JP2007003859A - Manufacturing method of electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a liquid crystal display device, capable of appropriately and easily satisfying demand for the increased number of pins and a narrowed pitch in an electrode section of a liquid crystal panel. <P>SOLUTION: Ahead of connection of a liquid crystal panel 1 and a flexible printed wiring substrate 2 using an anisotropic electric conduction film, the manufacturing method comprises; a preprocessing step for removing an organic orientation membrane and an inorganic membrane with water jet irradiation; a drying process step for drying the liquid crystal panel afterward; and a connection process step for electrically and mechanically connecting the liquid crystal panel 1 and the flexible printed wiring substrate 2 by the anisotropic electrical conduction film afterward, in a state that the electrode section 5 of the liquid crystal panel 1 and the electrode panel of the flexible printed wiring substrate 2 are faced and contacted together. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an electronic device, and is particularly suitable for application to a method for manufacturing a liquid crystal display device.

  In the manufacturing process of a liquid crystal display device (LCD), a liquid crystal panel (LCD panel) is manufactured by bonding an array substrate on which pixel electrodes are formed and a counter substrate on which common electrodes are formed through a liquid crystal layer. Yes. In the array substrate constituting the liquid crystal panel, an electrode portion for external connection is formed on the surface on the side facing the counter substrate and outside the bonding region with the counter substrate. The liquid crystal panel is electrically and mechanically connected to an external member such as a flexible printed wiring board or a semiconductor chip (LSI chip or the like) using this electrode portion.

  Conventionally, a liquid crystal panel and an external member are connected using an anisotropic conductive film (ACF) (see, for example, Patent Document 1 and Patent Document 2). In connection using an anisotropic conductive film, both electrode portions are brought into contact with each other and pressed (crimped) with the anisotropic conductive film interposed between the electrode portion of the liquid crystal panel and the electrode portion of the external member. ), The conductive particles contained in the anisotropic conductive film provide conduction between the electrode portions.

JP 2001-337340 A JP 2001-119116 A

By the way, in the manufacturing process of the liquid crystal panel, in order to regularly arrange the liquid crystal molecules, an organic alignment film made of an organic material such as polyimide or an inorganic material such as silicon oxide (SiO ₂ ) is formed on each facing surface of the array substrate and the counter substrate. An inorganic alignment film is formed. In forming such an alignment film on the array substrate, the alignment film is applied to the entire surface of the array substrate by spin coating or the like, and then the alignment is controlled by a rubbing method in which the surface of the alignment film is rubbed with a rubbing cloth.

  When the alignment film is formed on the array substrate in this way, the electrode portion is covered with the alignment film at the surface layer portion of the array substrate. The alignment film is electrically an insulator. For this reason, in the state where the electrode part of the array substrate is covered with the alignment film, when the liquid crystal panel and each electrode part of the external member are connected with the anisotropic conductive film, the alignment film becomes a hindrance between the electrode parts. It becomes difficult to take continuity.

  In addition, in order to electrically connect each electrode part of the liquid crystal panel and the external member with the anisotropic conductive film while the electrode part of the array substrate is covered with the alignment film, the conductive material included in the anisotropic conductive film is used. It is necessary to break through the alignment film with particles. At that time, in order to reliably break through the alignment film, it is necessary to make the particle size of the conductive particles larger than the film thickness of the alignment film.

  However, in recent years, with the increase in the definition of display images (increasing the number of pixels) and the reduction in size of liquid crystal panels, it has been required to increase the number of pins and the pitch of the electrode portion. There is a limit to increasing the size of the particles. The reason for this is that if the conductive particles are made larger, short circuit defects are likely to occur between adjacent electrode portions when the pitch of the electrode portions is reduced.

  The electronic device manufacturing method according to the present invention includes at least one of the first connection portion provided on the first connected member and the second connection portion provided on the second connected member. A pretreatment step of removing organic matter or inorganic matter adhering to the connection portion of the member by irradiation with a water jet, and after the pretreatment step, the first connection portion and the second connection portion are in contact with each other in the first state. A connecting step of electrically and mechanically connecting the connected member and the second connected member.

  In the method for manufacturing an electronic device according to the present invention, for example, the first connected member is a liquid crystal panel, the second connected member is an external member such as a flexible printed wiring board, and the first connected member and the first connected member. In the case where the two connected members are joined by the anisotropic conductive film, the organic matter or the inorganic matter attached to the electrode portion of the first connected member is removed by water jet irradiation in the pretreatment step, and then the first By electrically and mechanically connecting the first connected member and the second connected member in a state where the connecting portion and the second connecting portion face each other, the size of the conductive particles of the anisotropic conductive film can be reduced. Regardless of this, it is possible to reliably establish conduction between the electrode portions of the liquid crystal panel and the external member.

