JP4785486B2 - Electronic device manufacturing method and manufacturing apparatus - Google Patents

Description

  The present invention is a method of manufacturing an electronic device in which an electronic component such as an IC chip is bonded to a circuit board. In particular, when the electronic component is a bare chip IC, it relates to a field called flip chip mounting.

  Conventionally, for flip chip mounting of bare chip ICs, bumps called bumps made of solder, gold, etc. are provided on the electrodes of the IC, and heating or heating and pressing are used in combination with the electrodes facing the substrate side. By doing so, a method is known in which the solder is melt-bonded or bonded to gold and a metal such as tin on the substrate side.

  However, excessive stress is generated in the vicinity of the joint due to the difference in the linear expansion coefficient between the substrate and the IC, the temperature change and temperature distribution during heating and cooling, and the IC electrode of the IC chip 1 as shown in FIG. When the 61 and the substrate electrode 62 of the substrate 3 are flip-chip mounted at the joint 2 such as solder, an IC crack 63, a joint crack 64, and a substrate crack 65 are generated in the vicinity of the joint. Although not performed, peeling of the electrode sometimes occurred.

Therefore, various countermeasures have been considered in order to relieve stress in the vicinity of the joint portion of the electronic device. One of them is to cut grooves in the substrate. (For example, see Patent Document 1)
According to this electronic device, the stress generated in the vicinity of the joint can be released by the deformation of the groove and the reliability of the joint can be improved.

  As another measure, there is a method in which a stress relaxation layer is provided on a bump formed on an IC chip. (For example, see Patent Document 2 and FIG. 2).

  In this electronic device, the stress generated in the vicinity of the joint is absorbed by the stress relaxation layer formed in the bump part of the IC chip, thereby avoiding excessive stress concentration on hard and brittle parts such as the bump base and IC protective film. Therefore, the reliability of the joint can be improved.

  Furthermore, paying attention to the difference in the linear expansion coefficient between the IC chip and the substrate, heat bonding is performed so that the generation of stress due to the difference in the linear expansion coefficient is canceled near the center value of the temperature change range assumed in the usage environment. Thereafter, a manufacturing method has also been proposed in which one of the IC chip and the substrate is maintained at a high temperature while the other is cooled to a predetermined temperature (see, for example, Patent Document 3).

According to the method for manufacturing an electronic device described in Patent Document 3, the stress applied to the bonded portion in the used state after bonding is suppressed, and improvement in reliability can be expected.
Japanese Patent Laid-Open No. 53-38286 JP 2001-326235 A Japanese Patent Laid-Open No. 10-247670

  However, the following problems remain in the above-described conventional electronic device and method for manufacturing the electronic device.

  That is, in the electronic device provided with the stress relaxation portion on the substrate or IC chip described in Patent Documents 1 and 2, etc., the stress relaxation in the vicinity of the joint portion is excellent, but the IC is provided to provide the stress relaxation portion. In addition, there is a need to make a space on the board, and there are design restrictions and it is not suitable for miniaturization. Furthermore, a process for forming the stress relaxation part is also required, which is expensive and poor in productivity.

  In the conventional method of manufacturing an electronic device, the residual stress after being completely cooled to the operating temperature after bonding is reduced, but the IC chip and the substrate integrated by the heat bonding process are controlled at different temperatures. Cooling requires a very high degree of control, making the manufacturing equipment complex and expensive, and increasing product design constraints. In addition, when accurate control cannot be performed, a sufficient residual stress relaxation effect cannot be expected. Further, during the cooling process, the IC chip and the substrate are integrated at the joint and are in a state of being thermally conducted with each other, so that temperature differences occur in the IC chip, the substrate, and the joint, respectively. In particular, it is assumed that the temperature difference near the joint becomes large. There are also concerns about the occurrence of cracks and delamination due to the generation of stress due to temperature differences in these cooling processes, and a decrease in reliability.

  The present invention has been made in view of such circumstances, and its purpose is that it does not require labor, time and cost for production, is low in cost and excellent in productivity, and also reduces stress during bonding. It is an object of the present invention to provide a method for manufacturing a high-quality electronic device with excellent reliability.

  The present invention provides the following means in order to solve the above problems.

An electronic device manufacturing method of the present invention is an electronic device manufacturing method comprising: an electronic component having a plurality of electrodes on one surface; and a substrate having an electrode corresponding to the electronic component. And a tail heating step that is maintained at a temperature lower than the temperature at which the joint between the electronic component and the substrate is melted or reacted after the main heating and heating step for a certain period of time. .

