JP2004282021A - BONDING WIRE REINFORCING DEVICE, BONDING WIRE REINFORCING METHOD, BONDING DEVICE, RESIN MOLD SEMICONDUCTOR DEVICE PRODUCING BONDED WIRE REINFORCED, AND RESIN MOLD SEMICONDUCTOR DEVICE WITH BONDED WIRE REINFORCED - Google Patents

Abstract

PROBLEM TO BE SOLVED To suppress deformation of a wire after wire bonding.
A bonding wire reinforcing device 10 includes a fine powder sprayer 40 that sprays two kinds of resin fine powders 62 and 64, and a heater 70 that holds and heats a semiconductor device 80. The two types of fine powders 62 and 64 are two types of fine powder constituting a so-called two-component thermosetting resin that melts and solidifies by mixing at a predetermined temperature. The heater 70 is set to a temperature equal to or higher than the melting points of the two types of resins. The fine powders 62 and 64 sprayed onto the semiconductor device 80 by the fine powder sprayer 40 are attached to the upper surface of the wire 86, mixed and melted, and solidified, and an insulating resin thin film is formed on the upper surface of the wire 86. Is reinforced. The semiconductor device may be carried into a fine powder floating chamber in an atmosphere in which fine powder is suspended, and the fine powder may be attached to the entire surface of the wire. Moreover, you may incorporate a bonding wire reinforcement apparatus in a wire bonding apparatus.
[Selection] Figure 2

Description

  The present invention relates to bonding wire reinforcement, and in particular, a bonding wire reinforcement apparatus, a bonding wire reinforcement method, a bonding apparatus, a resin mold semiconductor device manufacturing apparatus, and a bonding wire that perform a process of increasing the strength of a wire after wire bonding. The present invention relates to a semiconductor device.

  A semiconductor element such as an LSI is die-bonded to a circuit board, an LSI bonding pad and a bonding lead of the circuit board are connected by wire bonding, and then packaged using a resin molding technique or the like. Here, as the wire for wire bonding, for example, a very thin gold wire having a diameter of 50 μm is used, for example, deformation occurs due to the flow of resin during resin molding. When the wire connecting the LSI and the circuit board is deformed, adjacent wires come into contact with each other, resulting in a short circuit accident. Even if the short circuit is not performed, the wire that transmits the signal is deformed, so that the distance between adjacent wires changes, affecting the impedance between the signal lines, and changing the frequency characteristics of the LSI. .

  In order to prevent such contact or deformation of the wire, Patent Document 1 discloses that a semiconductor chip and a lead frame are immersed in an insulating resin, or Teflon (registered trademark) liquid is injected from the top and bottom of the lead frame by an injection nozzle. It has been proposed to spray. Patent Document 2 describes that a reinforcing resin is applied to the wire root of the bonding lead portion. Patent Document 3 describes that after wire bonding is performed, the wire is applied before resin molding is performed. Including the undercoat of the pellet portion with a silicone gel is disclosed.

JP-A-2-246127 JP-A-8-186137 Japanese Patent Laid-Open No. 2-119147

  In recent years, with the miniaturization of LSIs and the miniaturization of packages, there is an increasing demand for so-called fine pitches that further narrow the pitch between wires in wire bonding. In wire bonding with a fine pitch, it may be necessary to manage the shape of the wire loop from the bonding pad to the bonding lead. Thus, under the demand for fine pitch, it is desirable to reduce the change in distance between adjacent wires.

  In the prior art, various methods for preventing contact or deformation of wires have been proposed, but even these methods cannot sufficiently suppress a change in distance between adjacent wires. For example, since the material used in Patent Document 1 is a liquid, the distance between adjacent wires may change due to immersion or spraying itself. Also in patent document 3, since silicone gel is used as an undercoat material, there is a possibility that the distance between adjacent wires may change due to the application of the gel to the wire itself. In Patent Document 2, since reinforcement is not performed on the loop portion of the wire, it cannot be expected to prevent a change in distance between adjacent wires.

  SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the prior art and suppress the deformation of the wire, a bonding wire reinforcing device, a bonding wire reinforcing method, a bonding device, a resin molded semiconductor device manufacturing apparatus, and a resin molded semiconductor device. Is to provide.

  In order to achieve the above object, a bonding wire reinforcing device according to the present invention is a device that reinforces a wire after connecting a bonding pad of a semiconductor element and a bonding lead of a substrate with a wire. An adhesion means for attaching the powder to the wire and a heating means for heating the fine powder are provided, and the fine powder of resin is melted on the wire and solidified to reinforce the wire.

  The particle diameter of the fine resin powder is preferably 1/100 or more and 1/3 or less of the wire diameter.

  The fine resin powder is preferably a fine powder of a thermosetting resin or a fine powder of a thermoplastic resin having a melting point higher than the heating temperature when the semiconductor element is subsequently packaged.

  Moreover, it is preferable that the fine powder of a thermosetting resin contains the fine powder of two types of resin solidified by a crosslinking reaction by mutually mixing and melting at a predetermined temperature.

