JP2014179420A - Method for bonding electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure a good bonding state between an electronic component and an electrode terminal, to improve productivity, and to downsize a substrate.SOLUTION: A method for bonding an electronic component comprises the steps of: mounting electrode terminals 4a of electronic components 4 having different heights on a plurality of electrodes 2a of a substrate 1 (component mounting step); mounting an organic film 5 thicker than a height difference between the highest electronic component and the lowest electronic component among a plurality of electronic components on the plurality of electronic components (organic film mounting step); uniforming the height of a pressed surface 5a of the organic film by applying a first pressure to the electronic component side by pressing a tabular pressing surface 58a of the pressing member 58 heated to a prescribed temperature against the organic film (organic film pressurizing step); and bonding each electrode terminal of the plurality of electronic components to each electrode of the substrate by applying a second pressure to the electric component side by the pressing member by pressing a tabular pressurizing surface 58a of a pressurizing member 58 against the pressed surface and heating the electronic component side for a prescribed time (bonding step).

Description

  The present invention relates to a technical field relating to a method for joining electronic components, in which each electrode terminal of a plurality of electronic components is joined to each electrode of a substrate by solid phase diffusion bonding by applying a predetermined temperature and pressure.

JP 2010-118534 A JP 2012-89740 A

  As a method for bonding electronic components such as semiconductor elements to a substrate, there is a bonding method using solder. The soldering method is that electronic components can be joined in a short time, the solder has high reliability in thermal distortion caused by temperature changes, and multiple electronic components are joined at once by reflow. This is advantageous in that it is possible.

  However, in the joining method using solder, it is difficult to join a plurality of electrode terminals of an electronic component at fine intervals, and the electrical conductivity and thermal conductivity of solder are lower than that of silver or the like. It has a drawback in that it is low.

  On the other hand, as a method for bonding an electronic component to a substrate, there is a method by solid phase diffusion bonding in which heating or pressurization or ultrasonic vibration is applied to perform bonding (see, for example, Patent Document 1).

  The method by solid phase diffusion bonding is a bonding method utilizing the diffusion phenomenon of atoms generated between metals (electrodes) that are not melted by heating or pressurization under certain conditions, and is generally several hundred degrees C lower than the melting point of solder. It is possible to lower the temperature in the joining operation as compared with the joining method using solder.

  Such a solid phase diffusion bonding method is, for example, a method in which a predetermined temperature and pressure are applied to directly bond an electrode terminal of an electronic component and an electrode of a substrate, or between an electrode terminal of an electronic component and an electrode of a substrate. There is a method in which a metal fine powder paste is applied and the metal fine powder paste is sintered and joined.

  The method by solid phase diffusion bonding has the advantage that it has good heat resistance and can ensure high electrical conductivity and thermal conductivity. Therefore, solid phase diffusion bonding is particularly effective for high-luminance LEDs (Light Emitting) as well as next-generation power semiconductors such as SiC (silicon carbide) and GaN (gallium nitride) that require good thermal and electrical characteristics. This is a bonding method that can be used in a wide range of fields, such as diode connection and LSI (Large Scale Integration) bonding.

  On the other hand, the solid phase diffusion bonding has a drawback that it requires a longer time than the soldering time in order to cause a high diffusion pressure and a sufficient diffusion reaction.

  By the way, a plurality of electronic components are often bonded to the substrate, but when a plurality of electronic components are bonded, the height of each electronic component may be different. In the conventional solid phase diffusion bonding in such a case, each electronic component is sandwiched between individual heaters, and a predetermined temperature and pressure are applied to each individual electronic component for a certain time.

  However, in a method in which individual electronic components are sandwiched between individual heaters and a predetermined temperature and pressure are applied for a certain period of time, a heater for heating and a motor for pressurization are applied to each individual electronic component. Therefore, the manufacturing cost of the component joining device (bonder) is increased, and a lot of time is required for the diffusion reaction.

  In addition, the parallelism of the plurality of electronic components to be bonded to the substrate is not uniform in addition to the height, and in order to pressurize the plurality of electronic components uniformly and bond to the substrate, the parallelism is adjusted. Such advanced control is necessary, and productivity is lowered.

