DE3033881A1 - Free-standing circuit module - with modules and conductors on two sides connected to two groups of connector pins - Google Patents

Abstract

A freestanding plug-in circuit module, specially for use as a coder-decoder module in digital telpheone exchange systems, includes a carrier board which has conductor tracks only in two planes, i.e. its front and its rear. A first part of the connector pins is connected with the group of conductor tracks on the front of the board, and a second part is connected to those on the rear. A first part of the terminals of modules mounted on the board, is joined to the inside ends of first conductor tracks, and a second part to those of a second group of conductor tracks. The board is made of Teflon (RTM), epoxy resin or polyimide. This permits a high packing density and facilitates cooling. The board has a good flexural rigidity.

Description

Housing-less circuit module and method for its

Production The invention relates to a vertically pluggable, particularly compact electrical circuit module, especially for encoder-decoder modules of a digital telephone switching system was developed, but that in itself can also be used as a small assembly in any systems and devices can, especially instead of dual-in-line modules with housing.

The invention is based on a housing-free circuit module, with - flat, insulating, flat support, for carrying cables and several electrical components, at least one of which is an integrated housing-less semiconductor circuit body is -, preferably pluggable and solderable, metal pins as electrical external connections, which are attached to only one side of the carrier, namely on the connection side are, the axes of which are directed perpendicularly away from the connection side and whose Axes simultaneously in, through the connection side and the side perpendicular to it of the carrier, are level, - a connecting side length that is considerably, E.g. three times greater than the length of the perpendicular side of the girder, - internal electrical connections in or on the carrier, for connecting with connectors the electrical components, and - Lines between the external connections and internal connections, possibly also between different internal connections.

Such a single-in-line circuit module is already, at least largely, by - DE-AS 1 912 260, in particular Fig. 1 in connection with Sp. 1, Lines 23 to 59, previously known. There are not, at least not expressly, the integrated semiconductor circuits present according to the invention are specified, and in particular in column 1, line 55 a square shape of the carrier is described, although the shape of the, there in Fig. 1 schematically and perispectively distorted shown, circuit module rather gives the impression of a rectangular shape - that is as if, as in the invention, the connection side with their metal pins considerably longer than the perpendicular side of the carrier would be chosen. As far as there in the text Microcircuits are specified, make the explanations there for these circuits rather the impression that there, unlike the invention, is exclusively on the equipping with several discrete lines, among each other at most via printed lines connected electrical components such as individual capacitors, resistors, transistors and diodes, see column 1, lines 27 to 31 and column 4, lines 20 to 39.

In the invention, however, an even higher packing density is required, namely the attachment of at least one integrated housing-less semiconductor circuit body (Chip) provided - which is generally also correspondingly high punctual Power losses and heating problems or characteristic curve stability problems with brings itself.

The invention, like this prior art, has that in the prior art advantage not fully appreciated by technology - as a special variant of a single-in-line module perpendicular inserted into a perforated plate, and there e.g.

additionally soldered to be able to, making the the front just like the back of the carrier well ventilated and thus the circuit module or its components can be cooled well (which in the case of the invention is a reliable Operation in particular of the semiconductor integrated circuit bodies, e.g. from against Temperature fluctuations are quite sensitive encoder-decoder chips, especially is important), i.e. the components can also be subjected to a higher load of electricity, before malfunctions occur, the inherent rigidity of the perpendicular solid A circuit module that is plugged / soldered into the perforated plate is similar to a stiffening one Rib for the perforated plate works, especially when such rib-shaped circuit modules plugged vertically both on the front and on the back of the perforated plate so that, with a high current load or with strong heating of the perforated plate, this perforated plate no longer deforms as easily as with dual-in-line modules, E.g. it can bulge or bend, and therefore not as easily as with dual-in-line modules the operation of the entire device or system, e.g. uniform cooling of all Circuit modules despite very tight packing density, can affect, and at Easily on both the front and the back of the wearer if required some additional discrete electrical components - e.g. for smoothing DC voltages, Resistors and capacitors - can be attached - the length of the lines to be able to make already quite short directly on the circuit module, whereby the circuit module can also be operated with particularly high frequencies, - the integrated semiconductor circuit body attached to the carrier is now also below dynamic in normal environmental conditions, i.e. reliable at high operating frequencies to be able to examine; the one still lying on the wafer, not yet from its neighboring semiconductor circuit bodies separate semiconductor circuit bodies, as well as the already separated but Semiconductor circuit bodies not yet attached to the carrier are, if at all, only dynamic with restrictions, under abnormal environmental conditions, testable; and - the circuit module is particularly handy, in particular particularly light in one Perforated plate, plug in and solder as well as particularly space-saving before its attachment to be able to stack or store on perforated plates in stacks or boxes.

