Patent Application
20190001425
The present invention relates to a heating apparatus and a method for producing a plate-like object, and more particularly, to a heating apparatus and a method for producing a plate-like object by which a heating target object can be heated uniformly.
In a thermal-bonding apparatus, for example, a soldering apparatus for soldering a work, the work as a target object of thermal-bonding is heated. A thermal-bonding apparatus for heating a target object of thermal-bonding is known and includes a mount table on which the target object is placed with one of its faces being in contact entirely with the mount table, and a heat emission heater for heating the mount table from the side opposite the target object side. The target object is heated via the mount table, which receives heat from the heat emission heater and undergoes a temperature rise (refer to Patent Document 1, for example).
Patent Document 1: JP 2014-143304 A
However, when a target object is heated with its one entire face being in contact with the mount table, uniform heat transfer from the mount table to the target object may not be achieved and the target object may therefore not be able to be heated uniformly.
The present invention has been made in view of the above problem, and it is, therefore, an object of the present invention to provide a heating apparatus and a method for producing a plate-like object by which a heating target object can be heated uniformly.
To achieve the above object, a heating apparatus according to the first aspect of the present invention is, as shown in
With this configuration, the predetermined clearance in which the fluid is present is formed between the front face of the heater and the face of the heating target object by the support member so that heat can be transferred from the heater to the heating target object via the fluid. Thus, the face of the heating target object can be heated uniformly.
As for the heating apparatus according to the second aspect of the present invention, as shown in
With this configuration, the heating target object can be supported with a simple configuration.
As for the heating apparatus according to the third aspect of the present invention, as shown in
With this configuration, the heating source and the jig can be separated and the degree of freedom of the configuration of the heating source and the jig can be improved. The jig may be configured to prevent the heating target object from being directly exposed to electromagnetic waves that cause heat generation.
As for the heating apparatus according to the fourth aspect of the present invention, as shown in
With this configuration, because the jig can be moved to the state of not being located in the position opposed to the heating source, maintenance (such as washout of volatiles) is facilitated. In addition, because the jig is moved together with the heating target object supported on the support member provided on the front face of the jig, the temperatures of the jig and the heating target object can be increased from ambient temperature. This facilitates the estimation of changes in temperature.
As for the heating apparatus according to the fifth aspect of the present invention, as shown in
With this configuration, the heating target object can be directly heated with the heating source without the intervention of the jig. Thus, another way of heating can be selected in addition to heating of the heating target object via the jig, and a variety of usage depending on the situation can be obtained.
As for the heating apparatus according to the sixth aspect of the present invention, as shown in
With this configuration, even if the heating target object has a portion susceptible to oxidation, the portion can be prevented from undergoing oxidation.
As for the heating apparatus according to the seventh aspect of the present invention, as shown in
With this configuration, the configuration in the chamber can be simplified and maintenance in the chamber can be carried out easily.
As for the heating apparatus according to the eighth aspect of the present invention, as shown in
With this configuration, the heating target object can be heated properly without overheating.
As for a method for producing a plate-like object according to the ninth aspect of the present invention, as shown in
With this configuration, the plate-like object can be produced by transferring heat from the heat generation unit to the heating target object via the fluid to heat a face of the heating target object uniformly.
To achieve the above object, a method for producing a plate-like object according to the tenth aspect of the present invention is, as shown in
With this configuration, the plate-like object can be produced by transferring heat from the heat generation unit to the heating target object via the fluid to heat a face of the heating target object uniformly.
According to the present invention, heat can be transferred from a heater or heat generation unit to a heating target object via a fluid. Thus, a face of the heating target object can be heated uniformly.
This application is based on the Patent Application No. 2016-183949 filed on Sep. 21, 2016 in Japan, the contents of which are hereby incorporated in its entirety by reference into the present application, as part thereof.
The present invention will become more fully understood from the detailed description given hereinbelow. Further range of application of the present invention will become clearer from the detailed description given hereinbelow. However, the detailed description and the specific embodiment are illustrated of desired embodiments of the present invention and are described only for the purpose of explanation. Various changes and modifications will be apparent to those ordinary skilled in the art on the basis of the detailed description.
