WO2008148622A2

WO2008148622A2 - Drying device

Info

Publication number: WO2008148622A2
Application number: PCT/EP2008/055742
Authority: WO
Inventors: Bernd Hoffmann
Original assignee: Productware Gmbh
Priority date: 2007-06-05
Filing date: 2008-05-09
Publication date: 2008-12-11
Also published as: WO2008148622A3; DE102007026485A1; EP2150761A2

Abstract

The invention relates to a device for drying or keeping piece goods or bulk material dry. Said device comprises a cover element (1) to be placed on an opening of a container (4) or of a compartment, a dry medium connection (2) configured for the connection to a dry medium source, and a dry medium supply element for supplying the dry medium to the opening.

Description

drying device

The present invention relates to a device for drying or keeping dry any dry material, in particular piece or bulk material.

There are a variety of applications for drying devices. Drying is generally understood to mean dehumidification (removal of water) and storage under dry storage in a dry atmosphere.

The present invention is particularly intended for the drying or dry keeping of electronic components.

The impact of humidity on the quality and reliability of electronic assemblies is not fully understood. It is believed that the plastics used in the most highly integrated components absorb moisture from the air. However, during processing of the electronic components, rapid local temperature rise may occur. The moisture trapped inside the components and circuit boards then expands very much during the heating process.

Especially with the use of lead-free solder alloys, which require higher processing temperatures (due to the higher melting temperature of the lead-free solders), the expansion of the trapped moisture can exceed the maximum mechanical strength of the components and printed circuit boards, resulting in damage to the electronic components, for example through cracks, popcoming and delamination.

It is therefore often common to maintain the electronic components in heated drying ovens to achieve a low residual moisture. Disadvantage of the heated drying ovens, however, is that the lead-free pads are only limited solderable due to the increased storage temperature. The reason for this is that so-called "baking" in drying furnaces causes the oxide layer on the tin-plated surfaces to grow considerably faster than the tin-lead solders that were previously customary.components and printed circuit boards are then practically no longer solderable, since the thick ones Oxide layers with the mildly activated flux of the electronics can no longer be reduced and eliminated. Furthermore, dry storage cabinets are known with very low humidity, which allow a reliable and temporally almost unlimited storage moisture sensitive components. With these dry storage cabinets, the relevant standard IPC / J-STD-033 can be met.

For an active drying according to the said standard, additional heat should be added to accelerate the dehumidification process and to ensure economically acceptable residence times during the active drying.

In dry cabinets or dry storage cabinets, a dry fluid, e.g. Nitrogen, dry compressed air or a special desiccant, led into the cabinet interior. The dry nitrogen or the dry compressed air displaces the moist air, so that the humidity is lowered inside the cabinet. If a special desiccant is used, in addition to the described displacement effect, there is still active dehumidification since the desiccant can remove moisture, e.g. by a chemical bond or by adsorption.

The known drying cabinets generally have a number of shelves, which are all arranged in the same chamber. When opening the cabinet door, for example, for the purpose of removal or storage of an electronic component, it comes by turbulence and suction inevitably to a deterioration of the atmosphere in the oven, so that after closing the door must be regulated by appropriately increased desiccant flushing and dehumidifying the air again. Although, if necessary, only a single component is removed from the drying oven, this has an effect on all other components stored in the drying cabinet.

In addition, the known drying cabinets are relatively expensive. In addition, an estimate of the need for storage volume must already be made when purchasing the drying cabinet. If the cabinet volume is chosen too large, then unnecessarily much drying medium is needed to dehumidify the entire cabinet interior. If, in addition, the supply of heat is provided, the amount of heat to be supplied also depends directly on the size of the cabinet. A half-occupied drying cabinet therefore consumes unnecessarily much energy.

Starting from the described prior art, it is an object of the present invention to provide an apparatus for drying or drying of Trockengutgut, which is easy to manufacture and can be easily adapted to the actual drying needs.