  ADVANTAGE OF THE INVENTION According to this invention, in electronic devices, such as a liquid crystal panel and a liquid crystal display device provided with this, it becomes possible to respond | correspond appropriately and easily to the request | requirement of the multi-pin and narrow pitch of an electrode part.

  Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
In the first embodiment of the present invention, a liquid crystal panel and a flexible printed wiring board are connected by FOG (Film On Glass) bonding using an anisotropic conductive film in a manufacturing process of a liquid crystal display device as an electronic device. The case of doing this will be described as an example.

  First, as two connected members to be connected, a liquid crystal panel 1 and a flexible printed circuit board (FPC) 2 are prepared as shown in FIGS. The liquid crystal panel 1 is obtained through a known substrate manufacturing process and substrate assembly process. In general, the liquid crystal panel 1 has a configuration in which an array substrate 3 on which pixel electrodes are formed and a counter substrate 4 on which common electrodes are formed are bonded together via a liquid crystal layer (not shown). In addition, a plurality of electrode portions (connection portions) 5 are formed on the array substrate 3.

  On the other hand, the flexible printed wiring board 2 is obtained by a well-known board manufacturing process. On the flexible printed wiring board 2, a plurality of wiring patterns 6 made of a low resistance metal such as aluminum or copper are formed corresponding to the plurality of electrode portions 5. An electrode portion (connecting portion) (not shown), for example, plated with gold is formed at the terminal portion of each wiring pattern 6. In this case, the electrode part 5 provided on the liquid crystal panel 1 side and the electrode part provided on the flexible printed wiring board 2 side correspondingly are arranged at the same pitch.

  FIG. 2 is an enlarged cross-sectional view of a portion where the electrode portion 5 of the liquid crystal panel 1 is formed. In the figure, an electrode portion 5 is formed on a glass substrate 7 which is a base of the array substrate 3. The electrode portion 5 is formed in a state where an insulating film 8 such as silicon oxide is partially opened. The electrode unit 5 has a two-layer structure in which a metal layer 9 and an ITO (Indium Tin Oxide) layer 10 are sequentially laminated on a glass substrate 7. The metal layer 9 is formed using a low resistance metal such as aluminum. The ITO layer 10 is formed on the metal layer 9 simultaneously with the pixel electrode when the pixel electrode is formed on the array substrate 3 using ITO. An alignment film 11 is formed on the glass substrate 7 so as to cover the electrode portion 5 and the insulating film 8. The alignment film 11 is made of an organic material (organic alignment film) such as polyimide or an inorganic material (inorganic alignment film) such as silicon oxide, and is formed on the entire surface of one side of the array substrate 3 with a uniform film thickness. The organic alignment film may be a thin film containing carbon such as diamond-like carbon.

  FIG. 3 is an enlarged cross-sectional view of an electrode portion forming portion of the flexible printed wiring board 2. In the figure, a wiring layer 13 is formed on a film substrate 12 serving as a base of the flexible printed wiring board 2. The wiring layer 13 forms the wiring pattern 6 and is covered with a resist film 14 made of an insulating material such as resin. Further, an electrode portion 15 made of a gold plating layer is formed at the terminal portion of the wiring layer 13.

  When the liquid crystal panel 1 and the flexible printed wiring board 2 having such a configuration are prepared, the pretreatment by the water jet irradiation and the drying treatment are sequentially performed on the liquid crystal panel 1 and the flexible printed wiring board 2 in advance, prior to the connecting step by FOG bonding. Do.

  In the pretreatment of the flexible printed wiring board 2, as shown in FIG. 4, the formation part of the electrode portion 15 (see FIG. 3) of the flexible printed wiring board 2 or the entire surface of one side of the flexible printed wiring board 2 including the formation part is provided. By irradiating the water jet, dust of organic matter (organic compound or the like) adhering to the electrode portion 15 of the flexible printed wiring board 2 is removed.

  On the other hand, in the pretreatment of the liquid crystal panel 1, as shown in FIG. 5, by irradiating the formation site of the electrode portion 5 of the liquid crystal panel 1 with a water jet, as shown in FIGS. The alignment film 11 covering the electrode portion 5 and the insulating film 8 on the glass substrate 7 is removed. At this time, it is desirable to install a cylindrical scattering prevention cover 16 over the portion where the electrode portion 5 is formed so that the water jet liquid does not splash on the substrate bonding portion of the liquid crystal panel 1 or the like.

