JP2012004435A - Method for manufacturing circuit device and resin sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a circuit device which places multiple resin sheets into a mold at one time, and to provide a resin sealing device used in the method.SOLUTION: A transport device 36 includes: a supporting part 41; arms 37 extending from the supporting part 41 to both sides; suction parts 38, each of which is provided at a lower end of each arm 37; and a cylindrical housing part 31 disposed at an upper portion of the supporting part 41. The transport device 36 has a function to transport multiple resin sheets 10 placed on a placing table 39 to a predetermined position of a mold.

Description

  The present invention relates to a circuit device manufacturing method and a resin sealing device used therefor.

  As a method of resin-sealing circuit elements such as semiconductor elements, there are a method of housing circuit elements inside a case material and a method of resin-sealing circuit elements with a sealing resin such as an epoxy resin. In recent years, a sealing method by resin sealing is frequently used from the viewpoint of productivity and the like. In the step of resin-sealing the circuit element, after the circuit element or the like is stored in the cavity of the mold, a liquid sealing resin is injected into the cavity to seal the circuit element (for example, Patent Document 1). ).

  Referring to FIG. 13A, the island 202 having the semiconductor element 204 fixed on the upper surface is accommodated in the cavity 214. A pod 220 communicating with the cavity 214 via the runner 218 is formed in the lower mold 226, and a tablet 228 is accommodated in the pod 220.

  Since the above-described mold is heated to the melting temperature or higher, the tablet 228 stored in the pod 220 is gradually melted to become a liquid sealing resin. Then, the liquid sealing resin pressurized by the plunger 222 is supplied to the cavity 214 via the runner 218 and the gate 216, and the semiconductor element 204 and the island 202 are sealed with the sealing resin.

  FIG. 13B shows the manufactured circuit device 200. The island 202, the semiconductor element 204, the fine metal wire 206, and the lead 210 are sealed with the sealing resin 208. In addition, the back surface of the island 202 is entirely covered with the sealing resin 208 in order to ensure pressure resistance and moisture resistance.

  However, in the sealing method described above, the lower surface of the island 202 may not be covered. Specifically, referring to FIG. 13B, in order to release heat generated from the semiconductor element 204 to the outside through the island 202 and the sealing resin 208, the lower surface of the island 202 is covered. It is better to make the sealing resin 208 to be thin. For example, if the thickness of the sealing resin 208 that covers the lower surface of the island 202 is reduced to about 0.5 mm or less, the heat dissipation of the entire device is improved. However, referring to FIG. 13A, in order to do so, it is necessary to narrow the gap between the lower surface of the island 202 and the inner wall of the lower mold 226 in the resin sealing step. There is a possibility that the sealing resin is not filled in the gap. When a region that is not filled with the sealing resin is generated, this region becomes a void and a defect occurs.

  A sealing method for avoiding such a problem is described in Patent Document 2 below. Referring to FIG. 3 of this document and the explanation thereof, the resin sheet 52 disposed on the lower surface of the circuit board 22 is melted, so that the circuit board 22 can be thinly resin-sealed.

  Specifically, first, a resin sheet 52 obtained by tableting a resin material is placed in the lower mold 44, and the circuit board 22 is placed on the upper surface of the resin sheet 52. The lower surface of the circuit board 22 is thinly covered with the resin sheet 52 heated and melted by the lower mold 44.

  Thus, by covering the lower surface of the circuit board 22 with the resin sheet 52, the lower surface of the circuit board 22 can be resin-sealed without generating voids.

JP 11-340257 A JP 2010-86993 A

  However, in the resin sealing method disclosed in Patent Document 2 described above, when a plurality of cavities are provided in one mold, it is necessary to dispose a resin sheet at a predetermined location in each cavity. Therefore, there is a problem that a great deal of labor is required for the arrangement of the resin sheet. Further, there is a problem that it is difficult to collectively arrange a plurality of resin sheets at accurate positions.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to manufacture a circuit device that enables resin sheets used for resin sealing to be collectively disposed in a mold. The object is to provide a method and a resin sealing device used therefor.

  The present invention is a method of manufacturing a circuit device in which a plurality of circuit elements are individually resin-sealed using a mold, and a plurality of resin sheets that are part of a sealing resin for sealing circuit elements are provided. After preparing on the mounting table and preparing a transport device having a plurality of suction sections at locations corresponding to the resin sheets, the surface of the resin sheet is sucked and transported by the suction sections A step of placing the resin sheet in the first sealing region of the first mold, a step of arranging the circuit element to be resin-sealed on the upper surface of the resin sheet, and a step of placing the circuit element in the first sealing region. A second mold having a second sealing region at a corresponding location is brought into contact with the first mold, and the resin is placed in a sealing region composed of the first sealing region and the second sealing region. A step of housing the sheet and the circuit element, a sealing resin injected into the sealing region, and The fusion was the resin sheet, the circuit element characterized by comprising a step of resin-sealing, the.

  Furthermore, the present invention is a resin sealing device for individually sealing a plurality of circuit elements with a sealing resin using a mold, and a first mold provided with a plurality of first sealing regions; A second mold in which a plurality of second sealing regions are provided in a portion overlapping with the first sealing region, and a part of the sealing resin in the first sealing region of the first mold A transport device that transports a resin sheet, and the transport device includes an adsorption unit that transports a plurality of the resin sheets simultaneously to the first sealing regions of the first mold. Features.

  According to the present invention, a plurality of resin sheets are collectively placed on each sealing region of the mold die by a transport device having a plurality of suction portions. Accordingly, since a plurality of resin sheets are simultaneously disposed in the predetermined region, the time and labor required for transporting the resin sheets are reduced.

  Furthermore, by adsorbing and transporting the upper surface of the resin sheet by the adsorbing portion, breakage of the resin sheet in the middle of transportation is suppressed, and the manufacturing cost is reduced.

