JP5457762B2 - Circuit device and manufacturing method thereof - Google Patents

Description

  The present invention relates to a circuit device for reducing an unfilled region of a full-mold package and a method for manufacturing the circuit device.

  An example of a conventional circuit device and a method for manufacturing the same will be described below. FIG. 7A shows a perspective view of a conventional package. FIG. 7B is a cross-sectional view of the package shown in FIG. 7A in the DD line direction. FIG. 8 shows a cross-sectional view of a conventional resin molding process.

  As shown in FIG. 7A, the resin package 52 of the hybrid integrated circuit device 51 is formed as a full package type covering the entire surface of the circuit board 59 (see FIG. 7B). A plurality of leads 55 are led out from the side surfaces 53 and 54 in the longitudinal direction of the resin package 52. Then, U-shaped holes 58 for screwing are arranged on the side surfaces 56 and 57 in the short direction of the resin package 52.

  As shown in FIG. 7B, the upper surface of the circuit board 59 is covered with an insulating layer 60, and a conductive pattern 61 is disposed on the upper surface of the insulating layer 60. A circuit element such as a semiconductor element 62 is fixed on the conductive pattern 61, and the conductive pattern 61 and the lead 55 are electrically connected by a thin metal wire 63. Then, the circuit board 59, the semiconductor element 62, the fine metal wire 63, and the like are completely sealed in the resin package 52.

  As shown in FIG. 8, the circuit board 59 is accommodated in the cavity 66 of the resin-sealed mold by sandwiching the leads 55 by the upper mold 64 and the lower mold 65 of the resin-sealed mold. At this time, a gap filled with resin is formed between the back surface of the circuit board 59 and the lower mold 65. 7A, since a plurality of leads 55 are arranged on the side surfaces 53 and 54 in the longitudinal direction of the resin package 52, for example, the side surfaces 56 and 57 side in the short direction of the resin package 52 Then, resin is injected into the cavity 66 (see, for example, Patent Document 1).

JP 2007-273698 A (page 7-9, FIGS. 1, 5)

  On the side surfaces 53, 54 in the longitudinal direction of the conventional resin package 52, a plurality of leads 55 are arranged at regular intervals, and there is no region where a gate portion (not shown) of a resin-sealed mold is arranged. Therefore, the gate portion of the resin sealing mold is arranged on the side surfaces 56 and 57 in the short direction of the resin package 52. As a result, the resin injected into the cavity 66 is filled into the cavity 66 along the longitudinal direction of the circuit board 59 from the gate portion, making it difficult to control the flow direction of the injected resin. Specifically, the resin is filled from the central region of the cavity 66 toward the facing surface side from the gate portion, so that the air in the cavity 66 becomes a certain region (air vent formation region) at the end of the cavity 66. It will be driven. However, since the resin is filled along the longitudinal direction of the circuit board 59, the depth of the cavity 66 is increased, and the flow direction of the resin is difficult to control. And it becomes difficult for the air in the cavity 66 to be driven into a certain region (air vent formation region) at the end of the cavity 66. As a result, there is a problem that air in the cavity 66 remains in the cavity 66 and an unfilled region (void) is generated in the resin package 52.

  In particular, on the back surface side of the circuit board 59, the heat generated from the semiconductor element 62 or the like and conducted to the circuit board 59 is efficiently released to the outside of the resin package 52, so that the resin thickness needs to be reduced. On the other hand, the surface side of the circuit board 59 completely covers the semiconductor element 62, the fine metal wires 63, etc., so that the resin thickness is increased and the resin flow path width is increased. With this structure, the resin filled in the cavity 66 flows more easily on the front surface side of the circuit board 59, and the resin wraps around the back surface side of the circuit board 59 also from the front surface side. As a result, as described above, on the back surface side of the circuit board 59, the resin flows from various directions, the air in the cavity 66 remains, and an unfilled region is easily generated in the resin package 52. Then, since the unfilled region is generated on the back surface side of the resin package 52, there arises a problem that the breakdown voltage characteristic of the hybrid integrated circuit device 51 is deteriorated.