  Here, the water jet is obtained by jetting a liquid from a nozzle at a high pressure. More specifically, for example, as shown in FIG. 7, the liquid stored in the tank 17 is pumped up by a pump 18, and a high pressure is applied to the pumped liquid by a pressurizer 19 and sent to the nozzle 20. It is jetted from the nozzle 20 as a jet jet. When the water jet generated in this way is irradiated to the liquid crystal panel 1 in a vertical direction, the surface layer portion of the liquid crystal panel 1 (array substrate 3) is thinly cut by the impact of the water jet at the irradiated portion.

  As the liquid used for generating the water jet, a liquid that can effectively remove organic substances and inorganic substances without damaging the gold plating of the electrode section 15 and the liquid crystal panel 1 is desirable. Specifically, pure water, water such as hydrogen peroxide, organic chemicals such as ethanol, acetone, and IPA (isopropyl alcohol), and inorganic chemicals such as diluted hydrofluoric acid, sulfuric acid, and ammonia, It can be used as a liquid. Further, in order to increase the removal effect by the water jet, it is possible to apply ultrasonic waves to the water jet or add an abrasive (for example, silica) to the water jet. Furthermore, by heating the liquid used for the water jet with a heater or the like, it is possible to eject the liquid from the water jet spray nozzle in a state where the temperature of the liquid is raised higher than the normal temperature.

  Note that organic dust covering the electrode portion of the flexible printed circuit board 2 is mainly attached during storage and transportation, so that the amount of adhesion can be suppressed to a small amount depending on the storage method and the transportation environment. Therefore, the water jet irradiation to the flexible printed circuit board 2 may be performed as necessary.

  After performing the above pretreatment process, it progresses to the drying process which dries the liquid crystal panel 1 and the flexible printed wiring board 2 which became wet by irradiation of a water jet. In the drying process, clean dry air is blown against the liquid crystal panel 1 and the flexible printed wiring board 2 as shown in FIGS. The dry air used for the drying process is a substance that is in a gaseous state at normal temperature, such as air, nitrogen, oxygen, and argon, and it is desirable that the purity of the gas is high. In addition, after spraying dry air or for a predetermined time, for example, the liquid crystal panel 1 or the flexible printed wiring board 2 is thrown into a high-temperature atmosphere higher than room temperature (for example, an atmosphere at 80 ° C.) The liquid crystal panel 1 and the flexible printed wiring board 2 may be stored in a high temperature atmosphere (for example, an atmosphere of 100 ° C.) higher than normal temperature using an oven or the like.

  In this way, by using drying by spraying dry air and drying by heating in the drying step, the liquid crystal panel 1 and the flexible printed wiring board 2 that have been subjected to the pretreatment (water jet irradiation) are dried more quickly and reliably. be able to. In the drying process of the liquid crystal panel 1, for example, as shown in FIG. 9, the liquid crystal panel 1 is placed and fixed on a disk-shaped stage 21, and the liquid crystal panel 1 is rotated at a high speed integrally with the stage 21 in this state. It is also possible to apply or use the dry drying method.

  After performing the drying process in this way, the process proceeds to the connection process. In the connecting step, as shown in FIG. 10, the electrode portions 5 and 15 of the liquid crystal panel 1 and the flexible printed wiring board 2 are aligned, and an anisotropic conductive film (not shown) is provided between the electrode portions 5 and 15. The electrode portions 5 and 15 are abutted with each other in between, and the liquid crystal panel 1 and the flexible printed wiring board 2 are electrically and mechanically connected by heating and pressurizing the electrode portions in this abutting state.

  Thereby, the liquid crystal panel 1 and the flexible printed wiring board 2 are connected via the anisotropic conductive film 22, as shown in FIG. At this time, the electrical connection between the liquid crystal panel 1 and the flexible printed wiring board 2 is performed by the conductive particles 23 dispersed in the film of the anisotropic conductive film 22. Further, the mechanical connection between the liquid crystal panel 1 and the flexible printed wiring board 2 is performed by an adhesive film serving as a base material of the anisotropic conductive film 22. In this case, the alignment film 11 has been removed on the electrode portion 5 of the liquid crystal panel 1 by water jet irradiation in the pretreatment step. For this reason, regardless of the size of the conductive particles 23 of the anisotropic conductive film 22, conduction can be reliably established between the liquid crystal panel 1 and the electrode portions 5 and 15 of the flexible printed wiring board 2. Moreover, since the stable conductive state is obtained between the electrode parts 5 and 15 using the anisotropic conductive film 22, generation | occurrence | production of the dispersion | variation in an electrical resistance, a short circuit defect, etc. can be reduced. Therefore, it is possible to appropriately and easily respond to the demands for increasing the number of pins and the pitch of the electrode portion 5 of the liquid crystal panel 1.