  The adhering means is preferably means for spraying fine powder of resin onto the wire. The adhering means is preferably means for carrying and holding the semiconductor element in a fine powder floating chamber in an atmosphere in which fine resin powder is floated.

  The heating means is preferably means for radiating and heating light having a wavelength matched to the light absorption characteristics of the fine resin powder to any place of the wire. Moreover, it is preferable that a heating means is a means to radiate | emit and heat the light of the wavelength match | combined with the light absorption characteristic of the wire to the arbitrary places of a wire.

  The bonding wire reinforcing method according to the present invention is a method of reinforcing a wire after connecting a bonding pad of a semiconductor element and a bonding lead of a substrate with a wire, and a resin fine powder is attached to the wire. And a heating step of heating the fine powder, wherein the fine powder of resin is melted on the wire and solidified to reinforce the wire.

  Further, the bonding apparatus according to the present invention is a bonding apparatus for connecting a bonding pad of a semiconductor element and a bonding lead of a substrate with a wire, and further includes an attaching means for attaching a fine powder of resin to the wire, and a fine powder. Heating means for heating, and the resin fine powder is melted on the wire after bonding and solidified to reinforce the wire.

  The resin mold semiconductor device manufacturing apparatus according to the present invention performs resin molding on a semiconductor device including a substrate, a semiconductor element disposed on the substrate, and a bonding wire connecting the substrate and the semiconductor element. A resin-molded semiconductor device manufacturing apparatus, in which a cavity for housing a semiconductor device before resin molding, a mold inlet for injecting mold resin into the cavity, and resin fine powder for reinforcing bonding wires are injected into the cavity A mold die having a fine powder inlet, an attaching means for supplying the resin fine powder to the fine powder inlet and attaching the resin fine powder to the bonding wire, and a heating means for heating the fine powder. Prepared, melt the resin fine powder on the bonding wire, solidify and reinforce the bonding wire, then mold injection Injecting a molding resin from and performing resin molding.

  The resin molded semiconductor device according to the present invention includes a substrate, a semiconductor element disposed on the substrate, and a bonding wire for connecting the substrate and the semiconductor element, and the resin molded semiconductor is entirely resin molded. The bonding wire is a surface of a resin thin film formed by adhering a fine powder of resin having a diameter sufficiently smaller than the diameter of the bonding wire to the bonding wire and melting and solidifying the fine powder on the bonding wire. It is characterized by having. The bonding wire preferably has a resin thin film on the surface opposite to the side facing the substrate.

  By at least one of the above-described configurations, the fine resin powder adhered to the wire is melted on the wire and solidified. That is, a solidified resin thin film is formed on the wire. Therefore, the wire is reinforced by the solidified resin thin film, and a change in the distance between adjacent wires can be suppressed. In addition, the load applied to the wire may be a force applied when the fine powder adheres or a force applied when the fine powder is melted and solidified. Compared to gel application, immersion, spraying, etc., it is greatly reduced.

  Further, with at least one of the above-described configurations, the fine powder can be efficiently captured by a sufficiently large wire as compared with its own size, and the uniformity of the resin thin film formed on the wire can be improved.

  In addition, the resin thin film formed on the wire is not softened again in the packaging process by at least one of the above-described structures, and for example, the change in the distance between adjacent wires is suppressed even when the mold resin flows. it can.

  Since most of the resins used in the packaging process are thermosetting resins that utilize a crosslinking reaction by mixing two types of resins, the same resin as that used in the packaging process can be used as a wire by at least one of the above-described configurations. It can be used to reinforce the packaging and can improve the consistency with the packaging process.

  Further, with at least one of the above-described structures, the fine powder can be attached to the entire surface of the wire by carrying the semiconductor element into the fine powder floating atmosphere.

  Moreover, the arbitrary place of a wire can be reinforced with at least 1 of the said structure.

  Also, according to at least one of the above-described configurations, a cavity for housing the semiconductor device before resin molding, a mold injection port for injecting mold resin into the cavity, and a resin fine powder for wire reinforcement are injected into the cavity. And a fine mold inlet. In this mold, resin fine powder can be introduced into the cavity from the fine powder inlet, so that the fine powder adheres to the bonding wire of the semiconductor device in the cavity, and the fine powder is melted and solidified on the bonding wire. Can be reinforced. Furthermore, since this mold mold can inject mold resin from the mold injection port, it is possible to continue resin molding while the semiconductor device after the reinforcement of the bonding wire is placed in the cavity. Therefore, the bonding wire can be reinforced and the resin mold can be performed by one manufacturing apparatus.

  According to at least one of the above-described configurations, the bonding wire is formed by attaching a fine resin powder having a diameter sufficiently smaller than the diameter of the bonding wire to the bonding wire and melting and solidifying the fine powder on the bonding wire. A resin thin film on the surface. Further, when the resin fine powder is supplied from above the substrate, the resin thin film is provided on the surface opposite to the side facing the substrate. That is, it is a feature of the wire according to the present invention that the surface has a resin thin film obtained by melting and solidifying resin powder that is solid at room temperature on the wire. Thereby, the change of the distance between adjacent wires can be suppressed.

