JP6539956B2 - Lead frame, resin molded body, surface mount type electronic component, surface mount type light emitting device, and lead frame manufacturing method - Google Patents

Description

  The present invention relates to a lead frame to which a chip part is attached, a resin molded body using the lead frame, a surface mounted electronic component, and a surface mounted light emitting device. The present invention also relates to a method of manufacturing a lead frame.

  Conventionally, when a chip (bare chip) such as a diode or a light emitting diode (LED) is sealed in a package, a lead frame for connecting the chip to the outside of the package has been widely used. In addition, when attaching a chip to a lead frame, there is known a so-called flip chip mounting technology in which the chip is directly attached to the lead frame instead of wire bonding.

  In such flip chip mounting, a lead frame may be used as a plurality of leads such as a positive electrode and a negative electrode. In such a case, the leads are separated for insulation, and the chip is mounted across the separated leads (see, for example, Patent Document 1).

Unexamined-Japanese-Patent No. 5-291345

  By the way, in recent years, the miniaturization of chips has progressed, the surface area of the chips has decreased, and the difficulty of heat radiation has increased. Therefore, there is a need to further improve the heat dissipation effect of the chip.

  An object of the present invention is to provide a lead frame that can easily improve the heat dissipation effect of a chip, a resin molded body using the lead frame, a surface mounted electronic component, and a surface mounted light emitting device. Another object of the present invention is to provide a lead frame manufacturing method for manufacturing this lead frame.

  The lead frame according to the present invention includes a plate-like first lead and a second lead for mounting a chip, and the first and second leads are spaced apart in the same plane, At least one of a first end which is an end on the spacing side of the first lead, and a second end which is an end of the second lead disposed opposite to the first end across the spacing. In the first region of the portion, the distance is narrower than the thickness of the central portion of the first and second leads, and the distance is such that the chip crosses the distance in the first region and one end thereof is the first lead, The other end is provided to be attachable to the second lead.

  According to this configuration, since the chip is mounted on the first lead and the second lead, the first lead and the second lead function as a heat dissipation plate of the chip. In addition, since the distance between the first lead and the second lead is smaller than the thickness of the central portion of the first and second leads, the area of the area where there is no lead is reduced, and the area of the first and second leads As a result of the increase in area, it becomes easy to improve the heat dissipation effect of the chip. Further, in the first region of the lead frame, when the chip is attached to the first lead and the other end to the second lead across the gap, the lead area facing the lower surface of the chip becomes large. It becomes easy to make the lead contact the lead and radiate heat.

  Further, the end face of the first lead and the end face of the second lead, which face each other across the gap in the first region, are the first and second leads from the attachment surface side of the chip in the first and second leads. It is preferable that the space is formed to be wider as it is separated in the thickness direction of the second lead.

  Since the distance in the first region is smaller than the thickness of the leads, when the lead frame is integrally molded with the resin, it is difficult for the resin to enter between the first lead and the second lead. Therefore, according to this configuration, the distance between the end face of the first lead and the end face of the second lead facing each other across the gap increases as the distance from the chip attachment surface to the thickness direction of the first lead and the second lead increases. By forming as described above, the resin is easily inserted between the both end surfaces, the bond between the first lead and the second lead and the resin becomes stronger, and the resin becomes difficult to peel off.

  Further, it is preferable that a protrusion is formed in the first area in the vicinity of an end edge extending along the interval on one surface of the first and second leads.

  According to this configuration, when the projection is formed on the chip mounting surface side, the projection is in contact with the lower surface of the chip to which it is attached, and the thermal resistance between the chip and the lead is reduced. Is easy to improve. In addition, when the projection is formed on the surface opposite to the chip attachment surface, the first lead and the second lead can be made by incorporating the resin into the resin when the first lead and the second lead are integrally molded with the resin. The bond between the resin and the resin becomes stronger, making it difficult for the resin to peel off.

  In addition, the first region is a region including central portions of the first and second edges and excluding the vicinity of both ends of the first and second edges, and the first region is the region among the first and second edges. Preferably, in the second region excluding the first region, the distance is equal to or greater than the thickness of the central portion of the first and second leads.

  According to this configuration, since the second regions, which are wider than the first region and wider than the lead thickness, are provided on both sides of the narrow first region, the second region to the first region are wider. The resin can be poured into the interval of As a result, it becomes easy to fill the resin into the gap of the first region where the gap is narrow and the resin hardly enters.

  Preferably, the second region includes a third region in which the distance is substantially constant, and a fourth region in which the distance gradually increases toward the ends of the first and second end edges.

  According to this configuration, when the lead frame is integrally molded with the resin, the resin is guided to the third region by the fourth region by gradually narrowing the introduction path of the resin, and the distance from the third region to the first region Since the resin can be poured into, it is easy to fill the resin in the interval where the interval is narrow and the resin is difficult to enter.

  Preferably, at least a part of the outer edge of the first and second leads is thinner than the central portion of the first and second leads.

  According to this configuration, at least a part of the outer edge of the first and second leads is thinned, so when the lead frame is integrally molded with the resin, the resin flow path becomes wider at the thin portion, and the lead frame As a result of the resin being easily spread over the entire surface, it becomes easy to efficiently and uniformly supply the resin to the lead frame. Further, the bond between the first lead and the second lead and the resin becomes stronger, and the resin is less likely to be peeled off from the first lead and the second lead.

  Moreover, it is preferable that the said space | interval in a said 1st area | region is less than 100 micrometers.

  In order to effectively produce the heat dissipation effect of the chip by the leads, the distance between the first regions to which the chip is attached is preferably less than 100 μm.

  Moreover, as for the said space | interval in a said 1st area | region, it is more preferable that it is less than 50 micrometers.

