WO2000021136A1

WO2000021136A1 - Electronic measuring and/or control instruments for refrigeration, heating and air conditioning comprising semi-conductor components achieved with high integration technologies

Info

Publication number: WO2000021136A1
Application number: PCT/IB1999/001636
Authority: WO
Inventors: Frank Monaco
Original assignee: Invensys Climate Controls Spa
Priority date: 1998-10-08
Filing date: 1999-10-06
Publication date: 2000-04-13
Also published as: IT1302781B1; ITUD980173A1; AU5879599A

Abstract

Electronic measuring and/or control instruments for refrigeration, heating and air conditioning, comprising at least a display/processing card (16) consisting of a substratum (13) on which a plurality of semi-conductor devices are mounted to constitute a plurality of leds, there being present at least a semi-conductor device with the function of a micro-processor, the semi-conductor devices (10) functioning as leds mounted naked, according to the 'die' mounting technology, directly on said substratum (13) of said card (16) and arranged in a spatial configuration such as to create, when they are selectively lit, a series of numbers according to the values to be displayed on each occasion.

Description

"ELECTRONIC MEASURING AND/OR CONTROL INSTRUMENTS FOR REFRIGERATION, HEATING AND AIR CONDITIONING COMPRISING SEMICONDUCTOR COMPONENTS ACHIEVED WITH HIGH INTEGRATION

TECHNOLOGIES" * * * * *

FIELD OF THE INVENTION This invention concerns electronic measuring and/or control instruments for refrigeration, heating and air conditioning, which comprise semi-conductor components achieved with high integration technologies.

The invention is embodied in the use and application of high integration technologies for the production of electronic instruments suitable for use as regulators and/or measurers to control and govern temperature, pressure and/or humidity in a room.

The invention offers extremely economical and functional solutions, and allows to obtain instruments which are smaller yet give the same performance, which cost less and are more f nctional . Moreover, the invention makes the process of producing the integrated circuits more economical and rational.

BACKGROUND OF THE INVENTION The state of the art includes electronic instruments and devices used to measure and govern the parameters, for example the temperature and humidity, of a room, a refrigeration assembly, a heating plant or other.

These instruments are normally applied in a panel, in holes or apertures of a standard size, suitably arranged on the walls of the apparatus on which they are mounted; the front part, with the display unit (normally with leds) and the setting and command organs, protrudes from the said hole.

These instruments or devices typically consist of a box which houses the cards which support the components needed for the instrument to function and to display and regulate the working parameters .

In the field of refrigeration, heating and air conditioning, and in particular in the specific field of commercial refrigeration, the state of the art includes the use of SMD (surface mounted device) technology or discrete technology for the components used.

These technologies provide that the various electronic semi-conductor devices, from the simplest diode to the most complex microprocessor, are housed inside containers which have the connection terminals in a single piece for connection to the paths of the printed circuit which acts as a support . The containers are usually called cases or packages; they are then mounted on the relative printed circuit by electrically connecting the relative connection terminals so as to obtain the desired circuit connections.

The containers have the principal function of ensuring a mechanical and environmental protection for the semiconductors, the connections and the substratum.

Compared with discreet component technology, the surface mounted device technology has the advantage that it reduces the costs and times required for mounting the components, and also allows to use both faces of the substratum itself with greater ease.

However, even if this technology is used, the presence of containers for the various semi-conductor devices entails the problem that it is substantially impossible to make the electronic circuitry much more compact; this imposes a limit on the planning combinations of the components and on the functions which can be obtained.

Sometimes, moreover, using this technology causes an increase in costs, since it is necessary to use a higher number of printed circuits, or to use printed circuits with a larger area, for the same number of components.

The present Applicant has tested and embodied this invention to overcome this problem and to obtain further advantages both in economic terms and in terms of optimizing the production process.

SUMMARY OF THE INVENTION The invention is set forth and characterized in the main claim, while the dependent claims describe other characteristics of the main embodiment.

The purpose of the invention is to optimize the construction of electronic measuring and control instruments in the field of refrigeration, heating and air conditioning, in order to obtain significant advantages in terms of containing the size and the costs and in terms of optimizing the production process.

To be more exact, the invention allows to make the electronic circuitry more compact and to apply a greater number of components on the same printed circuit, or substratum, of a standard size, or alternately, to make smaller instruments with equal functions and applications.