The circuit device of the present invention includes a rectangular circuit board in which a hybrid integrated circuit having a conductive pattern and a circuit element fixed to the conductive pattern is incorporated on an upper surface, and a pair of the circuit boards fixed on the conductive pattern. A plurality of leads respectively disposed along the longitudinal direction of the resin package, and a resin package covering the circuit board, and at least one side surface of the resin package led out by the leads is injected with resin between the leads There is a gap in which the gate portion is arranged, and the gap is arranged in a central region of the one side surface, and the resin package is a package that completely covers the circuit board, and on the surface side of the resin package characterized by Rukoto groove is formed along the one side surface to the resin injection gate side.

In the method of manufacturing a circuit device according to the present invention, a rectangular circuit board in which a hybrid integrated circuit having a conductive pattern and a circuit element fixed to the conductive pattern is incorporated on the upper surface is housed in a cavity of a resin-sealed mold. In the method of manufacturing a circuit device for forming a resin package by resin molding the circuit board, the leads are fixed on the conductive patterns along the longitudinal direction of the pair of circuit boards, and the leads are sandwiched. After the circuit board is housed in the cavity of the resin-sealed mold, the resin-sealed mold of the resin-sealed mold disposed in the center region on the side surface in the longitudinal direction of the circuit board and in the gap between the leads wherein the gate portion, the resin is injected into the cavity along the lateral direction of the circuit board, the entrance to the cavity of the gate portion, a back surface of the circuit board Characterized in that it is arranged at the same height as the gap between Aburafu metal mold.

  In the present invention, since the resin injection gate portion is provided in the central region of the side surface in the longitudinal direction of the resin package, the depth in the resin flow direction is narrowed, and generation of an unfilled region of the resin package can be suppressed.

  Further, in the present invention, since the grooves are disposed on the surface side of the resin package along the longitudinal direction, the flow of the resin on the surface side of the circuit board can be easily controlled.

  Further, in the present invention, the circuit element is arranged in a certain region on the circuit board, thereby preventing the metal thin wire from falling.

  Also, in the present invention, the resin filling gate portion is arranged in accordance with the gap between the circuit board and the lower mold, so that the resin on the back side of the circuit board is preferentially filled, and an unfilled region is generated. Can be suppressed.

  In the present invention, by adjusting the flow rate of the resin on the front surface side of the circuit board by the protruding portion of the upper mold, the resin injection speed can be increased, and the resin can be smoothly filled on the back surface side of the circuit board.

It is a perspective view for demonstrating the circuit apparatus in embodiment of this invention. It is a top view for demonstrating the circuit apparatus in embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a cross-sectional view, FIG. 2B is a cross-sectional view, and FIG. It is (A) top view and (B) sectional drawing for demonstrating the manufacturing method of the circuit device in embodiment of this invention. It is a figure for demonstrating the manufacturing method of the circuit device in embodiment of this invention. It is (A) sectional drawing, (B) sectional drawing, (C) sectional drawing for demonstrating the manufacturing method of the circuit device in embodiment of this invention. It is (A) perspective view for demonstrating the circuit apparatus in the conventional embodiment, (B) It is sectional drawing. It is sectional drawing for demonstrating the manufacturing method of the circuit apparatus in conventional embodiment.

  A circuit device according to an embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a perspective view illustrating a circuit device. FIG. 2 is a plan view illustrating the circuit device. 3A to 3C are cross-sectional views illustrating a circuit device.

  First, as shown in FIG. 1, the resin package 2 of the hybrid integrated circuit device 1 is a full mold type package that covers the entire surface of the circuit board 15 (see FIG. 2). A plurality of leads 5 are led out from the side surfaces 3 and 4 in the longitudinal direction of the resin package 2. On the other hand, U-shaped holes 8 for screwing are disposed on the side surfaces 6 and 7 in the short direction of the resin package 2. Then, on the side surface 4 side of the resin package 2, the leads 5 are spaced apart from both sides of the side surface 4, and a gate portion for resin injection is disposed in the central region.

