JP2011079055A - Substrate, block, apparatus, method and program for measuring reflow furnace - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate for measuring a reflow furnace, the substrate being endurable to repeated use and quantifying a condition inside the reflow furnace. <P>SOLUTION: The substrate for measuring a reflow furnace measures a condition inside a furnace when conveyed inside the reflow furnace. The substrate includes: a base material 130 composed of a planar member; one or more plates 140-160 which are arranged on the base material and which are known in heat capacity; and detection means (thermocouples 141-161) abutting on the plates and detecting temperature of the plates. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a reflow furnace measurement substrate, a reflow furnace measurement block, a reflow furnace measurement device, a reflow furnace measurement method, and a reflow furnace measurement program.

  When surface mounting electrical components and electronic components (hereinafter simply referred to as “components”) on an electronic circuit board (printed circuit board), the components are applied after applying cream solder to the connection lands formed on the surface of the electronic circuit board. And electrically and mechanically connect the parts to the connection lands by melting the cream solder in a reflow oven. By the way, since there are various types of components placed on the electronic circuit board, it is possible to reliably and electrically and mechanically apply these components without applying heat unnecessarily. Need to connect to.

  In recent years, switching to lead-free solder containing no lead has been advanced in consideration of environmental impact. Lead-free solder, for example, Sn-Ag lead-free solder has a melting point as high as around 220 ° C. compared to 183 ° C., which is the melting point of conventional lead solder (Sn—Pb solder). The applied temperature becomes higher. As a result, individual components placed on the electronic circuit board are exposed to a high temperature atmosphere as the soldering temperature increases.

  In order to cope with the high temperatures caused by lead-free solder, efforts are also being made to increase the heat resistance of individual components. However, at present, the heat resistance temperature of general parts is about 240 ° C. As a result, in the conventional lead solder, the difference (margin) between the melting temperature of the solder and the heat resistance temperature of the component can be secured at about 57 ° C., but the lead-free solder can secure only about 20 ° C.

  For this reason, temperature management of the reflow furnace is very important in order to perform soldering reliably using lead-free solder without affecting the parts by heat. Conventionally, as shown in Patent Document 1, for example, a reflow furnace that evaluates the surface temperature distribution of a printed circuit board in a reflow furnace by flowing an electronic circuit board having a plurality of thermocouples on the surface to the reflow furnace. Temperature management methods are known.

JP 2000-349431 A

  In the prior art, since an actual electronic circuit board (for example, a glass epoxy board) is used, the electronic circuit board deteriorates due to the influence of heat when it is repeatedly used. There is a problem that it occurs.

  In addition, since there are variations in thermal characteristics among individual electronic circuit boards, there is also a problem that the measurement values vary, and the state in the reflow furnace cannot be quantified with high accuracy.

  Therefore, the problem to be solved by the present invention is a reflow furnace measurement substrate, a reflow furnace measurement block, and a reflow furnace measurement device that can withstand repeated use and can accurately quantify the state in the reflow furnace. And a reflow furnace measurement method and a reflow furnace measurement program.

  In order to solve the above problems, the reflow furnace measurement substrate of the present invention is a reflow furnace measurement substrate that measures the state in the furnace when transported in the reflow furnace, and a base material constituted by a plate-like member. One or a plurality of plates with known heat capacities arranged on the substrate and detection means for detecting the temperature of the plates in contact with the plates.

  According to such a configuration, it is possible to provide a reflow furnace measurement substrate that can withstand repeated use and can accurately quantify the state in the reflow furnace.

  In addition to the above invention, another invention is characterized in that the plate is disposed on the substrate in a state of being substantially thermally insulated.

  According to such a configuration, accurate measurement is possible by eliminating thermal interference between the plate and the substrate.

  In addition to the above-mentioned invention, another invention is characterized in that the plate has a width wider than the pitch of the hot air blowing nozzles in a direction orthogonal to the conveying direction of the reflow furnace.

  According to such a configuration, since the hot air from the plurality of nozzles can be averaged and measured, the measurement can be performed under substantially the same conditions as on an actual electronic circuit board.

  According to another invention, in addition to the above invention, the plate includes a plurality of plates having different heat capacities, and the detection means detects the temperature of each of the plates.

  According to such a configuration, the temperature change of the component can be reliably measured by providing the plate corresponding to the heat capacity of the component arranged on the electronic circuit board.

  According to another invention, in addition to the above-mentioned invention, when the first portion of the base material loaded into the reflow furnace is the top and the last portion loaded is the last, the plate is It is characterized in that the heat capacity is arranged in ascending order from the top to the end of the material.

  According to such a configuration, measurement can be performed without disturbing the thermal state in the reflow furnace.

  In addition to the above invention, another invention is characterized in that a plurality of the plates having substantially the same heat capacity are arranged side by side in a direction perpendicular to the transport direction.

  According to such a structure, the difference in the heating capability in the direction orthogonal to the conveyance direction in the reflow furnace can be measured.

  In addition to the above invention, another invention is characterized in that the plate is arranged at a position where plates having substantially the same heat capacity are opposed to each other with the substrate interposed therebetween.

  According to such a structure, each temperature distribution of the up-down direction in a reflow furnace can be measured.

  In addition to the above invention, another invention is characterized in that the detection means is constituted by a thermocouple, and a detection portion of the thermocouple is thermally coupled to the plate.

  According to such a configuration, it becomes possible to detect the temperature change of the plate reliably and without delay.

  In addition to the above invention, another invention is characterized in that the thermocouple is thermally coupled to the plate by welding.

  According to such a configuration, it is possible to increase the thermal coupling and to prevent a decrease in thermal coupling due to secular change.

  In another invention, in addition to the above-described invention, the base material is provided with an opening of substantially the same size as the plate arranged in each part, and the plate is arranged on the opening. Thus, the contact area between the substrate and the plate is reduced, and these are thermally insulated from each other.

  According to such a configuration, thermal insulation can be achieved by using an opening that can be easily formed by, for example, pressing or laser processing.

  In addition to the above invention, in another invention, a low heat transfer member that covers at least a part of the plate is sandwiched between the base material and the plate, and the low heat transfer member The base material and the plate are thermally insulated from each other.

  According to such a configuration, it is possible to reliably achieve thermal insulation by using an appropriate low heat transfer member.

  In addition to the above invention, another invention is characterized in that the base material has substantially the same size as an electronic circuit board to be soldered in the reflow furnace.

  According to such a configuration, it is possible to perform measurement in an environment closer to actual conditions by reproducing a thermal environment by hot air similar to that of the electronic circuit board.

  In addition to the above invention, another invention is characterized in that the substrate has a width adjusting mechanism capable of adjusting a width in a direction orthogonal to the transport direction.

  According to such a configuration, the reflow process can be performed without changing the setting conditions represented by the width of the rail, even during the production of the electronic circuit board, regardless of the size of the electronic circuit board. It becomes possible to quantify the state in the furnace with high accuracy.

  In the reflow furnace measuring apparatus having any of the above-described reflow furnace measurement substrates, the present invention provides an input means for inputting data detected by the reflow furnace measurement substrate, and the input from the input means. Storage means for storing data.

  According to such a configuration, it is possible to provide a reflow furnace measuring apparatus capable of accurately quantifying the state in the reflow furnace.

  According to another invention, in addition to the above-mentioned invention, the storage means may store data obtained when the state in the reflow furnace is appropriate for the electronic circuit board to be soldered. It is stored, and it is determined whether or not the state of the reflow furnace at that time is appropriate by comparing the data obtained when the appropriate state is obtained with the newly obtained data. It has the determination means to do.

  According to such a configuration, it is possible to easily determine whether or not the state of the reflow furnace is an appropriate state, and operation in an inappropriate state can be avoided.

  Further, the present invention provides a reflow furnace measurement method having any of the above-described reflow furnace measurement substrates, an input step of inputting data detected by the reflow furnace measurement substrate, and the input that is input in the input step Storing the data in a storage device.

  According to such a method, it is possible to provide a reflow furnace measurement method capable of accurately quantifying the state in the reflow furnace.

  In the reflow furnace measurement program for measuring the state of the reflow furnace based on any of the above-described reflow furnace measurement substrates, the present invention provides a computer for inputting data detected by the reflow furnace measurement substrate. And a computer functioning as storage means for storing the data input from the input means.

  According to such a program, it is possible to provide a reflow furnace measurement program capable of accurately quantifying the state in the reflow furnace.