The applicant has no intention to give to public any disclosed embodiment. Among the disclosed changes and modifications, those which may not literally fall within the scope of the patent claims constitute, therefore, a part of the present invention in the sense of doctrine of equivalents.
Description will hereinafter be made of an embodiment of the present invention with reference to the drawings. The same or corresponding members are denoted with the same reference numerals in all the drawings, and their descriptions are not repeated.
Referring first to
In this embodiment, the substrate W, which is to be heated in the heating apparatus 1, is a thin substrate having a flat face Wf. While the face Wf is formed into a rectangular shape of 60 mm×90 mm in this embodiment, the face Wf may have a short side with a length of, other than 60 mm, such as 40 mm, 50 mm or 70 mm and a long side with a length of, other than 90 mm, such as 80 mm, 100 mm or 110 mm. The substrate W has a thickness of about 1 mm or less, and a substrate having a thickness of 0.4 mm or 0.8 mm, or any other thickness close thereto may be used, for example. Such a thin substrate may flap if the flow of gas around it is strong, and may warp when heated. Different portions of the face Wf of the substrate W may have different radiation factors depending, for example, on the presence or absence of a resist. In this embodiment, solder (not shown) is placed on one face of the substrate W, and then the substrate W is heated so as to melt the solder. To achieve good melting of the solder, the substrate W is preferably heated uniformly.
The heater 10 includes a jig 11 and an infrared ray lamp 13 (which is hereinafter referred to as “IR lamp 13”) as a heating source. The IR lamp 13 is an infrared ray lamp heater that receives one type of external energy, electrical energy, and converts the energy into heat. The IR lamp 13 can vary its output thermal energy in a highly responsive manner by varying its input electrical energy, and is highly responsive to temperature. The jig 11 functions as a temperature adjusting member for receiving heat generated by the IR lamp 13 and releasing heat toward the substrate W that is placed on the opposite side of the side that receives heat from the IR lamp 13. As the jig 11 is provided, the substrate W can be prevented from being directly exposed to the light from the IR lamp 13. Thus, even if the substrate W is a highly reflective object, a decrease in heating efficiency caused by reflection of the light from the IR lamp 13 on the substrate W can be avoided. In this embodiment, the jig 11 is formed into a rectangular plate-like member. The jig 11 has a front face 11f on which the support member 20 is disposed and the front face 11f is formed to have such a size and shape as to be able to cover the whole face Wf of the substrate W. The jig 11 is typically formed by machining aluminum or graphite. While the jig 11 may be formed of a material other than aluminum or graphite, the use of a material with high thermal conductivity is preferred. The jig 11 may be formed from a black body. The IR lamp 13 is placed apart from the jig 11 and adjacent to a reverse face 11r, which is the face opposite the front face 11f of the jig 11. In other words, in this embodiment, the jig 11 and the heating source (the IR lamp 13) are configured to be separate (independent) each other. With this configuration, the degree of freedom of the configuration of the jig and the heating source (i.e. what to employ as the jig and the heating source) can be improved. The IR lamp 13 is arranged to extend over generally the same area as the reverse face 11r so that it can apply heat as uniformly as possible to the entire reverse face 11r. The reverse face 11r preferably has high emissivity. In this embodiment, from the viewpoint of improving thermal responsiveness, the jig 11 is formed into a rectangular plate-like shape with a thickness of around 2 mm so that it has as small a thermal capacity as possible.