This is particularly important due to the fact that these instruments are applied in housing seatings of a standard size, and therefore an increase in their functions cannot be achieved by increasing the size, which is limited to that of the apertures made on the panels of the devices where said instruments are applied.

In addition, the invention allows to considerably reduce the total number of components needed to make a specific instrument .

With this invention it is therefore possible to increase the performance of the electronic device without increasing in a corresponding fashion the size or decreasing the size given the same performance; this brings a substantial advantage in terms of cost and efficiency of the device.

A preferential embodiment of the invention provides that the semi-conductor devices which constitute at least part of the components of the electronic circuit, from the simplest light-emitting diode (led) to the most complex microprocessor, are mounted "naked", that is to say, without a container, directly onto the printed circuit, using what is known as "die" technology.

The connections to the paths of the circuit are made first by applying the semi-conductor directly onto the printed circuit, for example by gluing it with an appropriate adhesive, and then making the necessary electric connections between the semi-conductor and the printed circuit according to the specific circuit pattern required by the electronic instrument .

The connection terminals protrude directly from the semiconductor element, and are connected on each occasion to the paths of the circuit according to the desired pattern.

This technology of mounting the components is already known in the art, and has already been used in other fields other than that of refrigeration and air conditioning instruments . In this specific field, however, it has not been possible until now to apply this technology because of the high costs of equipping and industrializing the plant, particularly with reference to the steps of calibrating and optimizing the production process to obtain a sufficient level of product reliability.

This technology of the semi-conductors, in the field of electronic instruments for commercial refrigeration and environmental air conditioning, allows to achieve significant advantages in terms of a saving in size, inasmuch as it allows the components to be mounted in a much more compact manner.

This greater compactness allows to reduce the number and/or the size of the printed circuits used in the device inasmuch as it allows to mount a greater number of components on the same printed circuit, with a consequent increase in the performance of the printed circuit given the same size, which is normally standard with regard to the device on which the instrument is mounted.

A further significant advantage is that, for the function of outward display required of the electronic instrument, it allows the use of suitable configurations of leds mounted according to the "die" technology, instead of the leds and led displays which are normally used according to conventional mounting technologies.

In the state of the art, the "die" technology has never been used for components proposed to perform a display function because of the difficulties involved in "channelling" the light produced by the leds and distributing it, uniformly and with sufficient light intensity, over a series of segments so as to form figures, or in correspondence with specific icons so as to supply indications and services to the user. According to the invention, a plurality of leds mounted with the "die" technology directly onto a substratum, in an appropriate configuration, are associated at the front with a plastic element provided with mating apertures configured so as to form a series of numbers, a series of points and/or a series of luminous windows.

In the preferential embodiment, the plastic element is white so as to give maximum light reflection on the walls. The plastic element is mounted flush on the support on which the "die" leds are mounted so as to avoid dispersing the light.

The purpose of the plastic element is, on the one hand, to convey the light through the relative apertures and to maintain the light intensity as bright as when it is produced by the leds, and on the other hand to create a protective cage for the leds underneath.

In the preferential embodiment of the invention, in front of the plastic element a metallic film is provided suitable to define figures and icons, which in turn is associated at the front with an opaque film suitable to spread the light of the leds.

In the preferential embodiment, the opaque film is of the adhesive type and can be replaced. According to a variant, the opaque film is associated directly with the plastic element.

The composite film (metallic film + opaque film) thus obtained, associated with the plastic element mentioned above, constitutes a mask which is applied directly to the supporting card of the leds to obtain the desired display.

The use of leds mounted directly on a substratum according to the "die" technology, using the embodiment described above, allows to obtain -an extremely compact display; it also gives a considerable versatility and the possibility of adapting the instrument to the specific requirements of the user.

Moreover, the light is perfectly channelled through the apertures on the plastic element, with no dispersion and no diffusion between adjacent segments and with a uniform luminosity along the segments.