It is a figure which shows the resin sheet of this invention, (A) is a perspective view, (B) is sectional drawing, (C) is sectional drawing which shows the state which press-processes a resin sheet. It is a perspective view which shows the transport apparatus and mounting base which are some resin sealing apparatuses of this invention. It is a figure which shows the manufacturing method of the circuit apparatus of this invention, (A) And (B) is sectional drawing. It is a figure which shows the manufacturing method of the circuit apparatus of this invention, (A) to (C) is sectional drawing. It is a figure which shows the manufacturing method of the circuit apparatus of this invention, (A) is sectional drawing, (B) And (C) is expanded sectional drawing. It is a figure which shows the manufacturing method of the circuit apparatus of this invention, (A) And (B) is sectional drawing. It is a figure which shows the hybrid integrated circuit device manufactured by the manufacturing method of the circuit device of this invention, (A) is a perspective view, (B) is sectional drawing. It is a figure which shows the manufacturing method of the circuit apparatus of this invention, (A) is a top view, (B) is the expanded top view, (C) is sectional drawing. It is a figure which shows the manufacturing method of the circuit apparatus of this invention, (A) is sectional drawing, (B) And (C) is expanded sectional drawing. It is a figure which shows the manufacturing method of the circuit apparatus of this invention, (A) And (B) is sectional drawing. It is a figure which shows the circuit apparatus manufactured by the manufacturing method of the circuit apparatus of this invention, (A) is a top view, (B) is sectional drawing. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the outdoor unit in which the hybrid integrated circuit device manufactured by the manufacturing method of the circuit device of this invention is integrated, (A) is a figure which shows an outdoor unit entirely, (B) is a hybrid integrated circuit device. It is a figure which shows the part in which is incorporated. It is a figure which shows the manufacturing method of the circuit device of background art, (A) is sectional drawing which shows a resin sealing process, (B) is sectional drawing which shows the manufactured circuit apparatus.

<First Embodiment>
A method of manufacturing a circuit device using the resin sealing device of this embodiment will be described in detail with reference to FIGS. In this embodiment, a hybrid integrated circuit device is manufactured by using a resin sealing device provided with the transport device 36 (or loading device) shown in FIG.

  First, the resin sheet 10 is manufactured.

  Referring to FIG. 1A, a resin sheet 10 according to the present embodiment is formed by pressing a granular powder resin mainly composed of a thermosetting resin, and has a sheet shape. ing. The resin sheet 10 is used when a circuit element such as a semiconductor element is resin-sealed using a mold, and constitutes a part of a sealing resin that seals the circuit element.

  The resin sheet 10 of the present embodiment can be applied to resin sealing of various types of circuit devices. For example, it is possible for a hybrid integrated circuit device in which a circuit board on which a large number of circuit elements are arranged is sealed with a resin. The circuit board is a metal board mainly composed of Cu or Al, and a metal board made of a metal alloy, and is applied when sealing the back surface of the metal board.

  Here, the circuit elements of the hybrid integrated circuit device generally include a plurality of semiconductor elements which are active elements, chip resistors or chip capacitors of passive elements.

  Furthermore, the resin sheet 10 of this embodiment can be applied to a lead frame type semiconductor device in which an island on which a semiconductor element is mounted is resin-sealed. This is applicable to large islands where the island size is large and the back surface cannot be sealed with a single transfer mold. For example, the island in this case has a size larger than 1/4 of the business card size. Since the island is large, a plurality of semiconductor elements may be mounted there, and the active element or the passive element may be mounted there.

  When resin sealing is applied to the hybrid integrated circuit device described above, referring to FIG. 5A, a circuit board 22 in which a large number of circuit elements are incorporated on the upper surface is prepared. It is disposed between the lower surface of the circuit board 22 and the lower mold 44. 6B, the lower surface of the circuit board 22 is thinly covered with the second sealing resin 24B made of the molten resin sheet 10. As shown in FIG. The second sealing resin 24B constitutes a part of the sealing resin that integrally covers the circuit element and the circuit board 22 together with the first sealing resin 24A injected from the gate 54.

  Here, in a general transfer mold, since the sealing is performed at one time, the amounts of the filler on the front and back of the substrate are almost the same. However, since the resin sheet 10 can be prepared separately, the amount of mixing on the front and back of the substrate can be made different. In particular, in an HIC that handles a large amount of power, an inverter, a vehicle-mounted HIC, etc., the amount of filler on the back surface of the metal substrate can be increased to increase heat dissipation. The front and back filler materials can also be different.

  When the resin sheet 10 is applied to a lead frame type semiconductor device, the lower surface of the island 72 on which the semiconductor element 80 is placed is covered with the resin sheet 102 with reference to FIG. .

  The planar size (L1 × L2) of the resin sheet 10 varies depending on the type of circuit device in which the resin sheet 10 is used. For example, when applied to resin sealing of the hybrid integrated circuit device 20 as shown in FIG. 7, the size of the resin sheet 10 is equivalent to that of the circuit board 22 and is about L1 × L2 = 60 mm × 40 mm. Further, when applied to resin sealing of the circuit device 70 as shown in FIG. 11, the planar size of the resin sheet 10 is equivalent to the island 72, and is, for example, about L1 × L2 = 10 mm × 10 mm. . Further, it may be the same as or slightly smaller than the cavity size as viewed from above the lower mold.

  With reference to FIG. 1 (A), thickness L3 of the resin sheet 10 is 0.1 mm or more and 0.6 mm or less, for example. By setting the thickness of the resin sheet 10 to 0.6 mm or less, as shown in FIG. 5B, the back surface of the circuit board 22 is thinly resin-sealed with the second sealing resin 24B made of the molten resin sheet 10. can do. On the other hand, by setting the thickness of the resin sheet 10 to 0.1 mm or more, the rigidity of the resin sheet 10 is ensured to a certain level or more, and cracking of the resin sheet 10 in the transportation stage is suppressed.

  FIG. 1B is an enlarged cross-sectional view illustrating a part of the resin sheet 10. Referring to this figure, the resin sheet 10 is composed of a number of granular powder resins 18. This powder resin 18 consists of thermosetting resins, such as an epoxy resin to which additives, such as a filler, were added, and the diameter of each powder resin 18 is 1.0 mm or less, for example. In order to increase the mixing rate, granular and crushed fillers may be mixed. Furthermore, silica, alumina, or a mixture thereof may be used.