  A groove 10 is disposed on the surface 9 of the resin package 2 along the longitudinal direction thereof. Although details will be described later, the groove 10 is provided to control the flow and speed of the resin during the resin molding process, and the side surface 4 side of the groove 10 has a width W1, and by adjusting the width W1, Flow and speed are adjusted. On the other hand, the side surface 3 side of the groove 10 has a width W2, and the position recognition marks 11 to 14 are arranged on the surface 9 of the resin package 2. For example, the position recognition mark 11 is a mirror surface, and the position recognition marks 12 to 14 are pear ground.

  Next, as shown in FIG. 2, a state in which the leads 5 are mounted on the rectangular circuit board 15 is shown. Although not shown, a conductive pattern 16 is disposed on the circuit board 15, and circuit elements such as semiconductor elements and capacitors are mounted on the conductive pattern 16 to form a hybrid integrated circuit. As described above, the groove 10 (see FIG. 1) is disposed on the alternate long and short dash line 17 of the circuit board 15, and only the conductive pattern 16 is disposed on the circuit board 15 located in the region of the width W1. On the other hand, a circuit element is mounted on the conductive pattern 16 in the circuit board 15 located in the region of the width W2. That is, in the region of the width W1, the resin inflow speed at the time of resin molding is high, and it is used as a region where no circuit element is arranged in order to prevent the metal thin wire from falling down.

  Next, FIG. 3A is a cross-sectional view taken along the line AA in FIG. As shown in the figure, the circuit board 15 is made of a metal substrate whose main material is a metal such as aluminum (Al) or copper (Cu), and has a thickness of about 1.5 mm, for example. For example, when an Al substrate is used as the circuit board 15, an oxide film is formed on the front and back surfaces and anodized.

The insulating layer 18 covers the entire upper surface of the circuit board 15 and has a thickness of about 50 μm. The insulating layer 18 is made of an epoxy resin that is highly filled with a filler such as Al ₂ O ₃ by about 60 to 80% by weight, for example. The insulating layer 18 is reduced in thermal resistance by mixing the filler, and heat dissipation from the circuit element 15 to the circuit board 15 is improved.

  The conductive pattern 16 is made of a metal such as Cu, and is arranged in a pattern on the upper surface of the insulating layer 18. The film thickness and width of the conductive pattern 16 are, for example, about 50 to 100 μm. Circuit elements such as a semiconductor element 19 and a chip capacitor 20 are mounted on the conductive pattern 16. As other circuit elements, for example, passive elements such as chip resistors, inductances, oscillators, and active elements are employed.

  The resin package 2 is formed so as to cover the entire surface of the circuit board 15. When the resin package 2 is formed by transfer molding, a thermosetting resin is used. When the resin package 2 is formed by injection molding, a thermoplastic resin is used. In the resin constituting the resin package 2, a filler such as silicon oxide for improving the thermal conductivity is mixed.

  The thickness T1 of the resin package 2 on the back surface side of the circuit board 15 is, for example, about 0.5 mm. By reducing the thickness T1, heat dissipation from the circuit board 15 to the outside of the resin package 2 is improved. As described above, the groove 10 is arranged in the resin package 2 on the surface side of the circuit board 15, and the thickness T2 of the resin package 2 in the arrangement region of the groove 10 is, for example, about 0.5 to 1.0 mm. The thickness T3 of the resin package 2 in other regions is, for example, about 3.5 mm. In this cross section, a resin injection gate is disposed on the side surface 4 of the resin package 2 as indicated by a circle 21. On the other hand, the lead 5 is led out from the side surface 3 of the resin package 2.

  Next, FIG. 3B is a cross-sectional view taken along the line BB in FIG. In addition, the same number is attached | subjected to the same structural member as the structural member shown to FIG. 3 (A), and the description is referred. In the cross section shown in the drawing, the lead 5 is also led out from the side surface 4 of the resin package 2, and the resin injection gate portion indicated by the circle 21 in FIG. 2A is not disposed.