  On the other hand, the reflow furnace measuring block of the present invention is a reflow furnace measuring block for measuring the state in the furnace when being transported in the reflow furnace, the base comprising a plate member, and the base One or a plurality of plates having a known heat capacity arranged on the material, and a detecting means that is in contact with the plate and detects the temperature of the plate, and the substrate is transported in the reflow furnace A mounting part that can be attached to and detached from the product to be attached is provided.

  According to this structure, it can be conveyed together in a reflow furnace by attaching the block for reflow furnace measurement to the articles conveyed in a reflow furnace.

  Further, the reflow furnace measurement block, and the article conveyed in the reflow furnace may be an electronic circuit board or a reflow furnace measurement board.

  Further, the reflow furnace measurement block can be attached to the front end in the transport direction of the article transported in the reflow furnace.

  According to the present invention, a reflow furnace measurement substrate, a reflow furnace measurement apparatus, a reflow furnace measurement method, and a reflow furnace that can withstand repeated use and can accurately quantify the state in the reflow furnace. A measurement program can be provided.

It is a figure which shows the structural example of the reflow furnace measuring apparatus which concerns on embodiment of this invention. It is a figure which shows the structural example of the test | inspection board | substrate shown in FIG. It is a figure which shows the attachment method of the plate shown in FIG. It is a figure which shows the state which narrowed the width | variety of the test | inspection board | substrate shown in FIG. It is a block diagram which shows the structural example of the personal computer shown in FIG. It is sectional drawing which shows schematic structure of the reflow furnace shown in FIG. It is a flowchart explaining an example of the process performed in embodiment shown in FIG. It is an example of the data stored in the personal computer shown in FIG. It is a figure which shows the temperature change in the furnace of the plate from which heat capacity differs. It is a figure which shows the relationship between relative heat capacity and peak temperature in the case of changing hot air intensity | strength. It is a flowchart explaining an example of the process performed in embodiment shown in FIG. It is a figure which shows another example of a base material. It is a figure which shows another example of a base material. It is a figure which shows another example of a base material. It is a figure which shows an example of the attachment method to the base material of a plate. It is a figure which shows an example of the attachment method to the base material of a plate. It is a figure which shows an example of the attachment method to the base material of a plate. It is a figure which shows an example of the attachment method to the base material of a plate. It is a figure which shows an example of the attachment method to the base material of a plate. It is a figure which shows the other structural example of the test | inspection board | substrate shown in FIG. It is a figure which shows the other structural example of the test | inspection board | substrate shown in FIG. It is another modification embodiment, and is a figure showing the state where the block for reflow furnace measurement was attached to the electronic circuit board with a thermocouple. It is a figure which shows the other state which attached the block for reflow furnace measurement to the electronic circuit board with a thermocouple. It is another modification embodiment, and is a figure showing the state where the reflow furnace measurement block was attached to the reflow furnace measurement substrate. It is another modification embodiment, and is a figure showing the state where the block for reflow furnace measurement was attached to the surface of the electronic circuit board with a thermocouple.

  Next, an embodiment of the present invention will be described.

(A) Embodiment of the Present Invention FIG. 1 is a diagram showing a configuration example of an embodiment of a reflow furnace measuring apparatus according to the present invention. As shown in this figure, the reflow furnace measuring device includes a verification substrate (corresponding to “reflow furnace measuring substrate” in the claims) 100, a personal computer 300, and a temperature measuring device 350 as main components. Then, the temperature in the reflow furnace 400 in an appropriate state using the thermocouple-equipped electronic circuit board 200 is measured by the test board 100 and is made into a database (quantified). Thereafter, the test board 100 is used. Thus, the state in the reflow furnace 400 can be known. The temperature measuring device 350 is a device that converts a voltage (analog signal) generated by a thermocouple disposed on the test board 100 or the thermocouple-equipped electronic circuit board 200 into digital data corresponding to the temperature and outputs the digital data. The temperature measuring device 350 may be built in the personal computer 300.

  FIG. 2 is a diagram illustrating a configuration example of the test board 100. As shown in this figure, the test board 100 connects a set of rails 110, 120 and rails 110, 120 mounted on a conveyor 404 indicated by a broken line provided in the reflow furnace 400 to each other. Have pantographs 170 and 180 for making the interval (interval between the rails 110 and 120) variable while maintaining a parallel state. A base material 130 is suspended between the central portions of the pantographs 170 and 180. One or a plurality of (in this example, three) plates 140 to 160 whose heat capacity and area are known in advance are arranged on the base material 130, and each plate 140 to 160 has a thermoelectric for measuring temperature. The temperature measuring sections 142 to 162 of the pairs 141 to 161 are in contact with each other. Note that the plates 140 to 160 are made of, for example, a metal such as stainless steel, aluminum, or silver, or ceramics having high thermal conductivity.

  Here, each of the rails 110 and 120 is made of a “U” -shaped metal (for example, stainless steel) whose inner side is open. Protrusions 172, 173, 182, and 183 of pantographs 170 and 180 are inserted into upper and lower ends (up and down direction in FIG. 2) of the rails 110 and 120, and holes 111, 112, 121, 122 are formed. Next to the holes 111, 112, 121, 122, long holes 113, 114, 123, 124 are provided, respectively, and the protrusions 174, 175, 184, 185 inserted therein are the long holes 113, The pantographs 170 and 180 can be expanded and contracted by sliding in 114, 123, and 124.

  The pantographs 170 and 180 are each composed of six link members. The link member is made of metal (for example, stainless steel). Holes 171 and 181 into which screws 176 and 186 are inserted are formed at the center of the pantographs 170 and 180. The base material 130 has a base portion 131 on which the plates 140 to 160 are placed, and extending portions 132 and 134 extending from the base portion 131 in the vertical direction. In addition, the base material 130 is comprised with the metal (for example, stainless steel). The base material 130 may be made of, for example, a ceramic plate-like member, made of heat-resistant glass, or made of heat-resistant plastic. Further, when the expansion / contraction width is increased or decreased, it can be dealt with by changing the number and dimensions of the link members.

  FIG. 3 is a diagram illustrating a state of the plate 140 placed on the base material 130. As shown in FIG. 3A, the base material 130 has an opening 136 indicated by a broken line. The opening 136 is formed to have substantially the same size as the plate 140 except for a portion fixed by the four screws 143. FIG. 3B is a cross-sectional view of FIG. As shown in this figure, the plate 140 is disposed on the opening 136 of the base material 130 and is fixed to the base material 130 by four screws 143. Each screw 143 is inserted so that the head is positioned on the base material 130 side. Thereby, it can prevent that the heat capacity which a head has is added to the heat capacity of plate 140, and it becomes an error. Between each screw 143 and the base material 130, a washer 144 having high thermal insulation performance, for example, formed of Teflon (registered trademark) or the like is inserted, and the heat of the base material 130 is applied to the plate 140. Prevent transmission. Note that the screw 143 may also be formed of a member having relatively high heat insulating properties (for example, heat resistant plastic, carbon fiber, ceramics). A female screw is formed in a portion of the base material 130 where the screw 143 is inserted, and the screw 143 is screwed into the portion and fixed. At the center of the back side of the plate 140 (the lower side of the figure), a thermocouple temperature sensing part (part where two kinds of metals are joined) 142 is thermally connected to the plate 140 by electric welding such as spot welding. It is joined to. Of course, welding other than electric welding may be used, or silver brazing or adhesion using a heat-resistant adhesive may be used. Although the washer 144 is used in the example of FIG. 3, the plate 140 may be directly disposed on the base material 130 without using the washer 144. Even in such an arrangement method, the contact area between the plate 140 and the base material 130 is reduced (for example, by reducing the overlapping width to about 0.25 mm or less), so that it is substantially thermally insulated. It can be made the state. In addition, 0.25 mm is an example, for example, about 1 mm may be sufficient. In short, it is only necessary to be thermally insulated.

  FIG. 4 is a view showing a state in which the width of the test board 100 shown in FIG. 2 is narrowed. As shown in FIG. 4B, when the width is narrowed, the pantographs 170 and 180 are contracted, and the protrusions 174, 175, 184 and 185 are in the elongated holes 113, 114, 123 and 124. It has moved to the inner part of. FIG. 4A is a side view when FIG. 4B is viewed from the direction of arrow X in the drawing. As shown in this figure, a rectangular opening 115 is formed on the side surface of the rail 110 for insertion of the side surface portion of the base portion 131 when the width is reduced. Although not shown in this figure, a similar opening 125 is also formed in the rail 120.