  Further, in the resin sheet 10, the filling rate of the powder resin 18 (ratio of the powder resin 18 to the total volume of the resin sheet 10) is 99% or more. Considering that the filling rate of the tablet used for general resin sealing is about 95%, the filling rate of the powder resin 18 in the resin sheet 10 of the present embodiment is very high. By increasing the filling rate of the resin sheet 10 in this way, the amount of air contained in the resin sheet 10 becomes extremely small, so that voids may be formed in the sealing resin formed by melting the resin sheet 10. It is suppressed.

  With reference to the cross-sectional view of FIG. 1C, a method for manufacturing the resin sheet 10 will be described.

  First, a powdered powder resin 18 is prepared. Specifically, after a predetermined amount of materials such as a powdered thermosetting resin, a filler, and a release agent are weighed, these materials are mixed by a mixer. Furthermore, a powdered resin material is formed by heating and mixing the mixed material and then crushing it.

  The ratio of the filler mixed in the powder resin 18 is, for example, 70% by weight or more and 90% by weight or less. And as a kind of filler, although the mixture of crystalline silica and crushed silica is adopted, fused silica, alumina, or silicon nitride may be adopted. Furthermore, the average particle diameter of the filler to be mixed is, for example, 20 μm or more and 30 μm or less.

  Here, the kind and amount of the filler contained in the resin sheet 10 may be the same as or different from the filler contained in the first sealing resin 24A (see FIG. 6B) described later. For example, the heat resistance of the second sealing resin 24 </ b> B made of the resin sheet 10 is reduced by adopting alumina having a low thermal resistance as a filler material contained in the resin sheet 10. Thus, heat generated by driving a circuit element such as a transistor can be discharged to the outside through the circuit board 22 and the second sealing resin 24B (see FIG. 6B). .

  The powder resin 18 having the above configuration is formed into a sheet by pressure molding (tablet processing) using a mold. Specifically, a mold composed of an upper mold 14 (first tableting means: the side to be struck) made of a metal such as stainless steel and a lower mold 16 (second tableting means: the side to be received as a tablet) is used. Tableting. The lower mold 16 includes a pedestal 21 whose upper surface is a flat surface, and a frame-shaped frame mold 12 placed on the upper surface of the pedestal 21. The upper mold 14 is movable in the vertical direction and has a shape that fits into the opening of the frame mold 12. The planar size of the opening of the frame mold 12 is equal to the size of the resin sheet 10 to be molded.

  A predetermined amount of the powder resin 18 having the above composition is accommodated in the opening of the frame mold 12 and flattened. Next, the upper mold 14 is lowered to apply a predetermined pressure to the powder resin 18 so that the powder resin 18 is integrated, and the resin sheet 10 shown in FIG. 1A is molded. Here, the pressure applied to the resin powder by the upper mold 14 is about several tens of tons. Moreover, this process is performed in the normal temperature atmosphere, without heating a metal mold | die.

  Here, referring to FIG. 1C, when supplying the powder resin 18 to the lower mold 16, means for suppressing scattering of the powder resin 18 may be provided. Specifically, a blowing unit such as a blower for blowing off the powder resin 18 remaining on the upper surface of the lower mold 16 and a dust collector for capturing the powder resin 18 blown off by the blowing unit may be provided.

  By doing in this way, it is prevented that the upper surface of the lower metal mold | die 16 is damaged with the powder resin 18 which remained, and also worsening of a working environment is suppressed. Specifically, since the powder resin 18 is supplied by a squeegee that moves on the upper surface of the lower mold 16, if the powder resin 18 remains on the upper surface of the lower mold 16, the powder resin is sandwiched between the lower mold 16 and the squeegee. As a result, the upper surface of the lower mold 16 may be damaged. In this embodiment, since the powder resin 18 remaining on the upper surface of the lower mold 16 is removed by the blowing means, generation of scratches due to the remaining powder resin 18 is suppressed.

  Moreover, the powder resin adhering to the surface of the resin sheet 10 manufactured is also removed by using a ventilation means in this process. Therefore, referring to FIG. 4, even when the resin sheet 10 is transported to the lower mold 44 for molding, a large amount of powdered resin material is prevented from adhering to the lower mold 44 together with the resin sheet 10. .

  Subsequently, with reference to FIG. 2 to FIG. 4, a process of placing the resin sheet 10 and the circuit element manufactured in the above process at a predetermined position of a mold for performing resin sealing will be described.

  FIG. 2 is a diagram showing a transport device 36 and a mounting table 39 used for transporting the resin sheet. Here, the resin sheet 10 disposed on the upper surface of the mounting table 39 is adsorbed by the transport device 36.

  The mounting table 39 is made of a metal plate such as aluminum. A mounting region 47 is formed by recessing a predetermined position on the upper surface of the mounting table 39 into a rectangular shape. The position of the placement region 47 corresponds to the position of the cavity 46 (sealing region: see FIG. 5) provided in the mold. Furthermore, the size of each placement region 47 in plan view is formed to be equal to or greater than that of the stored resin sheet 10. Thus, by storing the resin sheet 10 in each placement region 47, it is possible to arrange the required number of resin sheets 10 at accurate positions.

  The alignment unit 45 is a region where both ends of the mounting table 39 are recessed, and these positions correspond to the positions of the convex alignment unit 43 provided in the transport device 36. Therefore, when the transport device 36 is lowered when the resin sheet 10 disposed on the mounting table 39 is sucked by the transport device 36, the convex alignment portion 43 provided on the transport device 36 is provided on the mounting table 39. It fits into the recessed alignment part 45 made. As a result, each suction portion 38 of the transport device 36 sucks the upper surface of the resin sheet 10 stored in each placement region 47 of the placement table 39.