  Next, FIG. 3C is a cross-sectional view taken along the line CC of FIG. In addition, the same number is attached | subjected to the same structural member as the structural member shown to FIG. 3 (A), and the description is referred. In the cross section shown in the drawing, the conductive pattern 16 or the like is not disposed on the circuit board 15, and the thickness of the resin package 2 on the upper surface thereof is T2. As described above, the U-shaped holes 8 for screwing are disposed on the side surfaces 6 and 7 of the resin package 2. In the vicinity of the end of the circuit board 1, a hole 22 is formed by a guide pin that is fixed to the circuit board 15 during resin molding.

  As shown in the drawing, on the both side surfaces 6 and 7 side of the resin package 2, a region having a thickness T <b> 2 on the surface side of the circuit board 15 is arranged along the short direction of the circuit board 15. Although details will be described in the resin molding process, in the region of the thickness T2 of the resin package 2, since the speed of the resin at the time of resin molding can be slowed, the wraparound of the resin from the front surface side to the back surface side of the circuit board 15 is delayed. Can do. As a result, it is possible to prevent an unfilled region (void) from being generated in the resin package 2 on the back surface side of the circuit board 15, and it is possible to prevent the breakdown voltage characteristics of the hybrid integrated circuit device 1 from being deteriorated or the package is defective. That is, the above-described effects can be obtained by disposing a region thinner than the thickness T3 on the circuit board 15 on both side surfaces 6 and 7 of the resin package 2. In addition, in the arrangement | positioning area | region of the U-shaped hole 8, mechanical strength has priority and the thickness of the resin package 2 also becomes thick.

  Next, with reference to FIGS. 4-6, the manufacturing method of the circuit apparatus which is one Example of this invention is demonstrated. FIG. 4A is a plan view for explaining a lead frame. FIG. 4B is a cross-sectional view illustrating the mounting process. FIG. 5 is a diagram illustrating a resin molding process. 6A to 6C are cross-sectional views illustrating a resin molding process. In this embodiment, in order to describe the manufacturing method of the structure shown in FIGS. 1 to 3, the same constituent members are given the same reference numerals, and FIGS. refer.

  First, as shown in FIG. 4A, for example, a lead frame 31 mainly made of copper is prepared. The lead frame 31 extends in the X-axis direction on the paper surface, and a plurality of units 32 indicated by dotted lines are arranged on the lead frame 31. In each unit 32, a plurality of leads 5 are arranged apart from each other in the Y-axis direction on the paper surface, and the arrangement area of the circuit board 15 is in the central area. The plurality of leads 5 are connected to each other by a tie bar 33 extending in the X-axis direction on the paper surface and fixed to the lead frame 31. In addition, index holes 34 are provided in the upper and lower end regions in the X-axis direction of the lead frame 31 on the paper surface, and are used for positioning in each process.

  Next, as shown in FIG. 4B, a circuit board 15 is prepared, and an insulating layer 18 and a conductive pattern 16 are formed on the circuit board 15. Note that the circuit board 15 on which the insulating layer 18 and the conductive pattern 16 are formed in advance may be prepared. Next, in a die bonding process, a circuit element such as the semiconductor element 19 is fixed on the conductive pattern 16 with a conductive adhesive. Next, the semiconductor element 19 and the conductive pattern 16 are connected by the thin metal wire 35 in the wire bonding process. Thereafter, the lead 5 is fixed onto the conductive pattern 16 with a conductive adhesive, and the circuit board 15 is fixed to the lead frame 31 for each unit 32.

  Next, the resin molding process will be described with reference to FIGS.

  First, FIG. 5 shows a state in which the circuit board 15 is disposed in the resin-sealed mold 36 as indicated by a dotted line. In the resin-sealed mold 36, the circuit board 15 is installed in the cavity by sandwiching the leads 5 for each unit 32 of the lead frame 31. Then, resin is injected into the cavity from the gate portion 37 on the lower side of the drawing, and the cavity is filled with resin to form the resin package 2.

