_g0 often mow close together, the closer the narrower the conductors and the smaller the spacing between the conductors of the test object. In fact, such contacting devices mainly serve to connect the conductor tracks

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- still unconfirmed printed circuit boards for short circuit between ο

adjacent conductor tracks or other faults in the conductor tracks, e.g. Interruptions or the like. To be checked before working with further electronic components be ticked. In many cases, such contacting devices can also be used not only for the test purposes described above / but also for medical purposes, possibly for Meezweoke already assembled printed circuit boards or other electronic components, e.g. for resistance measurements and the like.

Known contacting devices of this type

as contact elements mostly spring-loaded contact bolts on, the free contact tips to the test points of the respective test object in electrical _ Contact with him to be pressed. It is known to design these contact pins in two parts. One part is a piston with a piston rod, which piston is arranged so that it can slide axially in a jacket tube of the spring contact pin, loaded by the spring is. The other part is a contact head that has a blind hole for inserting the piston rod. This contact head has the contact tip of the spring contact pin, which is used when testing test objects respective test item contacted. With a well-known

_3G contact bolts of this type are connected to the piston rod by two diametrically opposed overlap welding points, which are connected by means of a laser beam.

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_B welds were made and extend approximately to the longitudinal center axis of the piston rod. With the well-known

Xcontact bolts, the contact head and the piston with piston rod are each made of hardenable carbon steel, which leads to Polge has the fact that during welding the welds formed by the melting of the material harden because these cool down quickly as a result of the cool neighboring areas of the contact head and the piston rod. However, the hardened sweat is brittle. The electrical resistance

, _ stand of this contact pin is significantly affected by ίο

stinmt from the electrical contact resistance between the contact head and the piston rod in the area of the Sweat. As a result of the brittleness of the welds, this electrical resistance cannot be maintained in the operation of the contacting device due to stress cracks occurring in the operation increase significantly in a predictable manner, which is undesirable, since this also causes the electrical function of the contacting device in an unpredictable manner can be adversely affected, which also leads to incorrect tests of test objects that are not immediately recognizable all adverse effects can result.

It is therefore an object of the invention to provide a component of the type mentioned, whose electrical

Resistance during operation no longer leads to significant changes-30

ungen tends.

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This object is achieved according to the invention by a component according to claim 1.

This component results in a surprising way that its electrical resistance can be seen in the operation of the con taring device even with considerable mechanical Burdens are no longer or only significant at all times changed less than before. This allows the electrical function of the contacting device through the welded components of the relevant contact members are no longer impaired or disturbed as they were before. In addition, the strength of the mechanical connection of the two parts of the component by reducing the brittleness and increasing the Weld ductility improved. However, it is essential that the electrical resistance of the welded Components of the relevant contact members do not operate even under considerable mechanical loads can change more or at most only considerably less than before.

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Such a component can be, for example a contact pin of a spring contact pin or around the jacket tube with a connection end of a act such a spring contact pin or a component of a differently designed contact member,

jQ, for example, a contact pin which is in a hole Ij '

a plate of the carrier and guided through a |.

Spring or by its own weight, on a | Spring is supporting, axially loaded or it can |

the component is also a contact pin »

jg yours, which for example consists of a curved spiral spring and a ^: · _; There is a contact head welded to this, which contact head has the contact tip which, when testing electronic test objects, comes into contact with a point of the test object to be tested. A Contact member can therefore have a welded component or also consist of such a component itself. The part of a contacting device which has the contact members is also referred to as an adapter. The adapter therefore contains the mentioned spring contact

2g pins or other electrically conductive contact elements intended to come into contact with the test objects.

The welding can be done by any suitable welding technique. In view of the ge ring diameter of the parts to be joined is preferably laser beam welding and

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g Electron beam welding in question. In some cases, micro plasma welding can also be provided. But this is more difficult to do when it comes to maintaining tight tolerances on the size of the weld point. And they have to connect with each other-

.Q the parts of such a component in the area of the Center of gravity only small diameter of a maximum of a few millimeters, often less than 1 mm. Namely, in the contacting device normally a large number of the testing of individual positions

• _L5 len of the respective test specimen serving contact members should be arranged.