  In order to effectively produce the heat dissipation effect of the chip by the leads, the distance between the first regions to which the chip is attached is more preferably less than 50 μm.

  Moreover, it is preferable that the said space | interval in a said 1st area | region is formed by irradiating energy from one surface side with respect to a conductive plate-shaped member, and cut | disconnecting the said plate-shaped member.

  According to this configuration, it is easy to form an interval narrower than the thickness of the leads by narrowing down the irradiation width of energy.

  Moreover, it is preferable that the said energy is a laser beam.

  According to laser processing, it is easy to form the space of the first region with a line width smaller than the thickness of the lead, less than 100 μm, or less than 50 μm.

  In addition, it is preferable that a region different from the first region at the outer edge of the first and second leads is formed by etching or punching.

  Etching or punching is not suitable for forming a gap narrower than the thickness of the leads as in the first region, but the processing cost is low. Therefore, unlike the first region, it is easy to reduce the manufacturing cost of the lead frame by processing the portion where the lead interval does not need to be narrowed by etching or punching.

  A resin molded body according to the present invention includes the above-described lead frame and a resin layer integrally formed with the lead frame.

  Since this resin molded body is provided with the above-mentioned lead frame, it is easy to improve the heat dissipation effect of the chip.

  Further, in the surface mount type electronic component according to the present invention, the first end of the lead frame, the resin layer integrally formed with the lead frame, and the first end across the interval in the first region of the lead frame. The lead includes the chip whose other end is attached to the second lead.

  According to this configuration, the heat generated in the chip is dissipated by the first and second leads, and the distance between the leads in the first region is smaller than the thickness of the leads, whereby the heat radiation area of the first and second leads As a result of the increased lead area and the increased lead area facing the lower surface of the chip, it is easy to dissipate the heat of the chip to the first and second leads. As a result, it becomes easy to improve the heat dissipation effect of the chip.

  Further, in the surface mount type light emitting device according to the present invention, the first end of the lead frame, the resin layer integrally formed with the lead frame, and the first end across the distance in the first region of the lead frame. The lead includes the light emitting element as the chip, the other end of which is attached to the second lead.

  According to this configuration, the heat generated in the light emitting element is dissipated by the first and second leads, and the distance between the leads in the first region is made narrower than the thickness of the leads, so that the radiation of the first and second leads is dissipated. As the area is increased and the lead area facing the lower surface of the light emitting element is increased, it is easy to dissipate the heat of the light emitting element to the first and second leads. As a result, the heat dissipation effect of the light emitting element can be easily improved.

  A lead frame manufacturing method according to the present invention is the lead frame manufacturing method for manufacturing the above-described lead frame, and the space is cut by cutting a conductive plate member with a laser beam in the first region. The laser processing step to be formed, and the outer edge processing step of forming the outer edge of the first and second leads by cutting the plate-like member by etching or punching in a region different from the first region.

  According to this configuration, since the laser light is used for processing the first region, it is easy to form the interval narrower than the thickness of the lead. Further, unlike the first region, it is easy to reduce the manufacturing cost of the lead frame by processing a portion where it is not necessary to narrow the lead interval by etching or punching at low processing cost.

  Further, the outer edge processing step is a step of performing etching, and it is preferable to execute the outer edge processing step after the laser processing step is performed.

  According to this configuration, it is possible to remove the debris or dross generated in the laser processing process by etching.

  The lead frame, the resin molded body, the surface mounted electronic component, the surface mounted light emitting device, and the lead frame manufacturing method of such a configuration facilitate improving the heat dissipation effect of the chip.

FIG. 1 is a top view schematically showing an entire configuration of a lead frame according to an embodiment of the present invention. It is the elements on larger scale of the lead frame shown in FIG. It is a three-sided figure which showed the unit mounting area | region shown in FIG. 2 by the third trigonometry. It is a front view which shows the modification of the lead frame shown in FIG. It is a front view which shows the modification of the lead frame shown in FIG. It is XX sectional drawing which shows the modification of the lead frame shown in FIG. It is XX sectional drawing which shows the modification of the lead frame shown in FIG. It is the elements on larger scale which show the modification of the lead frame shown in FIG. It is an explanatory view for explaining an example of a manufacturing method of a lead frame concerning one embodiment of the present invention. It is an explanatory view for explaining an example of a manufacturing method of a lead frame concerning one embodiment of the present invention. It is a flowchart for demonstrating the manufacturing method of the surface mounted type light-emitting device which concerns on one Embodiment of this invention. It is explanatory drawing for demonstrating the manufacturing method of the surface mounted type light-emitting device shown in FIG. It is explanatory drawing for demonstrating the manufacturing method of the surface mounted type light-emitting device shown in FIG. It is explanatory drawing for demonstrating the manufacturing method of the surface mounted type light-emitting device shown in FIG. It is explanatory drawing for demonstrating the manufacturing method of the surface mounted type light-emitting device shown in FIG.

  Hereinafter, an embodiment according to the present invention will be described based on the drawings. In each of the drawings, the same reference numerals are given to components corresponding to each other, and the description thereof will be omitted. FIG. 1 is a top view schematically showing the entire configuration of a lead frame 1 according to an embodiment of the present invention. The lead frame 1 is formed by subjecting a thin plate-like, substantially rectangular metal plate or the like having a conductive property to processing such as etching or punching using a press. Although the material of the metal plate is not particularly limited, for example, iron, copper, phosphor bronze, copper alloy and the like can be used. In addition, the entire surface of the lead frame 1 or a part of the surface may be plated.