  The transport device 36 includes a support portion 41, an arm 37 extending from the support portion 41 to both sides, a suction portion 38 provided at the lower end of the arm 37, and a cylindrical storage portion 31 disposed above the support portion 41. And. The transport device 36 has a function of transporting the plurality of resin sheets 10 mounted on the mounting table 39 to a predetermined position of the mold.

  The support portion 41 is formed by molding a metal such as aluminum into a housing shape. Corresponding to each mounting region 47 of the mounting table 39, the arms 37 are led out from both side surfaces of the support portion 41 to the side. Further, the arm 37 has an alphabet “L” shape, and its end portion is shaped to face downward.

  At the lower end of each arm 37, a suction portion 38 made of an elastic body such as rubber is provided. When the support portion 41 sucks each resin sheet 10, the suction portion 38 attached to the lower end of the arm 37 contacts the upper surface of the resin sheet 10.

  Each arm 37 is provided with a circulation hole (flow passage) through which air for suction flows, and the circulation hole (flow passage) of each arm 37 passes through the inside of the support portion 41 to the outside. It communicates with the pump. Therefore, suction force is given to each suction portion 38 by performing suction by the pump.

  On the upper surface of the support portion 41, a cylindrical storage portion 31 is disposed. The storage unit 31 is an area in which the resin tablet is stored. Here, referring to FIG. 6 (A), the resin tablet is a solid resin as a sealing resin material injected into the cavity 46 in the resin sealing step. It is manufactured by a similar method.

  Protruding alignment portions 43 are provided on the lower surface of the support portion 41 near both ends. The alignment unit 43 has a position and shape corresponding to the concave alignment unit 45 of the mounting table 39. As described above, the alignment is performed by fitting the alignment portion 43 of the support portion 41 and the alignment portion 45 of the mounting table 39.

  Here, although the convex alignment part 43 is provided in the lower surface of the support part 41 of the transport apparatus 36 and the concave alignment part 45 is provided in the mounting base 39, the shape of these alignment parts 43 and 45 may be replaced. . That is, the shape of the alignment unit 43 of the transport device 36 may be concave, and the shape of the mounting table 39 may be convex.

  The arm portion for sucking the resin sheet and the tablet storage portion 31 may be formed separately. If they are integral, the resin sheet and the tablet can be transported at one time, and if they are separate, they can be performed separately. However, it is efficient because it can be processed all at once if integrated.

  With reference to FIG. 3, the process of adsorbing the resin sheet 10 by the transport device 36 will be described.

  First, referring to FIG. 3A, the transport device 36 is disposed above the mounting table 39. Further, the suction portion 38 attached to the tip of each arm 37 included in the transport device 36 is disposed above the vicinity of the central portion of the resin sheet 10 stored in each placement region 47 of the placement table 39. Then, while the resin sheet 10 is transported by the transport device 36, suction is performed by the suction portion 38 by operating a pump (not shown).

  When the transport device 36 is moved downward in this state, the suction portion 38 of the transport device 36 comes into contact with the upper surface of the resin sheet 10 and the resin sheet 10 is sucked. As described above, since the transport device 36 and the mounting table 39 are aligned by the alignment unit, the adsorption unit 38 adsorbs the vicinity of the center of the upper surface of the resin sheet 10.

  With reference to FIG. 3 (B), next, after the adsorption | suction part 38 adsorb | sucks the upper surface of the resin sheet 10, the transport apparatus 36 is moved upwards. Thus, the resin sheet 10 is separated from the mounting table 39 and transported by the transport device 36. Thereafter, the transport device 36 moves up to above the mold for performing resin sealing while the resin sheet 10 is adsorbed by the adsorbing portion 38.

  In this embodiment, as shown in FIG. 2, the transport device 36 is provided with a plurality of (here, 10) suction portions 38, so that a large number of resin sheets 10 can be collectively placed at accurate positions. Can be transported. Further, by using the alignment units 43 and 45, each suction unit 38 of the transport device 36 sucks a predetermined position of the resin sheet 10 placed on the placement table 39. Therefore, transportation is performed while accurately maintaining the relative positional relationship between the resin sheets 10.

  Next, referring to FIG. 4A, the transport device 36 in a state where the resin sheet 10 is adsorbed by the adsorbing portion 38 is moved to above the lower mold 44. The lower mold 44 is provided with a first sealing region 46A, which is a region where resin sealing is performed, and a pod 50A in which the tablet 58 is stored.

  In this state, referring to FIG. 4B, the transport device 36 is lowered to place the resin sheet 10 near the center of the upper surface of the first sealing region 46A. Further, the tablet 58 is supplied from the storage unit 31 to the pod 50A. Thereafter, after the suction force applied to the suction portion 38 of the transport device 36 is released, the transport device 36 is moved from above the lower mold 44 to the outside.

  With reference to FIG.4 (C), the circuit board 22 is mounted on the upper surface of the resin sheet 10 arrange | positioned at 46 A of 1st sealing areas. Here, a circuit board 22 in which a hybrid integrated circuit composed of a plurality of circuit elements such as transistors is incorporated is disposed on the upper surface of the resin sheet 10.

  Further, the lower mold 44 is heated to a temperature at which the resin material (thermosetting resin such as epoxy resin) included in the resin sheet 10 and the tablet 58 is melted. Therefore, when the resin sheet 10 and the tablet 58 are put into the lower mold 44, both begin to melt.

  Here, the lower mold is stopped from being heated, and the lower mold is lower than the melting temperature, and may be heated after being properly placed.

  5 and 6, next, the circuit board 22 is resin-sealed using a mold 40 for molding. In this embodiment, the upper surface, side surface, and bottom surface of the circuit board 22 are covered with a sealing resin.

  Referring to FIG. 5A, first, upper mold 42 (second mold) and lower mold 44 (first mold) are brought into contact with each other. As described above, the lower mold 44 is provided with the first sealing region 46A, and the upper mold 42 is provided with the second sealing region 46B. Therefore, the cavity 46 (sealing region) is formed by bringing the upper mold 42 and the lower mold 44 into contact with each other.