In this embodiment, the support member 20 includes a plurality of projections 21 disposed on the front face 11f of the jig 11. In this embodiment, each of the projections 21 constituting the support member 20 is fixed to the front face 11f and is formed integrally with the jig 11. The support member 20 is configured to be able to support the substrate W when the substrate W is placed on the plurality of projections 21. The substrate W is typically placed on the support member 20 with the face Wf being in contact with the projections 21. Each projection 21 of the support member 20 is formed to have such a height that a predetermined clearance S is provided between the front face 11f of the jig 11 and the face Wf of the substrate W when the substrate W is placed on the support member 20. The predetermined clearance S is a clearance that does not induce convection of a fluid (in this embodiment, treatment gas G) present between the front face 11f of the jig 11 and the face Wf of the substrate W. The expression “not induce convection of a fluid” as used herein means that it is enough if substantially no convection is induced. Typically, it means that convection that is so strong that the substrate W placed on the support member 20 is flapped by the fluid is not induced. The predetermined clearance S may be about 0.5 mm. Each projection 21 of the support member 20 has a tip (an end opposite the end in contact with the front face 110 that is formed to have as small area as possible so that no heat is directly transferred between the projections 21 and the substrate W. Direct heat transfer between the projections 21 and the substrate W may hinder uniform heat transfer to the entire face Wf of the substrate W. Then, the resulting temperature variation in the face Wf of the substrate W may cause adverse effects such as non-uniform melting of the solder (not shown) placed on the substrate W. Thus, the expression “no heat is directly transferred between the projections 21 and the substrate W” as used herein means that it is enough if substantially no direct heat transfer occurs. Typically, it means that heat transfer that causes temperature variation in the substrate W does not occur when the substrate W is heated with the heater 10. One specific configuration example is to support the substrate W at points or along lines. To support the substrate W at points or along lines is intended to support the substrate W in such a manner as to prevent non-uniform heat transfer (non-uniform contact) that causes adverse effects such as non-uniform melting of the solder (not shown) placed on the substrate W. In this embodiment, each of the projections 21 has a pointed tip as seen in a vertical cross-section.
As shown in the perspective view of
Referring again to
The gas supply unit 40 supplies a treatment gas G into the chamber 30 to create a preferable atmosphere when the substrate W is heated. The gas supply unit 40 includes a gas supply pipe 41 and a gas supply valve 42. The gas supply pipe 41 is a pipe constituting a flow path that directs the treatment gas G into the chamber 30. One end of the gas supply pipe 41 is connected to the chamber 30, and the other end of the gas supply pipe 41 is connected to a treatment gas supply source (not shown). The gas supply valve 42 is a valve that is installed in the gas supply pipe 41 to permit or interrupt the flow of the treatment gas G through the gas supply pipe 41. Typically, a control valve is used as the gas supply valve 42 to adjust flow rate. Typically, depending on the type of the substrate W, an inert gas such as nitrogen or argon, or a reducing gas such as a carboxylic acid, e.g. formic acid, is used as the treatment gas G.
The controller 60 serves to control the operation of the heating apparatus 1. The controller 60 is configured to be able to vary the output of the IR lamp 13 by a control signal sent, by wire or radio, from the controller 60 to the IR lamp 13. The controller 60 is electrically connected by wire or radio to the gas supply valve 42, and is configured to be able to adjust an opening of the gas supply valve 42 by a control signal sent thereto.
Referring next to
When the production of a plate-like object is started, the shutter 33 of the chamber 30 is opened and the substrate W with solder (not shown) placed on a face opposite the face Wf is transported into the chamber 30 (heating target object providing step: S1). Next, the substrate W is mounted on the support member 20 with the face Wf of the substrate W opposed to the front face 11f of the jig 11 to have the substrate W supported on the support member 20 (supporting step: S2). The controller 60 then starts heating the substrate W via the jig 11 by energizing the IR lamp 13 to output infrared rays (heating step: S3). The substrate W is heated in the following manner. The infrared rays irradiated from the IR lamp 13 reach the reverse face 11r of the jig 11 through the quartz glass 30Q and increase the temperatures of the jig 11 and the support member 20. Because the jig 11 has a relatively high thermal conductivity and a relatively small thermal capacity, the temperature of the entire jig 11 increases rapidly. After the temperature of the front face 11f of the jig 11 has increased in this way, the heat in the jig 11 transfers to the substrate W. At this time, because the substrate W is in contact with the support member 20 but supported along lines on the support member 20, no direct heat transfer from the support member 20 substantially occurs. As a result, heat transfer from the jig 11 to the substrate W is achieved primarily by heat transfer via the treatment gas G and heat transfer by convection, if any, is less than the heat transfer via the treatment gas G. In other words, heat transfer from the jig 11 to the substrate W is achieved exclusively via the treatment gas G present between the jig 11 and the substrate W. Thus, the substrate W can be heated uniformly with a simple configuration. The temperature of the jig 11 is preferably kept within a temperature difference of about 50° C. or less from the substrate W, for example.