  In the method of manufacturing the electronic device according to the present invention, the tail heating process is performed after the main heating process, and the temperature is maintained at a temperature higher than normal temperature and lower than the main heating for a certain time. Thereby, compared with cooling to normal temperature without passing through a tail heating process after this heating process, a temperature fall width becomes small. Therefore, the generation of stress due to the temperature difference generated in time series before and after the temperature decrease generated after the main heating process is reduced. Further, by performing the temperature decrease in two steps, the temperature distribution can be made uniform, the temperature difference generated in the surface direction can be reduced, and the generation of stress associated therewith can be suppressed. Furthermore, since the temperature decrease rate can be slowed, the generation of excessive stress due to rapid thermal contraction can be suppressed.

  Then let it cool to room temperature naturally. At this time, since the tail heating process exists, the temperature decrease width becomes smaller than the cooling to the normal temperature without the tail heating process after the main heating process, and the stress applied to the joint as in the tail heating process. Can be relaxed.

  According to another aspect of the present invention, there is provided an electronic device manufacturing method comprising: an electronic component having a plurality of electrodes on one surface; and a substrate having an electrode corresponding to the electronic component. A preheating step in which the bonding portion is preheated to a temperature lower than the temperature at which the bonding portion melts or reacts and higher than the normal temperature, and a main heating step for bonding the electronic component and the substrate.

  In the method for manufacturing an electronic device according to the present invention, first, an electronic component such as an IC chip and a substrate are heated to a temperature higher than normal temperature and lower than main heating by a preheating process. Next, in this heating step, the temperature is further raised to a temperature at which the electronic component and the substrate can be joined. Thereby, the temperature increase width in the main heating step is smaller than that from normal temperature to the main heating temperature without going through the preheating step. Therefore, the generation of stress due to the temperature difference generated in time series before and after the temperature increase in the main heating process is reduced. In addition, by performing the temperature increase in two steps, the temperature distribution can be made uniform, the temperature difference generated in the surface direction can be reduced, and the accompanying stress can be suppressed. Furthermore, since the rate of temperature rise can be slowed for the same process time, generation of excessive stress due to rapid thermal expansion can be suppressed. Conversely, if the heating rate is made the same, the temperature can be increased to a required temperature in a shorter time, and productivity can be improved.

  According to another aspect of the present invention, there is provided an electronic device manufacturing method comprising: an electronic component having a plurality of electrodes on one surface; and a substrate having an electrode corresponding to the electronic component. A preheating process in which the bonding part is preheated to a temperature lower than the temperature at which the bonding part melts or reacts and higher than room temperature, a main heating process for bonding the electronic component and the substrate, and a bonding part between the electronic component and the substrate are melted after the main heating and heating process. Or it has the tail heat process maintained at the temperature lower than the temperature which reacts and higher than normal temperature for a fixed time, It is characterized by the above-mentioned.

  In the method for manufacturing an electronic device according to the present invention, the combined use of the preheating process and the tail heating process makes it possible to further suppress stress and improve productivity.

  The preheating process and the tail heating process are assumed to be performed both in consideration of the specifications of the product and the manufacturing apparatus, and when only one of the processes is performed.

  The electronic device manufacturing method according to the present invention is the electronic device manufacturing method according to the present invention, wherein a solder bump is formed on the electrode portion of the electronic component, and the flux supplying step, the alignment step, and the mount before the preheating step. The junction temperature in the preheating step is lower than the melting point of the solder bump, and the junction temperature in the tail heating step is lower than the melting point of the solder bump.

  In the method for manufacturing an electronic device according to the present invention, the joining is performed by solder bumps formed on the electronic component. First, in the flux supply process, an appropriate amount of flux, which is an activator necessary for soldering, is supplied to the tip of the solder bump or the electrode portion of the substrate. Next, the alignment of the electronic component and the electrode of the substrate is performed by an alignment process. The flux supply process and the alignment process may be reversed. Next, the electronic component is placed on the substrate by a mounting process. At this time, the electronic component and the substrate are temporarily fixed by the adhesiveness of the flux.

  Thereafter, the temperature of the electronic component such as an IC chip and the substrate is raised to a temperature higher than normal temperature and lower than the melting point of the solder bump by a preheating process. Next, in this heating step, the temperature is further raised to a temperature higher than the melting point of the solder bump.