  The lead frame 1 is configured by arranging a plurality of unit mounting areas 10 in a matrix in vertical and horizontal directions. Each unit mounting area 10 includes a plate-like first lead 20 and a second lead 21 which are arranged in the same plane and separated from each other in the same plane. Slits 22 (spaces) extending in the longitudinal direction are formed between the first lead 20 and the second lead 21. The slits 22 constitute an interval between the first lead 20 and the second lead 21 belonging to the unit mounting area 10. Further, between each unit mounting area 10, the first lead 20 and the second lead 21 of each unit mounting area 10 are between the first lead 20 and the second lead 21 of another adjacent unit mounting area 10. It is arranged with intervals.

  The first lead 20 and the second lead 21 have a substantially rectangular shape. Through holes such as so-called anchor holes may be formed in the first lead 20 and the second lead 21. Although the example in which the lead frame 1 includes a plurality of unit mounting areas 10 is shown, the lead frame 1 may be configured from one unit mounting area 10.

  Hereinafter, the direction in which the first lead 20 and the second lead 21 are arranged will be referred to as the lateral direction, and the direction intersecting (substantially orthogonal, substantially orthogonal) with the lateral direction will be referred to as the longitudinal direction. Also, the first lead 20 and the second lead 21 may be collectively referred to simply as "lead".

  Around the aggregate 11 of the plurality of unit mounting areas 10, a substantially rectangular frame 12 surrounding the aggregate 11 is provided at intervals. In the figure, the frame 12 has a strip-shaped frame side 12 a extending in the lateral direction below the aggregate 11, a strip-like frame side 12 b extending in the lateral direction above the aggregate 11, and the aggregate 11. A strip-like frame side 12c extending along the vertical direction on the left side of the frame and a strip-like frame side 12d extending along the vertical direction on the right side of the assembly 11 are formed in a frame shape.

  The first leads 20 and the second leads 21 are connected to the first leads 20 and the second leads 21 of another unit mounting area 10 by connection pieces C described later. The assembly 11 is connected to the frame 12 by the connection piece C. As a result, the plurality of unit mounting areas 10 and the frame 12 are integrated as the lead frame 1 so that the unit mounting areas 10 are not separated.

  A plurality of long holes 14 elongated in the vertical direction are formed at predetermined intervals in the horizontal direction in the frame sides 12a and 12b of the frame 12, and the frame sides 12c and 12d are elongated in the horizontal direction A plurality of holes 14 are formed at predetermined intervals in the longitudinal direction. The long holes 14 indicate the dicing marks. In the cutting process to be described later, the lead frame 1 is first cut into a strip along the longitudinal direction by using the long hole 14 as a mark or inserting a dicing blade from the long hole 14. The lead frame 1 cut into strips is further cut along the lateral direction, whereby each unit mounting area 10 is separated into pieces. Although the example of cutting along the vertical direction has been described above, it may be cut along the horizontal direction first. The lead frame 1 is fixed in a mold having a cavity in a clamping step described later. At this time, for example, the edge of the cavity of the mold is arranged to cross the long hole 14 as indicated by a dashed dotted line 15.

  The lead frame 1 shown in FIG. 1 is a so-called MAP (Mold Array Package) type lead frame. When integrally molding a MAP type lead frame with a resin, a mold is used in which a single (one connection) cavity for containing the entire assembly 11 is formed. Thereby, for example, the entire area indicated by the alternate long and short dash line 15 in FIG. 1 is accommodated in a single cavity of the mold. In this state, the resin is supplied into the cavity from one end of the cavity of the mold to fill the cavity with the resin. Thus, a MAP-type resin molded body 5 described later is formed. In the MAP-type resin molded body 5, the entire assembly 11 is covered with resin. Then, the resin and the lead frame 1 are cut into a single piece to be singulated, and a surface mounted light emitting device 6 described later can be obtained.

  FIG. 2 is a partially enlarged view of the lead frame 1 shown in FIG. FIG. 2 shows four unit mounting areas 10 in an enlarged manner. In the example shown in FIG. 2, the second lead 21 and the first lead 20 are connected by, for example, a strip C extending between two unit mounting areas 10 adjacent to each other in the lateral direction. Further, between the two unit mounting areas 10 adjacent to each other in the vertical direction, the first leads 20 of each unit mounting area 10 and the second leads 21 are connected by, for example, connection strips C extending in a strip shape. Thereby, the positional relationship between each unit mounting area 10 and the positional relationship between the first lead 20 and the second lead 21 are maintained.

  In each of the first lead 20 and the second lead 21, two anchor holes H for improving the adhesion to the resin molded body are formed.

  FIG. 3 is a trihedral view showing the unit mounting area 10 shown in FIG. 2 by the third trigonometry. A first end edge 23 which is an end edge of the first lead 20 on the slit 22 side, and a second end edge 24 which is an end edge of the second lead 21 disposed opposite to the first end edge 23 across the slit 22 In a part of the first region A1 including the center of the gap, the distance W1 between the first lead 20 and the second lead 21 (the width of the slit 22, the distance between the first edge 23 and the second edge 24) is The thickness T1 is smaller than the thickness T1 of the central portion (the position of the center of gravity of the area) of the lead 20 and the second lead 21.

  The thickness T1 of the central portion of the first lead 20 and the second lead 21 is about 200 μm to 300 μm. The distance W1 between the first lead 20 and the second lead 21 in the first region A1 is 30 μm to 50 μm, and T1> W1. The spacing W1 is smaller than the thickness T1 and less than 100 μm, more preferably less than 50 μm.

  The chip 3 is flip-chip mounted so that the distance W1 is smaller than the thickness T1 and less than 100 μm, more preferably less than 50 μm, and straddles the first lead 20 and the second lead 21 as described later. Since the area of the first lead 20 and the second lead 21 arranged in the lower part of 3 increases, the contact area between the chip 3 and the first lead 20 and the second lead 21 can be easily increased, and the first lead It becomes easy to dissipate the chip 3 through the 20 and the second lead 21.

