JP6056400B2 - Lead frame manufacturing method, semiconductor device manufacturing method, lead frame base material, and semiconductor device - Google Patents

Description

  The present invention relates to a lead frame manufacturing method, a semiconductor device manufacturing method, a lead frame base material, and a semiconductor device.

  In order to satisfactorily connect a bonding wire connecting the semiconductor element and the lead frame to the lead frame, noble metal plating is performed on the inner lead of the lead frame (see, for example, Patent Document 1). As described above, when precious metal plating is applied to the lead frame, Au plating is conventionally applied to the entire surface of the lead frame. However, since it is necessary to reduce the manufacturing cost of the lead frame, a part of the lead frame is subjected to Au plating (referred to as partial Au plating), and thereafter, a part of the lead frame is replaced with Ag instead of Au plating. There is a shift to applying plating (referred to as partial Ag plating).

  On the other hand, a package such as QFN has been developed due to a demand for miniaturization or thinning of a semiconductor package, and a demand for partial Ag plating applied to a lead frame has become severe.

  Conventionally, Ag plating is performed on a predetermined position of a lead frame by arranging a jig on the lead frame (jig plating method). However, in recent years, it has been required to prevent Ag plating from adhering to the side surface and the back surface and to improve the processing accuracy of partial Ag plating. In order to meet such a demand, a plate making plating method is used instead of the jig plating method. Specifically, after a lead frame is formed into a predetermined shape by etching, a photoresist is applied to the entire lead frame, and Ag plating is selectively applied to a predetermined position of the lead frame using a photoengraving method. ing.

  However, in general, whether a jig plating method is used or a plate making plating method is used, a jig is prepared in advance (in the case of a jig plating method), or a photomask is manufactured. In addition to the cost of preparation, such as (in the case of plate making plating method), there is a problem that a long time is required for preparation.

JP 2001-77289 A

  On the other hand, in order to save preparation costs and time, the present inventors replaced so-called Ag nanopaste composed of Ag particles of nanometer (nm) order with respect to the lead frame instead of Ag plating. Considering inkjet printing. However, when Ag nano paste is inkjet printed, there is a problem that it is difficult to form Ag in a predetermined area because the Ag nano paste (ink) wets and spreads on the lead frame.

  If Ag nanopaste spreads on the lead frame, it will be cracked in the semiconductor package during reflow because the adhesion between the lead frame and the sealing resin deteriorates and the moisture absorption reliability deteriorates after being incorporated into the semiconductor package. There is a risk. Further, when the Ag nanopaste wets and spreads on the back surface of the lead frame, after the semiconductor package is mounted on the board, a dendrite of Ag is generated or grows by applying a bias voltage, which may cause a short circuit. (Electrochemical migration).

  The present invention has been made in consideration of such points, and a lead frame manufacturing method, a semiconductor device manufacturing method, a lead frame base, and the like that can prevent a problem that Ag nanopaste wets and spreads on the lead frame. An object is to provide a material and a semiconductor device.

  The present invention provides a lead frame manufacturing method including a die pad on which a semiconductor element is mounted and a lead portion provided around the die pad, and an electrical connection region provided at a predetermined position in the die pad or the lead portion. A resist layer that prevents the outflow of Ag nano paste is formed along the periphery of the electrical connection region of the lead frame base material by applying a resist material using the ink jet method and curing the process, by preparing the frame base material A step of applying an Ag nano paste on the electrical connection region defined by the resist layer using an inkjet method, a step of removing the resist layer from the lead frame substrate, and an Ag nano on the electrical connection region And a step of firing a paste.

  The present invention is a method for manufacturing a lead frame, wherein the resist material and the Ag nanopaste are applied from different application heads of the same inkjet apparatus.

  The present invention is the method for manufacturing a lead frame, wherein the electrical connection region is provided at the tip of the lead part of the lead frame base material, and the resist layer is provided across the lead part.

  The present invention is the method for manufacturing a lead frame, wherein the resist layer is provided over the entire periphery of the electrical connection region.

  The present invention is the method for manufacturing a lead frame, wherein the resist material includes a hot melt type resist.

  The present invention is the method for manufacturing a lead frame, wherein the hot melt type resist contains an olefin-based thermoplastic resin.

  The present invention is a method for manufacturing a lead frame, wherein in the step of removing the resist layer from the lead frame base material, the resist layer is removed with an alkaline aqueous solution or water.

  The present invention relates to a method for manufacturing a semiconductor device, comprising: a step of manufacturing a lead frame by a method of manufacturing a lead frame; a step of mounting a semiconductor element on a die pad of the lead frame; and an electrical connection region between the semiconductor element and the lead frame. A method for manufacturing a semiconductor device, comprising: a step of electrically connecting with a connecting portion; a step of sealing a die pad, a lead portion, a semiconductor element, and the connecting portion with a sealing resin. .

  The present invention provides a lead frame base material including a die pad on which a semiconductor element is mounted and a lead portion provided around the die pad, and an electrical connection region is provided at a predetermined position of the die pad or the lead portion. A resist layer for preventing the outflow of the Ag nanopaste is formed along the periphery of the substrate, and the Ag nanopaste is applied to the electrical connection region defined by the resist layer using an inkjet method. Lead frame substrate.

  In the semiconductor device, the lead frame die pad manufactured by the lead frame manufacturing method, the semiconductor element mounted on the die pad, and the electrode of the semiconductor element and the electrical connection region of the lead frame are electrically connected. And a sealing resin for sealing the connecting portion, the die pad, the lead, the semiconductor element, and the connecting portion.

