PLOT DE REPORT DE CONNEXION POUR LA FIXATION D'UNE BROCHE A GRIFFES SUR LA TRANCHE D'UN SUBSTRAT DE CIRCUIT HYBRIDE

The present invention relates to the hybrid circuitry [...] i.e. subsets of electronic components assembled

in a high density on a flat carrier substrate which is called

in general a thin wafer of ceramic covered on a

or both sides of a network of resistors and screen printed conductive tracks protected as by an insulating coating vitrified

and [...] pads for securing electronic components by soldering. It ℮ relating more particularly to the 3T [...] said carry pads that are disposed along the connection

the edges of the substrates and are designed to fix blades used for electrical connections of hybrid circuits with the outside environment.

In general the connection pins made

band by stamping and bending in a guiding sheet comprise a head terminating in a three legged elastic clamp offset on one side and adapted to latch on the edge of a substrate, two claws from substrate and the third on the other.

The studs carry edge connecting substrates for

receiving SSO pins conventionally consist, of two rectangular [...] ranges of the width of the clamp pins, facing to each other on opposite sides of an edge of the substrate, the locations of the three claws gripping the clamp of a

pin.

The mounting strips of connecting pins on the edges

the substrate occurs while the latter, still naked,

has been tinned for carry-all components and their solder reflow simultaneously, and that the studs carry connection are covered with domes of solder from a thickness hardly controllable, non-negligible relative to that of the substrate. It

this results in at least two disadvantages, the first being the difficulty of centering of the three gun of a pin on a stud

due to its raised double dome-like in shape of a sphere and the second being that the thickness domes of solder pad of a sometimes exceed the elastic limits of the clamp

dog pins and then causes a decrease in the spring effect which precluded to the claws of the clip back in contact with the substrate during reflow operation.

The present invention aims to combat these disadvantages that lengthen the installation time and result in a high rate of correction.

It concerns a pad transfer connection for attachment of a dog pin on the wafer of a hybrid circuit substrate having at least one range [...] placed over an edge of the substrate, the locations gripping claws of the pin forming the jaws of a resilient clip for engaging around the edge of the substrate and securing the pin and which is cut, for each claw of the pin from the side of the substrate where the land is positioned, a groove at the location of the sliding path followed by the claw in question of the spindle when it is placed on the edge of the substrate, which groove has a width slightly less than that of the claw so it bite on the range [...].

Advantageously, the pad transfer connection comprises

two ranges [...] facing each other on opposite sides of a substrate edge. In the case of a pin having a spring clip to three claws arranged side by side, the claw median from a first side of the substrate and the two outer prongs of the second side of the substrate, the range of the stud [...] carry connection arranged on the second side of the substrate is preferably in the form of a T, the grooves at the locations of the glide track two claws of the leg of the T-bounding outer

and abutting its shoulders while the range [...] carry the pad in place on the first side of the substrate preferably has the shape of a U, the groove at the location of the sliding path of the claw median penetrating between the arms of the U shape and abutting the bottom thereof.

The grooves at the locations of the glide track

the claws of the holder of a pin form valleys in the domes of solder pads overlying [...] plot3 of transfer which help center without difficulty the holder of a pin on the pad and on the other hand, exhibit this claw to a thickness sufficiently small enough of a different which remains in all cases within its elastic limits.

The reflow with simultaneous or subsequent recharging by dipping or soaking in a bath of solder pads and claws pins attached thereto causes the application by spring claws pins on the edge of the substrate and therefore the bolts are on the substrate to the solid solder, migration on the prongs of the solder pads are loaded and then covering the [...] dogs and [...] ranges by domes of solder.

Other features and advantages of the invention shall become apparent from the description hereinafter of an embodiment example. This description will be made opposite the drawing which comprises s

- 1 of Figures 2 and showing, perspective top view

and from below, a pin presented to a pad side edge connecting transfer according to the invention adapted to receive it;

4 - of Figures 3 and showing, perspective top view

and below, a spindle head in place over a pad transfer edge connector according to the invention and;

- of Figures 5, 6 and 7 showing in cross section the hooking claws of a spindle head on a pad transfer edge connecting element according to the invention before and after a reflow soldering without recharging or with solder.

Distinguished in Figures 1 and 2 a corner of substrate 10

hybrid circuit that carries two studs carry the edge and, opposite, a connector pin 30 for placement over one of the studs carry.