  In the first embodiment, the alignment film 11 is removed from the ITO layer 10 constituting the electrode unit 5 by irradiating the formation portion of the electrode unit 5 of the liquid crystal panel 1 with a water jet. In that case, a part (upper layer part) or all of the ITO layer 10 together with the alignment film 11 may be removed by water jet irradiation at the formation part of the electrode part 5. In that case, the thickness of the ITO layer 10 can be set as an allowable amount, and the amount of cutting by the water jet can be set roughly. Further, when the ITO layer 10 is removed together with the alignment film 11, a part (upper layer part) of the insulating film 8 is also removed simultaneously with the ITO layer 10, and when the entire ITO layer 10 is removed, as shown in FIG. In addition, the electrode portion 5 is formed only by the metal layer 9. Therefore, the same effect as described above can be obtained. Further, when all of the ITO film 10 is removed, the electrode portion 15 of the flexible printed wiring board 2 is directly connected to the metal layer 9 using the anisotropic conductive film 22, so that the electrical resistance of the connection portion Can be reduced.

  Moreover, in the said 1st Embodiment, although the liquid crystal display device was illustrated as an electronic device, this invention is not limited to this, It can apply widely also to the manufacturing method of electronic devices other than a liquid crystal display device. Hereinafter, specific examples will be sequentially described as other embodiments of the present invention.

[Second Embodiment]
In the second embodiment of the present invention, in order to realize, for example, a SIP (System In Package) structure in the manufacturing process of an electronic device including a semiconductor device, two large and small semiconductor chips are chip-on-chip ( A case where FCB (Flip Chip Bonding) bonding is performed with a COC) structure will be described as an example.

  First, as shown in FIGS. 13A and 13B, a first semiconductor chip 31 and a second semiconductor chip 32 are prepared as two connected members to be connected. The first semiconductor chip 31 is, for example, a DAC (Digital-to-Analog Converter) -IC chip, and the second semiconductor chip 32 is, for example, a memory IC chip. Each of the semiconductor chips 31 and 32 is configured based on a semiconductor substrate such as a silicon substrate, and is obtained by a known semiconductor manufacturing process. The planar size of the first semiconductor chip 31 is smaller than the planar size of the second semiconductor chip 32.

  A plurality of electrode portions 33 are formed on the first semiconductor chip 31, and a plurality of electrode portions 34 are also formed on the second semiconductor chip 32 correspondingly. The electrode portions 33 and 34 are formed on the first semiconductor chip 31 and the second semiconductor chip 32 in a one-to-one correspondence relationship. More specifically, the electrode portions 33 are arranged on the first semiconductor chip 31 in a predetermined pitch in two rows (2 rows × 8 pieces, a total of 16 pieces), and the electrode portions 34 are arranged in the second semiconductor chip 32. It is arranged in two rows (2 rows × 8 in total 16 pieces) at the same pitch as the electrode portion 33. In addition to the plurality of electrode portions 34, a plurality of electrode portions 35 for external connection are formed on the second semiconductor chip 32. The electrode part 35 is formed on the second semiconductor chip 32 at a position away from a region where the first semiconductor chip 31 is FCB bonded (a region where the electrode unit 34 is formed). Each of the electrode portions 33, 34, and 35 is formed by an electrode pad made of a low resistance metal such as aluminum, for example, but in addition to this, it is formed by a metal bump made of a low melting point solder, for example. There may be.

  14A is an enlarged cross-sectional view of a portion where the electrode portion 33 of the first semiconductor chip 31 is formed, and FIG. 14B is an enlarged cross-section of the portion where the electrode portion 34 of the second semiconductor chip 32 is formed. FIG. In the figure, organic dust 36 is attached on the electrode portion 33 of the first semiconductor chip 31. Organic dust 37 is also attached to the electrode part 34 of the second semiconductor chip 32. The organic dust 36 adheres to the first semiconductor chip 31 during storage and transport, and the organic dust 37 adheres to the second semiconductor chip 32 during storage and transport.