According to a variant of the "die" technology which can be applied to semi-conductor elements other than leds, after having mounted the semi-conductor elements and having made the necessary electric connections, at least some of the elements are protected by means of encapsulation in a plastic material, for example by pouring a drop of resin on top of them. BRIEF DESCRIPTION OF THE DRAWINGS

The attached Figures are given as a non-restrictive example and show a preferential embodiment of the invention wherein :

Fig. 1 shows a simplified assembly diagram of the semi- conductor devices on a printed circuit according to the known SMD assembly technique; Fig. 2 shows a simplified assembly diagram of the semiconductor devices on a printed circuit according to the known "die" mounting technique; Fig. 3 shows an example of a front-piece of a measuring and/or adjustment instrument made according to the invention with the "die" technology; Fig. 4 shows the front-piece of Fig. 3 associated at the front part with a plastic element to convey light; Fig. 5 shows the front-piece of Fig. 3 associated with a complete display mask, consisting of the plastic element plus a protective film, according to one embodiment of the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT According to Fig. 1, which represents the state of the art technique using the technology to mount the components known as "SMD", a finished semi-conductor device 10 constituting a component of an integrated circuit, such as a diode, a led, a transistor, a microprocessor, etc., is inserted inside a container 11; the container 11 includes pins 12 as part of itself, and is associated with a printed circuit, or substratum 13 , by means of said pins 12.

The pins 12 constitute the connection elements to establish the electric interconnections with the other components of the electronic circuit through the paths 15 of the printed circuit.

Fig. 2 is a general, simplified representation of the "die" technology wherein the semi-conductor device 10, without the container and therefore naked, is mounted and made solid directly onto the substratum 13, with the relative pins 14 which protrude at the sides and are connected directly to the paths 15 so as to establish the relative circuit interconnections, generally with the technique known as "bonding" .

The number of pins 14 with which each semi-conductor device 10 is equipped depends on the number of connections which have to be established according to the geography of the circuit and according to the device 10 itself.

The production process according to this technology then provides to make solid the semi-conductor device 10 directly onto the substratum 13 , by gluing it for example by means of an adhesive which can be electrically conductive, or not, or by welding it, or by using another technique.

Then, the electric connections are established by connecting the semi-conductor device to the paths 15 by means of the pins 14; finally, in a possible embodiment, each semi-conductor device 10 is covered with a plastic material, for example a drop of resin, in order to protect it both mechanically and also from environmental contamination .

The invention, as we said, provides the application of the "die" technology to electronic measuring, conditioning and refrigeration instruments.

This type of application to this type of instrument increases the level of integration which can be obtained and allows to obtain a significant saving in space, with the same components mounted; it therefore allows to optimize the geography of the circuit and to mount an ever higher number of semi-conductor devices 10, given the same space occupied. This entails an increase in the performance and functions of the electronic instrument while yet maintaining a limited and standard size with regard to the device on which the instrument is mounted.

This is very advantageous for electronic measuring and control instruments in refrigeration, heating or air conditioning systems, in that in the same space occupied by traditional instruments it is possible to provide a greater number of functions, memories, etc., thus expanding the intrinsic capacity of the instrument which in practice becomes a very advanced processing system with wide and extensive capacities.

Fig. 3 shows an example of a card 16 for electronic measuring and/or adjustment instruments made according to the invention, in this case a display/processing card.

In this specific case, the semi-conductor devices 10 partly consist of leds attached directly to the substratum 13, which constitutes a first element of direct electric connection, while the pin 14 laterally creates the second electric connection to the paths 15 of the printed circuit made on the substratum 13. Since, by using the "die" technology, it is possible to mount on the card 16 also a semi-conductor device 10 of the "die" type with a microprocessor function, (in this specific case mounted on the opposite side of the substratum 13 and shown by a line of dashes in Fig. 3) , the resulting card 16 becomes, with the addition of other components mounted on the card itself, a substantially autonomous, complete and high-performance unit in itself.

In fact, for example, the leds are already arranged, in this case, in a spatial configuration which is such as to create, when they are selectively lit, a series of numbers (four) according to the values to be displayed according to the instructions of the micro-processor. Fig. 4 shows the card 16 associated at the front to a plastic element 18 so as to constitute a component of the finished electronic instrument.

It should be noted that for instruments with a lower capacity and functionality, the card 16 may constitute the electronic component of the autonomous finished instrument.

The leds 10 are visible in Fig. 4 in the windows 17, which are suitably shaped and made on the plastic element mask 18, but they are then hidden and protected with respect to the outside by at least a film 20 (Fig. 5) which is applied to the front part of the plastic element 18.