  On the upper surface of the rectangular circuit board 22 made of a metal such as aluminum, a conductive pattern having a predetermined shape is formed by etching. A hybrid integrated circuit is formed by fixing a large number of circuit elements such as semiconductor elements at predetermined positions of the conductive pattern. In addition, leads 27 are fixed in the vicinity of both ends of the circuit board 22, and the leads 27 are held between the upper mold 42 and the lower mold 44. As a result, the position of the circuit board 22 inside the cavity 46 is fixed.

  With reference to FIG. 5 (B), in the initial stage of this process, the resin sheet 10 is in a solid state in which a granular thermosetting resin is press-processed. The mold 40 is equipped with a heater (not shown), and the mold 40 is heated to a temperature (for example, 170 ° C. or higher) at which the resin sheet 10 is melted and heat-cured.

  The thickness T2 of the resin sheet 10 is formed to be thicker than the thickness of the sealing resin (T1 shown in FIG. 7B) that covers the lower surface of the circuit board 22 in the manufactured hybrid integrated circuit device 20. Specifically, when the thickness T1 of the sealing resin shown in FIG. 7B is 0.1 mm or more and 0.3 mm or less, the thickness T2 of the resin sheet 10 is set to 0.4 mm or more and 0.6 mm or less. Is done.

  On the other hand, as described above, the position of the circuit board 22 inside the cavity 46 is fixed by holding the lead 27 by the mold. Therefore, the shape and position of the lead 27 are set so that the distance between the lower surface of the circuit board 22 and the upper surface of the inner wall of the lower mold 44 is T1 (see FIG. 7B).

  For this reason, when the resin sheet 10 and the circuit board 22 are placed on the lower mold 44 so as to overlap each other and the lead 27 is held by the mold 40, the lead 27 is elastically deformed. The resin sheet 10 is pressed against the lower mold 44 by the lower surface and fixed. In this figure, the state of the lead 27 elastically deformed by being held by the mold is shown.

  Since the mold 40 is heated as described above, the resin sheet 10 melts and softens as time passes, and the lower surface of the circuit board 22 is covered with the liquid or semi-solid resin sheet 10.

  Referring to FIG. 5C, as described above, the lead 27 is held by the mold in an elastically deformed state. Therefore, when the resin sheet 10 is softened and loses its supporting force, the shape of the lead 27 is changed. Returning to the original state, the circuit board 22 sinks downward. Along with the sinking of the circuit board 22, a part of the softened resin sheet 10 moves from the lower side to the side of the circuit board 22 to cover the side surface of the circuit board 22. Thus, the thickness T3 of the resin sheet 10 covering the lower surface of the circuit board 22 that has been sunk is, for example, not less than 0.1 mm and not more than 0.3 mm, and is equivalent to the thickness T1 of the sealing resin shown in FIG. It is.

  Next, referring to FIG. 6A, a sealing resin is injected into the cavity 46. Specifically, the tablet 58 put in the pod 50 </ b> A provided in the lower mold 44 is pressurized by the plunger 60.

  As described above, since the mold is heated to about 170 ° C. or higher, when the tablet 58 is put into the pod 50A, the tablet 58 is gradually melted. The sealing resin that has been melted into a liquid or semi-solid state flows through the runner 48, passes through the gate 54, and then is supplied to the cavity 46. In the following description, the sealing resin supplied from the gate 54 is referred to as a first sealing resin 24A, and the sealing resin made of the molten resin sheet 10 is referred to as a second sealing resin 24B.

  With reference to FIG. 6B, the injected liquid first sealing resin 24 </ b> A fills the cavity 46. Here, since the temperature of the mold is higher than the temperature at which the first sealing resin 24A is heated and cured, the first sealing resin 24A filled in the cavity 46 is polymerized and cured over time. To do. As shown in this figure, when the lower surface and the lower part of the side surface of the circuit board 22 are covered with the second sealing resin 24B made of the resin sheet 10, the upper surface and the upper part of the side surface of the circuit board 22 are second sealed. Covered with resin 24B.

  Here, the second sealing resin 24 </ b> B made of the resin sheet 10 is gelled after the first sealing resin 24 </ b> A is injected into the cavity 46. By doing in this way, since the 1st sealing resin 24A and the 2nd sealing resin 24B mix in a liquid state, both are integrated and a boundary is lost. As a result, the intrusion of moisture from the boundary to the inside is suppressed and the moisture resistance is improved.

  When both the first sealing resin 24A and the second sealing resin 24B are sufficiently polymerized and heated and cured by heating with the mold, the upper mold 42 and the lower mold 44 are separated from each other, and a molded product is obtained. Take out the hybrid integrated circuit device. Thereafter, the portion of the sealing resin filled in the air vent 56 and the runner 48 is separated from the sealing resin 24 main body.

  Through the above steps, the hybrid integrated circuit device 20 shown in FIG. 7 is manufactured.

  With reference to FIG. 7, the structure of the hybrid integrated circuit device 20 to which the above-described resin sheet is applied will be described. 7A is a perspective view of the hybrid integrated circuit device 20, and FIG. 7B is a cross-sectional view taken along line X-X 'of FIG. 7A.

  In the hybrid integrated circuit device 20, a hybrid integrated circuit including a conductive pattern 26 and circuit elements is constructed on the upper surface of the circuit board 22, and leads 27 connected to the circuit are led out to the outside. Furthermore, the hybrid integrated circuit constructed on the upper surface of the circuit board 22 and the upper surface, side surfaces and lower surface of the circuit board 22 are integrally covered with a sealing resin 24 made of a thermosetting resin.

  The circuit board 22 is a board made of a metal such as aluminum or copper, and its specific size is, for example, about vertical × horizontal × thickness = 61 mm × 42.5 mm × 1.5 mm. Here, a material other than metal may be employed as the material of the circuit board 22, for example, ceramic or resin material may be employed as the material of the circuit board 22.