  If the organic dust particles 36 and 37 adhere to the electrode portions 33 and 34 in this way, there is a risk of causing poor bonding due to this. Therefore, prior to connecting the first semiconductor chip 31 and the second semiconductor chip 32 by FCB bonding, pretreatment by water jet irradiation and drying treatment are sequentially performed on each of the semiconductor chips 31 and 32. .

  In the pretreatment of the first semiconductor chip 31, as shown in FIG. 15A, the formation portion of the electrode part 33 of the first semiconductor chip 31 is irradiated with a water jet to adhere to each electrode part 33. The organic waste 36 is removed. Similarly, in the pretreatment of the second semiconductor chip 32, as shown in FIG. 15B, each electrode portion is formed by irradiating the formation portion of the electrode portion 34 of the second semiconductor chip 32 with a water jet. The organic dust 37 adhering to 34 is removed. As the liquid used for generating the water jet, the same liquid as in the first embodiment can be used. In order to increase the removal effect of the water jet, it is possible to apply ultrasonic waves to the water jet, add an abrasive to the water jet, or increase the temperature of the liquid used in the water jet.

  After performing the above pretreatment process, it progresses to the drying process which dries each semiconductor chip 31 and 32 wet by irradiation of water jet. In the drying process, as shown in FIGS. 16A and 16B, clean dry air is blown onto each of the semiconductor chips 31 and 32. As the dry air used for the drying process, those exemplified in the first embodiment can be used. Moreover, it is also possible to apply or use together the drying process by heating, and the drying process by rotary swing-off as needed.

  After performing the drying process in this way, the process proceeds to the connection process. In the connecting step, as shown in FIGS. 17A and 17B, the first semiconductor chip 31 is aligned face-down so that both electrode portions 33 and 34 face each other on the second semiconductor chip 32. In this state, as shown in FIG. 18, the electrode portion 33 of the first semiconductor chip 31 and the electrode portion 34 of the second semiconductor chip 32 are brought into contact with each other, and heating / pressurization or ultrasonic waves are applied as necessary. Thus, the two semiconductor chips 31 and 32 are electrically and mechanically connected by FCB bonding. As a bonding method, not only FCB bonding but also TAB (Tape Automated Bonding) bonding can be applied.

  In the above manufacturing method, before the semiconductor chips 31 and 32 are FCB-bonded, the organic dusts 36 and 37 attached to the electrode portions 33 and 34 are removed by water jet irradiation. , 32 can be reliably connected between the electrode portions 33, 34. In addition, since a stable conduction state is obtained between the electrode portions 33 and 34, it is possible to reduce the occurrence of variations in electrical resistance, short-circuit defects, and the like.

[Third Embodiment]
In the third embodiment of the present invention, a case where a semiconductor chip and a flexible printed wiring board are connected by COF (Chip On Film) bonding in the manufacturing process of an electronic device including a semiconductor device will be described as an example.

  First, as shown in FIGS. 19A and 19B, a semiconductor chip 41 and a flexible printed wiring board 42 are prepared as two connected members to be connected. The semiconductor chip 41 is made of, for example, an IC driver, and is obtained by a known semiconductor manufacturing process. The flexible printed wiring board 42 is obtained by a well-known board manufacturing process.

  A plurality of electrode portions 43 are formed on the semiconductor chip 41, and a plurality of electrode portions 44 are also formed on the flexible printed wiring board 42 correspondingly. The respective electrode portions 43 and 44 are formed on the semiconductor chip 41 and the flexible printed wiring board 42 in a one-to-one correspondence relationship. More specifically, the electrode parts 43 are arranged on the semiconductor chip 41 in two rows at a predetermined pitch (2 rows × 8 pieces in total 16 pieces), and the electrode portions 44 are arranged on the flexible printed wiring board 42. It is arranged in two rows (2 rows × 8 pieces, a total of 16 pieces) at the same pitch as 43. The electrode part 43 of the semiconductor chip 41 is subjected to a gold plating process, and the electrode part 44 of the flexible printed wiring board 42 is subjected to a tin (Sn) plating process.

  20A is an enlarged cross-sectional view of a portion where the electrode portion 43 of the semiconductor chip 41 is formed. FIG. 20B is an enlarged cross-sectional view of the portion where the electrode portion 44 of the flexible printed wiring board 42 is formed. In the figure, organic dust 45 is attached on the electrode part 43 of the semiconductor chip 41. The organic dust 45 adheres to the semiconductor chip 41 during storage or transportation. On the other hand, an electrode portion 44 is formed on a film substrate 46 serving as a base of the flexible printed circuit board 42 in a state where a resist film 47 made of an insulating material such as a resin is partially opened. Organic dust 48 is attached. The organic dust 48 adheres while the flexible printed wiring board 2 is being stored or transported.