In this case, above a first film 20, normally made of metal and with the function of defining the figures and icons of the display, there is a second, opaque film 22 of the adhesive and replaceable type. To this end, Fig. 5 shows a complete card, consisting of the support 13 with the relative leds 10 mounted directly thereon, the plastic element 18 and the films 20 and 22, wherein, instead of the infra-red receiver 19 shown in the example in Fig. 4, there are icons 21 provided, portraying services and functions typical of these instruments.

In the support 13 underneath, four additional leds are provided in correspondence with the position of the icons 21.

In conventional embodiments, the display is achieved by means of single or multiple display leds, which have a considerably greater bulk and which include the relative pins to connect with the printed circuit.

With the embodiment according to the invention, the semi- conductor devices 10 functioning as leds are supported directly on the substratum 13 and therefore the thickness of the display card 16 functioning as a front-piece is drastically reduced. In this specific case, as we have said, the main processing unit, or micro-processor, is "die" mounted on the same card 16, precisely thanks to its limited size.

In conventional embodiments, for reasons of space it is normally mounted on a different card. Fig. 5, as we have said, shows an embodiment where there are four windows 23 next to the four-figure display; in correspondence with the windows 23 icons 21 (shown above and below in the Figure) are located which typically serve to indicate the status of the outlets of the electronic instrument .

By using "die" technology for the underlying semiconductor devices 10, it is possible to modify at will the designs of the icons 21 shown in the windows 23, simply by replacing the surface film 22 (as partly shown in the Figure) which is applied to the plastic 18 of the front- piece so as to constitute a protective mask, to adapt them to the specific application or to the requirements of the specific client, without needing to modify the plastic 18 underneath or the arrangement of the leds 10 mounted on the substratum 13.

The embodiment according to the invention also allows to consider the individual printed circuit, with the relative components attached thereto, as a standardized module in its own right, and can be used to make modules of electronic instruments for the field of refrigeration, heating and air conditioning, with variable size, function and performance.

Claims

CLAIMS 1 - Electronic measuring and/or control instruments for refrigeration, heating and air conditioning, said electronic instruments being suitable to be used as regulators and/or measurers to control and govern temperature, pressure and/or humidity in a room, comprising at least a display/processing card (16) consisting of a substratum (13) on which a plurality of semi-conductor devices are mounted to constitute a plurality of leds, there being present at least a semi-conductor device with the function of a microprocessor electrically connected to said leds by means of connection paths (15) made on said substratum (13) , the electronic instruments being characterized in that the semiconductor devices (10) functioning as leds are mounted naked, according to the "die" mounting technology, directly onto said substratum (13) of said card (16) and are arranged in a spatial configuration such as to create, when they are selectively lit, a series of numbers according to the values to be displayed on each occasion. 2 - Electronic instruments as in Claim 1, characterized in that they comprise a plastic element (18) associated at the front part with said card (16) and including windows (17) arranged in correspondence with the position of said leds, said plastic element (18) being suitable to convey and channel the light produced by the leds, maintaining the luminous intensity bright, and also to protect the leds themselves .

3 - Electronic instruments as in Claim 2, characterized in that said plastic element (18) is mounted flush directly on said card (16) .

4 - Electronic instruments as in Claim 2, characterized in that said plastic element (18) is white so as to give maximum reflection of the light emitted by said leds. 5 - Electronic instruments as in Claim 2, characterized in that they comprise at least a film (20, 22) arranged at the front part of said plastic element (18) and suitable to define at least the figures to be displayed. 6 - Electronic instruments as in Claim 5, characterized in that said film (22) is of the adhesive and replaceable type, and is suitable to define personalized icons (21) arranged in correspondence with respective underlying leds provided on said card (16) , said icons (21) portraying services and functions typical of said instruments.

7 - Electronic instruments as in Claim 1, characterized in that said semi-conductor device (10) with the microprocessor function is mounted with the "die" technology on the same substratum (13) on which said semi-conductor devices (10) functioning as leds are mounted.

8 - Electronic instruments as in Claims 3 or 4, characterized in that said card (16) constitutes a standardized component substantially finished in itself and which is usable, together with said plastic protective element (18) and films (20, 22) to make a complete electronic module for simple-function instruments.