  At this time, first, the gate portion 37 is arranged in the central region of the side surface in the longitudinal direction of the circuit board 15, thereby making it easy to control the injection of the resin into the cavity. Specifically, the resin is injected along the short direction of the circuit board 15, thereby reducing the depth in the resin injection direction. And as shown with a dashed-dotted line, resin is filled into the outer peripheral area | region from the center area | region in a cavity in the front and back of the circuit board 15. FIG. As a result, the air in the cavity is repelled to the end of the cavity where the air vent 38 is provided.

  Next, in the resin-sealed mold 36, air vent portions 38 are arranged on both sides on the upper side of the paper, and the air and resin in the cavity are discharged to the outside of the cavity. As described above, the air in the cavity is surely driven to the end of the cavity depending on the position of the gate portion 37. And the air vent part 38 is arrange | positioned in the area | region where resin is finally filled in a cavity, The air in a cavity is discharged | emitted efficiently and generation | occurrence | production of the unfilled area | region of the resin package 2 can be prevented.

  Next, although details will be described later with reference to FIG. 6A, a protrusion 39 is disposed on the upper mold of the resin-sealed mold 36 along the longitudinal direction of the circuit board 15. The protruding portion 39 is disposed in the vicinity of the gate portion 37, controls the flow and speed of the resin on the front surface side of the circuit board 15, and prevents the resin from wrapping around from the front surface side to the back surface side of the circuit board 15 and falling of the fine metal wires. To do.

  6A shows a cross section in which the gate portion 37 of the resin-sealed mold 36 is disposed, corresponding to the cross section in the direction of the line AA in FIG. The lead 5 is sandwiched between the contact surfaces of the upper mold 40 and the lower mold 41, and the circuit board 15 is accommodated in the cavity 42 of the resin-sealed mold 36. As indicated by a circle 43, the entrance of the gate portion 37 continuing to the cavity 42 opens from the lower mold 41 surface, for example, by about 0.55 mm, and is substantially the same as the gap between the circuit board 15 and the lower mold 41. Placed at height. The gap is a narrow region of about 0.5 mm, for example, but the resin injected from the gate portion 37 smoothly flows into the back side of the circuit board 15 without being blocked by the circuit board 15.

  On the other hand, the resin injected from the gate portion 37 flows through the gap between the side surface of the circuit board 15 and the upper mold 40 and also flows into the surface side of the circuit board 15. The gap on the front surface side of the circuit board 15 is, for example, about 3.5 mm, which is wider than the back surface side of the circuit board 15 and is an area where the resin flows easily. As described above, the resin flow on the surface side of the circuit board 15 is controlled by disposing the protrusion 39 on the upper mold 40. For example, by setting the gap between the surface of the circuit board 15 and the tip of the protruding portion 39 to about 0.5 to 1.0 mm, the speed of the resin flowing beyond the protruding portion 39 can be delayed.

  That is, on the back surface side of the circuit board 15, the resin filling speed is slow because the entire area is a narrow gap of about 0.5 mm, but the position on the front surface side of the circuit board 15 depends on the position of the gate portion 37 and the protrusion 39. By slowing down the resin filling speed, it becomes easy to preferentially fill the resin from the back side of the circuit board 15. In particular, in a region away from the gate portion 37, it is possible to suppress the occurrence of an unfilled region in the resin package 2 on the back surface side of the circuit board 15 by eliminating the wraparound of the resin from the front surface side to the back surface side of the circuit substrate 15. .

  Further, on the surface side of the circuit board 15, no circuit element is arranged in the region 44 closer to the gate portion 37 than the protruding portion 39, and no fine metal wire is arranged. Therefore, even when the injection rate of the resin from the gate portion 37 is increased, the metal thin wire collapse does not become a problem. As described above, since the speed of the resin to the area 45 beyond the protruding portion 39 is suppressed, the resin injection speed can be increased within a range where the metal thin wire collapse does not occur in the area 45. As a result, on the back surface side of the circuit board 15, the resin injection speed is high, and the resin is more preferentially filled than the front surface side of the circuit board 15.