  The thermocouple-attached electronic circuit board 200 is obtained by attaching a thermocouple to a predetermined portion of an electronic circuit board to be soldered in the reflow furnace 400. More specifically, a plurality of electronic components or electrical components are arranged on a glass epoxy substrate, for example, a component having low heat resistance and a small heat capacity (for example, LED (Light Emitting Diode)). In addition, a thermocouple is attached to a component (for example, an IC (Integrated Circuit) having a large size) that has a large heat capacity and is not likely to reach the melting point temperature of the solder. By flowing the thermocouple-attached electronic circuit board 200 into the reflow furnace 400, it is possible to know whether or not the temperature state in the furnace is appropriate for the electronic circuit board.

  FIG. 5 is a block diagram showing a configuration example of the personal computer 300 shown in FIG. As shown in this figure, a personal computer 300 includes a central processing unit (CPU) 301, a read only memory (ROM) 302, a random access memory (RAM) 303, a hard disk drive (HDD) 304, and a graphics card (GC) 305. , A display device 306, an I / F (Interface) 307, and a bus 308. Here, the CPU 301 controls each unit of the apparatus based on a program stored in the ROM 302 or the HDD 303. The ROM 302 stores basic programs and data executed by the CPU 301. The RAM 303 functions as a working area when the CPU 301 executes a program. The HDD 304 is a storage device that can store data in a hard disk that rotates at high speed and can read out stored data. As shown in FIG. 5, a program 310 and a DB (Data Base) 320 are stored in the HDD 303. The program 310 has an application program and an operating system that execute processing to be described later. The DB 320 mainly stores data acquired by the test board 100 (and the electronic circuit board with thermocouple 200).

  The GC 305 executes a drawing process based on the drawing command supplied from the CPU 301, converts the obtained image data into a video signal, and supplies the video signal to the display device 306. The display device 306 is configured by, for example, an LCD (Liquid Crystal Display) or the like, and displays a video signal supplied from the GC 305 on a display unit (liquid crystal panel). The I / F 307 inputs data related to the temperature output from the test board 100 or the thermocouple-equipped electronic circuit board 200 via the temperature measuring device 350. A bus 308 is a signal line group for connecting the CPU 301, the ROM 302, the RAM 303, the HDD 304, the GC 305, and the I / F 307 to each other and enabling data exchange between them. Although not shown in this figure, the I / F 307 is connected to a keyboard, a mouse, and the like as input devices, generates data corresponding to the operation of the operator, and supplies the data to the I / F 307.

  FIG. 6 is a cross-sectional view showing a schematic configuration of the reflow furnace 400. In the example of FIG. 6, the reflow furnace 400 includes a casing 401, a heating zone 402, a cooling zone 403, a conveyor 404, an inlet 405, and an outlet 406. Here, the housing 401 is constituted by, for example, a highly heat-insulating member disposed inside and a metallic member surrounding the outside. The heating zone 402 is disposed at a position (up and down) opposed to each other with the conveyor 404 interposed therebetween, and for example, heats an inert gas such as nitrogen gas and ejects it from a plurality of nozzles to heat the electronic circuit board. Has been. In this example, seven pairs of heating zones 402 are provided, but other numbers (for example, six or less or eight or more) may be used. Each nozzle is arranged in a direction orthogonal to the substrate transport direction, for example, at a pitch (nozzle pitch) of about 1 cm. The cooling zone 403 is disposed at a position facing the conveyor 404, and is configured to cool the circuit board by ejecting an inert gas such as nitrogen gas from a plurality of nozzles without heating. . Although this example has two pairs of cooling zones 403, other numbers (one or three or more) may be used. The conveyor 404 conveys the electronic circuit board from the inlet 405 side toward the outlet 406. Since only a part of both ends of the electronic circuit board is placed on the conveyor 404, the heated nitrogen gas can be jetted onto the lower surface of the electronic circuit board.

  The width of the plates 140 to 160 (the width in the left-right direction in FIG. 2) is desirably set to be wider than 1 cm which is the nozzle pitch. According to such a setting, since the hot air from a plurality of nozzles hits each of the plates 140 to 160, an average temperature can be measured, and measurement can be performed under conditions close to the actual state on the electronic circuit board. It is.

(B) Operation of the embodiment of the present invention Next, the operation of the embodiment will be described. For example, when flowing a new electronic circuit board to the reflow furnace 400, for a predetermined position of the target electronic circuit board (for example, a portion having a small heat capacity, a portion having a large heat capacity, and a portion having low heat resistance). Thus, the thermocouple-attached electronic circuit board 200 to which the thermocouple is attached is formed. The thermocouple-equipped electronic circuit board 200 formed in this way is connected to the temperature measuring device 350, and an input device (not shown) of the personal computer 300 is operated to execute the program 310 shown in FIG. The When the program 310 is executed, the processing of the flowchart shown in FIG. 7 is started. When the process of this flowchart is started, the reflow furnace condition setting is executed in step S0. Specifically, the temperature of each heating zone 402, the flow rate of the heating gas ejected from each nozzle, and the conveyance speed of the conveyor 404 are set according to the target electronic circuit board. Next, in step S <b> 10, the thermocouple-attached electronic circuit board 200 is caused to flow through the reflow furnace 400 by the operator. More specifically, the electronic circuit board with thermocouple 200 is placed on the conveyor 404 of the reflow furnace 400, and the electronic circuit board with thermocouple 200 is carried into the reflow furnace 400.

  In step S11, the CPU 301 acquires temperature data from the thermocouple-equipped electronic circuit board 200 via the temperature measuring device 350 at a predetermined sampling period (for example, at intervals of 0.25 seconds). The sampling period is preferably set according to the measurement target so as to satisfy the Nyquist theorem. Specifically, when there is a component (or plate) having a small heat capacity, the temperature changes rapidly, and thus the change is acquired as data. In step S <b> 12, the CPU 301 associates the temperature data acquired in step S <b> 11 with time data and stores it in the RAM 302, for example. Here, the time data refers to an elapsed time after the electronic circuit board with thermocouple 200 is flowed through the reflow furnace 400, for example. In addition, for example, the position of the thermocouple-attached electronic circuit board 200 in the reflow furnace 400 may be used. Regarding the information regarding the position of the electronic circuit board with thermocouple 200, for example, information indicating the operation state of the conveyor 404 may be acquired from the control unit of the reflow furnace 400.

  In step S13, based on the temperature data and time data acquired in step S11 and step S12, for example, a graph showing temporal changes in the temperature data of each thermocouple is displayed on the display device 306. , It is determined whether or not the state of the reflow furnace 400 is in an appropriate range. This determination is made so that the CPU 301 automatically determines based on a certain standard (for example, peak temperature of each component, temperature gradient, appropriate temperature holding time, duration of 200 ° C. or higher, duration of 150 ° C. or higher). Alternatively, it may be determined by the operator himself. More specifically, it is determined whether the peak temperature of each component is, for example, 250 ° C. or higher in order to prevent deterioration of the component due to heat. In order to prevent damage due to stress due to thermal expansion due to rapid temperature change, for example, it is determined whether or not the temperature gradient is 4 ° C./second or more. As an appropriate temperature holding time, it is determined whether or not it is held at 225 ° C. for 10 seconds or more in order to ensure reliable melting of the solder. Further, the duration time of 200 ° C. or higher is determined by taking into consideration the thermal load on the component and whether 200 ° C. or higher has continued for 60 seconds or longer. In addition, for a duration of 150 ° C. or more, is the time from 150 ° C. to 180 ° C. before the solder melts within 90 seconds ± 30 seconds so that the activator contained in the solder acts effectively? Determine. Note that determination methods other than these may be employed.

  In step S14, the setting of the reflow furnace 400 is changed so as to be in an appropriate state. Specifically, a desired state is achieved by adjusting the set temperature of each heating zone 402, the flow rate of the heated gas ejected from each nozzle, and the conveying speed of the conveyor 404. Note that this setting may also be automatically determined by the CPU 301 as described above, or may be determined by the operator himself. In addition, the process of step S10-S14 is repeatedly performed until the inside of the reflow furnace 400 will be in a desired state (appropriate state). In addition, an appropriate state is a state with a fixed width | variety, and by keeping various conditions in the said range, while performing soldering appropriately, generation | occurrence | production of the defect of a product can be prevented.

  In step S15, the test substrate 100 shown in FIG. More specifically, for example, the base material 130 on which the plates 140 to 160 having heat capacities (for example, maximum and minimum and intermediate heat capacities) corresponding to the electronic components mounted on the electronic circuit board is selected. The pantographs 170 and 180 are temporarily fixed by screws 176 and 186. And after adjusting the space | interval of the rails 110 and 120 so that it may become equal to the space | interval of the conveyor 404, it fixes by tightening the screws 176 and 186. Thereby, since the space | interval of pantographs 170 and 180 is fixed uniformly, the space | interval of the rails 110 and 120 is fixed uniformly. The test substrate 100 set in this way is placed on the conveyor 404, and conveyance into the reflow furnace 400 is started. At this time, as a mounting method on the conveyor 404, for example, it is desirable to mount so that a plate having a small heat capacity enters the reflow furnace 400 first. This is because, when a plate having a large heat capacity first enters the reflow furnace 400, the temperature is somewhat lowered, which affects subsequent plate measurements.