  Furthermore, in recent years, with the miniaturization of electronic devices and the like, there is a high demand for miniaturization of substrates, and the distance between electronic components joined to one substrate and the pitch between terminals of electronic components tend to be shortened. However, in order to arrange a heater for heating and a motor for pressurization for each electronic component, a large arrangement space is required. Therefore, depending on the method in which individual electronic components are sandwiched between individual heaters and a predetermined temperature and pressure are applied for a certain period of time, the distance between the electronic components and the pitch between the terminals of the electronic components are small. There is also a problem that it is difficult to perform the bonding, which hinders downsizing of the substrate.

  On the other hand, as a conventional method for joining a plurality of electronic components having different heights to a substrate by solid phase diffusion bonding, a plurality of electronic components are arranged in a liquid and the plurality of electronic components are pressurized by liquid hydrostatic pressure and liquid There is a method of joining by heating (see paragraphs 0044 and 0046 of Patent Document 2).

  In the method of pressurizing and joining a plurality of electronic components by the hydrostatic pressure of the liquid as described above, the time for the diffusion reaction is shortened, and advanced adjustments such as adjusting the parallelism of the electronic components to the substrate are performed. Control is also unnecessary, productivity is improved, and electronic components can be joined when the pitch between terminals is small, which contributes to miniaturization of the board.

  However, in the method of pressurizing and joining a plurality of electronic components with hydrostatic pressure of liquid, since the pressure applied to the electronic components is hydrostatic pressure, sufficient force is applied to the electrode terminals of the electronic components on the electrodes of the substrate. It may not be possible to secure a good bonding state between the electrode terminal of the electronic component and the electrode of the substrate.

  Therefore, the present invention has an object of overcoming the above-described problems, improving productivity while ensuring a good bonding state between the electrode terminal of the electronic component and the electrode of the substrate, and reducing the size of the substrate. And

  1stly, the bonding | joining method of the electronic component which concerns on this invention positions the said electrode terminal of the several electronic component which has at least 2 electronic components from which height differs, and each has several electrode terminals in the said several electrode, respectively. A plurality of organic films having a thickness greater than the difference in height between the electronic component having the highest height and the electronic component having the lowest height among the plurality of electronic components; An organic film mounting step for mounting on an electronic component, and the pressing surface of a pressing member having a flat pressing surface heated to a predetermined temperature is pressed against the organic film, and the electronic component side is pressed by the pressing member. An organic film pressurizing step for applying a first pressure to the organic film and making the height of the pressed surface of the organic film pressed against the pressing surface uniform, and the pressurizing member having a flat pressing surface Pressurized surface Press against the surface to be pressed, apply a second pressure to the electronic component side by the pressure member, and heat for a predetermined time to join each electrode terminal of the plurality of electronic components to each electrode of the substrate And a joining step.

  As a result, the second pressure is applied to the electronic component side by the pressing member in a state where the pressing surface of the pressing member is pressed against the pressed surface of the organic film that has been made uniform by the pressing member. Heated for a predetermined time.

  2ndly, in the joining method of the electronic component which concerns on above-described this invention, it has the peeling process which removes the said pressurization member and peels the said organic film from these electronic components as a post process of the said joining process. desirable.

  Thereby, the influence with respect to an electronic component by the impurity, gas, etc. which may be generated from an organic film is avoided.

  Thirdly, in the electronic component joining method according to the present invention described above, a release film for placing a release film on the plurality of electronic components between the component placing step and the organic film placing step. It is desirable to provide a placing step and place the organic film on the plurality of electronic components via the release film.

  Thereby, an organic film is peeled from an electronic component with a release film.

  Fourthly, in the electronic component joining method according to the present invention described above, the organic film includes a first layer and a second layer positioned on the electronic component side from the first layer, It is desirable that the glass transition point of the layer be higher than the glass transition point of the second layer.

  Thereby, when a 1st pressure is provided to an organic film in an organic film pressurization process, the 2nd layer changes greatly from the 1st layer.

  Fifth, in the above-described electronic component bonding method according to the present invention, at least a part of the pressing member is formed of a transparent material, an ultraviolet curable film is used as the organic film, and the organic film pressurizing step. It is preferable that the organic film is cured by irradiating the organic film with the pressing member and irradiating with ultraviolet rays.

  Thereby, hardening of an organic film is rapidly performed by irradiation of an ultraviolet-ray.

  Sixth, in the electronic component joining method according to the present invention, it is preferable that the pressing member is used as the pressing member, and the pressing surface is used as the pressing surface.