  Next, after maintaining for a certain period of time at a temperature higher than normal temperature and lower than the melting point of the solder bump by a tail heating process, it is naturally cooled slowly to normal temperature. In the cooling process, when the solder bump melting point is not reached, the bump solder is re-solidified and fixed. The temperature change after re-solidification causes stress in the vicinity of the joint due to the difference in the linear expansion coefficient between the substrate and the IC chip, causing cracks and peeling. According to the present invention, the temperature decrease rate and the temperature decrease width can be kept small even after re-solidification. Thereby, manufacture of the electronic device using a solder bump is realizable, suppressing the stress concerning a junction part.

  The electronic device manufacturing method of the present invention is characterized in that, in the electronic device manufacturing method of the present invention, the preheating step is near the flux activation temperature.

  In the method of manufacturing an electronic device according to the present invention, the temperature of the flux is raised to the activation temperature in the preheating process, that is, the temperature at which the oxidation-reduction function can be efficiently exhibited, for example, the optimum temperature selected from the range of about 80 to 200 ° C. By doing so, it is possible to simultaneously achieve reliable bonding (solder wetting) by the stress relaxation and the oxidation / reduction function of the flux.

The electronic device manufacturing method of the present invention is the electronic device manufacturing method of the present invention, wherein the preheating step or the tail heating step is supplied with heat from a ceramic heat plate installed below the substrate. In the method of manufacturing an electronic device according to the present invention, heat is transferred in a state where the ceramic plate adjusted to an appropriate temperature and the bottom surface of the substrate are in contact with or close to each other. Thereby, a preheating process and a tail heating process are simply realizable. Furthermore, since the thermal conductivity of ceramic is lower than that of metal or the like, the temperature change becomes gentle and the stress is relaxed.

  The electronic device manufacturing method of the present invention is the electronic device manufacturing method of the present invention described above, wherein the substrate is formed in a continuous tape shape and is transported while moving by a predetermined length for each process, and the preheating process or The tail heating process is characterized in that heat is supplied from a heat plate installed on the lower side of the substrate, and the heat plate has a protrusion and a notch.

In the method of manufacturing an electronic device according to the present invention, the preheating process, the main heating process, and the tail heating process are performed at fixed locations, and the protrusions of the heat plate adjusted to appropriate temperatures in the preheating process and the tail heating process. Heat is transferred with the part and the bottom of the substrate in contact or close to each other. Since the substrate moves through each process, it can save space and increase productivity.
Further, the heat from the heat plate is transmitted not only to the place where the main heating is performed but also to the peripheral substrate, and both the IC chip and the peripheral substrate are preheated immediately before the start of the main heating. When only the periphery of the IC chip portion is locally heated during the subsequent main heating, the temperature difference between the periphery and the IC portion can be reduced. Furthermore, only a necessary part can be heated by making it a notch part of a heat plate in the place which does not want to preheat-heat to a board | substrate.

  The electronic device manufacturing method of the present invention is characterized in that, in the electronic device manufacturing method of the present invention, the protrusion has a chamfered portion.

  In the method of manufacturing an electronic device according to the present invention, by providing a notch in the protrusion, it is possible to prevent the tape-like substrate from being caught by steps such as holes and patterns in the substrate when the substrate is transported.

  The electronic device manufacturing method of the present invention is characterized in that, in the electronic device manufacturing method of the present invention, the heating step uses an air heater.

  In the method of manufacturing an electronic device according to the present invention, only a necessary portion can be efficiently heated with high productivity by an air heater.

  The electronic device manufacturing method of the present invention is the above-described electronic device manufacturing method of the present invention, in which gold bumps are formed on the electrode portions of the electronic components, tin plating is formed on the electrode portions of the substrate, and the main heating. The process is performed by thermocompression bonding with a heating head, the preheating process is performed at 30 ° C. or higher and lower than 280 ° C., and the tail heating process is performed at 30 ° C. or higher and lower than 280 ° C. It is.

  In the method of manufacturing an electronic device according to the present invention, bonding is performed by a reaction between a gold bump formed on an electronic component and a tin plating formed on the substrate side to form a gold-tin alloy having a melting point of about 280 ° C. Is called. First, an electronic component such as an IC chip and a substrate are heated to a temperature higher than 30 ° C. and lower than 280 ° C., which is the melting point of the gold-tin alloy, by a preheating process. Next, in this heating step, the gold-tin eutectic alloy is bonded by pressing and heating from the upper surface of the IC chip with a head heated to an appropriate temperature higher than 280 ° C., for example, between 300 to 500 ° C. Get a part. Next, after maintaining at a temperature higher than 30 ° C. and lower than 280 ° C., which is the melting point of the gold-tin eutectic alloy, for a certain period of time by a tail heating process, it is naturally cooled to room temperature. Thereby, the manufacture of the electronic device using the gold bump can be realized while suppressing the stress applied to the joint portion. Furthermore, even when there is a soldering process after this, the joining reliability can be maintained without remelting.

