DE8717620U1 - Device for connecting a connection-incompatible integrated circuit to a printed circuit board - Google Patents

Description

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Description

The invention relates to a device for connecting at least one integrated circuit to a connection-incompatible solder socket on a circuit board. It is particularly intended for carrying out memory expansions by replacing memory chips (RAMs) on computer boards.

The rapid development of electronic storage technology towards ever greater capacities means that computers and programmable calculators become obsolete in relatively short time intervals, especially in terms of the available storage capacity, and are replaced by new models. Since this is often accompanied by a change in the operating system, a change in model almost always also requires the software to be changed, which can require a lot of work and expense.

This problem is eliminated if there is the possibility of expanding the memory. However, if the new memory modules are not compatible with the ones being replaced, problems can arise when replacing them. This is especially true for compact minicomputers and pocket calculators, where there is little space available for accommodating the expansion modules.

The invention is therefore based on the object of creating a device of the type specified at the outset, with which the connection of expansion modules is possible even in compact computers without requiring a great deal of space and effort.

To solve this problem, the combination of features specified in claim 1 is proposed. Further advantageous embodiments and developments of the invention emerge from the subclaims. 5

The inventive solution makes use of the idea that the missing connection compatibility between a new memory module and the prepared soldering socket on the circuit board can be created by using a suitable adapter board. According to the invention, the adapter board has continuous

"\ Edge contacts on/ which are on the existing solder

socket _and the circuit board and can be connected to them by solder connections. Furthermore, the adapter board according to the invention contains a soldering station that is compatible with the connection lugs of the integrated circuit designed as a flat package, the soldering fields of which are connected in a suitable manner to the edge contacts. In order to enable the adapter board to be aligned exactly on the soldering base, the edge contacts have a concave contour with an open edge. Furthermore, they are connected across the board edge to contact strips arranged on the two sides of the adapter board, which ensure that the adapter board can be reliably soldered onto the soldering base. Certain solder fields of the soldering station are connected via conductor tracks to soldering eyes, via which additional switching elements forming the expansion circuit can be connected to the memory module.

30

Since the adapter boards are relatively small, several of these boards can be arranged on a panel board during production, which is made by cutting open

edge-closed through-contacts can be separated from the latter to produce the edge-open edge contacts . According to a preferred embodiment of the invention, the adapter boards on the panel board are separated from one another on at least two opposite sides by edge perforations, the edge contacts forming components of the edge perforations.

The invention is explained in more detail below using the embodiments shown schematically in the drawing.

Fig. 1 shows a section of a circuit board of a

Single-board computer with attached adapter board;

Fig. 2 shows a section of a utility board containing several adapter boards.

The circuit board 10 of a single-board computer shown in detail in Fig. 1 contains, among other things, two microprocessors 16, 18 designed as integrated circuits and at least one soldering base 12 for receiving

a memory chip (RAM). To form a memory chip-25

Furthermore, in the embodiment shown, the originally present RAM module was desoldered and replaced by a memory chip 40 with a larger storage capacity. Since the new memory chip 40 is not compatible with the soldering base 12, the chip 40 was soldered to the soldering point 36 of an adapter board 30, which in turn is soldered with its edge contacts 32 to the soldering fields 14 of the soldering base 12. By appropriately wiring the conductor tracks 46

The missing connection compatibility is created on the adapter board 30. 0 memory chip 40 has
opposite the solder base 12, some superfluous address connections, which are connected via corresponding conductor tracks 46
inside the adapter board 30 with the solder pads 44

These solder pads 44 can be used to connect jumper wires

45, over which with the help of mechanical

or electronic switch the different address '

areas of the memory chip 40 are accessible. jj

10

The edge contacts 32 connect the contact strips arranged on the wide sides of the adapter board 30
34 over the edge of the board. They have a concave $ semi-circular contour and thus enable |-

a very precise alignment of the adapter board 30 on | the soldering fields 14 of the soldering base 12 of the circuit board
10. To facilitate the soldering process and if necessary
To be able to automate the process, the edge contacts 32, the contact strips 34 and the soldering

fields 38 of the soldering point 36 of the adapter board 30 are appropriately pre-tinned. The same applies to the solder eye 44.