  Thereby, it is not necessary to provide a dedicated pressing member and pressing member.

  Seventhly, in the electronic component joining method according to the present invention described above, the electrode terminal of the electronic component and the electrode of the substrate are gold, silver, copper, tin, nickel, zinc, antimony, bismuth, indium or the like. It is desirable to be formed of an alloy of

  Thereby, it becomes possible to use the material which has high jointability of both as an electrode terminal and an electrode.

  According to the method for bonding electronic parts of the present invention, a plurality of electronic parts having different heights are pressed at once by a pressure member through an organic film to apply pressure and heat for a predetermined time. As a result, productivity can be improved and a substrate can be miniaturized.

FIG. 2 to FIG. 17 show an embodiment of a method for joining electronic parts of the present invention, and this figure is a schematic sectional view of a parts joining apparatus. It is a schematic sectional drawing of the components joining apparatus which shows the state to which the pressurization head heater was moved. FIG. 4 to FIG. 11 show the procedure of the electronic component joining method, and this figure is an enlarged cross-sectional view showing a state in which a substrate is prepared. It is an expanded sectional view which shows a component mounting process. It is an expanded sectional view which shows an organic film mounting process. It is an expanded sectional view showing an organic film pressurization process. It is an expanded sectional view showing the state where giving of the 1st pressure to the organic film by a pressurization head heater was canceled. It is an expanded sectional view showing a joining process. It is an expanded sectional view showing the state where grant of the 2nd pressure to an organic film by a pressure head heater was canceled. It is an expanded sectional view which shows a peeling process. It is an expanded sectional view showing the state where the organic film is hardened by ultraviolet rays. The procedure of the electronic component joining method using the release film is shown together with FIGS. 13 to 17, and this figure is an enlarged cross-sectional view showing the release film placing step. It is an expanded sectional view which shows an organic film mounting process. It is an expanded sectional view showing an organic film pressurization process. It is an expanded sectional view showing the state where giving of the 1st pressure to the organic film by a pressurization head heater was canceled. It is an expanded sectional view showing a joining process. It is an expanded sectional view which shows a peeling process.

  EMBODIMENT OF THE INVENTION Below, the form for implementing the joining method of this invention electronic component is demonstrated with reference to an accompanying drawing.

<Schematic configuration of component joining device>
First, a schematic configuration of a component bonding apparatus (bonder) for bonding an electronic component to a substrate will be described (see FIG. 1).

  The component joining apparatus 50 includes a base case 51 and required parts disposed inside the base case 51. The base case 51 has a lower base 52 opened upward, a cylindrical upper base 53 penetrating vertically, and an inner base 54 provided inside the upper base 53.

  An internal space of the lower base 52 is formed as an arrangement space 52a. Substrates and electronic components, which will be described later, are arranged in the arrangement space 52a of the lower base 52, and at least a part of the joining operation of the electronic components to the substrate is performed in the arrangement space 52a.

  The upper base 53 is coupled at its lower end to the upper end of the lower base 52 so that it can be separated from the lower base 52.

  The inner base 54 is formed in a cylindrical shape penetrating vertically, and is attached to the upper base 53 in a state where the upper portion in the internal space of the upper base 53 is sealed. A screwing groove 54b is formed in the inner peripheral surface 54a of the inner base 54, and a pressure adjusting screw 55 that functions as a pressure adjusting valve is screwed into the screwing groove 54b.

  Oil 56 is sealed in a space extending from the inside of the upper base 53 to the inside of the inner base 54. The oil 56 is sealed in a state in which the oil 56 is sealed from below and sealed from the side to the upper base 53 and sealed from above to the pressure adjusting screw 55.

  The sealing member 57 has an outer peripheral portion attached to the inner peripheral portion of the upper base 53 and can be deformed according to the pressure (hydraulic pressure) of the oil 56. As the sealing material 57, for example, a rubber material or a thin film-like stainless steel film material is used.

  A pressure head heater 58 that functions as a pressing member and a pressure member is supported inside the upper base 53 so as to be movable up and down. Heat is transmitted to the pressure head heater 58 from a heating device (not shown), and the heating state of the pressure head heater 58 is controlled. The pressure head heater 58 is formed as a pressing surface 58 a having a flat bottom surface, and is disposed in a state where the top surface is in contact with the bottom surface of the sealing material 57. In the component joining device 50, heat is transmitted to the oil 56, whereby heat is transmitted to the pressure head heater 58 via the oil 56 and the sealing material 57, and the pressure head heater 58 is heated. The state may be controlled.