  The insulating layer 28 is formed so as to cover the entire surface of the circuit board 22. The insulating layer 28 is made of an epoxy resin highly filled with a filler. The conductive pattern 26 is made of a metal film such as copper having a thickness of about 50 μm, and is formed on the surface of the insulating layer 28 so as to realize a predetermined electric circuit. A pad made of the conductive pattern 26 is formed on the side from which the lead 27 is led out.

  The circuit elements of the semiconductor element 30A and the chip element 30B are fixed to predetermined portions of the conductive pattern 26 via a bonding material such as solder. As the semiconductor element 30A, a transistor, an LSI chip, a diode, or the like is employed. Here, the semiconductor element 30 </ b> A and the conductive pattern 26 are connected via a fine metal wire 32. As the chip element 30B, a chip resistor, a chip capacitor, or the like is employed. The electrodes at both ends of the chip element 30B are fixed to the conductive pattern 26 via a bonding material such as solder.

  The lead 27 is fixed to a pad provided in the peripheral portion of the circuit board 22 and functions as an external connection terminal through which an input signal and an output signal pass. Referring to FIG. 7B, a large number of leads 27 are provided along two opposing sides of the circuit board 22.

  The sealing resin 24 is formed by transfer molding using a thermosetting resin. In FIG. 7B, the conductive pattern 26, the semiconductor element 30 </ b> A, the chip element 30 </ b> B, and the thin metal wire 32 are sealed with the sealing resin 24. The upper surface, side surfaces, and lower surface of the circuit board 22 are covered with the sealing resin 24. The material constituting the sealing resin 24 is the same as that of the resin sheet 10 described above.

  With reference to FIG. 7B, the sealing resin 24 will be further described. The sealing resin 24 includes a first sealing resin 24A and a second sealing resin 24B. On the paper surface, the boundary between the first sealing resin 24A and the second sealing resin 24B is drawn, but both are integrated in an actual circuit device. The first sealing resin 24A is formed by injecting a liquid resin into the cavity of the mold, and the second sealing resin 24B is formed by melting a resin sheet disposed on the lower surface of the circuit board 22. The thickness T1 of the second sealing resin 24B that covers the lower surface of the circuit board 22 is very thin, for example, 0.1 mm or more and 0.3 mm or less. Since the thin second sealing resin 24B has a small thermal resistance, the heat released from the circuit element such as a semiconductor element is favorably released to the outside through the circuit board 22 and the second sealing resin 24B.

  Here, the boundary between the first sealing resin 24 </ b> A and the second sealing resin 24 </ b> B is located at a portion covering the side surface of the circuit board 22. The boundary portion between the two is slightly inferior in pressure resistance and moisture resistance as compared with other portions of the sealing resin 24. Therefore, when this boundary portion is disposed on the lower surface of the circuit board 22 and when the lower surface of the sealing resin 24 is in close contact with the heat sink, the circuit board 22 and the heat sink may be short-circuited via the boundary portion. On the other hand, since the side surface of the circuit board 22 rarely comes into contact with the outside, the risk of short-circuiting is small.

<Second Embodiment>
With reference to FIGS. 8 to 10, another method of manufacturing a circuit device will be described. The method of manufacturing the circuit device according to this embodiment is basically the same as that of the first embodiment described above, except that a lead frame type circuit device is manufactured. Further, the transport apparatus described in the first embodiment is also applied to transport of the resin sheet to the mold.

  Referring to FIG. 8, first, a lead frame 120 having a predetermined shape is prepared, and a semiconductor element 80 is connected to each unit 124 formed on the lead frame 120. 8A is a plan view showing the lead frame 120, FIG. 8B is a plan view showing the unit 124 included in the lead frame 120, and FIG. 8C is a cross-sectional view of the unit 124. .

  Referring to FIG. 8A, the lead frame 120 is formed in a predetermined shape by etching or pressing a metal plate made of a metal such as copper having a thickness of about 0.3 mm. Yes. In the lead frame 120, a plurality of blocks 122 are arranged apart from each other.

  Referring to FIG. 8B, inside the block 122, connecting portions 126, 128 extend in a lattice shape in the vertical direction and the horizontal direction. Then, the unit 124 is formed inside the region surrounded by the connecting portions 126 and 128. Specifically, the lead 78 integrally extends from the connecting portions 126 and 128 toward the inside of the unit 124. A rectangular island 72 is formed near the center of the unit 124, and the four corners of the island 72 are continuous with the connecting portions 126 and 128 via the suspension leads 86. Here, as a connecting means for connecting the island 72 and the connecting portion, a normal lead 78 may be adopted.

  Referring to FIG. 8C, semiconductor element 80 is fixed to the upper surface of island 72 included in each unit 124. The electrode provided on the upper surface of the semiconductor element 80 is connected to the lead 78 through the fine metal wire 82.

  Next, referring to FIG. 9, the island 72 having the semiconductor element 80 fixed on the upper surface is accommodated in the cavity 96 of the mold 90.

  With reference to FIG. 9A, here, after placing the resin sheet 102 on the lower surface of the inner wall of the lower mold 94, the island 72 is placed on the upper surface of the resin sheet 102. The island 72 is accommodated inside the cavity 96 by bringing the upper mold 92 and the lower mold 94 into contact with each other. Further, the suspension lead 86 continuing from the island 72 is sandwiched and fixed between the upper mold 92 and the lower mold 94. In this manner, the suspension leads 86 are held by the upper and lower molds, so that the vertical and horizontal positions of the island 72 in the cavity 96 are fixed. In the initial stage of this process, the resin sheet 102 is in a solid state in which a granular resin material is pressed. The mold 90 is equipped with a heater (not shown), and the mold 90 is heated to a temperature (for example, 170 ° C. or higher) at which the resin sheet 102 is melted and heat-cured.

  Referring to FIG. 9B, the thickness T5 of the resin sheet 102 is larger than the thickness of the sealing resin that covers the lower surface of the island 72 (T4 shown in FIG. 11B) in the manufactured circuit device 70. It is formed thick. Specifically, when the thickness T4 of the sealing resin shown in FIG. 11B is 0.1 mm to 0.3 mm, the thickness T5 of the resin sheet 102 is set to 0.5 mm to 0.6 mm. Is done.