The invention is based on features and. their advantages from the all not immediately, but, if at all, then only remotely on the edge Fantasy can be found in the state of the art mentioned.

Moreover, single-in-line circuit modules are nowadays for integrated Semiconductor circuit bodies, usually called chips, not common; instead of this are nowadays mainly dual-in-line circuit bodies common, but their The bottom is comparatively difficult to cool and there is a lot of space on the perforated plate require.

Similar circuit modules, but at least one of them The above features and the associated benefits are lacking in great Number known, for example, the subject of - DE-OS 2 150 223, in particular Fig. 1, in particular the special shape of the carrier by there the connection side is shorter than the perpendicular extension of the carrier, so that the corresponding Stiffness and particularly easy coolability is missing, - DE-PS 22 46 611, in particular FIG. 2, in particular again this special shape; Additionally it is no longer a small assembly of the lowest order, but rather a higher-order assembly, since it is more of a perforated plate, are to be attached to the circuit modules than immediately around a circuit module acts himself; - DE-OS 2 138 055 any detail about the shape of the carrier and about the type of components it carries, as well as the associated advantages in the invention, - DE-AS 1 292 715, in particular Fig. 3, the metal pins for Plugging or soldering into the perforated plate; and in Fig. 2 / below it is only around a carrier of a higher order, namely an adapter plug, instead of directly to a circuit module, - DE-AS 1 264 550, in particular Fig. 1 / bottom right, the Housingless (it is a common housing having circuit body) with correspondingly poor coolability and high space requirements, i.e. reduced Compactness, and - DE-PS 24 15 047, in particular Fig. 1, 2 and 4, again the relevant The shape of the carrier and the metal pins clearly allow the circuit module to be plugged in vertically.

The invention has further, through the teachings of DE-AS 1 912 260 unattainable advantages, namely those now through appropriate dimensioning achievable advantage, - with quantities in the integrated semiconductor circuit body that This semiconductor circuit body is only revealed during the, preferably dynamic, test for itself from the carrier again and easily through another semiconductor circuit body to be able to replace who now (maybe) has better dynamic behavior, whereby that of the removed semiconductor circuit body, because it does not itself have a housing has particularly little effort to produce before it is removed or thrown away required the de finally attached semiconductor circuit body for lack of its own Housing can be cooled particularly well and therefore particularly few changes in properties due to changing local overheating, also the carrier of the circuit module, including any vias between the front and front conductors the back, depending on the material (glass, ceramic, plastic), in particular through known processes such as cutting, punching, drilling and laser bombardment - the lines, especially in thin film technology, according to the carrier material to be able to produce in a manner known per se, - the carrier and space-saving material-saving to be able to make very thin, because he himself, if he is special is thin, then largely unbreakable compared to glass carriers and ceramic carriers remains and thus in particular the circuit module and the fitter or system administrator the application test or

Assembly of the module on the perforated plate is less at risk - one particularly high packing density on the perforated plate with particularly high compactness of the lines and the electrical components on the circuit module - the levels containing the lines, i.e. the front and rear of the wearer to be able to cool particularly strongly and easily, and with such a comparative thin carriers generally do not only have the lines on the front of the carrier from the air on the front of the wearer, but also through the wearer through better than before from the air on the back of the wearer to be able to cool, as well as in a corresponding way the lines on the back the wearer also better than before additionally from the air on the front of the To be able to cool the carrier.

These advantages are achieved in that - the carrier only on his Front and back, i.e. in two levels, contains lines - a first part the metal pins are connected to first lines on the front of the carrier plate is, - a second part of the metal pins with second leads on the back the support plate is connected, and - a first part of the connections of electrical Components with the inner connections first, and a second part of the connections of electrical components is connected to internal connections of second lines.