  When the conveyance is started, in step S <b> 16, the CPU 301 acquires the temperature data measured by the thermocouple in contact with the plates 140 to 160 of the test substrate 100 via the temperature measuring device 350. The temperature data acquired in step S16 is associated with time data in step S17 and stored in the RAM 302. Such a process is repeatedly executed at a predetermined cycle (for example, a cycle of 0.25 seconds) until the test substrate 100 is discharged from the reflow furnace 400.

  In step S18, the CPU 301 stores the data acquired in steps S16 to S17 in the DB 320 as appropriate state data. Thereafter, it is determined whether or not the state in the furnace is an appropriate state based on the appropriate state data. FIG. 8 is a diagram illustrating an example of appropriate state data stored in the DB 320. In the example of this figure, the elapsed time and the temperature data output from the thermocouples 141 to 161 are stored in association with each other. In the example of FIG. 8, the number of plates and thermocouples is three. However, the number may be two or less, or may be four or more. In the example of FIG. 8, only the acquired temperature data is stored. For example, the temperature gradient data is generated by dividing the change amount of the temperature data by the time required for the temperature data, and the temperature gradient data is combined. Alternatively, it may be stored alone. By using the temperature gradient data, a change in temperature per unit time can be known. Needless to say, data other than temperature gradient data (for example, heat transfer coefficient described later) may be stored.

  FIG. 9 is a diagram showing temporal changes in temperature data obtained from plates having different heat capacities with which thermocouples are in contact. In this figure, TC indicates the relative heat capacity. Here, the relative heat capacity refers to a relative heat capacity when compared with the heat capacity per unit area of a glass epoxy substrate having a thickness of approximately 1.6 mm. That is, when the heat capacity per unit area is the same as that of the 1.6 mm thick glass epoxy substrate, the relative heat capacity is “1”. Further, when the heat capacity per unit area is 1.5 times, the relative heat capacity is “1.5”. Note that a SUS304 material of 1 mm (or 0.8 mm) has the same heat capacity as that of a glass epoxy substrate having a thickness of approximately 1.6 mm. As the plates 140 to 160, SUS304 materials having different thicknesses are used. TC = 0 indicates a temperature change when the heat capacity is “0”, that is, when only the thermocouple is provided without the plate. The graphs of TC = 0, 0.55, 1.0, 1.5, 2.0, and 2.5 have heat capacities of 0, 0.55, 1.0, 1.5, and 2.0, respectively. , 2.5 shows changes in temperature data obtained from the thermocouple abutted on the plate. In this figure, the set temperatures of the first heating zone 402 to the seventh heating zone 402 are set to 180, 180, 180, 180, 220, 240, and 240 ° C., respectively. In addition, the vertical axis in the figure indicates the temperature (° C.), and the horizontal axis indicates the cumulative sampling number (times). By dividing the cumulative sampling number by 4, the elapsed time (seconds) can be obtained. That is, in the example of FIG. 9, the sampling period is set to 0.25 seconds. As can be seen from FIG. 9, the smaller the heat capacity, the more rapidly the temperature rises and the faster the peak temperature is reached.

  FIG. 10 is a diagram showing the relationship between the relative heat capacity and the peak temperature when the reflow furnace 400 is set similarly to the case of FIG. 9 described above. In this figure, L, M, and H indicate the setting conditions of the hot air intensity of the reflow furnace 400, and indicate L = Low, M = Middle, and H = high. Moreover, the frame shown with a broken line has shown the distribution range of the heat capacity of a general component.

  As shown in FIGS. 9 and 10 above, the heat capacities of general parts are distributed in a predetermined range. For example, parts having a large heat capacity and a slow rise in temperature, or a heat capacity having a small heat capacity and a rapid rise in temperature. For such parts, the temperature behavior of these parts can be known by selecting a plate close to its heat capacity. Also, for heat-sensitive parts such as electrolytic capacitors, the approximate heat capacity is investigated, and the behavior of the temperature can be known in the same way by using a plate with approximately the same heat capacity, so the part will be damaged beyond the heat resistance temperature. Can be prevented.

  Next, when the proper state data is stored in the DB 320 by the above processing, for example, when the state in the furnace is periodically inspected, the state in the furnace is inspected with the electronic circuit board being flowed. The process executed when the state in the furnace is inspected when the reflow furnace is restarted will be described. FIG. 11 is a flowchart for explaining the flow of processing executed in any of the cases described above when the appropriate state data is stored in the DB 320. When the process of this flowchart is started, the following steps are executed. That is, in step S30, the same verification substrate 100 as when the appropriate state data was measured is caused to flow in the reflow furnace 400 in the same state.

  In step S31, the CPU 301 acquires temperature data from the verification board 100 via the temperature measurement device 350 at the same sampling period as the appropriate state data. In step S32, the CPU 301 stores the temperature data acquired in step S31 in association with the time data in the RAM 302, for example. The time data is the same as that described above.

  In step S33, appropriate state data is acquired from the DB 320 of the HDD 303. Then, by comparing with the temperature data and time data acquired in steps S31 and S32, it is determined whether or not the newly acquired temperature data and time data are within a predetermined range. Specifically, for example, temperature data at a time corresponding to temperature data from each plate is acquired from appropriate state data, the square of the difference between the two is calculated, and the obtained values are cumulatively added. Then, by repeating such processing, a square cumulative value of the difference is calculated for each plate. And it is determined whether it is in a predetermined range by determining whether the obtained square accumulation value is below a predetermined threshold value. As a result, when it is determined that the temperature data of all the plates are within the predetermined range, the process proceeds to step S35, and otherwise, the process proceeds to step S36. In the above description, the determination is made based on the squared accumulated value of the differences, but other methods may be used. For example, the determination may be made based on the above-described criteria (for example, peak temperature, temperature gradient, appropriate temperature holding time, duration of 200 ° C. or higher, duration of 150 ° C. or higher). In short, as long as it is known that the state in the reflow furnace 400 is within an appropriate range, any determination method may be used.

  In step S35, the CPU 301 displays on the display device 306 that the reflow furnace 400 is in an appropriate state, and ends the process. On the other hand, in step S36, the CPU 301 displays on the display device 306 that the reflow furnace 400 is not in an appropriate state, and ends the process. When the state is not appropriate, for example, the appropriate state data of the plate determined to be not appropriate may be displayed on the display device 306 so that the newly acquired data can be compared. According to such a method, for example, since it is possible to know in which heating zone the temperature rise is not appropriate, the temperature rise can be appropriately controlled by readjusting the heating zone of the part. When it is determined that the reflow furnace 400 is not appropriate, the setting of the reflow furnace 400 may be automatically changed, or information regarding the setting change may be displayed on the display device 306.

  As described above, according to the embodiment of the present invention, the plates 140 to 160 whose heat capacities are known are attached to the base material 130, the thermocouples are brought into contact with the plates 140 to 160, and the thermocouples 141 to 161 are attached. Was used to detect the temperature of the plates 140-160. As a result, when the reflow furnace 400 is stored in the DB 320 as time-dependent changes in temperature in a proper state and the inspection in the furnace is performed, the test substrate 100 is again flowed into the furnace. By detecting a temporal change in temperature and comparing it with appropriate state data, it is possible to know whether or not the state in the furnace deviates from the appropriate state. That is, the test substrate 100 can be used as a ruler for the reflow furnace 400.

  Moreover, since the test | inspection board | substrate 100 is comprised with the metal member (for example, stainless steel etc.), even if it is a case where it uses repeatedly, it can prevent that material deteriorates with a heat | fever. For this reason, as compared with the case where a conventional electronic circuit board with a thermocouple is used, it is possible to repeatedly and accurately measure, thereby reducing costs and reducing measurement errors. In addition, when a thermocouple is attached to the electronic circuit board, the temperature of the element itself cannot be accurately measured if the thermocouple is not securely attached to the element. Since 160 and the thermocouples 141 to 161 are securely connected by welding or the like, accurate measurement without secular change is possible.