  If the organic particles 45 and 48 adhere to the electrode portions 43 and 44 in this way, there is a risk of causing poor bonding due to this. Therefore, prior to connecting the semiconductor chip 41 and the flexible printed wiring board 42 by COF bonding, a pretreatment by water jet irradiation and a drying process are sequentially performed on the semiconductor chip 41 and the flexible printed wiring board 42.

  In the pretreatment of the semiconductor chip 41, as shown in FIG. 21A, by irradiating the formation part of the electrode part 43 of the semiconductor chip 41 with a water jet, the organic dust adhering to each electrode part 43 is collected. 45 is removed. Similarly, in the pretreatment of the flexible printed circuit board 42, as shown in FIG. 21 (B), each electrode unit 44 is irradiated to each electrode unit 44 by irradiating the formation part of the electrode unit 44 of the flexible printed circuit board 42 with a water jet. The adhering organic dust 48 is removed. As the liquid used for generating the water jet, the same liquid as in the first embodiment can be used. In order to increase the removal effect of the water jet, it is possible to apply ultrasonic waves to the water jet, add an abrasive to the water jet, or increase the temperature of the liquid used in the water jet.

  After performing the above pretreatment process, it progresses to the drying process which dries the semiconductor chip 41 and the flexible printed wiring board 42 which became wet by irradiation of a water jet. In the drying process, as shown in FIGS. 22A and 22B, clean dry air is blown against the semiconductor chip 41 and the flexible printed wiring board 42. As the dry air used for the drying process, those exemplified in the first embodiment can be used. Moreover, it is also possible to apply or use together the drying process by heating, and the drying process by rotary swing-off as needed.

  After performing the drying process in this way, the process proceeds to the connection process. In the connection process, as shown in FIGS. 23A and 23B, the semiconductor chip 41 is aligned face down so that both electrode portions 43 and 44 are properly facing each other on the flexible printed wiring board 42. 24, the electrode portion 43 of the semiconductor chip 41 and the electrode portion 44 of the flexible printed wiring board 42 are brought into contact with each other, and heated and pressurized, or ultrasonic waves are added as necessary, thereby the semiconductor chip 41 and the flexible printed circuit. The wiring board 42 is electrically and mechanically connected by COF bonding using Au—Sn eutectic bonding.

  In the above manufacturing method, before the semiconductor chip 41 and the flexible printed wiring board 42 are COF-bonded, the organic dust 45 and 48 attached to the electrode portions 43 and 44 is removed by water jet irradiation. In addition, it is possible to reliably establish conduction between the electrode portions 43 and 44 of the flexible printed wiring board 42. In addition, since a stable conduction state is obtained between the electrode portions 43 and 44, it is possible to reduce the occurrence of variations in electrical resistance, short-circuit defects, and the like.

[Fourth Embodiment]
In the fourth embodiment of the present invention, in the manufacturing process of an electronic device including a semiconductor device (for example, a light emitting device of an optical pickup of an optical disk device), two large and small semiconductor chips are COCed using an anisotropic conductive film. A case of connecting with a structure will be described as an example.

  First, as shown in FIGS. 25A and 25B, a first semiconductor chip 51 and a second semiconductor chip 52 are prepared as two connected members to be connected. The first semiconductor chip 51 is composed of, for example, a compound semiconductor laser using gallium and nitrogen as materials, and the second semiconductor chip 52 is composed of, for example, a driving IC chip that drives the semiconductor laser. The semiconductor chip 51 is obtained by a known semiconductor laser manufacturing process, and the semiconductor chip 52 is obtained by a known semiconductor manufacturing process. The planar size of the first semiconductor chip 51 is smaller than the planar size of the second semiconductor chip 52.

  A plurality of electrode portions 53 are formed on the first semiconductor chip 51, and a plurality of electrode portions 54 are also formed on the second semiconductor chip 52 correspondingly. The electrode portions 53 and 54 are formed on the first semiconductor chip 51 and the second semiconductor chip 52 in a one-to-one correspondence relationship. More specifically, four electrode portions 53 are provided on the first semiconductor chip 51 at a predetermined pitch, and four electrode portions 54 are provided on the second semiconductor chip 52 at the same pitch as the electrode portions 53. Yes. In addition to the plurality of electrode portions 54, a plurality of electrode portions 55 for external connection are formed on the second semiconductor chip 52. The electrode portion 55 is formed on the second semiconductor chip 52 at a position deviating from a region where the first semiconductor chip 51 is bonded (region where the electrode portion 54 is formed). Each of the electrode portions 53, 54, 55 is formed by an electrode pad made of a low resistance metal such as aluminum.