  A stage heater 59 is disposed below the pressure head heater 58 on the bottom surface of the lower base 52. Similarly to the pressure head heater 58, heat is transmitted to the stage heater 59 as well, and the heating state of the stage heater 59 is controlled by a thermocouple or the like.

  In the component joining apparatus 50 configured as described above, when the pressure adjusting screw 55 is rotated by the driving device, the pressure (hydraulic pressure) of the oil 56 changes according to the rotation direction and the rotation amount of the pressure adjusting screw 55. Then, the pressure of the oil 56 is transmitted to the sealing material 57, the sealing material 57 is deformed, and the pressure head heater 58 is moved in the vertical direction with respect to the upper base 53 (see FIG. 2). Accordingly, the position of the pressing surface 58a of the pressure head heater 58 in the vertical direction is changed according to the rotation direction and the rotation amount of the pressure adjusting screw 55.

  As described above, the substrate 52, the electronic components, and the like are arranged in the arrangement space 52a of the lower base 52, and the pressurizing head heater 58 is moved in the vertical direction. Pressure is applied by the pressure head heater 58.

  In the above, the example in which the pressure head heater 58 is moved by the change of the hydraulic pressure accompanying the rotation of the pressure adjusting screw 55 is shown. However, other means other than the pressure adjusting screw 55, for example, a piston or a handle The hydraulic pressure may be changed by, for example, movement of the drive shaft by rotation of the motor.

  Further, the moving means of the pressurizing head heater 58 is not limited to a change in hydraulic pressure. For example, the pressurizing head heater 58 is moved by a mechanical driving means such as a gear or a motor or a change in air pressure. It is also possible to do.

<Method of joining electronic parts>
Hereinafter, a procedure of a method for bonding electronic components to a substrate will be described (see FIGS. 3 to 11). Bonding of the electronic component to the substrate is performed by solid phase diffusion bonding using an atomic diffusion phenomenon caused by heating or pressurization, and this solid phase diffusion bonding is performed by applying a predetermined temperature and pressure to the electrode terminal of the electronic component. This is done by directly bonding the electrodes of the substrate.

  In addition, a predetermined process among the processes for the substrate of the electronic component is performed by the component bonding apparatus 50. In the following description of each process, the pressure head of the component bonding apparatus 50 is used for simplification of the description. Only heater 58 and stage heater 59 are shown as needed.

  First, the substrate 1 is prepared and placed on a work table (not shown) (see FIG. 3). A drive circuit (not shown) is formed on the substrate 1, and a plurality of joints 2, 2,... Connected to the drive circuit are provided on the upper surface 1a of the substrate 1. The joining portion 2 is composed of a plurality of electrodes 2a, 2a,. A conductive portion 3 connected to a drive circuit is provided on the lower surface 1 b of the substrate 1. The electrodes 2a, 2a,... And the conductive portion 3 are formed of a predetermined metal material such as gold, silver, copper, tin, nickel, zinc, antimony, bismuth, indium, or an alloy thereof.

  Next, a component placement process is performed (see FIG. 4). In the component mounting step, the electrode terminals 4a, 4a,... Provided on the lower surfaces of the electronic components 4, 4,. . The electronic components 4, 4,... Include at least two electronic components 4, 4 having different heights.

  The electrode terminals 4a, 4a,... Are formed of a predetermined metal material such as gold, silver, copper, tin, nickel, zinc, antimony, bismuth, indium, or an alloy thereof.

  As described above, the electrodes 2a, 2a, ... of the substrate 2 and the electrode terminals 4a, 4a, ... of the electronic component 4 are made of gold, silver, copper, tin, nickel, zinc, antimony, bismuth, indium or By forming with these alloys or the like, it is possible to use a material having high bondability between the electrodes 2a, 2a,... And the electrode terminals 4a, 4a,. The room for improvement and material selection can be expanded.

  As described above, since the electronic parts 4, 4,... Have different heights, the electrode terminals 4a, 4a,... Are aligned with the electrodes 2a, 2a,. In a state where the components 4, 4,... Are placed, the positions of the electronic components 4, 4,... On the upper surfaces are made different depending on the height of the electronic components 4, 4,. ing.