When heating of the substrate W is started, the controller 60 opens the gas supply valve 42 to introduce the treatment gas G into the chamber 30 (S4). At this time, the treatment gas G should be introduced into the chamber 30 at such a flow rate that the substrate W supported on the support member 20 is not flapped by convection due to introduction of the treatment gas G. Even if the substrate W has a portion susceptible to oxidation such as a metal film, creation of an atmosphere of the treatment gas G in the chamber 30 can prevent the portion from undergoing oxidation when the substrate W is heated later. When the chamber 30, including the clearance S between the jig 11 and the substrate W, is filled with the treatment gas G, the shutter 33 is closed to seal the chamber 30, and then the controller 60 closes the gas supply valve 42. Alternatively, if the chamber 30 is provided with an air vent (not shown), the shutter 33 may be closed immediately after the substrate W is transported into the chamber 30 and then air may be discharged through the air vent (not shown) while the treatment gas G is supplied from the gas supply unit 40 into the chamber 30.
When the chamber 30 is filled with the treatment gas G, the controller 60 determines whether the plate-like object is completed (S5). The plate-like object is an object desired as an intermediate material including the substrate W with molten solder (not shown) thereon. Thus, whether the plate-like object is completed relates to whether the temperature of the substrate W increases and reaches the melting point of the solder (not shown). In this embodiment, the relationship between the output of the IR lamp 13 and the temperature rise of the substrate W has been previously obtained and stored in the controller 60. Then, it is determined whether the plate-like object is completed by seeing if, based on the relationship stored in the controller 60, the time for which infrared rays has been emitted from the IR lamp 13 is sufficient to provide the necessary amount of heat to melt the solder (not shown) on the substrate W without overheating the substrate W. If the plate-like object is not completed in the step of determining whether the plate-like object is completed (S5), the process returns to the step of determining whether the plate-like object is completed (S5). On the other hand, if the plate-like object is completed, the controller 60 turns off the IR lamp 13 to stop heating of the substrate W (S6). The process from the start of heating of the substrate W (S3) to a point immediately before stopping the heating of the substrate W (S6) corresponds to the heating step. After heating of the substrate W is stopped, the shutter 33 of the chamber 30 is opened and the completed plate-like object is taken out of the chamber 30 (S7). In this way, a plate-like object is produced. The shutter 33 may be opened and closed either manually or by the controller 60.
As described above, according to the heating apparatus 1 of this embodiment, because the substrate W from which a plate-like object is produced is supported along a plurality of lines on the support member 20 provided on the front face 11f of the jig 11, the substrate W is heated by heat transfer via the treatment gas G present between the jig 11 and the substrate W with a predetermined clearance S being maintained between the face Wf and the front face 11f. Thus, direct heat transfer from the jig 11 to the substrate W is prevented, and the substrate W can be heated uniformly with a simple configuration. If the predetermined clearance S were not present between the jig 11 and the substrate W and the substrate W were heated with the entire face Wf of the substrate W in contact with the front face 11f of the jig 11, in other words, if the substrate W were heated in a state where heat transfer caused by heat conduction due to contact between the substrate W and the jig 11 occurs, if the substrate W warped, the area of contact would exist only partially between the substrate W and the jig 11, making it difficult to heat the entire substrate W uniformly. In this regard, when the substrate W is heated by heat transfer via the treatment gas G present between the jig 11 and the substrate W with a predetermined clearance S being maintained between the face Wf of the substrate W and the front face 11f of the jig 11 as in the heating apparatus 1 according to this embodiment, the heat transfer from the jig 11 to the substrate W is substantially achieved by heat conduction via the treatment gas G. In this case, the heat conduction via the treatment gas G does not change significantly even if there is minor variation in the predetermined clearance S.