  In addition, it is possible to accurately model and grasp the parameters related to the temperature change by replacing the management target point of the electronic circuit board with a specific heat capacity value. That is, by associating the temperature change of the component with a known heat capacity value, the measurement can be performed reliably and without aging. Previously, thermocouples were placed at the measurement points on the electronic circuit board, and temperature measurements were made. However, there are variations in the thermal characteristics of individual electronic circuit boards, and the setting of the reflow furnace Since there were temperature variations due to conditions, heating stability and aging of the reflow furnace, the measured values varied, and the state in the reflow furnace could not be measured with high accuracy. However, according to the present embodiment, a plate having a known heat capacity and surface area is disposed in a state of being substantially thermally insulated from the base material, so that the heat transfer coefficient (unit area and unit temperature (difference) of the reflow furnace is provided. ) Can be accurately determined. That is, by disposing the plate in a state of being substantially thermally insulated from the substrate, the heat capacity and surface area can be regarded as the heat capacity and surface area of the plate itself. Therefore, by measuring the temperature of the plate, the amount of heat transferred can be obtained from the heat capacity and the temperature change, and the heat transfer coefficient is obtained by dividing the obtained amount of heat transferred by the surface area of the plate and the amount of temperature change. be able to. If such a heat transfer coefficient can be obtained, for example, a difference due to the type of reflow furnace, an individual difference between reflow furnaces of the same type, and a difference due to aging can be accurately obtained.

  In the above embodiment, since the plates 140 to 160 are arranged on the base material 130 in a state of being substantially thermally insulated, by reducing thermal interference with the base material 130, The heat capacity of each plate can be set accurately, and the temperature in the reflow furnace 400 can be accurately measured. In the present specification, “a state of being substantially thermally insulated” includes not only a state of being completely thermally insulated but also a state of low thermal conductivity.

  Moreover, in the above embodiment, since the base material 130 and the rails 110 and 120 are connected by the pantographs 170 and 180, the widths of the rails 110 and 120 are adjusted in accordance with the width of the conveyor 404 of the reflow furnace 400. be able to. Moreover, since the pantographs 170 and 180 are used, the width can be adjusted while keeping the rails 110 and 120 parallel. Further, by separating the distance between the base material 130 and the conveyor 404 by the pantographs 170 and 180, the influence of the low temperature in the vicinity of the conveyor 404 can be reduced, so that accurate measurement can be performed.

  Moreover, in the above embodiment, since the width | variety of the base material 130 was made substantially the same as the plates 140-160, it can prevent that a measurement error arises with the heat capacity of the base material 130. FIG. In addition, about the arrangement | positioning space | interval (interval of a conveyance direction) of the plates 140-160, it sets so that it may become substantially the same as the arrangement | positioning space | interval of the test | inspection board | substrate 100A, 100B shown in FIG. It is possible to measure under substantially the same conditions as the test boards 100A and 100B shown in FIG. 2, and the data measured on the respective boards can be used in comparison with each other.

  Moreover, in the above embodiment, since the thermocouples 141 to 161 are attached to the plates 140 to 160 by electric welding, these are thermally reliably connected, and the temperature change of the plates 140 to 160 is reliably ensured. In addition, it is possible to prevent these connection states from being changed due to aging and measurement errors. In electric welding, the thermocouple itself or the plate itself melts and welds to each other, so that the heat capacity of the plate does not increase (in the case of silver brazing, the heat capacity increases due to silver brazing). For this reason, generation | occurrence | production of the measurement error resulting from the increase in heat capacity can be prevented. In addition, since electrical welding is performed at a relatively high temperature, mechanical coupling can be performed reliably as well as thermal coupling.

  Moreover, in the above embodiment, when the state of the reflow furnace 400 becomes appropriate, the appropriate state data is stored in the DB 320 based on the measurement data from the thermocouples 141 to 161 attached to the plates 140 to 160. When it becomes necessary to know the state in the reflow furnace 400, the data obtained by flowing the test substrate 100 is compared with the appropriate state data, thereby quickly determining whether the state in the furnace is appropriate. Can be determined. By such quantification, it is possible to reliably prevent the state in the furnace from changing, causing poor soldering, and applying a thermal load to the component due to temperature abnormality. Further, since the test substrate 100 is formed of a heat-stable member, the state in the furnace can be accurately known without causing a measurement error even when repeatedly used.

(C) Other Embodiments FIG. 12 shows a configuration example of another base material 130A used in the test board 100 shown in FIG. In this example, eight plates 501 to 508 are attached. In addition, eight thermocouples (not shown) are attached to each plate, for example, by welding. Each plate is fixed by the same method as in FIG.

  As a method for setting the heat capacity of each heat plate, for example, the plates arranged in the horizontal direction in FIG. 12 have the same heat capacity, and the plates arranged in the vertical direction in FIG. The heat capacity is set to be large (that is, the plate is thick). In addition, instead of the plates 507 and 508 having the smallest heat capacity, an opening is provided at the center of the plate, which will be described later with reference to FIGS. 21 and 22, and a portion for detecting the temperature of the thermocouple is exposed in the opening. You may make it arrange | position the plate arrange | positioned in the state. By using a plate having such an opening, since hot air directly hits the thermocouple, the atmospheric temperature in the furnace can be measured. In addition, arrangement | positioning of heat capacity other than this may be sufficient.

  According to the embodiment shown in FIG. 12, the temperature change with respect to more heat capacity can be measured as compared with the test substrate 100 shown in FIG. 2, so that the state in the furnace can be known in more detail. Further, by arranging plates with the same heat capacity side by side, the temperature variation in the left-right direction can be measured.

  FIG. 13 shows a configuration example of another base material 130B used in the test board 100 shown in FIG. In this example, eight plates 551 to 558 are attached. In addition, eight thermocouples (not shown) are attached to each plate, for example, by welding. Each plate has a narrower width than the case shown in FIG. 12, and has a rectangular shape. Each plate is disposed in an opening 560 that is formed in the base material 130 </ b> B and is slightly larger than the plate 552. As an example, these sizes are set so that the gap between the opening 560 and the plate 552 is 0.25 mm. Further, attachment portions 571 and 572 are provided above and below the opening 560, and the plate 552 is fixed to the attachment portions 571 and 572 by screws 573 and 574. As a fixing method, the same method as in the case of FIG. 3 can be employed. Or you may make it attach the plates 551-558 directly with respect to the base material 130B, without using a washer of low heat conductivity.

  As a method for setting the heat capacity of each heat plate, for example, it can be set similarly to the case of FIG. 11 described above. Further, instead of the plates 557 and 558 having the smallest heat capacity, a plate having the opening described above may be arranged.

  According to the embodiment shown in FIG. 13, as in the case of FIG. 12, the temperature change with respect to a larger heat capacity can be measured as compared with the verification substrate 100 shown in FIG. Can know in more detail. Further, by arranging plates with the same heat capacity side by side, the temperature variation in the left-right direction can be measured. Furthermore, in the embodiment of FIG. 13, since the gap is provided between the opening and the plate and the plate is fixed by two screws, the thermal insulation state is further compared to the case of FIG. Can be improved.

  FIG. 14 shows an embodiment in which four plates having the same size as in FIG. 13 are fixed in the same manner as in FIG. That is, in this example, the four plates 601 to 604 are attached to the base material 130C as in the case of FIG. More specifically, taking the upper right plate 602 as an example, the plate 602 has a gap of 0.25 mm vertically and horizontally in the opening 610 formed in the base material 130C and slightly larger than the plate 602. It is fixed. Further, attachment portions 621 and 622 are provided above and below the opening 610, and the plate 602 is fixed to the attachment portions 621 and 622 with screws 623 and 624. As a fixing method, the same method as in the case of FIG. 3 can be employed. Or you may make it attach the plates 601-604 directly with respect to 130 C of base materials, without using a washer of low heat conductivity.

  According to such an embodiment, for example, when the range of the heat capacity of the components arranged on the electronic substrate is narrow, the temperature in the furnace is measured by the base material 130C on which a small number of plates are arranged. Can do. Thereby, since the amount of data can be reduced, it is possible to quickly determine whether or not the state is appropriate.

  FIG. 15 is a diagram illustrating another method for attaching the plate 140. In the example of FIG. 15, compared to the case of FIG. 3, the base material 130 </ b> D is provided with an opening 136 </ b> A that is slightly larger than the plate 140, and between the plate 140 and the end of the opening 136 </ b> A, for example, , 0.25 mm gap is formed. The rest of the configuration is the same as in FIG. According to such a configuration, by providing a gap between the plate 140 and the end portion of the opening 136A, the thermal insulation state of the base material 130D can be more surely ensured. It is possible to prevent transmission more reliably. Although the washer 144 is used in the example of FIG. 15, the plate 140 may be directly disposed on the base material 130D without using the washer 144. Even with such an arrangement method, the contact area between the plate 140 and the substrate 130D can be minimized, so that the plate 140 can be thermally insulated substantially.