  The length of the chips 3 distributed in the market is about 0.5 mm to 1 mm, and it is expected that the chips 3 of about 0.3 mm will be released. As described above, even if the chip 3 is 0.3 mm in length, if the distance W1 is less than 100 μm, the chip 3 can be stably held even if the chip 3 is flip-chip mounted across the distance W1. The first lead 20 and the second lead 21 can be attached. Furthermore, if the distance W1 is less than 50 μm, the stability of the chip 3 attached to the first lead 20 and the second lead 21 is improved.

  The lead frame 1 (unit mounting area 10) may be flip-chip mounted so as to straddle the first lead 20 and the second lead 21. The chip 3 may not be flip chip mounted so as to straddle the two leads 21.

  In addition, since the area of the first lead 20 and the second lead 21 functioning as a heat sink can be increased by narrowing the gap W1, the heat radiation efficiency of the chip 3 can be improved. Furthermore, when a light emitting element is used as the chip 3, the first lead 20 and the second lead 21 also function as a reflecting mirror, so the surface of the first lead 20 and the second lead 21 is increased by increasing the area The luminous efficiency of the mounting type light emitting device 6 can be improved.

  In the second area A2 which is an area excluding the first area A1 of the first edge 23 and the second edge 24, a third area A3 connected to the first area and having a substantially constant interval W3, and a third area A fourth area A4 in which the distance W4 gradually expands toward the end E of the first end edge 23 and the second end edge 24 in series with A3 is included.

  The distance W3 is, for example, about 200 μm to 300 μm, which is the same as the thickness T1. The interval W4 is about twice the thickness T1, for example, about 400 μm to 600 μm when the end E is reached, that is, when it is enlarged to the maximum.

  Thereby, when the lead frame 1 is integrally molded with the resin, the resin introduction path is gradually narrowed to guide the resin to the third region A3 by the fourth region A4, and from the third region A3 to the first region A1. Since the resin can be poured into the space W1 of the above, it is easy to fill the resin into the space W1 where the space is narrow and the resin is difficult to enter.

  In addition, it is not necessary to necessarily provide 4th area | region A4, and 3rd area | region A3 may be continued to the edge part E. FIG. In addition, the third area A3 may not be provided, and for example, as shown in FIG. 4, the fourth area A4 may be formed to be continuous with the first area A1. Further, the second region A2 may not be provided, and for example, as shown in FIG. 5, the first region A1 may be formed to cross the first lead 20 and the second lead 21.

  Furthermore, the third area A3 and the first area A1 do not necessarily have to be continuous, and the third area A3 and the fourth area A4 do not have to be continuous. For example, as shown in FIG. 8, a widened portion may be provided between the third area A3 and the first area A1 such that the distance is wider than that of the third area A3.

  Thin edge portions 20a and 21a having a thickness T2 thinner than the thickness T1 are formed on portions of the outer peripheries of the first lead 20 and the second lead 21 excluding the first region A1. The thin edge portions 20a and 21a are thinned by processing means such as half etching, for example. The thickness T2 is, for example, about half of the thickness T1, and is, for example, about 100 μm to 150 μm.

  Since the thin edge portions 20a and 21a are thinner than the inner region, when the lead frame 1 is integrally formed with the resin, the resin is easily spread over the entire area of the assembly 11, and the resin of the assembly 11 is Supply can be performed efficiently and uniformly. Further, the bond between the first lead 20, the second lead 21, and the connection piece C and the resin becomes stronger, and the resin is less likely to be peeled from the first lead 20, the second lead 21, and the connection piece C.

  In the first region A1, when the thickness of the first region A1 is thin when performing laser processing to be described later, deformation may occur. Therefore, from the viewpoint of preventing deformation due to laser processing, it is preferable to set the first region A1 to a thickness T1. In addition, if it is not desired to form the protrusions 26 described later, it is conceivable to supply gas to the cut portion to eliminate debris, but in this case, the first region A1 is not subjected to half etching and the first region A1 It is preferable to set the same thickness T1 as the other portions in that the gas can easily flow.

  For example, as shown in FIG. 7, the thin edge portions 20a and 21a may be formed in the first area A1. Further, the first lead 20 and the second lead 21 may not have the thin edge portions 20a and 21a, and only one of the first lead 20 and the second lead 21 has the thin edge portions 20a and 21a. It may be done.

  Referring to FIG. 3, the end face 23a of the first lead and the end face 24a of the second lead facing each other across the gap W1 in the first region A1 are chips mounted on the chip in the first lead 20 and the second lead 21. As the distance from the surface A side in the thickness direction of the first lead 20 and the second lead 21 increases, the distance is increased. That is, the end face 23 a and the end face 24 a are formed to be inclined so as to be separated from the chip mounting surface A in the thickness direction of the first lead 20 and the second lead 21.

  Since the distance W1 in the first region A1 is smaller than the thickness T1, when the lead frame 1 is integrally molded with the resin, the resin is less likely to enter between the end face 23a and the end face 24a. Therefore, by forming the end face 23a and the end face 24a so that the distance increases in the thickness direction of the first lead 20 and the second lead 21 from the chip mounting face A side, resin is formed between the end face 23a and the end face 24a. The bond between the first lead 20 and the second lead 21 and the resin becomes stronger, and the resin becomes difficult to peel off.

  The facing distance between the end face 23a and the end face 24a is the narrowest distance W1 on the chip mounting surface A, and the widest position is the distance W1 + α. α is, for example, about 20 μm, and more specifically, α is, for example, 10 μm or more and 30 μm or less.

  6 and 7 are cross-sectional views along the line X-X showing a modification of the unit mounting area 10 shown in FIG. The unit mounting area 10 shown in FIG. 6A is a protrusion 25 near the first end 23 and the second end 24 of the first area A1 on the chip mounting surface A of the first lead 20 and the second lead 21. Are formed along the edge. The height h1 of the protrusion 25 is, for example, about 0.1 μm to 9 μm.