Referring next to
In the heating apparatus 1A constituted as described above, when the substrate W is heated via the jig 11 in the chamber 30 to produce a plate-like object, the same procedure is followed as in the heating apparatus 1 (refer to
In addition, in the heating apparatus 1A, heating of the substrate W may be achieved by transporting the substrate W with solder placed thereon into the chamber 30 without using the carrier plate 1120, introducing the treatment gas G into the chamber 30 with the substrate W placed on the retainers 38 (as shown by chain double-dashed lines in
While the heating source is the IR lamp 13 in the above description, a heating source other than the IR lamp 13, such as a hot plate (a plate-like member that can achieve a temperature rise) or an electric device that generates Joule heat, may be employed. However, the IR lamp 13 is preferred because it facilitates temperature control. While the heater 10 is configured to have the jig 11 and the heating source (the IR lamp 13), which are separated from each other, in the above description, the jig 11 and the heating source may be constituted integrally with each other.
While the treatment gas G is introduced into the chamber 30 (S4) after heating of the substrate W is started (S3) in the above description, heating of the substrate W may be started after the treatment gas G is introduced into the chamber 30 or heating of the substrate W may be started simultaneously with the introduction of the treatment gas G into the chamber 30.
In the above description, when the substrate W is heated, an atmosphere of an inert gas or reducing gas used as a treatment gas G is created in the chamber 30. However, when oxidation of the substrate W does not cause any problem, the substrate W may be heated in an air atmosphere without using the treatment gas G. When the substrate W is heated in an air atmosphere, the chamber 30 may not be provided.
In the above description, the amount of heat generation from the IR lamp 13 is controlled by time based on the relationship between the output of the IR lamp 13 and the temperature rise of the substrate W obtained previously (open loop control). However, the amount of heat generation from the IR lamp 13 may be controlled by detecting a temperature of the substrate W or the jig 11 with a thermocouple or radiation thermometer and feeding back the detected temperature for adjustment of the output of the IR lamp 13 (closed loop control). When a temperature of the substrate W is detected, a temperature of a dummy substrate mounted adjacent to the substrate W on the support member 20 may be detected.
In the following, the results of verification of variation of temperature distribution caused by differences in the mode in which the substrate W is heated are described. As substrates W for verification, glass epoxy substrates having a rectangular shape of 60 mm×90 mm and a thickness of 0.8 mm with 35 μm copper foil attached to both sides were used. The substrates W were placed on the support member 20 mounted on the front face 11f of the jig 11 as shown in
In Example, the substrate W exhibited a relatively milder temperature rise than the jig 11 at the start of heating, and the rates of temperature rise of the jig 11 and the substrate W became equal to each other about 250 seconds after the start of heating. Meanwhile, the variation among the temperatures detected at the six points was 3 to 4° C. It should be noted that the substrate W was not held with pins in Example as in Comparative Example 1.
In Comparative Example 1, the substrate W exhibited a temperature rise similar to that of the jig 11 from the beginning of heating, and also experienced a sudden temperature change at some points. The variation among the temperatures detected at the six points was 3 to 6° C. In Comparative Example 1, the temperature variation was relatively small. This is partly because the entire face Wf of the substrate W was forcibly kept in contact with the jig 11 with pins so that the substrate W could not warp. When pins for holding the substrate W are provided, a drive unit for driving the pins is required. This not only complicates the structure but also makes maintenance difficult such as cleaning required when volatiles generated when the substrate W is heated has gotten into the complicated structure.
In Comparative Example 2, after the start of heating, a significant variation was observed among the temperatures detected at the six points from a little after approximately 150 seconds to 260 seconds with a maximum difference of 45° C. In Comparative Example 2, it is considered that variation of heat transfer caused by convection of gas is significant.
The above results demonstrated that the substrate W could be heated uniformly in Example without using pins as those used in Comparative Example 1.
All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.
The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) is to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.
Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.
1 heating apparatus
10 heater
11 jig
11
f front face
13 IR lamp
20 support member
30 chamber
38 retainer
40 gas supply unit
60 controller
S predetermined clearance
W heating target object
Wf face
| Number | Date | Country | Kind |
|---|---|---|---|
| 2016-183949 | Sep 2016 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2017/033555 | 9/15/2017 | WO | 00 |