  As described above, according to the bonding wire reinforcing device, the bonding wire reinforcing method, and the bonding device according to the present invention, deformation of the wire after wire bonding can be suppressed.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a conceptual diagram of a bonding wire reinforcing device 10. The bonding wire reinforcing device 10 includes a box-shaped hood 30, a fine powder sprayer 40 provided on the ceiling side of the hood 30, and a supply tank 60 that is connected to the fine powder sprayer 40 via a supply pipe 50 and stores fine powder. And a heater 70 installed in the hood 30.

  The box-shaped hood 30 is a partition chamber that prevents fine powder from scattering around when the resin powder is sprayed from the fine powder sprayer 40 onto the semiconductor device 80. The box-shaped hood 30 can be placed on, for example, a work table, and a work insertion / exit port 32 that can be opened and closed is provided on the front wall on the front side, and an exhaust duct 34 is provided on the side wall.

  The fine powder sprayer 40 is a device that sprays and sprays fine powder, and can be constituted by a blower, for example. A commercially available powder sprayer may be used. The supply amount adjusting unit 42 provided in the fine powder sprayer 40 has a function of adjusting the air flow rate of the blower and adjusting the opening of the throttle 52 provided in the middle of the fine powder supply path to control the fine powder spray amount to a predetermined amount. Controller.

  The supply tank 60 is a tank for storing two kinds of resin fine powders 62 and 64 mixed at a predetermined mixing ratio. As the material of the fine powders 62 and 64 of the two kinds of resins, a novolac type epoxy resin can be used as the first resin, and a novolac type phenol resin can be used as the second resin. The first resin and the second resin are so-called two-component thermosetting resins that are mixed with each other and heated at a predetermined temperature to be solidified by a crosslinking reaction. For specific resin specifications and the like, those used for semiconductor device packages can be used as they are.

  The particle size of the fine powder can be, for example, about 0.2-5 μm. The selection of the particle size of the fine powder is preferably performed according to the wire diameter. That is, it is preferably 1/100 or more and 1/3 or less of the wire diameter. More preferably, the range is approximately 1/50 to 1/10 of the wire diameter. For example, 1-5 μm is preferable when the wire diameter is 50 μm, and 0.2-1 μm is preferable when the wire diameter is 10 μm. Therefore, it is preferable to use a fine powder having a uniform particle size in a range corresponding to the target wire diameter. The fine powder having a predetermined particle diameter can be obtained, for example, by pulverizing a resin pellet used in a package of a semiconductor device with a pulverizer and selecting it with a particle size selector.

  The heater 70 is a heating device having a function of holding and heating the semiconductor device 80 to be reinforced with the bonding wire, and can be constituted by a hot plate, for example. In addition, lamp heating, a fan heater, or the like that heats the semiconductor device 80 by contacting the heated gas can also be used. The heating temperature is controlled by a temperature controller (not shown).

  Next, the operation of the above configuration will be described. In order to reinforce the bonding wire of the semiconductor device 80, first, the work insertion / removal port 32 of the hood 30 is opened and the semiconductor device 80 is placed on the heater 70 and held, and the semiconductor device 80 is predetermined by a temperature controller (not shown). Heat to the temperature of. The predetermined temperature is set to be equal to or higher than the crosslinking reaction temperature of the two kinds of resins. Thereafter, the fine powder sprayer 40 is activated to set the supply amount adjusting unit 42 to a predetermined supply amount. Thus, the two kinds of fine resin powders 62 and 64 are sprayed from the ceiling side of the hood 30 to the semiconductor device 80 on the heater 70 at a predetermined mixing ratio and a predetermined spray amount.

  For heating, the wire is heated in advance to raise the temperature, and the fine powder adhering to the high-temperature wire may be heated, or the fine powder is adhered to the low-temperature wire, and then the fine powder is heated together with the wire. May be. In the former case, fine powder adheres to the wire and melting starts.

  FIG. 2 is a partially enlarged view of the bonding wire reinforcing device 10. The semiconductor device 80 held on the heater 70 includes a substrate 82 and a semiconductor element 84 that is positioned and mounted on the substrate 82 by die bonding, and includes a bonding lead of the substrate 82 and a bonding pad of the semiconductor element 84. They are connected by a wire 86. This wire 86 is the object of reinforcement. In addition to a general LSI chip, the semiconductor element 84 may be a stacked element, that is, an element in which another semiconductor element is stacked on the semiconductor element. The substrate 82 may be a polyimide film substrate, a ceramic substrate, or the like, in addition to a laminated circuit substrate such as a glass epoxy circuit substrate.

  As described above, since the two kinds of resin fine powders 62 and 64 are sprayed onto the semiconductor device 80 from the fine powder sprayer 40, the fine powder sprayer 40 is applied to the upper surface of the substrate 82, the upper surface of the semiconductor element 84, and the upper surface of the wire 86. Fine powders 62 and 64 adhere.