  FIG. 6B is an explanatory view showing a state in which the chip 3 is mounted in the unit mounting area 10 shown in FIG. 6A. The chip 3 is attached to the first lead 20 at one end thereof and to the second lead 21 at the other end thereof in the first region A1 with the chip 3 straddling the gap W1. Electrodes 31 corresponding to, for example, a positive electrode and a negative electrode are respectively provided at both ends of the chip 3. Then, each electrode 31 is soldered and attached to the first lead 20 and the second lead 21 by the solder 32.

  Here, when the electrode 31 is small, the portion of the chip 3 where the electrode 31 is not provided may float without being in close contact with the first lead 20 and the second lead 21.

  Therefore, the protrusion 25 is provided in the vicinity of the first end edge 23 and the second end edge 24 of the first region A1 so that the protrusion 25 comes in contact with the chip 3. It is possible to facilitate heat conduction and improve the heat dissipation performance of the chip 3.

  The unit mounting area 10 shown in FIG. 7A is the first end 23 and the second end of the first area A1 on the back surface B opposite to the chip mounting surface A of the first lead 20 and the second lead 21. A plurality of protrusions 26 are formed near the edge 24 along the edge. The height h2 of the protrusion 26 is, for example, about 0.1 μm to 9 μm.

  FIG. 7B is an explanatory view showing a state in which the chip 3 is mounted in the unit mounting area 10 shown in FIG. 7A. The chip 3 is attached to the first lead 20 at one end thereof and to the second lead 21 at the other end thereof in the first region A1 with the chip 3 straddling the gap W1. Electrodes 31 corresponding to, for example, a positive electrode and a negative electrode are respectively provided at both ends of the chip 3. Then, each electrode 31 is soldered and attached to the first lead 20 and the second lead 21 by the solder 32.

  Here, no protrusion is formed on the chip mounting surface A of the first lead 20 and the second lead 21 shown in FIG. 7B, and the chip mounting surface A is flat. As a result, by making the electrode 31 as large as possible, the area where the chip mounting surface A of the first lead 20 and the second lead 21 and the electrode 31 are in close contact and soldered is increased, and the chip 3 and the lead frame It is possible to facilitate heat conduction between 1 and 1 and to improve the heat dissipation performance of the chip 3.

  In addition, since the protrusion 26 is formed on the back surface B side near the first end edge 23 and the second end edge 24 of the first region A1, when the first lead 20 and the second lead 21 are integrally molded with a resin When the protrusion 26 is embedded in the resin, the bond between the first lead 20 and the second lead 21 and the resin becomes stronger, and the resin becomes difficult to peel off.

  In particular, the protrusion 26 is formed on the thin edge portions 20a and 21a which are the back surfaces of the important places where the chip 3 is mounted on the first lead 20 and the second lead 21 and which have a small thickness and weak lead strength. Because of this, by strengthening the bond with the resin of the portion where the strength is weak as such, it becomes possible to improve the reliability of the finished product such as the surface mount type light emitting device 6 or the like.

  Next, a method of manufacturing the lead frame 1 will be described. 9 and 10 are explanatory views for explaining an example of a method of manufacturing the lead frame 1 according to the embodiment of the present invention. Although only the unit mounting area 10 is shown in FIGS. 9 and 10 to simplify the description, in actuality, the entire lead frame 1 is processed as described later. The following description demonstrates the example which forms thin edge part 20a, 21a also to 1st area | region A1. In the following description, the same steps will be denoted by the same step numbers and the description thereof will be omitted.

  In the example shown in FIG. 9, first, a metal plate 35 of thickness T1 is prepared (step S1), an etching process is performed on the metal plate 35 (step S2), and then a laser process (step S2). Execute S3). The etching process corresponds to an example of the outer edge process.

  In the etching process (step S2), portions of the first lead 20 and the second lead 21 excluding the first region A1 and the connection piece C are formed by etching. In the etching process, no resist is formed on both sides of the portion where the metal plate 35 is to be cut. A resist is formed on the chip mounting surface A, while the first region on the back surface B side, in the vicinity of the inner side of the position to be the outer edge of the first lead 20 and the second lead 21 (location where thin edges 20a and 21a are to be formed). No resist is formed except for A1.

  Thus, in the etching process, an intermediate body 36 having a shape in which the first lead 20 and the second lead 21 are connected in the first region A1 is formed. At this time, the back surface B is half-etched to form thin thin edge portions 20a and 21a.

  Next, in the laser processing step (step S3), the first region A1 is cut along the vertical direction in the figure by laser processing, and a gap W1 is formed between the first lead 20 and the second lead 21. Be done. As described above, by performing the laser processing in the laser processing step, it is possible to form the minute interval W1 narrower than the thickness T1.

  As a method of processing the metal plate 35, various processing methods such as etching and punching with a die can be used besides laser processing. However, if the distance W1 is narrower than the thickness T1 of the metal plate 35, as in the first area A1, in etching, melting erosion spreads in the lateral direction in the process of melting and eroding the thickness T1 by the etchant. As a result, it is difficult to make the distance W1 narrower than the thickness T1. Also, in the case of punching using a die, if the distance W1 is made narrower than the thickness T1, the shape of the convex portion of the die becomes a thin plate, and the die has strength for punching the thickness T1. Therefore, the distance W1 can not be narrower than the thickness T1.

  On the other hand, in the case of laser processing, it is easy to make the distance W1 narrower than the thickness T1. For example, a fiber laser can be used as a laser device used for laser processing. Further, as an oscillation method of a laser, for example, a CW oscillation method (Continuous Wave Operation) and a pulse oscillation method can be suitably used. In the CW oscillation type laser device, so-called thermal processing is performed, and in the pulse oscillation type laser device, so-called non-thermal processing (ablation processing) is performed.