Allow the additional measures mentioned in the subclaims to achieve additional advantages, namely the measure according to claim 2, to achieve a tight packing of the perforated plates closely fitted with the circuit modules, without preventing the good cooling of the circuit modules, 3, a particularly good one Flexural rigidity of the perforated plate along the connection side of the soldered circuit modules to achieve, especially if the perforated plate on both sides with such circuit modules is equipped, 4, crossings of the lines on the front and back of the carrier to enable, as well as the electrical mounted on one carrier surface To connect components with lines of the opposite carrier surface and To solder connections of the electrical components in the holes of the pressure contacts, 5 to 9, to choose different carrier materials depending on your needs - e.g. a good Adhesion of the respectively selected metals, or metal layers, of the lines on the relevant plastic carrier or high rigidity or good temperature resistance to achieve 10 b & s 1 ?, the mechanical properties of the plastic Carrier, in particular with regard to machinability, e.g. by drilling, as well as with regard to To improve rigidity in spite of the fact, 13, the assembly of the circuit module with regard to the connections of the internal connections of the carrier to the connections of the semiconductor circuit module to improve, with a dynamic preliminary test of the fastened on an intermediate carrier Semiconductor circuit bodies before their connection on the internal connections of the carrier already possible under largely final environmental conditions, what the complications reduced, 14, the cooling of the circuit module during assembly of the circuit module to further improve, 15, in a simple manner the lines, the internal connections and connect them to the component terminals, and 16, the dropping or slipping of components, in particular from below or to the side of the Each component carrier layer to be attached while the solder paste melts to prevent in the oven.

The invention and its developments are illustrated in the figures The illustrated embodiment is further explained, with FIG. 1 showing the front side, and Fig. 2 shows the rear of this circuit module. The frameless circuit module shown shows the flat, insulating, flat support T, which is used for carrying of lines, e.g. L1 on the front side shown in Fig. 1 and L2 on the in Fig. 2 shown rear side, serves, as well as for carrying one or more electrical Components, including at least one integrated semiconductor circuit body, serves, here namely from the two integrated semiconductor circuit bodies without a housing H1 and H2, one of which is, for example, an encoder-decoder chip and the other of which is a Represents 2-wire-4-wire fork chip. Preferably plug-in and solderable metal pins M are so on only one as external electrical connections in a single-in-line manner Side A of the carrier T attached, namely on the connection side A that the axes of the metal pins M are directed perpendicularly away from the connection side A and at the same time in, through the connection side A and the perpendicular side S of the carrier T educated, level lying. The length of the connection side A is considerable, e.g. three times, greater than the length of the perpendicular side S of the carrier, which is completely rectangular here T, so that the carrier T inserted vertically into a perforated plate lengthways the perforated plate its long side A stiffened. The electrical internal connections I, see. Fig. 2, serve to connect with connections of the electrical components, see H1 and H2. Corresponding internal connections are used, covered in FIG. 1 by small insulating foils F1, for connecting to additional discrete resistors R and discrete capacitors C. The lines L1, L2 connect the external connections M with internal connections I as well different, see Fig. 2, internal connections I with each other.

The two integrated semiconductor circuit bodies H1, H2 have no housing, e.g. protected with a lacquer instead of a housing, and here on an intermediate carrier film attached, see Siemens, Bauteile report 16 (1978) H.2, pp. 40 to 44 ç DE-PS 24 14 297; as well as VDI nachr.

Aug. 29, 1980, p. 5, left / top. In the one shown in the figures Incidentally, the example is a 2-chip eroder-decoder module, possibly also with hybrid chip, a PCM telephone switching system, which can contain thousands of such modules per central office. Several more discrete electrical components, namely capacitors C and resistors R, are in particular attached to the circuit module because of the smoothing of the DC supply voltage (because they could not be integrated with the corresponding size), so that the circuit module is a complete circuit unit in itself.

The semiconductor circuit bodies HI, H2 without housing on the said to attach flexible intermediate carrier film ZT, and the connections of the intermediate carrier film ZT to connect each with internal connections 1, allows the assembly of the circuit module with regard to the connections of the internal connections I of the carrier T with the connections of the semiconductor circuit module H1, H2, with a dynamic preliminary test the semiconductor circuit body H1, H2, fastened on an intermediate carrier ZT their connection with the internal connections I of the carrier T, already largely under final environmental conditions, especially those caused by bond terminals what the complications in the later assembly on the perforated plate in the Testing of the circuit module reduced.