  FIG. 3 is a diagram illustrating a state in which the fine powders 62 and 64 attached to the upper surface of the wire 86 are melted and solidified. FIG. 3A is a view showing immediately after the attachment. Since these are heated to the melting point or more by the heater 70, as shown in FIG. 3B, mixing and melting occurs at the portions in contact with each other in the two kinds of fine resin powders 62 and 64 attached. Next, another fine powder is melted while being mixed with the melted liquid portion one after another, and the range of mixing and melting is expanded. FIG. 3C is a diagram showing a state in which a plurality of mixed melting portions are connected and the entire upper surface of the wire 86 is covered. Thus, the upper surface of the substrate 82, the upper surface of the semiconductor element 84, and the upper surface of the wire 86 are covered with the molten resin. Then, the crosslinking reaction proceeds, the molten resin portion is solidified, an insulating resin thin film is formed, and the wire is reinforced. Since the resin thin film is for reinforcing the wire, it is not always necessary to cover the entire surface of the wire.

  Next, the semiconductor device in which the upper surface of the substrate 82, the upper surface of the semiconductor element 84, and the upper surface of the wire 86 are covered with the resin thin film is removed from the heater 70 and carried out of the hood 30. Thereafter, the semiconductor device is packaged using a predetermined resin molding apparatus. For the packaging, the same resin as that used for reinforcing the bonding wire is used, so that the package can be matched with the resin thin film formed on the upper surface of the substrate 82, the upper surface of the semiconductor element 84, and the upper surface of the wire 86. be able to. That is, since the resin thin film formed for reinforcement and the resin of the package are the same resin, characteristics such as thermal expansion coefficient and moisture permeability can be made the same.

  FIG. 4 is a schematic diagram of the semiconductor device 90 packaged by the resin mold 88. Inside the resin mold 88, the semiconductor element 84 is mounted on the substrate 82, and the bonding pad of the semiconductor element 84 and the bonding lead of the substrate 82 are connected by a wire 87 reinforced with a resin thin film whose surface is solidified. Has been. As described above, the resin thin film on the surface of the wire is attached to the wire with a fine powder of resin having a diameter sufficiently smaller than the diameter of the wire, for example, 1/100 or more and 1/3 or less of the wire diameter. The resin thin film is formed by melting and solidifying the fine powder, and is the same material as the resin mold 88.

  FIG. 5 is a view showing another bonding wire reinforcing device 100 of a fine powder adhesion system. In the bonding wire reinforcing device 100, the fine powder 62, 64 is sufficiently filled in the hood 102, the fine powder is brought into a suspended atmosphere, and the semiconductor device 80 is carried into the atmosphere. A fine powder sprayer 104 is provided on the ceiling side of the hood 102, and a heater 106 is installed in the hood 102. The fine powder sprayer 104 is supplied with two kinds of fine powders 62 and 64 from a supply tank (not shown) through a supply pipe 110, and a throttle 112 is provided in the middle of the supply pipe 110. As the hood 102, the fine powder sprayer 104, the heater 106, the supply pipe 110, and the throttle 112, the same ones as described in FIG. 1 can be used.

  In the above configuration, the hood 102 is sealed in a state where the semiconductor device 80 is not carried into the hood 102, and the fine powders 62 and 64 are sprayed into the hood 102 from the fine powder sprayer 104. The spraying speed and spraying time are set so as to have an arbitrary fine powder concentration in the hood 102. For example, it is possible to make the spraying speed slower than that shown in FIG. 1 and to make the fine powders 62 and 64 have any concentration over time. . After confirming that the inside of the hood 102 has reached an arbitrary fine powder concentration, the throttle 112 is closed and the operation of the fine powder sprayer 104 is also stopped. A light breeze may be sent into the hood 102 to generate an appropriate stirring flow. At this time, the inside of the hood 102 is a so-called fine powder floating chamber.

  Next, the heater is set to a predetermined temperature to raise the temperature. Then, the semiconductor device 80 to be reinforced is loaded into the hood 102 having an arbitrary fine powder concentration from the workpiece intake 108a. Since the fine powder is floating in the hood 102, the fine powders 62 and 64 can be attached to the entire periphery of the wire of the semiconductor device 80, that is, including the lower side of the wire. Accordingly, the resin thin film can be formed by mixing and melting and solidifying the entire surface of the wire. The film thickness of the resin thin film can be controlled by the time for which the semiconductor device 80 is placed on the heater 106.

  In order to take out the semiconductor device after the wire is reinforced from the hood 102, it may be performed from the work intake 108a, as in the description of FIG. Further, as shown in FIG. 5, a work intake port 108a and a work take-out port 108b are provided so as to correspond to the walls on both sides of the hood 102, and a semiconductor belt is automatically loaded and unloaded using a transfer belt. You may go. For example, by controlling the transport speed of the transport belt in the hood 102, the thickness of the resin thin film formed is controlled, and the work intake port 108a and the work take-out port 108b are opened and closed in synchronization with the transport speed. The semiconductor device 80 can be automatically carried in, formed into a resin thin film, and carried out automatically. A transport robot may be used in addition to the transport belt. In FIG. 1, the same automatic loading / unloading configuration can be applied.