  FIG. 16 is a diagram illustrating another method for attaching the plate 140. In the example of FIG. 16, compared to the case of FIG. 3, the base material 130 </ b> E is provided with an opening 136 </ b> B that is slightly smaller than the plate 140. It is set to be about 5 mm. In the example of FIG. 16, instead of the washer 144, the plate 140 and the base material 130E have substantially the same shape (“B” shape) as the overlapping portion, and there are four holes through which the screw 143 passes. The seal member 700 made of Teflon having low thermal conductivity is provided at a location. According to such a configuration, it is possible to ensure a substantially thermally insulated state and a state in which the space between the plate 140 and the base material 130E is completely sealed, so that one hot air escapes to the other (for example, from above) Hot air from the bottom or hot air from below from above) can be prevented, so that hot air from above and below can be prevented from interfering with each other.

  FIG. 17 shows an example in which two plates 140 and 740 are arranged so as to face each other. In this example, the base material 130F is provided with an opening 136B similar to the case of FIG. 16, and the two plates 140 and 740 are disposed so as to face each other with the opening 136B interposed therebetween. Further, a seal member 700 similar to that in FIG. 16 is sandwiched between overlapping portions of the plate 140 and the base material 130F, and the same size as the plate 140 is provided between the seal member 700 and the base material 130F. For example, a sheet member 702 made of Teflon having low thermal conductivity is disposed. A seal member 701 similar to that in FIG. 16 is sandwiched between overlapping portions of the plate 740 and the base material 130F, and the same size as the plate 140 is provided between the seal member 701 and the base material 130F. A sheet member 703 made of the above-described Teflon is disposed. Thermocouples 141 and 741 are fixed to the plates 140 and 740 by welding or the like. The plates 140 and 740, the seal members 700 and 701, the sheet members 702 and 703, and the base material 130F are fixed by four rivets 143A.

  In the configuration shown in FIG. 17, the two plates 140 and 740 are thermally insulated from each other, and the two plates 140 and 740 are also thermally insulated from the base material 130F. It is in a state. Further, since these two plates 140 and 740 are attached in the same manner to the base material 130F, the heat capacities are almost equal. For this reason, it is possible to reliably measure the temperature change of the plates 140 and 740 due to the hot air from above and the hot air from below at substantially the same position without interfering with each other. This makes it possible to determine whether the settings (temperature and air volume) between the nozzles facing each other in the vertical direction are appropriate. Note that the head of the rivet 143A may be processed so as to have heads in both the plates 140 and 740 so that the heat capacities thereof are equal.

  FIG. 18 shows an embodiment in which the plate 740 and others are removed from the embodiment of FIG. That is, in comparison with FIG. 17, the plate 740, the thermocouple 741, the seal member 701, and the sheet member 703 are excluded. Moreover, in the example of FIG. 18, the screw | thread 143 is arrange | positioned and fixed so that a head may come down. A rivet may be used instead of the screw 143.

  According to such an embodiment, the base member 130G and the plate 140 are thermally insulated substantially by the seal member 701, and the opening 136B is blocked by the sheet member 703, thereby blocking the influence of hot air from below. In addition, it is possible to reliably measure the temperature change of the plate 140 caused only by hot air from above.

  In the embodiment described above, an opening is provided in the base material, and the plate is disposed so as to overlap the opening. However, it is also possible not to provide the opening. FIG. 19 shows an embodiment in which a base material 130H having no opening is used. FIG. 19A shows an example in which a plate 140 to which a thermocouple 141 is fixed is attached to a base material 130H having no opening with screws 143 (or rivets) through a Teflon washer 144. Is shown. In this example, since the plate 140 and the base material 130H are thermally insulated by the washer 144, the heat between the plate 140 and the base material 130H is obtained even when there is no opening. Interference can be eliminated and the heat capacity of the plate 140 can be kept constant. Moreover, since the influence of the hot air from the bottom can be eliminated, the temperature change due only to the hot air from the top can be measured.

  In the example shown in FIG. 19B, a plate 140 to which a thermocouple 141 is fixed is attached to a base material 130H that does not have an opening, and a Teflon sealing member 700 (a figure having a “B” shape). 16 shows an example in which the screw 143 (or rivet) is attached via a seal member similar to that in the case of 16. In this example, since the plate 140 and the base material 130H are thermally insulated by the seal member 700, the plate 140 and the base material 130H are disposed between the plate 140 and the base material 130H even when there is no opening. Thermal interference can be eliminated and the heat capacity of the plate 140 can be kept constant. Moreover, since the influence of the hot air from the bottom can be eliminated, the temperature change due only to the hot air from the top can be measured. Further, in this example, there is no gap between the plate 140 and the base material 130H, so that temperature change due to hot air that wraps around the back side of the plate 140 from the gap can be prevented. In order to eliminate the influence of radiant heat caused by hot air from below, a sheet member 702 having the same size as the plate 140 is disposed between the substrate 130H and the seal member 700, as in FIG. May be.

  Further, in order to measure the temperature change due to the hot air from above and below at the same position, for example, the configuration shown in FIGS. 19A and 19B is arranged below the substrate 130H as in FIG. May also be provided. According to such a structure, the temperature change by each of the hot air from the top and the bottom in the same position can be measured independently and reliably.

  The above embodiment has been described on the assumption that it is attached to the pantographs 170 and 180 of the test board 100 shown in FIG. 2, but other than this, for example, as shown in FIGS. The test boards 100A and 100B may be configured by placing a plate on the metal plate-like members 800 and 900 having the same size as the above.

  First, in the example of FIG. 20, the test substrate 100A has openings 801 to 807 formed on, for example, a plate member 800 made of stainless steel, and plates 810 to 870 are arranged in the openings 801 to 807, respectively. Has been. 20A shows a top view and FIG. 20B shows a side view. The part shown with the broken line has shown that the blind plate 880 is arrange | positioned. Although not shown in detail in the drawing, an opening is also provided in a portion where the blanking plate 880 is disposed, and the blanking plate 880 is fixed by a screw or the like to close the unused opening.

  The plate 810 is provided with a circular opening 813 at the center thereof, and a thermocouple 811 is fixed to the opening 813 in an exposed state. This plate 810 is provided mainly for measuring the atmospheric temperature in the furnace, and the heat capacity is the minimum (almost close to “0”) because it is the capacity of only the junction of the thermocouple 811. .

  The plates 820, 840, 860, and 870 are set so that their heat capacities increase in this order. Specifically, when the heat capacity of the plate 840 is “1”, the relative heat capacities of the plates 820, 860, and 870 are “0.55”, “1.45”, and “2.0”, respectively. Is set to Needless to say, other settings may be used. The plates 830 to 850 are set to have the same heat capacity.

  Thermocouples 821 to 871 are fixed to the plates 820 to 870 by welding or the like, respectively, and the temperature of each plate can be detected. Further, the plates 810 to 870 are fixed to the plate member 800 by four screws 812 to 872, respectively. In addition, it is also possible to arrange a new plate in a portion where the blind plate 880 is attached, or to attach the blind plate 880 excluding an existing plate.

  The test board 100A shown in FIG. 20 can be used in the same manner as the test board 100 described above. In addition, when flowing the test | inspection board | substrate 100A into the reflow furnace 400, the lower edge part of FIG. 20 is first entered into a furnace so that it may enter into a furnace in order with the small heat capacity of a plate. Thereby, the thermal state is disturbed by the plate having a large heat capacity, and it is possible to prevent the plate having a small heat capacity from being affected by the disturbance and causing a measurement error.

  Further, in the test substrate 100A shown in FIG. 20, since the plates having the same heat capacity are arranged side by side in the direction orthogonal to the traveling direction, it is possible to measure the presence or absence of temperature variation depending on the position in the furnace.

  20 has the same size as the target electronic circuit board, as described above, the temperature distribution is reproduced by reproducing the same hot air flow as the electronic circuit board. Can be measured accurately.

  Next, in the example of FIG. 21, the test substrate 100B has openings 901 to 907 formed on, for example, a plate member 900 made of stainless steel, and plates 910 to 970 are formed in the openings 901 to 907, respectively. Has been placed. 21A shows a top view and FIG. 21B shows a side view. The part shown with the broken line has shown that the blind plate 980 is arrange | positioned. As in the case described above, although not shown in detail in the drawing, an opening is also provided in a portion where the blind plate 980 is disposed, and the blind plate 980 is screwed to close the unused opening. It is fixed by.