  Further, as described above, the position of the island 72 inside the cavity 96 is fixed by holding the suspension lead 86 by the mold. Therefore, the shape and position of the suspension lead 86 are set such that the distance between the lower surface of the island 72 and the upper surface of the inner wall of the lower mold 94 is T4 (see FIG. 11B). For this reason, when the resin sheet 102 and the island 72 are superposed on the lower mold 94 and the suspension lead 86 is held by the mold 90, the upper mold 92 is pressed and bent downward from above. The suspension lead 86 is elastically deformed, and as a result, the resin sheet 102 is pressed against the lower mold 94 by the lower surface of the island 72 and fixed. This figure shows a state of the suspension lead 86 that is elastically deformed by being held by a mold. Further, the shape of the suspension lead 86 in a state where it is not deformed is indicated by a dotted line.

  Since the mold 90 is heated, the resin sheet 102 is melted and softened over time, and the lower surface of the island 72 is covered with the liquid or semi-solid resin sheet 102.

  With reference to FIG. 9C, as described above, the suspension lead 86 is held in the mold in an elastically deformed state. Therefore, when the resin sheet 102 is softened and loses its supporting force, the suspension lead 86 The shape returns to its original shape, and the island 72 sinks downward. Along with the sinking of the island 72, a part of the softened resin sheet 102 moves from the lower side of the island 72 to the side to cover the vicinity of the lower end of the side surface of the island 72.

  Thus, the thickness T6 of the resin sheet 102 covering the lower surface of the submerged island 72 is, for example, not less than 0.1 mm and not more than 0.3 mm, and is equivalent to the thickness T4 of the sealing resin shown in FIG. is there. Further, here, the side surface of the island 72 is covered with the resin sheet 102 although it is hidden behind the suspension lead 86.

  Here, in the above description, the island 72 and the resin sheet 102 have the same size in plan view, but the resin sheet 102 may be formed larger than the island 72. As a result, the island 72 can be supported by the resin sheet 102 more stably. Further, the entire lower surface of the lower mold 94 may be covered with the resin sheet 102.

  A plurality of islands 72 may be provided in one unit. In this case, the resin sheet 10 may be disposed for each island 72, or a plurality of islands 72 may be supported by one large resin sheet 102.

  Referring to FIG. 10A, next, sealing resin is injected into the cavity 96. Specifically, the tablet 108 is put into the pod 100 provided in the lower mold 94 and heated and melted, and then the tablet 108 is pressurized by the plunger 110. As described above, since the mold is heated to about 170 ° C. or more, when the tablet 108 is put into the pod 100, the tablet 108 is gradually melted. The sealing resin that has been melted into a liquid or semi-solid state flows through the runner 98, passes through the gate 104, and then is supplied to the cavity 96. In the following description, the sealing resin supplied from the gate 104 is referred to as a first sealing resin 74A, and the sealing resin composed of the molten resin sheet 102 is referred to as a second sealing resin 74B.

  Referring to FIG. 10B, the injected liquid first sealing resin 74A is filled in the cavity 96. Here, since the temperature of the mold is higher than the temperature at which the first sealing resin 74A is heated and cured, the first sealing resin 74A filled in the cavity 96 is polymerized and gelated over time. (Hardened).

  When both the first sealing resin 74A and the second sealing resin 74B are sufficiently polymerized and heated and cured by heating with the mold, the upper mold 92 and the lower mold 94 are separated from each other, and a molded product is obtained. Take out the circuit device.

  With reference to FIG. 11, the structure of the circuit device 70 manufactured by the above-described method of manufacturing a circuit device will be described. 11A is a plan view of the circuit device 70, and FIG. 11B is a cross-sectional view.

  The circuit device 70 includes a semiconductor element 80, an island 72 on which the semiconductor element 80 is mounted, a lead 78 connected to the semiconductor element 80 via a metal thin wire 82, and a seal that integrally seals them. Resin 74.

  The semiconductor element 80 is, for example, an IC, LSI, or discrete transistor in which a large number of electrodes are formed on the upper surface, and is fixed to the upper surface of the island 72.

  The island 72 is formed in a square shape near the center of the circuit device 70 and is formed slightly larger than the semiconductor element 80 fixed to the upper surface. For example, if the size of the semiconductor element 80 fixed to the upper surface is 10 mm × 10 mm, the size of the island 72 is about 12 mm × 12 mm. The back surface of the island 72 is thinly covered with a sealing resin 74. Further, suspension leads 86 extend outward from the four corners of the island 72.

  The lead 78 is connected to the electrode of the semiconductor element 80 via the fine metal wire 82, and one end is exposed to the outside from the sealing resin 74. Here, a large number of leads 78 are arranged so as to surround the semiconductor element 80.

  The sealing resin 74 is formed by transfer molding using a thermosetting resin. In FIG. 11B, the sealing resin 74 covers the semiconductor element 80, the fine metal wires 82, part of the leads 78, and the side surfaces and the lower surface of the island 72 with the sealing resin 74.

  Referring to FIG. 11B, the sealing resin 74 includes a first sealing resin 74A and a second sealing resin 74B. On the paper surface, the boundary between the first sealing resin 74A and the second sealing resin 74B is drawn, but in an actual circuit device, both are integrated. The thickness T4 of the second sealing resin 74B that covers the lower surface of the island 72 is, for example, 0.1 mm or more and 0.3 mm or less and is very thin.

  Also in this embodiment, the boundary between the first sealing resin 74A and the second sealing resin 74B is arranged on the side of the island 72, and this has the advantage of ensuring the pressure resistance.

<Third Embodiment>
With reference to FIG. 12, the structure of the outdoor unit 130 in which the circuit device manufactured by the manufacturing method described above is incorporated will be described. Here, the hybrid integrated circuit device 20 (see FIG. 7) described in the first embodiment is incorporated in the outdoor unit 130, but the circuit device 70 described in the second embodiment (see FIG. 11). May be incorporated.