  FIG. 6 is a diagram illustrating a configuration of a wire bonding apparatus 120 having a bonding wire reinforcing function. The wire bonding apparatus 120 includes (a) a wire bonding preheating station, (b) a wire bonding station, and (c) a bonding wire reinforcing station. These stations are connected by a work transfer mechanism 130, and the semiconductor device is sequentially transferred while undergoing a predetermined process at each station. For the workpiece conveyance mechanism 130, belt conveyance, robot conveyance, or the like can be used.

  (A) The wire bonding preheating station includes a preheater 132 for wire bonding, and has a function of preheating the semiconductor device 79 after die bonding. (B) The wire bonding station includes a main heater 134 for wire bonding and a mechanism 136 for wire bonding, and has a function of performing wire bonding on the semiconductor device 79 after die bonding. As the mechanism 136 for performing wire bonding, a general wire bonding mechanism, for example, an ultrasonic wire bonding mechanism can be used. The set temperature of the main heater 134 can be about 200 ° C., for example.

  The bonding wire reinforcing station in (c) can be configured using the same elements as those of the bonding wire reinforcing device described in FIG. 1 or FIG. In the example of FIG. 6, the hood 122 is provided on the workpiece conveyance mechanism 130, the fine powder sprayer 124 is provided on the ceiling side of the hood 122, and the wire reinforcement heater 126 is provided on the lower portion of the workpiece conveyance mechanism 130. The fine powder sprayer 124 is supplied with two kinds of fine powders 62 and 64 via a supply pipe from a supply tank (not shown). A work intake port 128 a and a work take-out port 128 b are provided on the walls on both sides of the hood 122. The hood 122 is connected to an exhaust duct (not shown).

  In the wire bonding apparatus 120 shown in FIG. 6, the semiconductor device 79 is pre-heat-treated and wire-bonded by the work transfer mechanism 130, and the semiconductor device 80 after the wire bonding is kept at a wire bonding temperature, for example, 200 ° C. Into the hood 122. The wire reinforcing heater 126 is set so that the temperature of the wire is equal to or higher than the melting points of the two types of resins when the semiconductor device passes over the wire reinforcing heater 126. The fine powder 62, 64 is sprayed from the fine powder sprayer 124 in accordance with the transport speed at which the semiconductor device passes through the hood 122 by the work transport mechanism, and the fine powder 62, 64 adheres to the wire and is mixed, melted, and solidified. It progresses and a resin thin film is formed. The semiconductor device in which the resin thin film is formed and the wire is reinforced is automatically carried out of the hood 122 by the work transfer mechanism 130.

  As described above, by providing the wire bonding apparatus with the bonding wire reinforcing station, it is possible to quickly reinforce a very thin wire that is easily deformed after wire bonding. Therefore, a change in the distance between adjacent wires can be suppressed in subsequent handling.

  In the above description, the heating device has been described as the wire being heated to the melting point of two types of resins or higher using a heater that holds and heats the semiconductor device 80 itself. In these cases, the mixing and melting starts almost simultaneously with the fine powder adhering to the wire. In addition to this, fine powder is deposited on a wire having a temperature equal to or lower than the melting point of two types of resins, for example, a wire at normal temperature, and then the fine powder is heated together with the wire by a heater so as to have a temperature equal to or higher than the melting point of the two types of resins. Good. In this case, after confirming that a sufficient amount of fine powder adheres on the wire, the supply of fine powder can be stopped and heating can be performed to the melting point of the two types of resins or more, so the formation of the resin thin film can be controlled. It becomes easier.

  FIG. 7 is a diagram illustrating an example in which the light irradiator 140 is used as a heating device. The light irradiator 140 is an optical device having a function capable of irradiating an arbitrary position of the wire 86 with beam-shaped light using a condensing element. Therefore, an arbitrary range can be melted and solidified with respect to the fine powders 62 and 64 attached on the wire 86.

  The wavelength of the irradiated light is preferably a wavelength that matches the light absorption characteristics of the fine powders 62 and 64. An appropriate coloring material can be included in the fine powders 62 and 64 to improve the absorption of light energy.

  Moreover, the wavelength according to the light absorption characteristic of a wire can also be used for the wavelength of the irradiated light. For example, in the case of a gold wire, an arbitrary place of the wire can be heated by irradiation using a wavelength of about 400 nm or less.

  Conveniently, resin molding can be continuously performed on a semiconductor device subjected to wire bonding by a single device following the reinforcement of the wire. FIG. 8 shows a manufacturing apparatus 200 for such a resin mold semiconductor device. The manufacturing apparatus 200 is not shown with an upper mold 230, a fine powder sprayer 240 disposed so as to cover a resin fine powder inlet 232 provided on the upper side of the upper mold 230, and a fine powder sprayer 240. A supply pipe 250 connecting the fine powder supply tank and a lower mold 270 combined with the upper mold 230 are included.