  The plate 910 is provided with a circular opening 913 at the center thereof, and the thermocouple 911 is fixed to the opening 913 in an exposed state. The plate 910 is provided for the same purpose as described above.

  The plates 920 to 940 have the same heat capacity. The plates 950 to 960 have the same heat capacity. Furthermore, when the heat capacities of the plates 950 to 970 are “1”, the plates 920 to 940 are set so that the relative heat capacities are as small as “0.1”. Needless to say, other settings may be used.

  Thermocouples 921 to 971 are fixed to the plates 920 to 970 by welding or the like, respectively, and the temperature of each plate can be detected. Further, the plates 910 to 970 are fixed to the plate member 900 by four screws 912 to 972, respectively. In addition, it is also possible to newly arrange a plate in a portion where the blind plate 980 is attached, or to attach the blind plate 980 excluding an existing plate.

  The test substrate 100B shown in FIG. 21 can be used not only in the same manner as the test substrate 100 described above, but also when measuring the basic performance of the reflow furnace 400. That is, the temperature of the atmosphere in the furnace can be measured by the plate 910, and the temperature of the hot air averaged by the plates 920 to 940 having a very small heat capacity can be measured. That is, since the plates 920 to 940 are sized so that the hot air equivalent to two nozzles is hit, the average temperature of the hot air can be measured. Moreover, since the heat capacity of the plates 920 to 940 is set to be very small, the temperature changes without delay according to the temperature fluctuation of the hot air. For this reason, by using the plates 920 to 940, a temperature close to the actual temperature (effective temperature) on the electronic circuit board can be detected. Further, by arranging the plates having the same heat capacity in the left-right direction, it is possible to detect temperature variations in the direction orthogonal to the traveling direction in the furnace. Similarly, according to the plates 950 to 970, it is possible to know the temperature increase capability by observing the temperature change of a plate having a certain large heat capacity. Similarly to the case described above, by arranging plates having the same heat capacity in the left-right direction, it is possible to detect variations in the temperature rise capability in the direction perpendicular to the traveling direction in the furnace.

  In the example of FIGS. 20 and 21, the plate is attached by the same method as in FIG. 3 described above, but it can also be attached by the same method as in FIGS. 13 and 15 to 19, for example. Moreover, you may make it arrange | position two plates in the position which opposes on both sides of a plate-shaped member.

(D) Modified Embodiment The above-described embodiment is an example, and there are various modified embodiments other than this. For example, in the above embodiment, the temperature measurement is performed by the personal computer 300. However, for example, the above-described processing may be executed by a control computer provided in the reflow furnace 400.

  In the embodiment shown in FIG. 2, the configuration has two pantographs, but only one pantograph (for example, only the pantograph 170), and the other has two plate-like members orthogonal to the rails 110 and 120. It is good also as a structure which fixes so that a long hole may be formed in the center part of these two plate-shaped members, and a screw may be inserted in a long hole part. Even with such a configuration, the rails 110 and 120 can be translated.

  Further, in each of the above embodiments, the thermocouple is arranged on the back side of the plate. However, for example, it may be arranged on the front side of the plate. It is also possible to measure the temperature difference by arranging both on the back side and the front side.

  In each of the above embodiments, the reflow furnace 400 shown in FIG. 6 is the object of measurement, but it goes without saying that a reflow furnace having a configuration other than this may be used. For example, furnaces with different numbers of heating zones or cooling zones, or heating zones or cooling zones arranged near the inlet and outlet are not arranged facing each other up and down, but only in either the upper or lower side It may be a thing.

  Further, in the processing shown in FIG. 7 and FIG. 11, only the data in the proper state is stored, but the data in the inappropriate state (inappropriate state data) is measured by the test board, and this is also stored together. It may be. According to such an embodiment, when the measurement data does not match the appropriate state data (or has a certain amount of deviation), the measured data is within a predetermined range when it is close to an inappropriate state compared to the inappropriate state data. If not, it may be determined in step S34. Further, by storing a plurality of inappropriate state data, the boundary between the appropriate state and the inappropriate state can be clarified. Alternatively, a very critical state may be stored as a “critical improper state”, and the reflow furnace may be immediately stopped when the critical improper state matches the measurement data.

  In each of the above embodiments, the test board 100, the thermocouple-equipped electronic circuit board 200, the temperature measuring device 350, and the personal computer 300 are connected by wire, but may be connected wirelessly. Further, the calibration board 100 is provided with a temperature measuring device 350 and a storage device (for example, a semiconductor memory) for storing the output thereof, and the temperature in the reflow furnace 400 is temporarily stored in the storage device and then transferred to the personal computer 300. It may be.

(E) Other Modified Embodiments In the present embodiment described above, the state in the reflow furnace 400 is accurately grasped as objective data using the verification substrate 100, but the verification substrate 100 is used. It is also possible to grasp the data. For example, data is collected using a reflow furnace measurement block 1040 that can be directly attached to the electronic circuit board with thermocouple 200.

  FIG. 22 is a plan view showing a state where the reflow furnace measurement block 1040 is attached to the electronic circuit board with thermocouple 200.

  This electronic circuit board with thermocouple 200 is the same as that shown in this embodiment, and thermocouples 1003 are attached to predetermined parts 1002a to 1002d such as ICs or IC sockets on the board or in the vicinity thereof. ing.

  As shown in FIG. 22, the reflow furnace measurement block 1040 has a heat capacity and an area that are known in advance on a base material 1020 (having a function equivalent to that of the base material 40 of the test substrate 100 in the present embodiment). Three plates 1010 to 1012 are placed. The three plates 1010 to 1012 are arranged side by side at intervals in the up and down direction of FIG. 22 (the transport direction 1050 of the thermocouple-equipped electronic circuit board 200). In addition, this arrangement | positioning can be changed suitably, for example, you may arrange | position three side by side in the paper surface left-right direction (direction orthogonal to the conveyance direction 1050).

  The mounting structure between the base material 1020 and the plates 1010 to 1012 and the shape and mounting structure of the plate 1010 to 1012 and the thermocouple temperature detecting portion 142 are the above-described (A) embodiment of the present invention or (D) deformation. The structure described in the embodiment can be used. Therefore, the detailed description regarding these attachments is abbreviate | omitted.

  Further, the number of the three plates 1010 to 1012 shown in FIG. 22 is not limited to three. That is, it can also comprise so that 1 or several plate may be attached. For example, as shown in FIG. 23, the reflow furnace measurement block 1041 can be formed using five plates 1010 to 1014. As shown in FIG. 23, these five plates 1010 to 1014 are arranged in a form of 3 rows and 2 columns on a base material 1021 having a width wider than that of the base material 1020 described above. Note that other arrangements may be used.

  As shown in FIGS. 22 and 23, the reflow furnace measurement blocks 1040 and 1041 include an attachment portion 1045 for attachment to the front end portion 200a of the thermocouple-equipped circuit board 200. More specifically, the reflow furnace measurement blocks 1040 and 1041 are attached to the front end portion 200a of the thermocouple-equipped electronic circuit board 200 so as to protrude forward of the thermocouple-equipped electronic circuit board 200.

  The thermocouple-attached electronic circuit board 200 is transported in the direction of the arrow 1050 in the reflow furnace 400. Therefore, the front end portion 200a of the thermocouple-attached electronic circuit board 200 has a front end at the top of the drawing in FIGS.

  Thus, the reason why the reflow furnace measurement blocks 1040 and 1041 are attached to the front end portion 200a of the electronic circuit board with thermocouple 200 is to more accurately grasp the heat data in the reflow furnace 400. That is, when the reflow furnace measurement block 1040 is attached to the rear end portion of the electronic circuit board with thermocouple 200, the measurement is performed in a state where the heat is disturbed after the electronic circuit board 200 has passed, It is difficult to obtain more accurate measurement data. Therefore, in order to perform measurement without being disturbed, the electronic circuit board 200 is attached to the front end portion 200a.

  As shown in FIGS. 22 and 23, the mounting portion 1045 described above is provided on both sides of the base material 1020, and protrudes rearward from the rear end portion of the base material 1020 toward the thermocouple-equipped electronic circuit board 200 side. ing. The attachment portion 1045 and the thermocouple-attached electronic circuit board 200 are fastened and attached by a fastening member 1046 such as a screw.

  In addition, the attachment structure of the attachment part 1045 and the electronic circuit board 200 with a thermocouple can be implemented using another structure. For example, a clip structure using elasticity such as a spring may be adopted for the mounting portion, and the front end portion 200a of the thermocouple-attached electronic circuit board 200 may be sandwiched. Moreover, the structure attached by pin coupling etc. may be sufficient.