  For example, in the case where a CW oscillation type laser device is used in the laser processing step (step S3), the distance between the laser light incident side is increased by irradiating the intermediate body 36 with the laser light (energy) from the back surface B side As shown in FIG. 6A, the end face 23a and the end face 24a can be formed such that the distance increases as the distance from the chip mounting surface A to the first lead 20 and the second lead 21 increases. . At this time, as a result of the metal (so-called dross) melted by the laser light remaining on the chip mounting surface A, the projection 25 is formed.

  Thus, according to the CW oscillation type laser device (thermal processing), the distance between the end face 23a and the end face 24a increases as the distance from the chip mounting surface A to the thickness direction of the first lead 20 and the second lead 21 increases. It is easy to form the projection 25 on the chip mounting surface A in the vicinity of the first end 23 and the second end 24 of the first region A1 while forming as described above.

  Further, for example, when a pulse oscillation type laser device is used in the laser processing step (step S3), by irradiating the intermediate body 36 with laser light from the back surface B side, the interval becomes wider at the laser light incidence side, As shown in FIG. 7A, the end face 23a and the end face 24a can be formed such that the distance between the end face 23a and the end face 24a increases in the thickness direction of the first lead 20 and the second lead 21 from the chip mounting surface A side. At this time, the metal material is melted, evaporated, and scattered instantaneously at the portion of the surface of the intermediate body 36 where the laser light is irradiated. Then, the scattered metal material (so-called debris) is attached on the surface of the laser beam incident side (rear surface B side), and the projection 26 is formed.

  Thus, according to the pulse oscillation type laser device (non-thermal processing), the distance between the end face 23a and the end face 24a increases in the thickness direction of the first lead 20 and the second lead 21 from the chip mounting surface A side. It is easy to form the protrusion 26 on the back surface side near the first end edge 23 and the second end edge 24 of the first region A1 while forming to spread.

  In the example shown in FIG. 10, after preparing the metal plate 35 of thickness T1 (step S1), the laser processing step (step S3) is first executed to form the intermediate 37, and then the intermediate 37 is formed. The etching process (step S2) is performed. In the laser processing step (step S3) shown in FIG. 10, laser processing is performed over the entire vertical surface of the metal plate 35 so as to cross the metal plate 35 in the vertical direction in the drawing. Only the portion corresponding to A1 may be subjected to laser processing, and the other portions may be processed in the etching processing step of step S2.

  In the example shown in FIG. 10, in the etching process (step S2), the chip mounting surface is located in the vicinity of the inner side of the position to be the outer edge of the first lead 20 and the second lead 21 (location to form thin edge portions 20a and 21a) A resist is formed on A, while no resist is formed on the back surface B side including the first region A1. Thus, the half etching is performed also on the first region A1.

  According to the example shown in FIG. 10, the projection 26 formed when the metal plate 35 is irradiated with laser light of pulse oscillation type from the back surface B side in the laser processing step (step S3) is an etching processing step (step S2). ) Is removed by half etching. When the lead frame 1 is integrally molded with a resin, the protrusions 26 may inhibit the flow of the resin depending on the molding conditions of the resin. Therefore, in such a case, as shown in FIG. 10, the projection 26 can be removed by executing the etching process (step S2) after the laser processing (step S3) is performed.

  Next, a method of manufacturing a surface-mounted light emitting device, which is an example of a resin molded body and a surface-mounted electronic component, using the lead frame 1 configured as described above will be described. An example of manufacturing a surface mounted light emitting device 6 using a light emitting element such as a light emitting diode as the chip 3 will be described.

  FIG. 11 is a flowchart for explaining the method of manufacturing the surface mount type light emitting device according to the embodiment of the present invention. 12 to 15 are explanatory views for explaining a method of manufacturing the surface mount type light emitting device shown in FIG. Although various resin molding methods can be used as such a manufacturing method, for example, a transfer molding method can be suitably used.

  First, a clamping step is performed to fix the lead frame 1 in a predetermined mold in which a cavity corresponding to the shape of the resin molded body to be formed is formed (step S11). The mold comprises, for example, two mold blocks, and the assembly 11 shown in FIG. 1 is accommodated and fixed in the mold cavity by sandwiching the lead frame 1 with the two mold blocks. It has become so. The mold corresponds to the MAP method, and the entire assembly 11 can be accommodated in a single cavity.

  Next, a resin molded body forming step is performed in which resin is supplied into the cavity of the mold from one end side in the longitudinal direction of the lead frame 1 to form a resin molded body by the MAP method (step S12). Various resin can be used for resin molding, for example, thermosetting resin can be used suitably. When a thermosetting resin is used, the resin can be reliably cured by heating the resin filled in the cavity of the mold.

  In the resin molded body forming step, the mold shape in the cavity is set so that the mounting position of the chip 3 in each unit mounting area 10 is exposed. As a result, the resin layer is formed integrally with the lead frame 1, and the chip 3 can be mounted on the exposed surface portions of the first lead 20 and the second lead 21.

  In the resin molded body forming process, the resin is supplied into the cavity of the mold, and the gap between the first lead 20 and the second lead 21 and the gap between the first lead 20 and the second lead 21 and the mold (for example, The resin is filled in the upper surface of the first lead 20 and the second lead 21.

  In the resin molded body forming step, the third area A3 and the fourth area A4 are formed between the first lead 20 and the second lead 21, and the thickness of the thin edge portions 20a and 21a is thinner than the thickness T1. The thickness T2 and the end face 23a and the end face 24a are formed such that the distance increases in the thickness direction of the first lead 20 and the second lead 21 from the chip mounting surface A side. The bond between the first lead 20 and the second lead 21 and the resin becomes stronger.