By the welding of each welding point of the relevant component, so for example. The contact bolt and / or of the jacket tube with the connection end of a spring contact pin or the like., is tempered by tempering and its brittleness and thus the risk of cracking is lost or greatly reduced, remains the electrical resistance of the welded component

nc during operation even with strong mechanical loads essentially unchanged.

It can preferably be provided that the hardness of the weld at the weld point is approx. 550-650 HV.

The tempering of the component can often expediently take place in a vacuum or under protective gas.

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The parts of the component 5 that are welded to one another

can be connected by one or more welding points. The weld points can be designed as lap weld points or as fillet or corner weld points.

The materials of which the two parts of the component to be welded together are made can be the same or different. It is essential that the melt produced during welding contains enough hardenable steel or consists of completely hardenable steel that the welds harden during the frizzy cooling of the weld immediately following the welding. Both parts can preferably consist of steel, particularly expediently made of carbon steel (carbon steel). Other types of steel can also be used.

In many cases it is sufficient, if only

one of the two parts consists of steel and the other part, for example, of copper beryllium or some other material.

The start-up tentatures and the duration of start-up have changed the sweat and the desired loss of their hardness and fatigue to be judged and can be determined on a case-by-case basis. The structure of the sweat and the sweat are changed by the lacccn hardened and tempered.

QQ The tempering temperature can be several 100 ° C, preferably 250 to 650 ° C but may also be higher or lower depending on the case. The tempering temperature can preferably be 30 minutes to two hours Take effect on the component and it is slowly cooled down after <3s tempering.

In the drawing a spring contact pin is shown, of the two components according to exemplary embodiments

of the invention. The single figure shows a partially sectioned side view of a spring contact pin of a contacting not shown in detail

1 5 device.

The one shown in FIG. 1 "forming a contact member Spring contact pin 10 consists of a straight metallic contact pin 11, a straight metallic one Jacket tube 12, a straight metallic connection end 13 and a metallic compression spring 15. The contact pin 11 forms a welded component «. The parts 12, 13 are also welded to one another to form a component 17. Of the Contact bolt 11 · consists of two integral parts 30, 32. One part is a rotationally symmetrical, straight, thin rod 30, which is enlarged in diameter at its rear end and here forms a piston 31 which is guided straight in the jacket tube 12 and to which the cylindrical piston rod 33 is connected in one piece, the diameter of which can now generally be at most 3 mm, preferably 0.4 to 2.0. The second part is the contact head 32, which has a blind hole 34 into which the piston rod 33 is inserted with its front end. This contact head 32 has the contact tip 36. Furthermore, there is a dash-dotted line *; a test item 37

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g indicated, with the ee btpw. around a circuit board or "the like. acts" to which the contact tip 36 for electrical testing of a point is pressed by him. A contacting device, which usually has a large number of such spring contact pins, can test objects more quickly Check the sequence for electrical faults. This spring contact pin 10 is intended to to be used in a so-called adapter of a contacting device, which adapter has a plurality or in general a large number of such spring contact

Ig has pins that are spaced close to the center

are arranged side by side from one another * The cylindrical jacket tube 12 can, for example, have an outer diameter of 0.5 - 5 mm or be slightly larger or smaller « The connecting end 13 generally has a maximum diameter of 3 mm, preferably from about 0.6 to 1.6, but can also be a little larger or smaller. The thickness of the peripheral wall 38 of the bag hole of the Contact head 32 can preferably be 0.1-0.4 ram, but in some cases also be larger or smaller.

This contact head 32 is in this embodiment with the piston rod 33 inserted into it by means an overlap welding point 14 and a corner welding point 14 'connected.

The cylindrical, rod-shaped, metallic connection end is inserted a piece into the jacket tube 12 and with connected to this by a fillet weld point 14 ". And although the rear end of the jacket tube 12 is turned out in the shape of a truncated cone for this purpose, so that after insertion

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of the connecting end 13 is a groove 29, In the the fillet weld point 14 "is attached, his So name is derived from the word "throat".