  According to another aspect of the present invention, there is provided an electronic device manufacturing apparatus comprising: an electronic component having a plurality of electrodes on one surface; and a substrate having an electrode corresponding to the electronic component. And a tail heating means for maintaining for a certain time at a temperature lower than the temperature at which the bonded portion of the electronic component and the substrate melts or reacts after the main heating heat and higher than room temperature. .

  In the apparatus for manufacturing an electronic device according to the present invention, a manufacturing apparatus for realizing stress relaxation and productivity improvement by the tail heat process described above can be provided.

  According to another aspect of the present invention, there is provided an electronic device manufacturing apparatus comprising: an electronic component having a plurality of electrodes on one surface; and a substrate having an electrode corresponding to the electronic component. It has preheating means preheated to a temperature lower than the temperature at which the joining portion melts or reacts and higher than room temperature, and a main heating means for joining the electronic component and the substrate.

  In the apparatus for manufacturing an electronic device according to the present invention, a manufacturing apparatus for realizing stress relaxation and productivity improvement by the preheating process as described above can be provided.

  According to another aspect of the present invention, there is provided an electronic device manufacturing apparatus comprising: an electronic component having a plurality of electrodes on one surface; and a substrate having an electrode corresponding to the electronic component. Preheating means that is preheated to a temperature lower than the temperature at which the joint part melts or reacts and higher than room temperature, a main heating means that joins the electronic component and the substrate, and a joint part between the electronic component and the substrate melts or reacts after the main heating. And tail heat means for maintaining for a certain period of time at a temperature lower than the room temperature and higher than the room temperature.

  In the electronic device manufacturing apparatus according to the present invention, it is possible to provide a manufacturing apparatus for realizing stress relaxation and productivity improvement by the preheating process and the tail heating process described above.

  According to the method for manufacturing an electronic device according to the present invention, it is possible to improve the productivity at low cost without taking time, cost and cost, and to reduce the stress applied to the joint portion and to improve the connection reliability. To improve the quality.

  Embodiment 1 of the present invention will be described below with reference to FIGS.

  FIG. 1 shows that each process is simultaneously performed on a continuous tape-shaped substrate 3 while moving the IC chip 1 in the transport direction A at regular intervals (in this case, the distance between the IC chips 1). It shows how it is.

  On the IC chip 1, bumps 2 are formed on the electrode portions, for example, of a Sn—Ag-based solder alloy having a melting point of about 225 ° C. The tape-like substrate is a polyimide base and has flexibility, copper wiring, and the wiring surface in the vicinity of the joint is gold or solder plated.

  The heat plate 6 is integrally formed so as to straddle the preheating unit 101, the main heating unit 102, and the tail heating unit 103 in a state where it is in contact with or close to the lower surface of the substrate 3, and is made of ceramic or the like. It is controlled so that the surface temperature becomes 150 ° C. by feedback control while monitoring the temperature near the surface with a temperature sensor by inserting a sheet heater or contacting a seat heater from the lower side.

  On the left side, not shown, the bump 2 of the IC chip 1 is an electrode (not shown) of the substrate 3 immediately before being transferred to the preheating portion through the flux supply process, the alignment process, and the mounting process. Are in a state of being temporarily fixed due to the adhesiveness of the flux.

In the preheating portion 101, heat from the heat plate 6 is transmitted to the IC chip 1 and the substrate 3 that have moved from the left direction (not shown), and the IC chip 1, the vicinity of the bump 2 portion, and the substrate 3 on the heat plate are The temperature is raised to about 150 ° C. When a certain time has elapsed, the sheet moves in the conveyance direction A and moves to the main heating unit 102 .

In the main heating unit 102, the air heater 4 is fixed to the upper part, and hot air 5 is blown onto the upper surface of the IC chip 1. The air heater 4 controls the hot air 5 by the electric power applied to the hot wire resistance visible inside and the flow rate of fluid such as air or nitrogen flowing inside. In some cases, a shutter function is provided so that the hot air 5 is applied only for a predetermined time, and the hot air 5 is shut off after the predetermined time has elapsed. The IC chip 1 conveyed from the preheating part is heated by the hot air 5 from the heat plate 1 and the air heater 4 and the hot air 5 and the air heater are set so that the vicinity of the bump 2 part is higher than the melting point of the solder, for example, 250 ° C. Adjust the position of 4. As a result, the bumps 2 are melted and bonded to the substrate-side electrode (not shown).