  In the resin molded body forming step, after the resin is filled in the cavity of the mold as described above, the resin is heated to cure the resin, and the resin molding in which the lead frame 1 and the resin layer are integrally molded The body is manufactured. Thus, a MAP-type resin molded body is obtained in which the resin layer is formed so as to collectively cover the plurality of unit mounting areas 10 (aggregates 11) altogether.

  FIG. 12 is a top view schematically showing the appearance of a resin molded body 5 which is an example of the resin molded body formed in the resin molded body forming step. The resin molded body 5 shown in FIG. 12 is configured by integrally molding a resin layer 50 on the lead frame 1. Thus, a flat plate-shaped resin molded body 5 is formed.

  FIG. 13 is an explanatory view schematically showing another example of the resin molded body 5 formed in the resin molded body forming step. FIG. 13A is a perspective view schematically showing the entire configuration of the resin molded body 5. FIG. 13 (b) is a plan view schematically showing the structure of the main part of the resin molded body 5. FIG. 13C is a perspective view schematically showing the configuration of the reflector 63 in which the resin molded body 5 is singulated for each unit mounting area 10.

  The resin molded body 5 shown in FIG. 13 has the lead frame 1, the resin layer 60 integrally formed on the surface of the lead frame 1, and the first region A1 of the first lead 20 and the second lead 21 exposed on the bottom surface 62. And a concave portion 61. The resin layer 60 has a plurality of holes forming the recess 61, and includes a reflector 63 that reflects light from the optical semiconductor element in a predetermined direction.

  The back surface B of the first lead 20 and the second lead 21 is exposed on the same plane as the back surface of the resin layer 60 on the back surface of the resin molded body 5 to function as an electrode of the surface mount type light emitting device. The reflector 63 shown in FIG. 13C includes one unit mounting area 10, a resin layer 60 formed on the surface (light emitting element mounting surface) of the unit mounting area 10 and a part of the back surface, and a bottom surface 62. A concave portion 61 in which the first region A1 of the first lead 20 and the second lead 21 is exposed is provided.

  Next, a mounting step of mounting the chip 3 on the resin molded body 5 configured as described above is performed (step S13). As the chip 3, various light emitting elements such as a light emitting diode (LED) can be used, for example.

  Specifically, for example, the chip 3 is flip-chip mounted so as to straddle between the first lead 20 and the second lead 21 of the resin molded body 5 shown in FIGS. 12 and 13, and one electrode of the chip 3 is The other electrode is connected to the second lead 21. In the case of the resin molded body 5 shown in FIG. 13, the chip 3 is mounted on the resin molded body 5 in a state of being accommodated in the recess 61.

  Next, a sealing step of sealing the chip 3 mounted on the resin molded body 5 with a translucent resin is performed (step S14). For example, in the case of the resin molded body 5 shown in FIG. 12, the chip 3 is sealed by forming a translucent resin layer on the upper surface of the resin molded body 5 so as to cover the entire assembly 11 on which the chip 3 is mounted. Be done. For example, in the case of the resin molded body 5 shown in FIG. 13, the chip 3 is sealed by filling the concave portion 61 with the translucent resin.

  Next, a cutting step of cutting the resin molded body 5 along the lateral direction and the longitudinal direction is performed so as to separate the unit mounting areas 10 of the lead frame 1 integrated with the resin molded body 5 with each other. (Step S15). The surface-mounted light emitting device 6 is singulated by the cutting process. Thereby, the surface mounted light emitting device 6 is obtained.

  Although the example shown in FIG. 11 shows an example in which the cutting step (step S15) is performed after the mounting step (step S13) and the sealing step (step S14), the mounting step is performed after the cutting step (step S15) The process (step S13) and the sealing process (step S14) may be performed. Alternatively, the configuration may be such that the mounting step (step S13), the cutting step (step S15), and the sealing step (step S14) are performed in order.

  Further, although the etching process is shown as an example of the outer edge process, the intermediate 36 or the intermediate 37 may be punched by a die instead of the etching process.

  FIG. 14 is a perspective view schematically showing an example of the configuration of the surface mount type light emitting device 6 obtained by dividing the resin molded body 5 shown in FIG. 12 into pieces. The surface mount type light emitting device 6 shown in FIG. 14 does not have the second region A2 as shown in FIG. 5, and a lead frame formed such that the first region A1 crosses the first lead 20 and the second lead 21. Shows an example using.

  The surface mount type light emitting device 6 shown in FIG. 14 has a substrate 51 obtained by dividing the resin molded body 5 into pieces for each unit mounting region 10, and a first region A1 exposed on the surface of the substrate 51. Translucency that seals the chip 3, the chip 3, the first lead 20, and the second lead 21 flip-chip mounted so as to span between the first lead 20 and the second lead 21 with a translucent resin And a resin layer 55. Although FIG. 14 shows an example in which the light transmitting resin layer 55 is formed in a plate shape, the light transmitting resin layer 55 may be formed in a shape other than a plate shape, such as a lens shape.

  Since the surface mount type light emitting device 6 shown in FIG. 14 does not have the reflector 63, the entire area of the first lead 20 and the second lead 21 is used as a reflecting mirror. Therefore, by using a lead frame formed such that the first region A1 crosses the first lead 20 and the second lead 21, the area of the first lead 20 and the second lead 21 functioning as a reflecting mirror is increased. The light extraction efficiency of the light obtained by the light emission of the chip 3 to the outside of the surface mounted light emitting device 6, that is, the light emitting efficiency of the surface mounted light emitting device 6 can be improved.

  Further, since the distance W1 between the slits 22 in the first region A1 is smaller than the thickness T1 of the first lead 20 and the second lead 21, the reflecting mirror and the distance between the leads are wider than the thickness T1. The area of the first lead 20 and the second lead 21 functioning as a heat dissipation plate can be increased, and the light emission efficiency and heat dissipation characteristics of the surface mount type light emitting device 6 can be improved.