A first part of the metal pins M is connected to first lines L1 connected to the front of the carrier shown in Fig. 1. A second part of the Metal pin M is connected to second lines L2 on the back side shown in FIG. 2 of the carrier connected. Furthermore, a first part of the connections is electrical Components H1, H2, R, C with the internal connections I of the first lines L1 and a second part of the connections of electrical components H1, H2, R, C with the internal connections second lines L2, in part via vias D of the one shown in FIG Front, connected. In this way, a particularly high level of compactness is achieved respectively.

Packing density achieved by - also crossing lines L1, L2, especially because of the plated-through holes D, are permitted - the lines LI, L2, especially short, low inductance and low stray capacitance are therefore also for high operating frequencies can be low-interference despite the high compactness.

This single-in-line module can be plugged vertically into a perforated plate and there, for example, can also be soldered, whereby the front as well as the back of the carrier T is well ventilated and thus the circuit module or

its components and lines L1, L2 can be cooled well, which is particularly important for reliable operation of the chips. This allows these components are additionally loaded with more electricity before their faults Enter operation. The own rigidity of the vertically firmly inserted into the perforated plate, In particular, the soldered circuit module acts similarly to a stiffening rib for that perforated plate, especially if both such rib-shaped circuit modules plugged vertically on the front as well as on the back of the perforated plate were, whereby, with high current load or with strong heating of the perforated plate, this perforated plate no longer deforms as easily as with dual-in-line modules, e.g. bulge or

can bend and not as easily as with dual-in-line modules impair the operation of the device or system containing the circuit module can, for example, no longer provide uniform cooling so easily all Circuit modules of a telephone switching system, despite their large number with very tight packing> can prevent. In addition, this special, unusual, handy single-in-line design a particularly cost-effective / low-effort Installation of just such telephone switching systems ijt: # im.r extremely high number such circuit modules per telephone exchange.

The arrangement of the lines L1, L2 directly on the carrier T of the Circuit module, e.g., about 1 x 3 inches (Figs. 1 and 2 are 2-fold linearly enlarged, approximately true-to-scale representations), is in particular adapted to the need to attach all metal pins M along the connection side A. and still achieve a high level of compactness with short cable lengths.

The chips HI, H2 attached to the carrier T are now on the circuit module can also be reliably tested dynamically, i.e. at high operating frequencies, whereby the Circuit module particularly handy, especially easy to plug into a perforated plate and solderable and particularly space-saving, before mounting on perforated panels, in stacks or cardboard boxes are stackable or storable.

In the event of defects in the HI, H2 chip that show up during the dynamic test, the chip in question can be removed from the carrier T again and easily through another chip of the same type can be replaced, which is now required during the test can exhibit dynamic behavior.

You can see the lines L1, L2 on the front and back of the carrier T cool particularly vigorously and slightly.

With such a comparatively thin carrier, the lines are thereby L1 on the front of the carrier T (Fig. 1) not just from that Air on the front of the carrier T, but also through the carrier T. also cooled by the air on the back of the carrier T (Fig. 2), especially when the carrier T is made of thin plastic. The lines are in a corresponding manner T2 on the back of the carrier T (Fig. 2) also particularly well from the air the front of the carrier T (Fig. 1) cooled.

A length of the side S of 1 inch / inch or less allows it to be narrow Pack of perforated panels closely fitted with the circuit modules, without the good ones To prevent cooling of these circuit modules. A length of the connection side A of at least 1.5 inches permits particularly good flexural rigidity of the perforated plate to reach along the connection side A of the soldered circuit modules, especially if the perforated plate is equipped with such circuit modules on both sides.

If the carrier T is made of ceramic or glass, one can special achieve great rigidity of the circuit module. The lines Ll, L2 can easily can also be applied using thin-film technology, e.g. with the familiar layer sequence Carrier-titanium-palladium-gold. The risk of high losses / operating temperatures the carrier T and thus the perforated plate warp and thus with a high packing density hinder the necessary cooling of the electrical components, is with ceramic carriers and Glass carriers particularly low.

If the carrier T consists of plastic, or at least high plastic advantages it is particularly easy to edit. Carrier T, including any Vias D between conductors on the front and back are therefore easy to manufacture or form, in particular by cutting, punching and drilling.