This object is achieved in that the device comprises a cover element which is provided for placing on the opening of a container or a compartment, wherein the device further comprises a dry medium connection, which is suitable for connection to a dry medium source is provided, as well as a dry medium supply for supplying the dry medium in the opening.

The drying device according to the invention essentially consists of a cover element, which can be placed on any container or (shelf) compartments. By this measure, the dry volume can be easily adapted to the actual needs. The dry material to be dried is only placed in any container of suitable size and is then covered with the lid member. Dry medium can then be introduced into the interior of the container with the aid of the dry medium supply and displaces the existing (moist) atmosphere there.

Usually electronic components are shipped or delivered in standard containers. For storage, the electronic components, which are often welded in foil under a protective gas atmosphere, are removed from the container and, if necessary, the film is removed and the desired number of components removed. The currently not required components are then placed in the usual drying cabinets, often the entire standard container, in which the electronic components are located, is set in the cabinet.

According to the invention, a drying device is now used whose essential component is a cover element. This cover element can for example be easily placed on the open standard container. The cover element has a dry medium connection, via which a drying medium, such as nitrogen or dry compressed air, the drying device can be supplied. Furthermore, a dry medium supply is provided, via which the dry medium is transferred into the container opening.

When the lid member rests on the container opening, the drying medium is fed via the dry-medium connection of the drying apparatus and forwarded via the dry-medium feed into the interior of the container or compartment.

In principle, the cover element can be designed in such a way that it can be inserted or placed in commercially available standard containers. In this case, the dimensions of the lid member substantially correspond to the size of the container opening. Of course, such a cover element can also be placed on a smaller container opening, wherein it is only important that the dry medium supply is arranged such that with their help the drying medium can be introduced into the interior of the container. Airtight sealing of the container by means of the lid member is not necessary for most applications. Since dry medium is supplied to the container, without anyway excess gas from the container be dissipated. This can be done, for example, via the forming gap between the container opening on the one hand and the cover element on the other.

Alternatively, the cover element could also be designed so that it can be placed on shelf compartments. This makes it possible to explain individual compartments of a shelf to the drying room, in which the compartment is closed by means of the lid member. In this case, a device should be provided by means of which the cover element can be fastened to or in the shelf opening. This may for example also be a circumferential inflatable seal.

In a particularly preferred embodiment, the dry medium supply consists of a distributor or diffuser and a preferably flexible connecting hose, wherein the distributor or diffuser is connected to the cover element via the connecting hose. Thus, the distributor or diffuser can be placed as far down as possible, preferably at the bottom of the container before placing the lid member on the container opening. The dry-stored electronic components can then be introduced into the container, and they may also partially rest on the manifold. Now, if the lid is placed, it can be supplied via the appropriately trained dry medium supply the dry medium substantially near the bottom of the container. Any air in the container with high humidity is then quickly and reliably evacuated from the container with the aid of the dry medium.

In a further particularly preferred embodiment, the cover element has a vent opening. As already mentioned, it is necessary that the displaced air or the displaced gas is discharged from the container. If the lid member is formed such that it closes the container or the shelf substantially sealing, the lid member must have a corresponding vent opening. Conveniently, the vent opening is closed with a pressure relief valve, so that the vent opening is opened only when the pressure within the container is greater than the ambient pressure. This prevents high-humidity air from entering the container via the vent opening from the outside.

In a further preferred embodiment, a sensor for measuring moisture and / or temperature is provided, wherein the sensor is preferably arranged in or on the cover element. With this sensor the humidity and / or the temperature within the container or shelf should be measured. As a result, it is possible, for example, to throttle or switch off the supply of the medium when falling below a corresponding limit moisture in order to save on dry medium. Furthermore, it is provided in a preferred embodiment that a heating element is provided for heating the container or the container interior. The heating element may be, for example, an infrared radiator. In a particularly preferred embodiment, the heating element is designed such that it heats the supplied drying medium. For example, a resistance heater can be used here.