  FIG. 15 is a perspective view schematically showing a configuration of the surface mounted light emitting device 6 obtained by dividing the resin molded body 5 shown in FIG. 13 into pieces.

  The surface mount type light emitting device 6 shown in FIG. 15 has one unit mounting area 10 obtained by singulating the resin molded body 5 (lead frame 1), and the chip mounting surface A and the back surface of the unit mounting area 10 A resin layer 60 formed on a portion of B, a recess 61 in which the first region A1 of the first lead 20 and the second lead 21 is exposed on the bottom surface 62, and a first lead 20 of the first region A1 in the recess 61 And the second lead 21 so that the chip 3 is flip-chip mounted.

  According to the surface-mounted light emitting device 6 shown in FIG. 15, since the distance W1 between the slits 22 in the first region A1 is narrower than the thickness T1 of the first lead 20 and the second lead 21, the thickness T1 The area of the first lead 20 and the second lead 21 functioning as a reflecting mirror and a heat sink can be increased compared to when the distance between the leads is wide, and the luminous efficiency and the heat radiation characteristics of the surface mount type light emitting device 6 can be improved. .

  In addition, since the second area A2 in the unit mounting area 10 is covered with the reflector 63 and is not exposed, even if the intervals W3 and W4 of the second area A2 are wider than the first area A1, the reflectance may be lowered. Absent. Further, since the resin is easily introduced into the spaces W3 and W4 of the second region A2, the coupling between the first lead 20 and the second lead 21 and the reflector 63 becomes strong.

  The chip 3 is not necessarily limited to the light emitting element. The chip 3 may be an element provided with two electrodes other than the light emitting element, such as a diode or a surge absorber, for example. In the case of a surface mount type electronic component provided with a chip other than a light emitting element as the chip 3, a translucent resin is used or a reflector 63 for reflecting light is formed in the above-mentioned sealing step (step S14). It manufactures by the manufacturing method similar to the above-mentioned except that there is no need.

DESCRIPTION OF SYMBOLS 1 lead frame 3 chip 5 resin molding 6 surface mounting type light emitting device 10 unit mounting area 11 assembly 12 frame 12 a, 12 b, 12 c, 12 d frame side 20 first lead 21 second lead 20 a, 21 a thin edge 22 slit 23 First edge 24 Second edge 23a, 24a End face 25, 26 Projection 31 Electrode 32 Solder 35 Metal plate 36, 37 Intermediate 50 Resin layer 51 Substrate 55 Transparent resin layer 60 Resin layer 61 Recess 62 Bottom surface 63 Reflector A chip mounting surface A1 first region A2 second region A3 third region A4 fourth region B back surface C connection piece E end H anchor holes T1, T2 thickness W1, W3, W4 distance

Claims (13)

Including plate-like first leads and second leads for mounting a chip;
The first and second leads are spaced apart in the same plane,
At least a first end edge which is an end edge on the spacing side of the first lead, and a second end edge which is an end edge of the second lead disposed opposite to the first end edge across the spacing In some first regions, the spacing is narrower than the thickness of the central portion of the first and second leads,
In the first area, the chip straddles the space in the first area, and one end of the chip is attachable to the first lead, and the other end is attachable to the second lead.
The first region is a region including central portions of the first and second edges and excluding the vicinity of both ends of the first and second edges,
In the second region of the first and second edges excluding the first region, the distance is equal to or greater than the thickness of the central portion of the first and second leads,
The second region is a lead frame including a third region in which the distance is substantially constant, and a fourth region in which the distance gradually increases toward the ends of the first and second edges. The end face of the first lead and the end face of the second lead, which face each other across the gap in the first region, are the first and second end faces of the first and second leads from the attachment surface side of the chip. lead frame according to claim 1 Symbol mounting is formed such that the spacing is enlarged as the distance to the lead in the thickness direction. 3. The lead frame according to claim 1, wherein a protrusion is formed on one surface of the first and second leads near an edge extending along the distance in the first area. The lead frame according to any one of claims 1 to 3 , wherein the distance in the first region is less than 100 μm. The lead frame according to claim 4 , wherein the distance in the first region is less than 50 μm. The space according to any one of claims 1 to 5 , wherein the space in the first region is formed by irradiating the conductive plate-like member with energy from one side to cut the plate-like member. Lead frame as described in Section. The lead frame according to claim 6 , wherein the energy is a laser beam. The lead frame according to any one of claims 1 to 7 , wherein a region different from the first region at the outer edge of the first and second leads is formed by etching or punching. A lead frame according to any one of claims 1 to 8 ;
A resin molded body comprising a resin layer integrally formed with the lead frame. A lead frame according to any one of claims 1 to 8 ;
A resin layer integrally formed with the lead frame;
A surface mount type electronic component comprising: the chip in which one end is attached to the first lead and the other end is attached to the second lead across the distance in the first region of the lead frame. A lead frame according to any one of claims 1 to 8 ;
A resin layer integrally formed with the lead frame;
A surface mount type light emitting device comprising: a light emitting element as the chip having one end attached to the first lead and the other end attached to the second lead across the distance in the first region of the lead frame. A lead frame manufacturing method for manufacturing a lead frame according to any one of claims 1 to 8 , comprising:
A laser processing step of forming the gap by cutting the conductive plate member in the first region with a laser beam;
An outer edge processing step of forming outer edges of the first and second leads by cutting the plate-like member by etching or punching in a region different from the first region. The outer edge processing step is a step of performing etching,
The method for manufacturing a lead frame according to claim 12 , wherein the outer edge processing step is performed after the laser processing step is performed.

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