&zgr; For the memory chip 40, surface- mounted chips are used.

tible housing shapes with connecting legs bent outwards or inwards, such as S0 housing (small outline),
SMD housing (Surface Mount Device) or PLCC housing
(Plastic Leaded Chip Carrier). \

The insulating gaps 39 between the soldering fields \

38 of the soldering station 36 are smaller than the width of the |

Connection lugs of the flat pack forming the memory chip 40. The gaps 39 are also advantageously narrower than the soldering fields themselves. This achieves.

that the memory chip 40 can be positioned without difficulty on the pre-tinned soldering fields 38 of the soldering station 36, which are thus slightly protruding from the adapter plate, without the connection lugs penetrating into the gaps 39 and becoming caught there.

Since the adapter board 30 has relatively small dimensions, several adapter boards can be combined on a utility board 48 during production. The adapter boards 30 are separated from one another on the panel board 48 by edge perforations 50, so that the individual adapter boards 30 can be separated from the panel board 48 by simply cutting or punching them in the area of the edge perforations. Some of the holes forming the edge perforations 50 are designed as through-holes 51, which, when cut, form the edge contacts 32 for the connection to the solder base 12. In order to avoid connection errors, the through-holes 51 marked at their ends within the edge perforation 50 by gaps 52 free of drilling. The wall thickness of the board material is suitably chosen so that it can be cut with sharp scissors. This works with a wall thickness of less than 0.4 mm, preferably 0.2 to 0.35 mm, whereby the perforations serve as a guide for the scissor cut. The thin board wall thickness has also proven to be advantageous when soldering the adapter board 30 onto the soldering base 12.

Claims (10)

G 87 17 S20.3 Dr.-Ing. Eckhard Wolf Protection claims 1. Device for connecting at least one integrated circuit, in particular a memory chip, to a connection-incompatible soldering base of a printed circuit board, characterized by an adapter board (30) which has edge contacts which fit onto the soldering base (12) of the printed circuit board (10) and can be directly connected thereto by solder connections, a soldering station (36) intended for the connection lugs (42) of the integrated circuit (40) designed as a flat package, and conductor tracks (46) connecting the soldering fields (38) of the soldering station (36) to the edge contacts (32), wherein the edge contacts formed by cutting open edge-closed through-holes (51) (32) have a concave contour with an open edge and are connected across the board edge (33) to contact strips (32) arranged on the two broad sides of the adapter board (30). 2. Device according to claim 1, characterized in that the adapter board (30) has soldering pads (44) connected to certain soldering fields (38) of the soldering station (36) for the connection of external switching elements to the integrated circuit (40). 3. Device according to claim 1 or 2, characterized in that the edge contacts (32), the contact strips (34), the soldering fields (38) and optionally the soldering eyes (44) of the adapter board (30) are pre-tinned. 4. Device according to one of claims 1 to 3, characterized in that the insulating gaps (39) are smaller than the width of the connection lugs (42) of the flat pack (40) to be soldered. 5. Device according to one of claims 1 to 3, characterized in that the soldering fields (38) of the soldering station (36) are wider than the insulating gaps (39) formed between them. 6. Device according to one of claims 1 to 5, characterized in that several similar adapter boards (30) are arranged on a panel board (48) and can be separated from the latter by cutting open the edge-closed vias (51). 7. Device according to claim 6, characterized in that the adapter boards (30) on the utility board (48) are separated from one another at least on two opposite edges by edge perforations (50), that the edge contacts (32) are part of the edge perforations (50), and that the edge perforations (50) can be severed by separating the individual adapter boards (30). 8. Device according to claim 7, characterized in that the edge perforations (50) have a perforation-free gap (52) at the ends of the edge contacts (32). 9. Device according to one of claims 1 to 8, characterized in that the adapter board (30) or the blank board (48) has a wall thickness of less than 0.4 mm, preferably from 0.2 to 0.35 mm. 10. Device according to one of claims 1 to 9, characterized in that the integrated circuit (40) has a surface-mountable housing form.