  Next, FIG. 6B shows a cross section in which the gate portion 37 of the resin-sealed mold 36 is not disposed, corresponding to the cross section in the BB line direction of FIG. Also in this cross section, as described above, by controlling the flow and speed of the resin on the front surface side of the circuit board 15 by the protrusion 39 of the upper mold 40, the back surface side of the circuit board 15 is preferentially filled with the resin. It becomes easy.

  Next, FIG. 6C shows a cross section in which the air vent portion 38 is disposed. In this cross section, the circuit board 15 maintains an appropriate position in the cavity 42 by the position pins 46 provided in the upper mold 40. As described above, the resin is preferentially filled from the back surface side of the circuit board 15, and the circuit board 15 easily tilts toward the upper mold 40, but the tilt is prevented by the position pins 46. Further, by reducing the gap between the circuit board 15 and the upper mold 40 along the short direction of the circuit board 15, as described above, the resin wraps around from the front surface side to the back surface side of the circuit board 15. Can be prevented.

  In addition, the air driven into the end of the cavity 42 flows into the air vent portion 38 together with the resin, thereby preventing the unfilled region in the resin package 2 from being generated. As indicated by a circle 47, the passage between the cavity 42 and the air vent portion 38 is widened, and the resin is also allowed to flow into the air vent portion 38, thereby preventing the occurrence of an unfilled region at the end of the resin package 2. it can. The upper mold 40 may be provided with a passage 48 through which only air escapes from the air vent portion 38.

  Finally, the resin package 2 is separated for each unit 32 from the lead frame 31 released from the resin sealing mold 36, and the hybrid integrated circuit device 1 shown in FIG. 1A is completed.

DESCRIPTION OF SYMBOLS 1 Hybrid integrated circuit device 2 Resin package 10 Groove 15 Circuit board 31 Lead frame 37 Gate part 38 Air vent part 39 Protrusion part

Claims (4)

A rectangular circuit board in which a hybrid integrated circuit having a conductive pattern and a circuit element fixed to the conductive pattern is incorporated on the upper surface;
A plurality of leads fixed on the conductive pattern and respectively disposed along the longitudinal direction of the pair of circuit boards;
A resin package covering the circuit board;
At least one side surface of the resin package from which the lead is led out has a gap where a resin injection gate portion is arranged between the leads, and the gap is arranged in a central region of the one side surface,
The resin package is a package that fully covers the circuit board, wherein the surface side of the resin package, characterized by Rukoto groove is formed along the one side surface to the resin injection gate side Circuit device.   The circuit device according to claim 1, wherein the circuit element is disposed on the circuit board between the other side surface where the lead is led out from the groove. A rectangular circuit board in which a hybrid integrated circuit having a conductive pattern and a circuit element fixed to the conductive pattern is incorporated on the upper surface is accommodated in a cavity of a resin-sealed mold, and the circuit board is resin-molded. In a method for manufacturing a circuit device for forming a resin package,
A lead is fixed on each of the conductive patterns along the longitudinal direction of the pair of circuit boards, the leads are sandwiched, and the circuit boards are stored in the cavities of the resin-sealed molds. Resin is injected into the cavity along the short direction of the circuit board from the gate portion of the resin-sealed mold, which is a central region on the side surface in the longitudinal direction and disposed in the gap between the leads. ,
The circuit device manufacturing method , wherein an entrance of the gate portion into the cavity is arranged at the same height as a gap between a back surface of the circuit board and the resin-sealed mold . The resin-sealed mold on the surface side of the circuit board is provided with a protruding portion along the longitudinal direction of the circuit board, and the flow rate of the resin flowing to the circuit board surface side is increased by the protruding portion. 4. The method of manufacturing a circuit device according to claim 3, wherein the circuit device is slowed down.

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