  The outdoor unit 130 is configured such that a condenser 133, a fan 136, a compressor 132, and the hybrid integrated circuit device 20 are mainly built in a housing 131.

  The compressor 132 has a function of compressing a refrigerant such as ammonia using the driving force of the motor. Then, the refrigerant compressed by the compressor 132 is sent to the condenser 133, and the fan 136 blows wind on the condenser 133, so that the heat contained in the refrigerant inside the condenser 133 is released to the outside. Further, after the refrigerant is expanded, it is sent to the evaporator in the room to cool the air in the room.

  Here, the hybrid integrated circuit device 20 has a function of controlling the rotation of a motor that drives the compressor 132 or the fan 136, and is fixed to a mounting substrate 135 provided inside the outdoor unit 130.

  FIG. 12B shows a structure to which the hybrid integrated circuit device 20 is attached. Here, the lead 27 is inserted and mounted on the mounting substrate 135. The back surface of the hybrid integrated circuit device 20 is in contact with the smooth surface of the heat sink 134.

  In this embodiment, the sealing resin that covers the lower surface of the hybrid integrated circuit device 20 is formed extremely thin by a manufacturing method using a resin sheet. For this reason, the heat generated by driving the circuit elements incorporated in the hybrid integrated circuit device 20 is conducted to the heat sink 134 through the circuit board and the sealing resin and then released to the outside.

10 resin sheet 12 frame mold 14 upper mold 16 lower mold 18 powder resin 20 hybrid integrated circuit device 22 circuit board 24 sealing resin 24A first sealing resin 24B second sealing resin 26 conductive pattern 27 lead 28 insulating layer 30A Semiconductor element 30B Chip element 31 Storage part 32 Metal thin wire 36 Transport device 37 Arm 38 Adsorption part 39 Mounting base 40 Mold 41 Support part 42 Upper mold 43 Alignment part 44 Lower mold 45 Alignment part 46 Cavity 46A First sealing Region 46B Second sealing region 47 Placement region 48 Runner 50A Pod 54 Gate 56 Air vent 58 Tablet 60 Plunger 70 Circuit device 72 Island 74 Sealing resin 74A First sealing resin 74B Second sealing resin 78 Lead 80 Semiconductor element 82 Metal thin wire 86 Hanging lead 90 Mold 92 Upper mold 94 Lower mold 96 Cavity 98 Runner 100 Pod 102 Resin sheet 104 Gate 106 Air vent 108 Tablet 110 Plunger 120 Lead frame 122 Block 124 Unit 126 Connection unit 128 Connection unit 130 Outdoor unit 131 Housing 132 Compressor 133 Condenser 134 Heat sink 135 Mounting substrate 136 Fan

Claims (10)

A method of manufacturing a circuit device in which a plurality of circuit elements are individually resin-sealed using a mold,
A step of preparing a plurality of resin sheets to be a part of a sealing resin for sealing a circuit element on a mounting table;
After preparing a transport device having a plurality of suction portions at locations corresponding to the respective resin sheets, the surface of the resin sheet is sucked and transported by the suction portions, and then the first sealing region of the first mold is used. Placing the resin sheet;
Placing the circuit element to be resin-sealed on the top surface of the resin sheet;
A second mold having a second sealing area at a location corresponding to the first sealing area is brought into contact with the first mold, and includes the first sealing area and the second sealing area. Storing the resin sheet and the circuit element in a sealing region;
A step of resin-sealing the circuit element with a sealing resin injected into the sealing region and the molten resin sheet;
A method for manufacturing a circuit device, comprising: In the step of placing the resin sheet, a resin tablet is supplied from the transport device to the pod of the first mold,
The method for manufacturing a circuit device according to claim 1, wherein, in the resin sealing step, the sealing resin composed of the molten resin tablet is injected into the sealing region. In the step of placing the circuit element, a circuit board having a plurality of the circuit elements fixed on the upper surface is placed on the upper surface of the resin sheet,
The method for manufacturing a circuit device according to claim 1, wherein, in the resin sealing step, a lower surface of the circuit board is covered with the molten resin sheet. In the step of placing the circuit element, an island having the circuit element fixed on the upper surface is placed on the upper surface of the resin sheet,
The method for manufacturing a circuit device according to claim 1, wherein, in the resin sealing step, a lower surface of the island is covered with the molten resin sheet. A resin sealing device that individually seals a plurality of circuit elements with a sealing resin using a mold,
A first mold provided with a plurality of first sealing regions;
A second mold provided with a plurality of second sealing regions in a portion overlapping the first sealing region;
A transport device for transporting a resin sheet that is a part of the sealing resin to the first sealing region of the first mold;
The said transport apparatus is provided with the adsorption | suction part which transports the said some resin sheet simultaneously with respect to each said 1st sealing area | region of a said 1st metal mold | die, The resin sealing apparatus characterized by the above-mentioned. Further comprising a mounting table on which the resin sheet before being adsorbed to the transport device is mounted;
The resin sealing device according to claim 5, wherein the mounting table includes a mounting region on which the resin sheet is mounted, corresponding to the first sealing region of the first mold. . The transport device further includes a support portion and a plurality of arms led out from the support portion to the side,
The resin sealing device according to claim 5, wherein the suction portion is provided at a lower end of the arm. The first mold is provided with a plurality of pods for storing resin tablets before being heated and melted,
The resin sealing device according to any one of claims 5 to 7, wherein a storage portion in which the resin tablet is stored and transported is provided at a position corresponding to the pod of the transport device.   By aligning the first alignment unit provided on the mounting table and the second alignment unit provided on the transporting device, the mounting region of the mounting table, the suction unit of the transporting device, The resin sealing device according to claim 6, wherein the resin sealing devices are aligned. The first alignment part of the mounting table has a concave shape,
The second alignment portion of the transport device has a convex shape;
The resin sealing device according to claim 9, wherein the alignment is performed by fitting the first alignment unit and the second alignment unit.

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