The hybrid circuit substrate 10 is comprised of a thin wafer of ceramic on the order of 0.6 mm thickness on each of s ℮ the 3 faces an array of strip conductors 11, 12, 13, 14 which is covered by a screen printed insulating protection layer vitrified 15, 16 and leads to pads [...] in chip component pads and carry the edge. The studs carry edge connecting each have two ranges [...] 17, 18 facing to each other on either side of an edge of the wafer of the substrate 10. These ranges [...] 17, 18, as those of the connecting components support domes solder resulting from a tinning, bare of the aroma 10, [...] brazing, in a single reflow operation, of all connections after placement of components on the substrate 10.

The connecting pin 30 made by stamping and bending

a guiding sheet has a connector tail 31 provided with an enlarged head attachment 32 extended with three claws 33, 34, 35 arranged side by side and bent side according

a suitable folding to form a resilient clip side opening and flared jaws adapted to the thickness of the substrate 10.

The two outer prongs 33, 35 folded to their [...] according to a same profile constitute the lower jaw of the clip while the claw - that middle folded only halfway along overhangs the other two and constitutes the upper jaw of the clip.

The tinned pads 17, 18 carry a stud connection

which interleave with the claws 33, 34, 35 of the clip connection pin 30 are notched grooves 19, 20, 21 which are perpendicular to the edge of the substrate and terminate on the latter.

A width somewhat smaller than claws 33, 34, 35, they follow the glide track their [...] of

placing a connector pin 30 on the pad transfer connection.

In the present embodiment a reduced spacing between the ORO -

* microsympatric (l/10ème inch or 2.54 mm) [...] pads 17, 18

a pad transfer connection do not exceed the total width of three claws 33, 34, 35 connection pin so

than 17 where rests the single finger middle 34

is notched a middle groove 19 giving it the general form of a 0 and 18 than that which does the

two outer prongs 33, 35 is notched on either side by two grooves 20 and 21 forming it generally T-shape.

In the case of a least reduces spacing, [...] ranges from one pad transfer connection can exceed the width of the three claws 33, 34, 35 of a connecting pin, wherein the 17 bears the single finger middle 34 maintaining the form of a 0 but with wider wing and that 18 where abut outer two clamps 33, 35 taking a W shape.

More pads carry neighboring connection may also be joined to carry more pins in parallel and allow such as changing a current magnitude greater.

[...] ranges thereof facing each other on either side of an edge of the substrate 10 then form the bars which run along this edge

and are notched perpendicular grooves spaced in accordance with the separation of the indicia claws 33, 34, 35 of the pins engaging fastening thereto.

The grooves 19, 20, 21 at locations of the slideways claws 33, 34, 35 of the holder of a pin 30 form valleys between or at the edges of domes of solder pads covering the [...] 17, 18 carry a stud connection in which a wedging engagement claws 33, 34, 35. This ensures on the one hand self-centering of the clamp pin 30 on the pad transfer - and decreases the magnitude of the opening of the clamp by preventing it from having to absorb any thickness overlying the domes of solder pads [...] 17, 18.

As shown in Figures 3, 4 and 5, the prongs 33, 34, 35 of the clip connection pin 30 once in place over a pad transfer connection biting on the edges of the pads [...] 17, 18 of this stud, the middle claw 34 by its end and each of its lateral edges and the outer claws 33,

35 by ends and opposite side edges 36, 37 · this is achieved, by forming the middle groove 19 forming the opening of the U shape of the range [...] 17 a smaller width, e.g. 0.02 to 0.25 mm, than the middle claw 34 and to the spacing between the grooves 20, 21 determines the width of the leg of the T-shape of the range [...] 18

a greater width, for example of 0.1 to 0.5 mm, the spacing of the two outer prongs 33, and 35 - in the example represented,

the width of the opening of the U-shape of the range [...]

17 is 0.5 mm for a width of the claw median of 0.55 mm and the width of the leg of the T-shape of the range of 0.8 mm [...] 18 a distance a of the antrum outer prongs 33,

35 of 0.55 mm -

Owing to the slight overlap held between the claws 33,

34, 35 connection pin 30 and the lands [...] 17,

18 carry connecting the bond pad, the solder contained in the domes can easily migrate on SAL claws 33, 34. 35 during a reflow operation. Figure 6 shows the result obtained after a reflow process, without charging solder, the solder in SAL domes [...] pads 17, 18 having joined, by capillary action, the edges and the ends of the claws 33, 34,

35 of the pin 30 - la fig. 7 shows the result after

a reflow solder and a recharging of simultaneous

or later by immersion or wetting dan3 a solder bath

the one or more edges of the substrate 10 carrying pads carry connection equipped with pins, the solder bath temperature as that deposited initially on the pads [...] 17, 18 having formed new domes completely covering the claws 33, 34, 35 of the pin 30.