  Next, an organic film placing step is performed (see FIG. 5). In the organic film placing step, the organic films 5, 5,... Are placed on the upper surfaces of the electronic components 4, 4,. As the organic film 5, for example, a film formed of a thermoplastic resin material is used.

  The organic films 5, 5,... Are thicker than the difference in height between the electronic component 4 having the highest height and the electronic component 4 having the lowest height among the electronic components 4, 4,. The size of the lower surface is larger than the size of the upper surface of the electronic components 4, 4,. Therefore, when the organic films 5, 5,... Are placed on the electronic components 4, 4,..., The outer peripheral portions of the organic films 5, 5,. It is made into the state protruded sideways from 4, .... In the state where the organic films 5, 5,... Are placed on the electronic components 4, 4,..., The positions of the organic films 5, 5,. ,... Are different depending on the height. The upper surfaces of the organic films 5, 5,... Are respectively pressed surfaces 5a, 5a,.

  As described above, the substrate 1 is placed on the stage heater 59 in the arrangement space 52a of the component bonding apparatus 50 in a state where the organic films 5, 5,. Then, an organic film pressurizing step is performed (see FIG. 6). In the organic film pressurizing step, all the organic films 5, 5,... Are pressed downward at a time by the pressurizing head heater 58 functioning as a pressing member, and the organic films 5, 5,. A pressure P1 of 1 is applied. At this time, the pressure head heater 58 and the stage heater 59 are heated in order to promote the deformation (softening) of the organic films 5, 5,. The pressure head heater 58 is formed as a pressing surface 58a having a flat bottom surface.

  When the pressure head heater 58 and the stage heater 59 are heated in this way, the temperature of the organic films 5, 5,... Becomes higher than the glass transition point. The temperature is lower than when the stage heater 59 is heated. Accordingly, the organic films 5, 5,... Are deformed by heating, but at this time, the electrode terminals 4 a, 4 a,. ... not joined.

  The pressing head heater 58 is pressed downward against the pressed surfaces 5a, 5a,... Of the organic films 5, 5,... And moved downward by the rotation of the pressure adjusting screw 55. A first pressure P1 is applied to the organic films 5, 5,.

  When the first pressure P1 is applied to the organic films 5, 5,... By the pressure head heater 58, the organic films 5, 5,. The pressed surfaces 5a, 5a, ... of the applied organic films 5, 5, ... are made uniform (see H shown in Figs. 6 and 7).

  At this time, as described above, the thickness of the organic films 5, 5,... Is the highest among the electronic components 4 and the lowest electronic components 4. Since it is thicker than the difference in height, all the organic films 5, 5,... Are surely crushed by the pressure head heater 58, and the pressed surface 5a of the organic films 5, 5,. The heights of 5a,.

  Moreover, since the magnitude | size of the lower surface of organic film 5,5, ... is made larger than the magnitude | size of the upper surface of electronic components 4,4, ..., organic film 5,5, ... is a pressure head. In a state of being crushed by the heater 58, at least a part of the side surfaces of the electronic components 4, 4,... Is covered with each part of the organic films 5, 5,.

  Further, the thickness of the organic films 5, 5,... Is based on the difference in height between the electronic component 4 having the highest height and the electronic component 4 having the lowest height among the electronic components 4, 4,. Are thickened, so that each part of the organic films 5, 5,... Crushed by the pressure head heater 58 is the upper surface of all the electronic components 4, 4,. It remains between 58 pressing surfaces 58a. Therefore, the pressing surface 58a of the pressure head heater 58 is not in contact with the electronic components 4, 4,..., And unnecessary load on the electronic components 4, 4,. It is possible to prevent the electronic components 4, 4,... From being damaged or scratched.

  Furthermore, since all the organic films 5, 5,... Are pressed downward by the pressurizing head heater 58 at a time, the pressed surfaces 5a, 5a,. High-level control such as adjustment of parallelism for each of the parts 4, 4,.

  Subsequently, the pressure head heater 58 is moved upward by the rotation of the pressure adjusting screw 55, and the pressure head heater 58 is separated upward from the organic films 5, 5. Application of the first pressure P1 to the films 5, 5,... Is released (see FIG. 7). At this time, for example, the board 1 or the like on which the electronic components 4, 4,... Are placed may be temporarily taken out from the arrangement space 52 a of the component bonding apparatus 50 and cooled, or the board 1 or the like may be cooled. The heating of the pressurizing head heater 58 and the stage heater 59 may be stopped and cooled without taking out from the heater.