The carrier T can then save space and material even can be made very thin because, even if he is particularly thin, in comparison- to the brittle glass and ceramic supports remains largely unbreakable and because of it in particular the circuit module and the fitter or system administrator in the application or exam or

Assembly of the circuit module on the perforated plate, less endangered than T.

Polyimide, epoxy resin and Teflon were found to be particularly suitable Plastics for the carrier T, these plastics fillers, e.g. paper and / or Glass fibers, which improves the mechanical properties of Tråger T, especially with regard to its machinability, e.g. by drilling, as well as with regard to Rigidity despite thinness, allowed to be further improved. Such holes are e.g. for plugging in the other components R, C important. or. for attaching vias D between lines L1 on the front and lines L2 on the rear.

Metallic shields F, which are e.g. earthed, do not improve only the insensitivity to interference, but also improve the cooling. Isolation foils F1 prevent short circuits.

The cooling of the circuit module is further improved, if at least some of the intermediate carrier films ZT and / or other electrical components C, R in, not shown in the figures for the sake of clarity, windows in the carrier T are attached, so the internal connections I are at the windows.

The example shown in the figures can be produced in that in successive process steps - the first lines L1 and first Internal connections I with first solder paste of first high melting point be printed on the front of the carrier, see Fig.1, - on this first Internal connections I the corresponding connections of the electrical to be connected to it Components, see R, C are placed or pressed, - in the furnace by melting the first Solder paste these connections are made - the second lines L2 and second Inner connections I with second solder paste of the second, compared to the first melting point low, melting point can be printed on the back of the carrier, see Fig. 2, - on these second internal connections I the corresponding connections of the with it Electrical components to be connected, see ZT / Hl, ZT / H2, are placed or pressed, and in addition the metal pins M, especially after covering them with the Lines L1 / L2 to be connected end with second solder paste, plugged onto the carrier T. and - in the furnace at a relatively low temperature, namely by melting the second solder paste without remelting the first solder paste, the connections of the lines L1 / L2 with the metal pins M and the connections of the second internal connections I with the relevant component connections ZT or H1, H2.

The use of two types of solder paste prevents the Electrical components attached to the front are unsoldered when the electrical components to be attached to the rear are soldered on.

However, the circuit module is also made with a single mass of solder paste can be produced in that in successive process steps - all lines L1, L2 and all internal connections I with solder paste of the same melting point on the front and printed on the back of the carrier T, - at least some of the electrical components, e.g. R / C apart from their own connections, to be fixed with glue on the support T, and in addition the metal pins M are placed on the carrier T, and - in the oven by melting the solder paste all Connections of the metal pins M with the lines L1, L2 and all connections of the Internal connections I with the connections of the electrical components R, C, ZT / H1, ZT / H2 are produced at the same time.

The example shown in the figures can therefore also be produced by that in successive process steps the lines and internal connections printed with solder paste on the corresponding sides of the carrier that subsequently on these Innenan connections the corresponding connections of the to be connected with it electrical components are placed or pressed, and that finally in the oven Melt the solder paste the connections are made. If, when laying or Press the corresponding connections of these electrical components on the relevant Internal connections I, at the same time the relevant component apart from its connections sticks with adhesive on the carrier T, you can see that it falls off or slips Components, especially from atlf below or to the side of the respective carrier layer components to be attached while the solder paste is melting in the furnace.

Experiments showed that the production of the one shown in the figures frameless single-in-line circuit module costs less than half that, what a similar dual-in-line module with housing would cost, although the invention Single-in-line circuit module, particularly in terms of rigidity and cooling Packing tight on a fully equipped perforated plate, in addition has its own advantages.

16 claims 2 figures

Claims (16)