  In the tail heat portion 103, the vicinity of the IC chip 1 and the bump 2 portion heated to about 250 ° C. is cooled while releasing heat to the atmosphere and the heat plate 6. However, when the temperature difference from the heat plate becomes small, the temperature is reduced. The descending becomes gentle and eventually descends to near the surface temperature of the heat plate 6 of 150 ° C. When the bump 2 falls below the melting point, it resolidifies, and the IC chip and the substrate are mechanically and electrically bonded.

  On the right side (not shown), the vicinity of the IC chip 1 and the bump 1 conveyed from the tail heat unit 103 is cooled at room temperature.

  FIG. 7 is a graph showing temperature profiles in Example 1 of the present invention and a conventional method for manufacturing an electronic device. The horizontal axis indicates time X, the vertical axis indicates temperature Y, the solid line indicates an example of the profile 51 near the junction of the present invention, the dotted line indicates an example of the profile 52 near the conventional junction, and the alternate long and short dash line indicates the peripheral portion of the substrate of the present invention. A profile 53 and a two-dot chain line show a profile 54 around the conventional substrate. The peripheral portion of the substrate refers to a portion that is slightly separated from the IC on the substrate and is not significantly affected by the main heating. The part where the lines overlap is slightly shifted for easy viewing. The preheating unit 101, the main heating unit 102, and the tail heating unit 103 correspond to the locations in FIG.

  At the preheating start time t1, the profile 51 near the joint of the present invention and the profile 52 near the conventional joint are the same at room temperature T1, but in the process up to the main heating start time t2, Since the profile 52 is not subjected to the preheating process, it remains at room temperature T1, but in the profile 51 near the joint of the present invention, the temperature rises toward the preheat temperature T2. Here, since the heating source in the preheating process is a ceramic heat plate having a lower thermal conductivity than that of metal, the temperature rise is moderate. If the heat conduction / heat conduction of the heat plate is high, the heat plate approaches the preheat temperature T2 more rapidly. On the other hand, the peripheral portion of the substrate is substantially the same as that in the vicinity of the joint portion in the present invention and the conventional one.

  From the main heating start time t2 to the main heating end time t3, the temperature in the vicinity of the junction increases toward the main heating temperature T3. In the meantime, in the profile 51 near the joint of the present invention, the main heating temperature T3 (250 ° C.) − Preheat temperature T2 (150 ° C.) = Temperature change 100 ° C. T3 (250 ° C.) − Normal temperature T 1 (25 ° C.) = Temperature change 225 ° C. The smaller the temperature change, the smaller the internal stress. Further, the substrate peripheral portion maintains the preheat temperature T2 in the substrate peripheral portion profile 53 of the present invention, and the conventional substrate peripheral portion profile 54 remains at room temperature. In the case of the present invention, the temperature difference between the vicinity of the bonding portion and the substrate periphery at the main heating end time t3 is the main heating temperature T3 (250 ° C.) − Preheat temperature T2 (150 ° C.) = Temperature difference 100 ° C. This heating temperature T3 (250 ° C.) − Normal temperature T1 (25 ° C.) = Temperature difference 225 ° C. The generation of stress due to the temperature difference is more advantageous in the present invention.

  From the main heating end time t3 to the tail heat end time t4, the temperature decreases in the cooling step. In the conventional profile 52 in the vicinity of the joint, the temperature rapidly decreases from the main heating temperature T3 to the normal temperature T1 through the bump melting point T5 with a curve that reverses the time of the main heating. In the profile 51 in the vicinity of the joint of the present invention, the temperature gradually decreases toward the tail heat temperature T4 via the bump melting point T5. Further, even after the tail heat end time t4, the temperature of the profile 51 near the joint of the present invention slowly decreases.

  Again, there is a relationship between stress and temperature change similar to that during preheating, but in the cooling process, if the melting point of the bump falls below T5 (220 ° C.), the solder of the bump is re-solidified and fixed. The stress applied to the vicinity of the joint due to the difference in the linear expansion coefficient between the substrate and the IC chip has a particularly large influence on the occurrence of cracks and peeling. In addition, the inclination during cooling (cooling rate) is preferably small, but the profile 51 near the joint of the present invention is also smaller. Further, the substrate peripheral portion maintains the preheat temperature T2 in the substrate peripheral portion profile 53 of the present invention, and the conventional substrate peripheral portion profile 54 remains at room temperature. Similarly, the present invention is smaller in the temperature difference between the periphery of the substrate and the vicinity of the junction.