  By cooling in this way, the organic films 5, 5,... Formed of the thermoplastic resin material are crystallized and cured, and can proceed to the next step.

  Next, a joining process is performed (see FIG. 8). In the bonding process, when the substrate 1 or the like has been taken out from the arrangement space 52a of the component bonding apparatus 1, the substrate 1 or the like is again placed on the stage heater 59 in the arrangement space 52a. The bonding process can be performed by placing the substrate 1 and the like in a pressure device different from the component joining device 50. In the following, the substrate 1 and the like are again mounted on the stage heater 59 in the arrangement space 52a. An example will be described.

  In the joining step, the second pressure P2 is applied to the organic films 5, 5,... By the pressure head heater 58 that functions as a pressure member. The pressing head heater 58 is pressed downward against the pressed surfaces 5a, 5a,... Of the organic films 5, 5,... And moved downward by the rotation of the pressure adjusting screw 55. A second pressure P2 is applied to the organic films 5, 5,.

  At this time, in order to join the electrode terminals 4a, 4a, ... of the electronic components 4, 4, ... to the electrodes 2a, 2a, ... of the substrate 1, the second pressure P2 described above is applied. In addition, the pressure head heater 58 and the stage heater 59 are heated.

  When the pressure head heater 58 and the stage heater 59 are heated, the electrode terminals 4a, 4a,... Of the electronic components 4, 4,. Are directly joined by solid phase diffusion.

  Above, the example which uses the pressurization head heater 58 which functions as a pressing member in an organic film pressurization process as a pressurization member in a joining process was shown. Therefore, by using the pressure head heater 58 as a pressing member and a pressing member in this way, there is no need to provide a dedicated pressing member and a pressing member, respectively, in the joining operation of the electronic components 4, 4,. Costs can be reduced by shortening the working time and the number of parts.

Subsequently, the pressure head heater 58 is moved upward by the rotation of the pressure adjusting screw 55, and the pressure head heater 58 is separated upward from the organic films 5, 5. Application of the second pressure P2 to the films 5, 5,... Is released (see FIG. 9). At this time, for example, the board 1 or the like on which the electronic components 4, 4,... Are placed may be taken out from the arrangement space 52 a of the component bonding apparatus 50 and cooled. The heating of the pressure head heater 58 and the stage heater 59 may be stopped and cooled without taking out.
Next, a peeling process is performed (refer FIG. 10). In the peeling process, the organic films 5, 5,... Crushed by the pressure head heater 58 are peeled off from the electronic components 4, 4,.

  As described above, the organic films 5, 5,... Are peeled off from the electronic components 4, 4,. It is possible to avoid an influence on the electronic components 4, 4,... Due to certain impurities, gas, etc., and to ensure a good driving state of the electronic components 4, 4,.

  In addition, there is no possibility that the organic films 5, 5,... Have an influence on the electronic components 4, 4,. If the driving state can be ensured, the peeling step can be omitted. In this case, since the peeling process is not performed, the work time in the joining work of the electronic components 4, 4,... Is shortened, and the productivity can be improved.

  By performing each step as described above, the joining of the electronic components 4, 4,... To the substrate 1 is completed, and the circuit board 6 is formed.

  In the above, an example in which a film formed of a thermoplastic resin material is used as the organic films 5, 5,... It is also possible to use a film formed of a curable resin material. When a film formed of a thermosetting resin material is used as the organic films 5, 5,..., In the pressurizing step for applying the first pressure P1 to the organic films 5, 5,. The organic films 5, 5,... Are cured by transferring heat from the heated pressure head heater 58 and stage heater 59, so that the organic films 5, 5,.・ ・ No need to cool and harden.

  Therefore, the work time in the joining work of the electronic components 4, 4,... Is shortened, and the productivity can be improved.

  Moreover, as the organic films 5, 5,..., For example, a film formed of an ultraviolet curable resin material can be used.

  When a film formed of an ultraviolet curable resin material is used as the organic films 5, 5,..., Part or all of the pressure head heater 58 that functions as a pressure member is not melted by the ultraviolet rays. A transparent material such as a transparent glass material is used (see FIG. 11). In this case, after the organic films 5, 5,... Are deformed by the pressure head heater 58 in the pressurizing step, the ultraviolet light S, S,. It is possible to proceed to the next step by irradiating 5, 5,... To cure the organic films 5, 5,.