  The contents of the substrate 82, the semiconductor element 84, the wire 86, and the fine powder sprayer 240, the fine powder supply tank (not shown), and the supply pipe 250 that constitute the semiconductor device 80 subjected to wire bonding will be described with reference to FIG. The description is omitted because it is the same as the element having the same name. The lower mold 270 may constitute an assembled mold together with the upper mold 230, and may be a jig that can position and arrange the semiconductor device 80 as shown in FIG. This jig may be a heater as described in FIG.

  The upper mold 230 has a mold injection port 234 for injecting a mold resin together with a resin fine powder introduction port 232, and a cavity 236 that is a recess through which these molds communicate. Here, the semiconductor device 80 before molding is positioned and arranged on the lower mold 270, and the upper mold 230 is positioned and combined from above, so that the semiconductor device 80 can connect the terminal portion of the substrate 82. Except for being housed inside the cavity 236. A space defined by the cavity 236 and the upper surface of the lower mold 270 is filled with mold resin as described later. That is, the size of the space portion is the size of the resin molding of the semiconductor device 80.

  A procedure for manufacturing a resin molded semiconductor using the manufacturing apparatus 200 having such a configuration will be described with reference to FIGS. First, a process of setting a semiconductor device in a mold is performed. Specifically, as described with reference to FIG. 8, the lower mold 270, the semiconductor device 80, and the upper mold 230 are positioned so that a portion to be molded of the semiconductor device 80 before molding is accommodated in the cavity 236. And fix. Then, a fine powder sprayer 240 is placed so as to cover the resin fine powder inlet 232 of the upper mold 230. The supply pipe 250 is preferably flexible so that the fine powder sprayer 240 can move.

  Next, a step of attaching the resin fine powder to the wire is performed. Specifically, as shown in FIG. 9, two types of resin fine powders 62 and 64 from the upper mold 230 are introduced into the cavity 236 and adhered to the wire 86 of the semiconductor device 80. Since the contents of the two types of resin fine powders 62 and 64 are the same as those described in FIG. 2, detailed description thereof will be omitted. As shown in FIG. 8, when the fine resin powders 62 and 64 are supplied from above the substrate, the fine resin powders 62 and 64 adhere to the upper surface of the wire 86.

  Moreover, the process of heating fine powder is performed. Specifically, when the lower mold 270 is a heater, the heater is operated to heat the entire semiconductor device 80 together with the wire 86 to which the resin fine powder is adhered. Alternatively, the entire semiconductor device 80 may be heated in advance so that the temperature of the wire 86 is raised before the resin fine powder is adhered. The temperature of the wire 86 may be raised in advance by supplying hot air from the resin fine powder inlet 232 without using a heater. By this heating, resin fine powders 62 and 64 are melted and solidified on the wire 86 by the same process as described with reference to FIG. 3, and a resin thin film 66 is formed on the surface of the wire 86. FIG. 10 is a diagram showing this state. In this way, the wire 87 reinforced with the resin thin film on the surface is obtained.

  Next, a step of filling the mold resin is performed. Specifically, as shown in FIG. 11, a mold resin 287 is injected into a cavity 236 from a mold injection port 234 of the upper mold 230 and filled. Prior to this, the resin fine powder inlet 232 is preferably sealed. For this step, for example, a general injection molding technique in which injection molding is performed under predetermined pressure conditions and heating conditions can be used. From this point, this step can be called an injection molding step.

  As the mold resin, the same resin as that used for reinforcing the wire can be used. If the injection molding process has a strength that can withstand the load of the resin mold even before the resin fine powder is completely solidified, filling of the mold resin or the like can be started. In particular, if the resin used for the reinforcement of the mold resin and the wire is the same, the consistency of the resin properties between the resin thin film and the mold resin can be achieved by performing injection molding before the resin fine powder is completely solidified. And the bond strength between the two resins can be increased.

  When the injection molding process is completed, the upper mold 230 and the lower mold 270 are separated, and the semiconductor device 290 packaged by the molded resin 288 that has been molded and solidified is taken out. In this way, the resin mold semiconductor device 290 having the wire 87 reinforced by the resin thin film inside can be obtained by performing the resin molding subsequent to the wire reinforcement using the manufacturing apparatus 200.

  FIG. 13 is a cross-sectional view around the wire 86 of the resin molded semiconductor device 290. Thus, the resin thin film 66 is formed on a part of the surface of the wire 86, in the case of FIG. 8, on the surface opposite to the side facing the substrate 82, and the molded resin 188 is wrapped around these. Yes. By making the mold resin material the same as the resin used for reinforcing the wire as described above, it is possible to match the characteristics of the resin thin film 66 and the molded resin 288 such as the thermal expansion coefficient and moisture permeability. it can. Even in this case, the boundary portion where the resin thin film and the liquid mold resin that are being melted and solidified on the wire are in contact with the mold resin only portion or the boundary portion between the wire 86 and the mold resin in terms of physical properties. There seems to be something different. For example, since the degree of polymerization reaction is generally low at the boundary between different materials, it is expected that the physical properties of the boundary portion between the resin thin film 66 and the molded mold resin 288 are different from other portions. Therefore, it is preferable to use observation of physical properties around the wire 86 as a means for confirming the formation state of the resin thin film 66.