Claims. Lo circuit module without housing, with -even, insulating, flat Carrier, for carrying cables and several electrical components, of which at least one is an integrated semiconductor circuit body without a housing, preferably pluggable and solderable metal pins as external electrical connections, 1 which is attached to only one side of the carrier, namely on the connection side are whose axes are directed perpendicularly away from the connection side and whose Axes simultaneously in, through the connection side and the side perpendicular to it of the beam formed, lie level, a connection side length, which is considerably, E.g. three times greater than the length of the perpendicular side of the girder, electrical internal connections in or on the carrier, for connecting with connectors the electrical components and cables between the external connections and internal connections, possibly also between different internal connections, especially for the encoder-decoder of a PCM telephone switching system, which is not available e t that the carrier (T) only on its front (Fig. 1) and back (Fig. 2), thus in two planes, lines (L1, L2) contains - a first part of the metal pins (M) is connected to first lines (L1) on the front side of the carrier (T), - a second part of the metal pins (M) with second lines (L2) on the back of the carrier (T) is connected, and - a first part of the connections of electrical components (C, R) with the internal connections (I) first (L1), and a second part of the connections of electrical components (E1, H2) with the internal connections (I) second lines (L2), possibly via vias (D) from the front here is connected. 2. Circuit module according to claim 1, d a d u r c h g e k e n Note that - the vertical side (S) is 1 inch or less long. 3. Circuit module according to claim 1 or 2, d a d u r c h g e It is not indicated that - the connection side (A) is at least 1.5 inches long. 4. Circuit module according to one of the preceding claims, d a d u r c h e k e n n n z e i c h n e t that - between first lines (L1) and second lines (L2) vias (D) are attached. 5. Circuit module according to one of the preceding claims, d u r c h e k e n n n z e i c h n e t that - the carrier (T) made of ceramic or Glass is made. 6. Circuit module according to one of claims 1 to 4, d a d u notify that - the carrier (T) made of punchable organic Made of plastic. 7. Circuit module according to claim 6, d a d u r c h g e k e n It is noted that - the carrier (T) consists of polyimide. 8. Circuit module according to claim 6, d a d u r c h g e k e n It is noted that - the carrier (T) consists of epoxy resin. 9. Circuit module according to claim 6, d a d u r c h g e k e n It should be noted that - the carrier (T) is made of Teflon. 10. Circuit module according to one of claims 6 to 9, d a d It is not stated that - the plastic contains a filling compound. 11. Circuit module according to claim 10, d a d u r c h g e k e n n z e i c h n et that - the filler contains or represents paper. 12. Circuit module according to claim 10 or 11, d a d u r c h It is not noted that - the filling compound contains or represents glass fibers. 13. Circuit module according to one of the preceding claims, d a d u r c h e k e n n n z e i c h n e t that - the semiconductor circuit body (s) (H1, H2) is / are attached to a flexible intermediate carrier film (ZT) without a housing and - the connections of the intermediate carrier film (ZT) each with internal connections (I) are connected. 14. Circuit module according to claim 13, d a d u r c h g e k e n n z e i h n e t that - at least some of the intermediate carrier films (ZT) and / or other electrical components (R, C) are connected to internal connections (I), which in turn are attached to the edge of windows in the support (T). 15. A method for producing the circuit module according to one of the preceding claims, d a d u r c h g e n n n z e i c h n e t that in successive process steps - the first lines (L1) and the first Inner connections with first solder paste of first high melting point on the front (Fig. 1) of the carrier (T) are printed - on these first internal connections the corresponding connections of the electrical components to be connected (R, C) are placed or pressed, - in the oven by melting the first solder paste Connections are made - the second lines (L2) and second internal connections (I) with second solder paste of second, compared to the first melting point, low, Melting point are printed on the back (Fig. 2) of the carrier (T) - on these second internal connections (I) the corresponding connections of the to be connected therewith electrical components (H1, H2 or ZT) are placed or pressed, and additionally the metal pins (M), especially after covering them with the lines (L1, L2) end to be connected with second soldering paste on the carrier (T), and - in the furnace at a relatively low temperature, namely by melting the second Solder paste without remelting the first solder paste, the connections of the lines (L2, L1) with the metal pins (M) and the connections of the second internal connections (I) with the relevant component connections (H1, H2 or ZT). 16. A method for producing the circuit module according to one of the Claims 1 to 14, d u r c h e k e n n z e i c h n e t that in one another following procedural steps all lines (L1, L2) and all internal connections (1) with solder paste of the same melting point on the front (Fig. 1) and on the back (Fig. 2) of the carrier (T) are printed - at least a part of the electrical components (R, C), apart from their connections, with adhesive on the Support (T) are attached, and in addition the metal pins (M) 'on the support (T), and in the oven by melting the solder paste all the connections the metal pins (M) with the lines (L1, L2) and all connections of the internal connections (I) with the component connections (R, C, H1, H2).