  In this way, by using a film formed of an ultraviolet curable resin material as the organic films 5, 5,..., The organic films 5, 5,. The organic films 5, 5,... Are cured quickly, and productivity can be improved by shortening the curing time.

  Alternatively, the organic film 5 may be formed in a two-layer structure so that the glass transition point of the upper first layer is higher than the glass transition point of the lower second layer.

  As described above, the organic film 5 has a two-layer structure, and the glass transition point of the first layer is made higher than the glass transition point of the second layer, whereby the first pressure is applied to the organic film 5 in the organic film pressurizing step. When the second layer is deformed more easily than the first layer, a part of the crushed organic films 5, 5,... Is formed on the upper surface of the electronic component 4 and the pressing surface 58 a of the pressure head heater 58. The load on the electronic component 4 during pressurization can be reduced.

  In the above, an example in which the organic films 5, 5,... Are placed on the upper surfaces of the electronic components 4, 4,. When the height of 4,... Is the same or when the difference in height is small, one organic film 5 is placed in a state of straddling the plurality of electronic components 4, 4,. You may make it do.

<Method using release film>
Next, a method for joining the electronic components 4, 4,... Using the release film will be described (see FIGS. 12 to 17). In addition, the joining method using a release film is a method in which a release film placement step is added between the above-described component placement step and organic film placement step, and the other steps are the contents described above. Therefore, only the matters different from the above-described steps will be described in detail below.

  If an application | coating process and a component mounting process are performed, a release film mounting process will be performed next (refer FIG. 12). In the release film placing step, the release films 7, 7,... Are placed on the upper surfaces of the electronic components 4, 4,. As the release film 7, for example, a metal film or a film of polyimide or the like having higher release properties with respect to the electronic component 4 than the organic film 5 is used.

  The release films 7, 7,... Are larger than the sizes of the upper surfaces of the electronic components 4, 4,. Are placed on the outer peripheral side of the release films 7, 7,... Sideways from the electronic components 4, 4,.

  Next, an organic film mounting step is performed (see FIG. 13). In the organic film placing step, the organic films 5, 5,... Are placed on the upper surfaces of the release films 7, 7,.

  Next, an organic film pressurizing step is performed (see FIG. 14). In the organic film pressing step, all the organic films 5, 5,... And all the release films 7, 7,. The first pressure P1 is applied to the organic films 5, 5,... And the release films 7, 7,. At this time, the pressure head heater 58 and the stage heater 59 are heated in order to promote the deformation (softening) of the organic films 5, 5,... And the release films 7, 7,.

  When the first pressure P1 is applied to the organic films 5, 5, ... and the release films 7, 7, ... by the pressure head heater 58, the organic films 5, 5, ... are separated. The height of the pressed surfaces 5a, 5a,... Of the plurality of organic films 5, 5,. Is made uniform (see H shown in FIGS. 14 and 15).

  At this time, the organic films 5, 5,... And the release films 7, 7,... Have lower surfaces larger than the upper surfaces of the electronic components 4, 4,. When the films 5, 5,... And the release films 7, 7,... Are crushed by the pressure head heater 58, at least a part of the side surfaces of the electronic components 4, 4,. Are covered with a part of each of the release films 7, 7,. In the state where at least a part of the side surfaces of the electronic parts 4, 4,... Is covered with each part of the organic films 5, 5,. The release films 7, 7,... Are in close contact with the side surfaces of 4, 4,..., And the organic films 5, 5,.

  Subsequently, a joining process is performed, and the electrode terminals 4a, 4a, ... of the electronic components 4, 4, ... are joined to the electrodes 2a, 2a, ... of the substrate 1, respectively (Fig. 16). reference).

  Next, a peeling process is performed (refer FIG. 17). In the peeling process, the organic films 5, 5,..., And the release films 7, 7,. .

  At this time, the electronic components 4, 4,... Are release films that are higher than the organic films 5, 5,. Since the mold films 7, 7,... Are in close contact, the organic films 5, 5,... Can be easily and reliably peeled off from the electronic components 4, 4,. It is possible to improve productivity by improving productivity.

  Moreover, the influence on the electronic components 4, 4,... Due to impurities or gas that may be generated from the organic films 5, 5,. A good driving state can be ensured.