Next, a second embodiment of the present invention will be described with reference to FIG. Here, Example 2 is an embodiment as a reference example, and is hereinafter referred to as Reference Example 1 for convenience. Note that the same reference numerals in the first embodiment denote the same parts as those in the first embodiment, and a description thereof will be omitted. The difference between Example 1 of Reference Example 1, Example 1, heat plate 6, up reheat section 101, the heating unit 102, whereas was installed over tail heat unit 103, reference example 1 , the heat plate 11 is installed so as to extend over only the main heating unit 102 and the tail heating unit 103.

That is, in the first reference example , the preheating step is omitted, and stress relaxation applied to the joint is realized by the functions of the main heating unit 102 and the tail heating unit 103 . Depending on the specifications of the IC chip 1 and the substrate 3, it may be possible to sufficiently secure the reliability of the joint. Moreover, the heat plate 11 becomes small and the controllability of temperature can be improved.

  In addition, when the heat plate 11 having the same size is installed so as to straddle the preheating part on the left side and the main heating part 102 for one cycle and the tail heating process is omitted, it is moved to the preheating side by one cycle. If the heater plate 11 is not installed in the lower part of the main heating and the tail heat is performed for a longer time, the heater plate 11 may be installed at any position where preheating or tail heat can be realized. However, it does not matter even if it extends over any process.

Next, Embodiment 3 of the electronic device manufacturing method according to the present invention will be described with reference to FIG. Here, Example 3 is an embodiment as a reference example, and is hereinafter referred to as Reference Example 2 for convenience. Note that the same reference numerals in the reference example 2 denote the same components as those in the first embodiment, and a description thereof will be omitted. While differs from the embodiment 1 of Reference Example 2, in Example 1, heat plate 6, up reheat section 101, the heating section 102, was installed together across tail heat portion 103, heat plate 21, 22 and 23 in reference example 2, respectively, up reheat section 101, the heating unit 102 is that is installed separately to tail heat unit 103.

According to the present reference example 2, up reheat section 101, the heating unit 102, tail heat unit 103, for each step, optimum temperature, position, by the size, more effective stress relief It becomes possible. Also, the heat plate is if installed one or more positions can be realized preheat or tail heat omitting the heating step, preheating side or the possible or to several established to tail Heat side Become. It can be assumed that the air heat 4 is omitted, the heat plate 22 is set to a higher temperature, and the main heating is performed by supplying heat from the heat plate 22.

Next, Embodiment 4 of the electronic device manufacturing method according to the present invention will be described with reference to FIG. Here, Example 4 is an embodiment as a reference example, and is hereinafter referred to as Reference Example 3 for convenience. In Reference Example 3 , the same components as those in Example 1 are denoted by the same reference numerals, and the description thereof is omitted. The difference between the reference example 3 and the example 1 is the heating method in each step.

  That is, the heat plate is not installed, but in the preheating unit 101, the infrared lamp 31 is installed above the IC chip 1 and heated by irradiating the heat ray 32. In the main heating unit 102, the thermocompression bonding head 33 is provided. Heating is performed by coming into contact with the upper surface of the IC, and in the tail heat unit 103, the air heater 4 is installed on the lower side of the substrate and heated by applying hot air to the lower surface of the substrate. Each heating condition is adjusted to be optimal, and the stress relaxation effect is exhibited. These heating means may be installed in any process of the preheating unit 101, the main heating unit 102, and the tail heating unit 103, including a method not introduced in this embodiment. A plurality of heating means may be used in the same process.

Next, a fifth embodiment of the method for manufacturing an electronic device according to the present invention will be described with reference to FIG. Here, Example 5 is an embodiment as a reference example, and hereinafter referred to as Reference Example 4 for convenience. Note that the same reference numerals in the reference example 4 denote the same parts as those in the first embodiment, and a description thereof will be omitted. The difference from Example 1 of Reference Example 4 is that, first, the transportation of the manufacturing apparatus is stopped for some reason such as maintenance, break, trouble occurrence, etc., the heat plate 6 moves in the escape direction B, That is, the distance from the substrate 3 is far away, and the hot air from the air heater 4 does not hit the IC chip 1.

  That is, if the heat plate 6 remains close to the substrate while the transport of the manufacturing apparatus is stopped, the heat of the heat plate 6 is supplied to the substrate 3, the IC chip 1, and the bump 2 for a long time. In some cases, the flux deteriorates in the preheating portion, and problems such as a decrease in adhesiveness and activity may occur. Therefore, when the conveyance of the apparatus is stopped, this problem can be avoided by controlling so that heat is not supplied to the substrate 3, the IC chip 1, and the bump 2.