  26A is an enlarged cross-sectional view of a portion where the electrode portion 53 of the first semiconductor chip 51 is formed, and FIG. 26B is an enlarged cross-section of a portion where the electrode portion 54 of the second semiconductor chip 52 is formed. FIG. In the drawing, organic dust 56 is attached on the electrode portion 53 of the first semiconductor chip 51. Organic dust 57 is also attached to the electrode portion 54 of the second semiconductor chip 52. The organic dust 56 adheres during storage and transport of the first semiconductor chip 51, and the organic dust 57 adheres during storage and transport of the second semiconductor chip 52.

  If the organic particles 56 and 57 adhere to the electrode portions 53 and 54 as described above, there is a risk of causing poor bonding due to this. Therefore, prior to bonding (connecting) the first semiconductor chip 51 and the second semiconductor chip 52 with an anisotropic conductive film, pretreatment by water jet irradiation is performed on each of the semiconductor chips 51 and 52. Then, the drying process is performed in order.

  In the pretreatment of the first semiconductor chip 51, as shown in FIG. 27A, the formation portion of the electrode part 53 of the first semiconductor chip 51 is irradiated with a water jet to adhere to each electrode part 53. The organic waste 56 is removed. Similarly, in the pretreatment of the second semiconductor chip 52, as shown in FIG. 27B, each electrode portion is formed by irradiating a water jet to the formation portion of the electrode portion 54 of the second semiconductor chip 52. Organic dust 57 adhering to 54 is removed. As the liquid used for generating the water jet, the same liquid as in the first embodiment can be used. In order to increase the removal effect of the water jet, it is possible to apply ultrasonic waves to the water jet, add an abrasive to the water jet, or increase the temperature of the liquid used in the water jet.

  After performing the above pretreatment process, it progresses to the drying process which dries each semiconductor chip 51 and 52 wetted by irradiation of a water jet. In the drying process, as shown in FIGS. 28A and 28B, clean dry air is blown onto each of the semiconductor chips 51 and 52. As the dry air used for the drying process, those exemplified in the first embodiment can be used. Moreover, it is also possible to apply or use together the drying process by heating, and the drying process by rotary swing-off as needed.

  After performing the drying process in this way, the process proceeds to the connection process. In the connecting step, as shown in FIGS. 29A and 29B, the first semiconductor chip 51 is aligned face-down so that both electrode portions 53 and 54 are properly facing each other on the second semiconductor chip 52. In this state, as shown in FIG. 30, the electrode portion with the anisotropic conductive film 58 interposed between the electrode portion 53 of the first semiconductor chip 51 and the electrode portion 54 of the second semiconductor chip 52. The two semiconductor chips 51 and 52 are electrically and mechanically connected to each other by the anisotropic conductive film 58 by abutting 53 and 54 with each other and heating / pressurizing or applying ultrasonic waves as necessary.

  In the above manufacturing method, before joining the respective semiconductor chips 51, 52, the organic dust 56, 57 adhering to the electrode portions 53, 54 is removed by irradiation with a water jet. It is possible to reliably establish conduction between the electrode portions 53 and 54 of the 52. In addition, since a stable conduction state is obtained between the electrode portions 53 and 54, it is possible to reduce the occurrence of variations in electrical resistance, short-circuit defects, and the like.

  The present invention is not limited to those exemplified in each of the above embodiments. For example, when a semiconductor chip is mounted on an interposer made of a silicon substrate or the like, glass, hard resin, glass epoxy, ceramics or the like is used as a base material. The present invention can be widely applied to mounting a semiconductor chip on a rigid printed wiring board, connecting a light emitting diode and a substrate, or connecting a light emitting laser and a substrate.

  The semiconductor chip is not limited to silicon or a compound using silicon and germanium. For example, germanium, a compound of gallium and nitrogen, a compound of gallium and phosphorus, a compound of gallium and indium, polysilicon, and amorphous silicon A semiconductor material such as the above may be used. In addition, as a function of the semiconductor chip, an IC (Integrated Circuit), a semiconductor laser, a DLP (Digital Light Processing) device, a light emitting diode, a solar cell, and the like can be considered.