Furthermore, it may be advantageous for some applications if a flow rate regulator is provided for controlling the Trockenmediumzuführmenge.

Thus, it is possible, for example, to control the supply of the dry medium as a function of the measured temperature and / or humidity.

In a further particularly preferred embodiment, a drying rack is provided with a plurality of compartments or containers, wherein at least one compartment or at least one container is equipped with the cover element already described or can be closed by this. The drying rack may have a central desiccant port through which desiccant may be supplied from a dry medium source to the drier shelf. It is further provided that the drying rack has a corresponding distribution device, so that the supplied via the desiccant terminal dry medium is distributed to a plurality of subjects or containers tern.

The distribution device may include a plurality of desiccant supply ports, wherein each desiccant supply port is connectable to a dry media port of the drying device.

Further advantages, features and applications of the present invention will become apparent from the following description of some preferred embodiments and the accompanying figures.

Show it:

FIG. 1 shows a first embodiment of the drying device according to the invention,

FIG. 2 shows a second embodiment of the drying device according to the invention,

FIG. 3 is a schematic diagram illustrating the use of the first embodiment of the drying apparatus;

FIG. 4 shows a third embodiment of the drying device,

FIG. 5 shows a fourth embodiment of the present invention,

FIG. 6 shows an embodiment of the drying rack according to the invention, Figure 7 shows a fifth embodiment of the present invention and Figure 8 shows a sixth embodiment of the present invention.

FIG. 1 shows a first embodiment of the present invention. The drying device has a cover element 1, a dry fluid connection 2 and a dry fluid supply 3. The dry fluid supply 3 consists of a diffuser, which is connected via a flexible hose to the cover element 1. The dry fluid, which may be, for example, nitrogen or dry compressed air, is supplied via a fluid source (not shown) to the cover element 1 via the drying fluid connection 2 and discharged again via the diffuser 3.

FIG. 2 shows a second embodiment of the invention, it also being apparent here how the cover element 1 is placed on a container 4. The embodiment shown in Figure 2 differs from the first embodiment shown in Figure 1 only in that a fluid flow regulator 6 and a vent opening 5 are provided. For use düng the drying device, the lid member 1 is placed on any container 4, wherein the opening of the container 4 may not be greater than the outer dimensions of the lid member 1, so that by placing the lid member 1 on the opening of the container 4 this substantially is closed. The diffuser 3 is placed on the bottom of the container 4 and via the fluid flow regulator 6, the amount is set to be supplied to the drying medium. The drying medium is transferred via the diffuser 3 into the container interior and displaces the therein, possibly moist air, which can escape via the vent opening 5.

For clarification, FIG. 3 once again schematically shows how the drying device functions. First, as can be seen in the upper image of Figure 3, the diffuser 3 is inserted into the container 4. Then, a plurality of electronic components 7 are inserted into the container so that they partially lie on the diffuser 3. Then, the lid member 1 is placed on the container opening and desiccant supplied through the diffuser 3, so that the desiccant flows around the individual electronic components 7 and displaces the optionally humid container interior air.

FIG. 4 shows a further embodiment of the invention. Here, a temperature and / or humidity sensor 8 is additionally provided, which is also placed in the container interior. This temperature and / or humidity sensor is read out via a data logger 9, which records and stores the corresponding measured values. If necessary, the stored measured values can then be accessed via a suitable computer 10. If necessary, it is possible to regulate the amount of the dripping fluid by means of the regulator 6 as a function of the measured temperature and / or humidity. Finally, in Figure 5, yet another embodiment of the invention is shown. Here, a heating device 1 1 is additionally provided, which is connected to the sensor 8 for determining temperature and / or humidity. On the basis of the measured temperature and / or humidity value, the temperature of the dry medium to be supplied can be adjusted with the aid of the heating device 11.