Next, a sixth embodiment of the electronic device manufacturing method according to the present invention will be described with reference to FIG. Note that the same reference numerals in the sixth embodiment denote the same components as those in the first embodiment, and a description thereof will be omitted. The difference between the sixth embodiment and the first embodiment is that the movement distance between each process is doubled, and each process is moved according to the conveyance order C. The lower surface portion is a cutout portion 43 of the heat plate 6, and the preheating portion 101, the main heating portion 102, and the tail heat portion 103 are such that the protruding portions 42 of the heat plate 6 are close to the substrate 3, and The protrusion 42 of the tail heat portion 43 is chamfered on the upper left side.

  In order to improve productivity, when two joining processes are provided on the same line, one piece is transported. At this time, if a flat heat plate as shown in FIG. 1 is installed, the heat is also transferred to an IC (here, IC chip 41) which is not related to one of the bonding processes. For example, the bonding process is performed later. There are problems such as deterioration of the flux at the joint portion of the IC and effects on the characteristics and reliability due to the thermal history. Therefore, this problem can be avoided by providing a notch under the IC chip 41. In addition, there is a problem that a step or a notch (not shown) of the substrate is caught on the corner of the projection 42 during conveyance. By installing, it is possible to eliminate or reduce the catch. Here, the chamfered portion 44 is provided only in the tail heat portion, but it may be provided in a protruding portion in another process.

  The technical scope of the present invention is not limited to the above embodiment, and various combinations and changes can be made without departing from the spirit of the present invention.

  For example, the electronic component may be a PZT, a crystal, a SAW device, a sensor, a light emitting element, a cooling element, or the like in addition to the IC chip. In the case of solder, the bump is Sn-Ag, Sn-Cu, Sn-Ag-Cu, Sn-Zn, Sn-Bi, Sn-In, Sn-Sb, Sn-- Pb type, Au-Sn type, etc. may be used. In the case other than solder, copper, silver, nickel, aluminum, etc. may be used in addition to gold.

  In addition to the tape-shaped substrate, the substrate may be transported in a single piece or on a carrier, or may be in the form of a line or imposition in a strip shape. In addition to polyimide, the substrate may be PET, liquid crystal polymer, glass epoxy, ceramic, silicon, aluminum nitride, etc., and may be flexible or rigid. In addition to copper, the wiring may be silver, gold, aluminum, nickel, or the like. The surface treatment of the electrode portion may be formed by plating, sputtering, vapor deposition or the like of solder, silver, etc. in addition to Au and Sn.

  In addition to ceramic, the heat plate may be selected from any material having an optimum heat conduction coefficient and heat transfer coefficient in order to control the heating / cooling curve.

1 is Example 1 of an electronic device manufacturing method according to the present invention. 7 is a second embodiment of a method for manufacturing an electronic device according to the present invention. It is Example 3 of the manufacturing method of the electronic device which concerns on this invention. It is Example 4 of the manufacturing method of the electronic device which concerns on this invention. 9 is a fifth embodiment of the method for manufacturing an electronic device according to the present invention. 10 is a sixth embodiment of the method for manufacturing an electronic device according to the present invention. It is a graph which shows the temperature profile in Example 1 of the manufacturing method of the electronic device which concerns on this invention, and the manufacturing method of the conventional electronic device. It is sectional drawing which shows an example of the conventional electronic device.

Explanation of symbols

A Transport direction B Escape direction C Transport order X Time Y Temperature T1 Normal temperature T2 Preheating temperature T3 Main heating temperature T4 Tail heat temperature T5 Bump melting point t1 Preheating start time t2 Main heating start time t3 Tail heating end time 1, Tail heat end time 1, 41 IC chip 2 Bump 3 Substrate 4 Air heater 5 Hot air 6, 11, 21, 22, 23 Heat plate 31 Infrared lamp 32 Hot wire 33 Thermocompression bonding head 42 Protrusion 43 Notch 44 Chamfer 51 Profile near the joint of the present invention 52 Profile of the vicinity of the conventional bonding portion 53 Profile of the peripheral portion of the substrate of the present invention 54 Profile of the peripheral portion of the conventional substrate 61 IC electrode 62 Substrate electrode 63 IC crack 64 Bonding crack 65 Substrate crack 101 Preheating portion 102 Heating portion 1 3 tail heat section

Claims (12)