It is FIG. (1) explaining the manufacturing method of the electronic device which concerns on 1st Embodiment of this invention. It is FIG. (2) explaining the manufacturing method of the electronic device which concerns on 1st Embodiment of this invention. It is FIG. (3) explaining the manufacturing method of the electronic device which concerns on 1st Embodiment of this invention. It is FIG. (4) explaining the manufacturing method of the electronic device which concerns on 1st Embodiment of this invention. It is FIG. (5) explaining the manufacturing method of the electronic device which concerns on 1st Embodiment of this invention. It is FIG. (6) explaining the manufacturing method of the electronic device which concerns on 1st Embodiment of this invention. It is FIG. (7) explaining the manufacturing method of the electronic device which concerns on 1st Embodiment of this invention. It is FIG. (8) explaining the manufacturing method of the electronic device which concerns on 1st Embodiment of this invention. It is FIG. (9) explaining the manufacturing method of the electronic device which concerns on 1st Embodiment of this invention. It is FIG. (10) explaining the manufacturing method of the electronic device which concerns on 1st Embodiment of this invention. It is a figure (the 11) explaining the manufacturing method of the electronic device which concerns on 1st Embodiment of this invention. It is FIG. (12) explaining the manufacturing method of the electronic device which concerns on 1st Embodiment of this invention. It is FIG. (1) explaining the manufacturing method of the electronic device which concerns on 2nd Embodiment of this invention. It is FIG. (2) explaining the manufacturing method of the electronic device which concerns on 2nd Embodiment of this invention. It is FIG. (3) explaining the manufacturing method of the electronic device which concerns on 2nd Embodiment of this invention. It is FIG. (4) explaining the manufacturing method of the electronic device which concerns on 2nd Embodiment of this invention. It is FIG. (5) explaining the manufacturing method of the electronic device which concerns on 2nd Embodiment of this invention. It is FIG. (6) explaining the manufacturing method of the electronic device which concerns on 2nd Embodiment of this invention. It is FIG. (1) explaining the manufacturing method of the electronic device which concerns on 3rd Embodiment of this invention. It is FIG. (2) explaining the manufacturing method of the electronic device which concerns on 3rd Embodiment of this invention. It is FIG. (3) explaining the manufacturing method of the electronic device which concerns on 3rd Embodiment of this invention. It is FIG. (4) explaining the manufacturing method of the electronic device which concerns on 3rd Embodiment of this invention. It is FIG. (5) explaining the manufacturing method of the electronic device which concerns on 3rd Embodiment of this invention. It is FIG. (6) explaining the manufacturing method of the electronic device which concerns on 3rd Embodiment of this invention. It is FIG. (1) explaining the manufacturing method of the electronic device which concerns on 4th Embodiment of this invention. It is FIG. (2) explaining the manufacturing method of the electronic device which concerns on 4th Embodiment of this invention. It is FIG. (3) explaining the manufacturing method of the electronic device which concerns on 4th Embodiment of this invention. It is FIG. (4) explaining the manufacturing method of the electronic device which concerns on 4th Embodiment of this invention. It is FIG. (5) explaining the manufacturing method of the electronic device which concerns on 4th Embodiment of this invention. It is FIG. (6) explaining the manufacturing method of the electronic device which concerns on 4th Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Liquid crystal panel, 2, 42 ... Flexible printed wiring board, 5, 15, 33, 34, 43, 44, 53, 54 ... Electrode part, 11 ... Alignment film, 22, 58 ... Anisotropic conductive film, 23 ... Conductive particles, 31, 32, 41, 51, 52 ... semiconductor chip, 36, 37, 56, 57 ... organic waste

Claims (5)

Of the first electrode portion provided on the first connected member and the second electrode portion provided on the second connected member, an organic or inorganic substance attached to the electrode portion of at least one connected member A pretreatment step to be removed by water jet irradiation;
After the pretreatment step, the first connected member and the second connected member are electrically and mechanically connected in a state where the first electrode portion and the second electrode portion are in contact with each other. A method for manufacturing an electronic device, comprising: a connecting step. The method for manufacturing an electronic device according to claim 1, further comprising a drying step of drying the member to be connected that has been irradiated with the water jet in the pretreatment step before the connection step. The method of manufacturing an electronic device according to claim 1, wherein an ultrasonic wave is applied to the water jet in the pretreatment step. The method for manufacturing an electronic device according to claim 1, wherein an abrasive is added to the water jet in the pretreatment step. Of the first connected member and the second connected member, one of the connected members is a liquid crystal panel,
2. The method of manufacturing an electronic device according to claim 1, wherein in the pretreatment step, the organic alignment film or the inorganic alignment film covering the electrode portion of the liquid crystal panel is removed by water jet irradiation.

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