  Furthermore, it is possible to shield impurities and gases that may be generated from the organic films 5, 5,... By the release films 7, 7,. The influence of the organic films 5, 5, ... on the electronic components 4, 4, ... can be avoided.

  By performing each step as described above, the joining of the electronic components 4, 4,... To the substrate 1 is completed, and the circuit board 6 is formed.

  In the above, an example in which the release films 7, 7,... Are placed on the upper surfaces of the electronic components 4, 4,. When the heights of 4, 4,... Are the same or when the difference in height is small, a single release film 7 is placed across the plurality of electronic components 4, 4,. It may be arranged.

<Summary>
As described above, in the joining method of the electronic components 4, 4,..., The heights of the pressed surfaces 5 a, 5 a,. In this state, the pressure head heater 58 heats and presses the electrode terminals 4a, 4a,... Of the plurality of electronic components 4, 4,. It is directly joined to.

  Therefore, the electrode terminals 4a, 4a,... Of the plurality of electronic components 4, 4,... Are joined to the electrodes 2a, 2a,. Therefore, the time for the diffusion reaction is shortened as a whole, and there is no need for advanced control such as adjustment of parallelism of each electronic component 4, 4,. The electrode terminals 4a, 4a,... Of the plurality of electronic components 4, 4,... Are joined to the electrodes 2a, 2a,. , And the electrode terminals 4a, 4a,... Of the substrate 1 and the electrodes 2a, 2a,. 1 can be miniaturized.

  Moreover, even when each position and each height of the electronic components 4, 4,... Are changed, the above-described joining method can be used, and versatility can be improved.

<Others>
Although the example which joined the electrode terminal 4a of the electronic component 4 to the electrode 2a of the board | substrate 1 by solid-phase diffusion was shown above, this invention joins semiconductor chips (electronic components) and makes a composite component, for example. The present invention can be widely applied to the field of mounting substrates (circuit boards) such as bonding of electrodes in so-called chip-on-chip and semiconductor packages, and semiconductor devices.

58 ... Pressure head heater (pressing member) (pressurizing member)
DESCRIPTION OF SYMBOLS 1 ... Board | substrate 2 ... Electrode 4 ... Electronic component 5 ... Organic film 7 ... Release film

Claims (7)

A component placing step of placing the electrode terminals of a plurality of electronic components including at least two electronic components having different heights and having a plurality of electrode terminals, respectively, in alignment with the plurality of electrodes;
An organic film placing step of placing an organic film thicker than the difference in height between the electronic component having the highest height and the electronic component having the lowest height among the plurality of electronic components; ,
The pressing surface of the pressing member that has a flat pressing surface and heated to a predetermined temperature is pressed against the organic film, the first pressure is applied to the electronic component side by the pressing member, and the pressing surface is An organic film pressurizing step for making the height of the pressed surface of the pressed organic film uniform,
The pressing surface of the pressing member having a flat pressing surface is pressed against the pressed surface, the second pressure is applied to the electronic component side by the pressing member and heated for a predetermined time. A bonding step of bonding each electrode terminal of the electronic component to each electrode of the substrate. The electronic component joining method according to claim 1, further comprising a peeling step of removing the pressure member and peeling the organic film from the plurality of electronic components as a subsequent step of the joining step. Between the component placement step and the organic film placement step, a release film placement step of placing a release film on the plurality of electronic components,
The method for bonding electronic components according to claim 2, wherein the organic film is placed on the plurality of electronic components via the release film. The organic film is composed of a first layer and a second layer positioned on the electronic component side from the first layer,
The method for bonding electronic components according to claim 1, wherein the glass transition point of the first layer is higher than the glass transition point of the second layer. At least a part of the pressing member is formed of a transparent material,
An ultraviolet curable film is used as the organic film,
5. The electron according to claim 1, claim 2, claim 3, or claim 4, wherein in the organic film pressurizing step, the organic film is cured by transmitting the pressing member through the organic film and irradiating ultraviolet rays. Part joining method. The pressing member is used as the pressing member,
The electronic component joining method according to claim 1, wherein the pressing surface is used as the pressing surface. The electrode terminal of the electronic component and the electrode of the substrate are formed of gold, silver, copper, tin, nickel, zinc, antimony, bismuth, indium, or an alloy thereof. The method for joining electronic components according to claim 4, claim 5 or claim 6.

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