A main heating step of joining an electronic component heated by the main heating unit and having a plurality of electrodes on one surface and a substrate having an electrode corresponding to the electrode of the electronic component;
After the main heating step, heat is supplied from the tail heat portion, and the tail heat step is maintained for a certain time at a temperature lower than a temperature at which the electronic component and the bonded portion of the substrate are melted or reacted at a temperature higher than room temperature, and
A method of manufacturing an electronic device having
Before the main heating step, a flux supply step for temporarily fixing the electronic component and the substrate on which solder bumps are formed on the electrodes, an alignment step, and a mounting step,
Preheating after the mounting step and before the main heating step, heat is supplied from a preheating portion, and the electronic component and the temporarily fixed portion of the substrate are preheated at a temperature lower than the temperature at which the electronic component and the temporarily fixed portion are melted or reacted. Having a process,
The substrate is formed in a continuous tape shape and conveyed while moving by a predetermined length for each process,
The tail heat part is composed of a heat plate installed on the opposite side of the substrate from the bonding part side, a part close to or in contact with the substrate is composed of a protrusion part, and the protrusion part is have a chamfer for chamfering the corners on the side of the side or contact proximate to the substrate and previously by the movement of the substrate,
The main heating unit is configured by the heat plate, and the heat plate is configured such that a portion adjacent to or in contact with the substrate of the main heating unit and the tail heat unit is configured by a protrusion, and the main heating unit A notch between the portion and the tail heat portion,
The preheating portion is configured by the heat plate, and the heat plate is configured such that a portion adjacent to or in contact with the substrate of the preheating portion and the main heating portion is configured by a protrusion, and the preheating portion and the method of manufacturing an electronic device, characterized by chromatic notches between the heating unit. 2. The electronic device according to claim 1, wherein the protrusion of the main heating unit includes a chamfered portion that chamfers a corner on a side that comes close to or comes into contact with the substrate in advance by movement of the substrate. Production method. 3. The electronic device according to claim 1 , wherein the protrusion of the preheating unit includes a chamfered portion that chamfers a corner on a side that comes close to or comes into contact with the substrate in advance by movement of the substrate. Manufacturing method. 4. The electron according to claim 1, wherein, in the preheating step and the tail heating step, temperatures of the temporarily fixed portion and the joint portion are lower than a melting point of the solder bump. 5. Device manufacturing method. 5. The method of manufacturing an electronic device according to claim 1 , wherein the preheating step includes preheating at a temperature near a flux activation temperature. The method for manufacturing an electronic device according to claim 1 , wherein the heat plate is made of ceramic. The method of manufacturing an electronic device according to claim 1 , wherein the main heating unit uses an air heater. An electronic component having a plurality of electrodes on one surface, and a main heating unit that has an electrode corresponding to the electronic component, is formed in a continuous tape shape, and is joined by heating to a substrate conveyed by movement;
A tail heat portion that maintains a temperature lower than a temperature at which the electronic component and the bonding portion of the substrate are melted or reacted at a temperature higher than room temperature for a certain period of time;
An apparatus for manufacturing an electronic device having
A preheating part for preheating at a temperature lower than the temperature at which the electronic component and the temporarily fixed portion of the substrate are temporarily fixed and melted or reacted, and higher than room temperature;
The main heating unit joins the temporarily fixed electronic component and the substrate,
The tail heat part is composed of a heat plate installed on the opposite side of the substrate from the bonding part side, a part close to or in contact with the substrate is composed of a protrusion part, and the protrusion part is have a chamfer for chamfering the corners on the side of the side or contact proximate to the substrate and previously by the movement of the substrate,
The main heating unit is configured by the heat plate, and the heat plate is configured such that a portion adjacent to or in contact with the substrate of the main heating unit and the tail heat unit is configured by a protrusion, and the main heating unit A notch between the portion and the tail heat portion,
The preheating portion is configured by the heat plate, and the heat plate is configured such that a portion adjacent to or in contact with the substrate of the preheating portion and the main heating portion is configured by a protrusion, and the preheating portion and the An apparatus for manufacturing an electronic device, comprising a notch portion between the main heating portions . 9. The electronic device according to claim 8 , wherein the protrusion of the main heating unit includes a chamfered portion that chamfers a corner on a side adjacent to or in contact with the substrate as the substrate moves. Manufacturing equipment. 10. The electronic device according to claim 8 , wherein the protrusion of the preheating portion includes a chamfered portion that chamfers a corner on a side that comes close to or comes into contact with the substrate as the substrate moves. Manufacturing equipment. 11. The apparatus for manufacturing an electronic device according to claim 8 , wherein the heat plate is made of ceramic. The apparatus for manufacturing an electronic device according to claim 8 , wherein the main heating unit uses an air heater.

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