DE8905703U1 - Soldering frame - Google Patents

Description

^GR89 64064

Siemens AG
Solder frame

The innovation relates to a soldering frame with support rails for holding assembled circuit boards to be soldered automatically, where the support rails have spring-loaded clamping elements on their long sides for holding the circuit boards.

In a known soldering frame of this type (illustration on the cover of the book by RJ Klein "Weichlöten in det Elektronik", 1986), spring bodies with a U-shaped cross-section are placed and fastened over the support rails, which have individually spring-loaded clamping elements formed by punching out their legs that run along the long sides of the support rails . Each individual spring-loaded clamping element is bent at its lower end towards the adjacent support rail, so that a support is formed for an assembled circuit board to be soldered . Due to their spring properties, the clamping elements absorb thermal expansion of the circuit board to be soldered when it is heated during the soldering process .

The innovation is based on the task of designing a solder frame with old support rails so robustly with regard to the spring-loaded clamping elements that the clamping elements do not become damaged even after frequent insertion and removal of circuit boards.

To solve this problem, in a soldering frame of the type specified at the beginning, the spring-loaded clamping elements are, according to the innovation, spring-loaded pressure pieces held in lateral recesses of the support rails.

A major advantage of the new soldering frame is that the spring-loaded pressure pieces are relatively

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2 GR 89 G 4 064 are insensitive and stable, i.e. they cannot be damaged or bent when circuit boards to be soldered are inserted into the soldering frame or when circuit boards that have already been soldered are removed from the soldering frame. In addition, the spring-loaded pressure pieces can generate such a large clamping force that the circuit boards inserted into the new soldering frame cannot be pushed out upwards during the soldering process; no further measures are required in this regard.

In the case of the new soldering frames, the spring-loaded pressure pieces can be designed in different ways. For example, they can be cuboids or cylinders set into recesses in the support rails, each of which is supported by a The springs are pressed outwards by a spring housed in the mounting rail. It is considered advantageous if the spring-loaded pressure pieces have recesses for accommodating the circuit boards, whereby the recesses can be formed, for example, by steps or notches. These recesses then also form the support for the circuit boards.

In a particularly preferred embodiment of the soldering frame according to the invention, the spring-loaded pressure pieces are ball pressure pieces, and the support rails have pressure pieces have support steps for the circuit boards on their long sides. The particular advantage of pressure pieces designed in this way is that they are relatively easy to obtain and can be easily held in the support rails.

Sometimes circuit boards have to be soldered that have recesses on the sides. In the area of such recesses, the circuit boards are not clamped between the mounting rails, so that undesirable bending can easily occur during soldering. can follow. To avoid this, according to a further design of the new soldering frame, the support rails

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3 GR 89 64 064 I

provided with longitudinal grooves on their upper or lower side, in |

whose fastening elements can be moved with support brackets |

are stored. 1

To explain the innovation, see I

Figure 1 is a plan view of an embodiment of the !

new soldering frame, in [

Figure 2 is a section along the line II-II according to Figure 1 i

and in j

Figure 3 is a section along the line III-III of Figure 1 j

reproduced. \

The soldering frame 1 of the illustrated embodiment, which is moved in the direction of arrow 2 for soldering, is provided with a guide plate 4 on its front side 3. On its rear side 5, another guide plate 6 is attached to the soldering frame 1.

The guide plates^ 4 and 6 are used to hold j

Support rails 7 and 8, which - as shown in particular in Figure 3 - \

are provided with slots 9 at their ends. The slots 9 \ ,

the support rails 7 and 8 take a bent strip 10 of the guide plates 4 and 6 respectively on the bent strip

10 the support rails are movable transversely to the transport direction 2,

bar and are adjusted to the desired position using clamping screws 11. |

locked in position. *

Each support rail 7 or 8 is equipped with spring-loaded pressure pieces!

12. These spring-loaded pressure pieces 12 are designed as t

Ball thrust pieces; each ball thrust piece consists of I

from a sphere which, in a manner known per se (not shown), |

is inserted into a blind hole and partially through |

an opening in the blind hole protrudes. In the blind hole j there is also a cylinder spring, also not shown for the sake of clarity, which presses the ball outwards after the blind hole is closed.

i

In particular, Figure 2 shows that each support rail 7 or ■

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4 GR 89 G 4 0 6 4 8 are provided with support shoulders 14 and 15 or 16 and 17. In the embodiment shown in Xb, a circuit board 18 to be soldered with electrical components indicated in Fig. 1 by diagonal hatching rests on the support shoulders 15 and 16 and is clamped between ball pressure pieces 12 of the support rails 7 and 8; the ball pressure pieces 12 give way when the circuit board 18 expands when heated and thus prevent the circuit board from bending during soldering. If necessary, known tension wires running transversely to the support rails in the soldering frame can be provided for further support of the circuit boards.

From Figures 1 and 2 it can also be seen that the support rails 7 and 8 are provided with grooves 15 in which fastening elements 20 can be moved longitudinally. The fastening elements 20 are connected to a support hook 21 which is required in the event that - as shown - a circuit board 18 with a recess 22 is to be soldered. The circuit board 18 is supported in the area of the recess 22 by the support hook 21 or its projection 23, thereby preventing bending in the area of the recess 22. The support hook 21 is also provided with further spring-loaded pressure ball pieces 24, so that bending due to thermal expansion is also prevented in the area of the circuit board 18 which is adjacent to the recess 22.

In particular, it can be seen from Figure 1 that the support hook 21 is provided with a longitudinal slot 25 so that it can be moved transversely with respect to the support rail 7; its position can thus be adjusted according to the recess of the circuit boards to be soldered. The support hook 21 is fixed in the desired position with the aid of a clamping screw 26.

Finally, it should be noted that sometimes conductors

01 04

5 GR 89 64

1 plates are to be soldered which are provided with components that protrude downwards, as is the case with component 27 (see Figure 3). Since this protruding component should not come into contact with the solder, the guide

5 sheet 4 in the illustrated embodiment sawn downwards.

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Claims (3)

Protection claims 6 GR 89 G 4 1. Soldering frame with support rails (7,8) for holding automatically soldered, assembled circuit boards (18), whereby 5 the support rails (7,8) have spring-loaded j Clamping elements (12,13) for holding the circuit boards (18) ' exhibit, ' characterized in that the spring-loaded clamping elements are spring-loaded pressure pieces (12,13) held in lateral recesses of the support rails (7,8). 2. Soldering frame according to claim 1, characterized in that the spring-loaded pressure pieces have external recesses for receiving the circuit boards. 3. Soldering frame according to claim 1, characterized in that the spring-loaded pressure pieces are ball pressure pieces (12, 13) and that the support rails (7, 8) below the ball pressure pieces (12, 13) have support shoulders (14 to 17) for the circuit boards (18) on their long sides. |e 25 4. Soldering frame according to one of the preceding claims* '';. characterized in that the support rails (7,8) are provided on their top or bottom with longitudinal grooves (19) in which fastening elements (20) with support hooks (21) are slidably mounted. iS 30 02 01