  In the above description, the fine powder is directly attached to the wire. However, before the fine powder is attached to the wire, means for promoting adhesion can be provided. As the means for promoting adhesion, electrostatic adhesion promoting means can be used. For example, a charging means is provided for applying a positive or negative charge to the wire, and applying a charge of the opposite polarity to the charge applied to the wire to the fine powder. The amount of charge applied to the wire is sufficiently low so as not to deteriorate the characteristics of the semiconductor element. In this way, by applying charges of opposite polarity to each other between the wire and the fine powder, an electrostatic attractive force can be generated between the wire and the fine powder. Adhesion can be promoted.

  Further, surface tension adhesion promoting means can also be used. For example, a low viscosity liquid is sprayed on the wire. The viscosity and spraying force of the liquid to be sprayed are set so as to have a low viscosity and a weak spraying force so as not to affect the deformation of the wire. By having the liquid on the wire, the fine powder can be easily captured on the wire by the surface tension, and adhesion can be promoted.

  In the above description, a thermosetting resin is used to reinforce the bonding wire. In addition, a thermoplastic resin may be used. In this case, a thermoplastic resin having a melting point higher than the processing temperature when the semiconductor device is subsequently packaged is used.

  In this manner, the fine powder of the resin can be adhered to the wire and melted and solidified on the wire to reinforce the wire. The reinforcement of the wire by such a method also has the following advantages.

  That is, for reinforcing the wire, it is not always necessary to cover the entire circumference of the wire, so that the apparatus can be simplified. For example, in the case of a conventional method in which an insulating film is provided on a wire in order to prevent a short circuit due to contact between adjacent wires, it is necessary to cover the entire circumference of the wire, and when there is a wire hidden by surrounding wires, etc. This is because a method such as immersing in a coating agent must be taken and the operation may become complicated.

  That is, in the case where a coating agent such as a liquid resin is applied or immersed in the wire, sufficient reinforcing strength may not be given to the wire even if it is dried or heat-cured. Therefore, the wire may be deformed by subsequent resin sealing or the like, and in order to prevent a short circuit due to this, it is necessary to cover the entire circumference of the wire. On the other hand, in the embodiment according to the present invention, resin fine powder that is solid at normal temperature is attached to the wire and melted and solidified on the wire, so that sufficient reinforcing strength can be obtained.

  Further, the deformation of the wire itself can be prevented, and the change in impedance, which is difficult with the conventional method, can be prevented. FIG. 14 is a diagram for explaining the relationship between wire deformation and impedance characteristic change. Here, a pair of wires 86a and 86b in which the strength of the wire is sufficient and the wire is not deformed, and another set of wires 86c and 86d in which the wire is deformed because the strength of the wire is not sufficient Are shown in the same figure. Adjacent wires are capacitively coupled (capacitance coupling: C) and inductive coupling (inductance coupling: L). The magnitude of these bonds depends on the spacing between adjacent wires and the shape of the wires. In FIG. 14, the pair of wires 86 c and 86 d with deformation is considerably narrower than the pair of wires 86 a and 86 b without deformation, and the capacity between them is increased. doing.

  Thus, when the strength of the wire is not sufficient and the wire is deformed in the molding process or the like, the capacitance between the wires changes, and the impedance between the wires, that is, between the signal terminals of the semiconductor element 84 changes accordingly. The inductive coupling also changes in the same manner, which causes a change in impedance characteristics between the signal terminals of the semiconductor element 84. According to the embodiment of the present invention, the resin thin film is formed on the surface of the wire, the strength of the wire is reinforced, the deformation of the wire itself can be prevented, and the change of impedance can be prevented.

It is a conceptual diagram of the bonding wire reinforcement apparatus in embodiment which concerns on this invention. It is the elements on larger scale of the bonding wire reinforcement apparatus in embodiment which concerns on this invention. In embodiment which concerns on this invention, it is a figure which shows a mode that the fine powder adhering to the upper surface of a wire melts and solidifies. It is a schematic diagram of the semiconductor device packaged by the resin mold in the embodiment according to the present invention. It is a figure which shows the bonding wire reinforcement apparatus in other embodiment. In embodiment which concerns on this invention, it is a figure which shows the structure of the wire bonding apparatus provided with the bonding wire reinforcement function. In other embodiment, it is a figure which shows the example which uses a light irradiation device for a heating apparatus. In embodiment which concerns on this invention, it is a figure which shows the manufacturing apparatus of a resin mold semiconductor device. In embodiment which concerns on this invention, it is a figure which shows the process of making resin fine powder adhere to a wire. In embodiment which concerns on this invention, it is a figure which shows a mode that the resin thin film is formed on the surface of a wire. In embodiment which concerns on this invention, it is a figure which shows the process of filling mold resin. It is a figure which shows the resin mold semiconductor device in embodiment which concerns on this invention. In embodiment concerning this invention, it is sectional drawing of the circumference | surroundings of the wire of a resin mold semiconductor device. It is a figure explaining the relationship between a deformation | transformation of a wire and a change of an impedance characteristic.