All welding points 14, 14 ', 14 "each consist of one

weld the resulting 10

Melting from the materials of each with each other ..

welded parts 30, 32 or 12, 13 have arisen.

Every weld contains hardenable steel to such an extent

or consists of hardenable steel, that it can be used in Ver-15

weld through to the respective welding point adjacent cold areas of the relevant parts 30, 32 and 12, 13 for very rapid cooling of the melts and the resulting welding comes from them, so that

these welds harden and become brittle as a result 20

and also high hardnesses of e.g. 950 HV (Vickers hardness) to have.

These brittle welds create the risk of it

in the operation of this spring contact pin 10, so if he 25th

built into the adapter of the contacting device with its contact tip test specimens with axial sliding contacted in the jacket tube 12, due to the brittleness the welding causes cracks in the weld, which increases the electrical contact resistance between the through it each connected parts 30, 32 or »12, 13 can greatly increase, whereby the electrical resistances of the components 11, 17 can increase disruptively, since these transition resistances significantly reduce the electrical resistances of these two components 11, 17 35

can determine. Om to fix this danger or strong

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to reduce / each of these two components 11 and 17 is tempered at temperatures of preferably 250-650 ° C for a longer time and then slowly cooled to room temperature.

The brittleness of the sweat after the hardness before the

Tempering is especially high when at least one of the Parts 12, 13 to be welded to one another in each case or 30.32 made of carbon steel (carbon steel). The invention can therefore be used particularly advantageously, if so, however, it is not there limited, as it is when using other types of steel also too brittle, the risk of cracking during operation in concealed welding. the The invention is therefore to ver for such material pairings each with one another to form a component welding parts provided which when welding lead to brittle welding points, which, when the component is in operation, increases the risk of electrical contact resistance between the parts welded to one another contain considerably increasing cracking. By doing in these cases the sweat is left on, loses they wholly or largely their brittleness while reducing their hardness. This will make the The risk of the weld cracking during operation of the component in question is greatly reduced or entirely Fixed.

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The material of the parts 30, 32 or 12, 13 that are welded to one another can preferably be wholly or in the essential carbon steel (be carbon steel, since carbon steel low electrical resistance and good flexibility Has. C-steel can also be soldered, which is useful for both the «Inde 13 as well as for the Kontaktboleen 11 can be of importance.

The rod-like connection end 13 of the spring contact pin serves the electrical connection of an electrical conductor. For example, an electrical connector socket can be plugged onto this rod-shaped connection end 13 or a wire to be clamped or soldered etc.,

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Claims (1)

* ♦ I llj t IB «f · • ·> ■ · * t · siü ia · ι · - 1 - claims for protection 1. Electrical, multi-part component for a the testing of electronic test specimens in Hessen, such as circuit boards or the like, serving contacting device, which component is part of a contact member, z. B. a spring contact pin, or it forms and is intended to participate in the conduction ■, ·· of electricity, testing or Measure a point of the respective test serves when this point is through a contact tip of the relevant contact member of the contacting 15 device is contacted, wherein the component knows through at least one spot weld verb has both parts, the weld of the weld spot from the one created during welding Melt the materials of these parts formed 20th and the sweat from it to such an extent Hardenable steel contains that it hardened on cooling, characterized in that the welds of the at least one welding point (14, 14 '; 14 ") ι of the component (11; 17) annealed and its hardness 26th is a maximum of 700 HV. 2. Component according to claim 1, characterized in that that the hardness of the sweat of at least one Welding point (14, 14 '; 14 ") of the component (11; 30th 17) is approx. 550 - 650 HV. 3. Component according to claim 1 or 2, characterized in that it is a contact pin (11). 36 5567 - 2 - 5 4. Component according to claim 1 or 2, characterized t draws that it consists of a jacket tube (12) and I a metal rod connected to it I-like connection end (13) consists. . 10 5. Component according to one of the preceding claims, dadch ge f: indicates that at least a part of the at least • parts (11, 12; 30, 32) connected by a welding point ; ' entirely or essentially made of steel, preferably 1 is made of carbon steel. \ 15 ί "■" 6. component according to claim 1, 2 or 5, characterized 9 e- i indicates that it is a contact pin. 26th