  As described above, by attaching the reflow furnace measurement blocks 1040 and 1041 to the electronic circuit board with thermocouple 200, the thermal data of the actual electronic circuit board with thermocouple 200 can be obtained directly, while the reflow furnace The measurement data 1040 and 1041 can simultaneously acquire thermal data as an invariable measurement standard.

  As a processing method of this data, for example, the heat state in the reflow furnace 400 is determined using the upper limit value and the lower limit value of the thermal data at each point measured on the electronic circuit board with thermocouple 200. On the other hand, even if the circuit board 200 itself is deteriorated due to heat by transporting the electronic circuit board with thermocouple 200 a plurality of times in the reflow furnace 400, the invariable measurement measured by the reflow furnace measuring blocks 1040 and 1041. Based on the reference, the state of the reflow furnace 400 can be accurately grasped. In this case, the reflow furnace measurement blocks 1040 and 1041 may be replaced with a new circuit board 200 instead of the deteriorated board for measurement.

  On the other hand, the reflow furnace measuring block can be attached to an article conveyed in the reflow furnace 400 in addition to being attached to the thermocouple-attached electronic circuit board 200. FIG. 24 is a plan view showing a state in which the reflow furnace measuring block 1041 is attached to the front end portion 1030a of the verification substrate 1030 (equivalent to the verification substrate 100 in the present embodiment) conveyed in the reflow furnace 400. Note that the reflow furnace measurement block shown in FIG. 24 is the same as the reflow furnace measurement block 1041 shown in FIG. 23 as an example.

  On both sides of the test substrate 1030, which is the front end portion 1030a of the test substrate 1030, a grip portion 1047 is provided that extends forward in the transport direction 1050. The gripping portion 1047 is configured to sandwich both sides of the reflow furnace measurement block 1041, whereby the reflow furnace measurement block 1041 is attached to the test substrate 1030. This attachment structure is an example, and may be attached with a fastening member such as a screw or a pin, or may be a clip-type sandwiched attachment structure.

  Thus, if the reflow furnace measurement block 1041 is attached to the verification board 1030, the number of measurements can be easily added even when the number of thermal data to be measured on the verification board 1030 is insufficient. be able to.

  Further, as shown in FIG. 24, a data logger 1031 connected to each thermocouple can be mounted on the test board 1030. The data logger 1031 measures and stores data of each thermocouple. This eliminates the need for wiring extending from the test substrate 1030 to the temperature measuring device 350 (see FIG. 1), and makes it possible to perform measurement more easily.

  Further, in the above-described modified embodiment, the reflow furnace measurement blocks 1040 and 1041 are configured to protrude forward from the front end portions 200a and 1030a of the test substrate 200 or the reflow furnace measurement substrate 1030, but they are not protruded. An aspect may be sufficient. FIG. 25 is a plan view showing a state in which the reflow furnace measurement block 1042 is attached to the surplus space in the front portion on the electronic circuit board with thermocouple 200.

  In the reflow furnace measurement block 1042, one plate 1010 is placed on the base material 1022. The electronic circuit board with thermocouple 200 and the reflow furnace measurement block 1042 are attached by fastening members (not shown) such as screws. As described above, when the number of plates 1010 is small (the number of thermal data to be verified is small), the reflow furnace measurement block 1042 is mounted in the front gap portion (excess space) of the thermocouple-attached electronic circuit board 200. Is more convenient.

100, 100A, 100B Verification board (reflow furnace measurement board)
110, 120 rail 130, 130A-130H base material 140-160 plate 141-161 thermocouple (detection means)
170,180 Pantograph (width adjustment mechanism)
200 Electronic circuit board with thermocouple 300 Personal computer 301 CPU (determination means)
304 RAM (storage means)
307 I / F (input means)
310 program 320 DB
350 Temperature measuring device 400 Reflow furnace 402 Heating zone 403 Cooling zone 404 Conveyor 1002a to 1002d Electronic component 1003 Thermocouple 1010 to 1015 Plate 1020, 1021, 1022 Base material 1040, 1041, 1042 Reflow furnace measuring block 1045 Mounting portion 1046 Fastening member

Claims (21)

In the reflow furnace measurement substrate that measures the state in the furnace when transported in the reflow furnace,
A substrate constituted by a plate-shaped member;
One or more plates of known heat capacity disposed on the substrate;
Detection means that is in contact with the plate and detects the temperature of the plate;
A substrate for measuring a reflow furnace, comprising:   The reflow furnace measurement substrate according to claim 1, wherein the plate is disposed on the base material in a substantially thermally insulated state.   The reflow furnace measurement substrate according to claim 1, wherein the plate has a width wider than the pitch of the hot air blowing nozzles in a direction orthogonal to the transport direction of the reflow furnace. The plate includes a plurality of plates having different heat capacities,
The detection means detects the temperature of each of the plates;
The substrate for reflow furnace measurement according to any one of claims 1 to 3, wherein:   The plate has a heat capacity from the top to the end of the substrate when the first portion of the substrate is loaded into the reflow furnace at the top and the last portion of the plate is loaded at the end. 5. The reflow furnace measurement substrate according to claim 4, wherein the substrates are arranged in ascending order.   The reflow furnace measurement substrate according to any one of claims 1 to 3, wherein a plurality of the plates having substantially the same heat capacity are arranged side by side in a direction orthogonal to the transport direction.   The reflow furnace measurement substrate according to any one of claims 1 to 3, wherein the plates are arranged at positions where plates having substantially the same heat capacity face each other with the base material interposed therebetween.   The reflow furnace measurement substrate according to any one of claims 1 to 7, wherein the detection means includes a thermocouple, and a detection portion of the thermocouple is thermally coupled to the plate. .   9. The reflow furnace measuring substrate according to claim 8, wherein the thermocouple is thermally coupled to the plate by welding.   The base material is provided with an opening having substantially the same size as the plate disposed in each part, and the contact area between the base material and the plate is disposed on the opening. The reflow furnace measurement substrate according to any one of claims 1 to 9, wherein the substrate is made to be in a state of being substantially insulated thermally.   A low heat transfer member covering at least a part of the plate is sandwiched between the base material and the plate, and the base material and the plate are thermally insulated substantially by the low heat transfer member. The substrate for reflow furnace measurement according to any one of claims 1 to 10, wherein the substrate for reflow furnace measurement is in a closed state.   The reflow furnace measuring substrate according to any one of claims 1 to 11, wherein the base material has substantially the same size as an electronic circuit board to be soldered in the reflow furnace.   The substrate for reflow furnace measurement according to any one of claims 1 to 11, wherein the base material has a width adjusting mechanism capable of adjusting a width in a direction orthogonal to the transport direction. In the reflow furnace measuring device having the reflow furnace measuring substrate according to any one of claims 1 to 13,
Input means for inputting data detected by the reflow furnace measurement substrate;
Storage means for storing the data input from the input means;
A reflow furnace measuring apparatus comprising: The storage means stores the data obtained when the state in the reflow furnace is in an appropriate state for the electronic circuit board to be soldered,
It has a judging means for judging whether or not the state of the reflow furnace at that time is appropriate by comparing the data obtained when the appropriate state is obtained and the newly obtained data. ,
The reflow furnace measuring apparatus according to claim 14. In the reflow furnace measurement method for measuring the state of the reflow furnace based on the reflow furnace measurement substrate according to any one of claims 1 to 13,
An input step of inputting data detected by the reflow furnace measurement substrate;
A storage step of storing the data input in the input step in a storage device;
The reflow furnace measuring method characterized by having. In the reflow furnace measurement program for measuring the state of the reflow furnace based on the reflow furnace measurement substrate according to any one of claims 1 to 13,
Computer
Input means for inputting data detected by the reflow furnace measurement substrate;
Storage means for storing the data input from the input means;
A computer-readable reflow oven measurement program that allows the computer to function as. A reflow furnace measuring block that measures the state in the furnace when transported in the reflow furnace,
A substrate constituted by a plate-shaped member;
One or more plates of known heat capacity disposed on the substrate;
Detection means that is in contact with the plate and detects the temperature of the plate;
With
The reflow furnace measuring block, wherein the base member is provided with a mounting portion that can be attached to and detached from an article conveyed in the reflow furnace.   The reflow furnace measurement block according to claim 18, wherein the article conveyed in the reflow furnace is an electronic circuit board.   19. The reflow furnace measurement block according to claim 18, wherein the article conveyed in the reflow furnace is a reflow furnace measurement substrate.   The reflow furnace measurement block according to any one of claims 18 to 20, wherein the reflow furnace measurement block is attached to a front end in a conveyance direction of an article conveyed in the reflow furnace.

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