The device according to the invention has the advantage that when removing an electronic component, only the relevant container or the relevant shelf is temporarily exposed to ambient air. In contrast, in the drying devices known in the prior art, it is necessary to apply ambient air to the entire contents of the cabinet for a short moment.

Since after a drying cabinet opening with high energy consumption, the moisture penetrated must be removed again, the device according to the invention ensures an economical handling of the dry medium.

In the commercial cabinet systems, the electronic components that are to be kept dry, usually set on shelves in containers. Usually one tries to use the cabinet as economically as possible, which leads to the fact that a lot of components are placed in the oven, so that only a small space remains between the individual containers. As a result, an effective circulation of the dry medium, in particular in the area in the immediate vicinity of the components to be dried, is made more difficult. By using the diffuser according to the invention, which is connected via a flexible hose to the cover element, it is possible to position it at the bottom of the container, so that the electronic components to be dried are flowed around directly with the dry medium.

A drying rack according to the invention is shown in FIG. The shelf 12 has a series of shelves, in each of which one or more containers are set. Each container has a cover element with drying fluid supply 2. The shelf has a central drying fluid connection 13. From this connection 13, a distributor extends to different drying fluid outlets 14, which can each be connected to a dry fluid connection of a cover element 1.

FIG. 7 shows a further embodiment of the invention. In this embodiment, the original lid 1 of the container 4 is used. To the bottom (in some cases it can also be the top or a container wall) of the lid 1, a supply box 15 is screwed or glued. The supply box has a dry fluid connection and a diffuser 3, which is connected via a flexible line to the supply box 15. The lid may in some embodiments have a cutout for the flexible dry fluid line. The supply box can of course also have an integrated temperature and / or humidity sensor and / or a heating element. It is therefore - in contrast to the embodiments of Figures 1 to 6 is not necessary to guide the dry fluid within the lid member.

Finally, a sixth embodiment is shown in FIG. This embodiment differs from the embodiment of Figure 7 essentially in that the supply box 15 is arranged at the bottom of the container 4. Therefore, the diffuser 3 is integrated in the supply box.

LIST OF REFERENCES:

1 cover element

2 dry fluid connection

3 diffuser

4 containers

5 vent

6 fluid flow regulator

7 electronic components

8 humidity sensor

9 data loggers

10 computers

1 1 heater

12 shelf

13 main terminal

14 dry fluid outlet

15 supply box

Claims

Patent claims

1. Device for drying or keeping dry bulk or bulk material, with a lid member for placing on an opening of a container or a compartment, a dry medium connection, which is intended for connection to a dry medium source, and a dry medium supply for supplying the dry medium in the opening.

2. Device according to claim 1, characterized in that the dry medium supply consists of a distributor and a preferably flexible connecting hose, wherein the distributor is connected via the connecting hose with the cover element.

3. Device according to one of claims 1 to 2, characterized in that the cover element has a vent opening.

4. Apparatus according to claim 3, characterized in that the vent opening is closed by a pressure valve, which opens upon reaching a certain pressure.

5. Device according to one of claims 1 to 4, characterized in that a sensor for measuring humidity and / or temperature is provided, wherein the sensor is preferably arranged in or on the cover element.

6. Device according to one of claims 1 to 5, characterized in that a heating element is provided for heating the container.

7. Device according to one of claims 1 to 6, characterized in that a heating element is provided for heating the supplied dry medium.

8. Device according to one of claims 1 to 7, characterized in that a Flußmen- genregier, preferably a nitrogen regulator, is provided for controlling the Trockenmediumzuführmenge.

9. Drying rack with a plurality of compartments or containers, wherein at least one compartment or container with a device according to one of claims 1 to 8 is closed.

10. Drying rack according to claim 9, characterized in that a dry medium connection for connection to a dry medium supply line and a distributor device for the Distributing the dry medium is provided to a plurality of subjects or containers.

11. Drying rack according to claim 10, characterized in that the distribution device has a plurality of dry medium supply ports, wherein each dry medium supply connection with a dry medium connection of a cover element is connectable.