Explanation of symbols

  10,100 Bonding wire reinforcement device, 30,102,122 Hood, 32 Workpiece inlet / outlet, 34 Exhaust duct, 40,104,124,240 Fine powder sprayer, 42 Supply amount adjusting unit, 50,110,250 Supply pipe, 60 Supply tank, 62, 64 fine powder, 66 resin thin film, 70, 106 heater, 79 semiconductor device after die bonding before wire bonding, 80 semiconductor device after wire bonding, 82 substrate, 84 semiconductor elements, 86, 86a, 86b, 86c, 86d Wire, 87 Reinforced wire, 88 Resin mold, 90 Packaged semiconductor device, 108a, 128a Work inlet, 108b, 128b Work outlet, 120 Wire bonding device, 126 Wire reinforcement heater, 130 Work transport mechanism, 132 Preheater, 134 Main heater, 136 Wire bonding mechanism, 140 Light irradiator, 230 Upper mold, 232 Fine powder inlet, 234 Mold injection port, 236 Cavity, 270 Lower mold, 287 Mold Resin, 288 Mold resin molded, 290 Resin mold semiconductor.

Claims (13)

A device for reinforcing a wire after connecting a bonding pad of a semiconductor element and a bonding lead of a substrate with a wire,
Means for attaching resin fine powder to the wire;
Heating means for heating the fine powder;
A bonding wire reinforcing device comprising: a resin fine powder melted on a wire and solidified to reinforce the wire. The bonding wire reinforcing device according to claim 1,
The bonding wire reinforcing device, wherein the particle diameter of the resin fine powder is 1/100 or more and 1/3 or less of the wire diameter. The bonding wire reinforcing device according to claim 1,
The bonding wire reinforcing device, wherein the fine resin powder is a fine powder of a thermosetting resin or a fine powder of a thermoplastic resin having a melting point higher than a heating temperature when a semiconductor element is subsequently packaged. The bonding wire reinforcing device according to claim 3,
The bonding wire reinforcing device, wherein the fine powder of the thermosetting resin includes two kinds of fine powders of the resin that are solidified by a crosslinking reaction by mixing and melting each other at a predetermined temperature. The bonding wire reinforcing device according to claim 1,
The bonding wire reinforcing device, wherein the adhering means is means for spraying fine powder of resin onto the wire. The bonding wire reinforcing device according to claim 1,
A bonding wire reinforcing device, wherein the adhering means is means for carrying and holding a semiconductor element in a fine powder floating chamber in an atmosphere in which a fine powder of resin is floated. The bonding wire reinforcing device according to claim 1,
The bonding wire reinforcing device, wherein the heating means is means for radiating and heating light having a wavelength matching the light absorption characteristics of the fine resin powder to an arbitrary place on the wire. The bonding wire reinforcing device according to claim 1,
The bonding wire reinforcing apparatus, wherein the heating means is means for radiating and heating light having a wavelength matching the light absorption characteristics of the wire to an arbitrary place on the wire. A method of reinforcing a wire after connecting a bonding pad of a semiconductor element and a bonding lead of a substrate with a wire,
An attaching step for attaching a fine powder of resin to the wire;
A heating step of heating the fine powder;
A bonding wire reinforcing method comprising: reinforcing a wire by melting and solidifying resin fine powder on the wire. In a bonding apparatus for connecting a bonding pad of a semiconductor element and a bonding lead of a substrate with a wire,
Means for attaching resin fine powder to the wire;
Heating means for heating the fine powder;
A bonding apparatus, wherein a fine powder of resin is melted on a wire after bonding and solidified to reinforce the wire. A resin molded semiconductor device manufacturing apparatus for performing resin molding on a semiconductor device including a substrate, a semiconductor element disposed on the substrate, and a bonding wire connecting the substrate and the semiconductor element,
A cavity for storing a semiconductor device before resin molding;
A mold injection port for injecting mold resin into the cavity;
Fine powder inlet for injecting resin fine powder for bonding wire reinforcement into the cavity,
A mold having
An attachment means for supplying resin fine powder to the fine powder inlet and attaching the resin fine powder to the bonding wire;
Heating means for heating the fine powder;
A resin mold reinforced with a bonding wire, wherein the resin fine powder is melted on a bonding wire, solidified to reinforce the bonding wire, and then a mold resin is injected from a mold inlet to perform resin molding Semiconductor device manufacturing equipment. A resin mold semiconductor device including a substrate, a semiconductor element disposed on the substrate, and a bonding wire connecting between the substrate and the semiconductor element, the whole being resin molded,
The bonding wire has a resin thin film formed on the surface by bonding a fine powder of resin having a diameter sufficiently smaller than the diameter of the bonding wire to the bonding wire and melting and solidifying the fine powder on the bonding wire. A resin mold semiconductor device in which the bonding wire is reinforced. In the resin mold semiconductor device according to claim 12,
The bonding wire has a resin thin film on the surface opposite to the side facing the substrate.

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