  According to the present invention, a resist layer that prevents the outflow of Ag nanopaste is formed around the electrical connection region along the periphery of the electrical connection region. This can prevent the Ag nanopaste from getting wet and spreading when the Ag nanopaste is applied onto the electrical connection region using the inkjet method.

FIG. 1 is a plan view showing a lead frame. 2 is a cross-sectional view showing the lead frame (a cross-sectional view taken along the line II-II in FIG. 1). FIG. 3 is a plan view showing a semiconductor device according to an embodiment of the present invention. 4 is a cross-sectional view showing a semiconductor device according to an embodiment of the present invention (a cross-sectional view taken along line IV-IV in FIG. 3). 5A to 5E are cross-sectional views showing a method for manufacturing a lead frame according to an embodiment of the present invention. 6A to 6D are cross-sectional views illustrating a method for manufacturing a lead frame according to an embodiment of the present invention. FIG. 7 is a schematic perspective view showing the ink jet apparatus. FIG. 8 is a partially enlarged plan view showing a lead frame substrate according to one embodiment of the present invention. 9A to 9E are cross-sectional views illustrating a method for manufacturing a semiconductor device according to an embodiment of the present invention. FIG. 10 is a partially enlarged plan view showing a modification of the lead frame base material. FIG. 11 is a partially enlarged plan view showing another modification of the lead frame base material.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

Construction of the lead frame initially, to FIG. 1 and FIG. 2, the outline of the lead frame. 1 and 2 are views showing a lead frame.

  As shown in FIGS. 1 and 2, the lead frame 10 is provided with a planar rectangular die pad 11 on which a semiconductor element 21 (described later) is mounted, the periphery of the die pad 11, and the semiconductor element 21 and an external circuit (not shown). And a plurality of elongated lead portions 12 for connecting the two.

  Among these, an outer frame 13 that supports the die pad 11 and the lead portion 12 is provided around the lead portion 12. Further, suspension leads 14 are coupled to the four corners of the die pad 11, and the die pad 11 is coupled and supported to the outer frame 13 via the four suspension leads 14.

  Adjacent lead portions 12 are separated from each other via a space. Each lead portion 12 is also separated from the die pad 11 through a space. Further, the back surface of each lead portion 12 is exposed to the outside from the semiconductor device 20 (described later), and this back surface is an outer lead portion that is electrically connected to an external circuit (not shown). 17 is constituted.

  Each lead portion 12 has an outer end portion 12a located on the outer frame 13 side and an inner end portion 12b located on the die pad 11 side. An electrical connection region 15 (inner lead portion) is provided at the inner end portion 12 b of each lead portion 12. In this case, the electrical connection region 15 is a region electrically connected to the semiconductor element 21 via the bonding wire 22 as will be described later.

  An Ag formation portion 16 is provided on the electrical connection region 15 formed in each lead portion 12. As will be described later, the Ag forming portion 16 is formed by applying and baking Ag nanopaste 16a using an ink jet method.

  The Ag forming portion 16 is for connecting the bonding wire 22 to the lead portion 12 satisfactorily. The Ag forming portion 16 contains Ag obtained by firing and recrystallizing Ag (silver) nanoparticles. The Ag (silver) nanoparticles may have a diameter of 3 nm to 100 nm, for example. In addition, the thickness of the Ag formation part 16 is good also as 1 micrometer-10 micrometers, for example.

  In FIG. 1, the Ag forming portion 16 is indicated by hatching. In FIG. 1, for convenience, some of the electrical connection regions 15 are not provided with the Ag forming portions 16 in some of the electrical connection regions 15, but in reality, the Ag forming portions are formed on all the electrical connection regions 15. 16 is provided

  In addition, each Ag forming portion 16 may be provided in the entire region of each electrical connection region 15 or may be provided only in a part of each electrical connection region 15.

  The lead frame 10 described above is made of a metal such as copper, copper alloy, 42 alloy (Ni 42% Fe alloy) as a whole. The lead frame 10 can have a thickness of 0.05 mm to 0.5 mm, although it depends on the configuration of the semiconductor device 20 to be manufactured.

  In FIG. 1, only one die pad 11 is shown for convenience, but in actuality, a single lead frame 10 is manufactured with a plurality of die pads 11 attached thereto. In FIG. 1, a region S (virtual line) indicates a region corresponding to one semiconductor device 20 in the lead frame 10.

Configuration of Semiconductor Device Next, the semiconductor device will be described with reference to FIGS. 3 and 4 are schematic cross-sectional views showing a semiconductor device (QFN type).

  As shown in FIGS. 3 and 4, the semiconductor device (semiconductor package) 20 includes a die pad 11, a plurality of lead portions 12 arranged around the die pad 11, a semiconductor element 21 mounted on the die pad 11, A plurality of bonding wires (connection portions) 22 for electrically connecting the lead portion 12 and the semiconductor element 21 are provided. The die pad 11, the lead portion 12, the semiconductor element 21, and the bonding wire 22 are resin-sealed with a sealing resin 23.

  Among these, the die pad 11 and the lead part 12 are produced from the lead frame 10 described above. The configurations of the die pad 11 and the lead portion 12 are the same as those shown in FIGS. 1 and 2 described above, and detailed description thereof is omitted here.

  Further, as the semiconductor element 21, various semiconductor elements generally used in the past can be used, and are not particularly limited. For example, an integrated circuit, a large-scale integrated circuit, a transistor, a thyristor, a diode, or the like is used. it can. The semiconductor element 21 has a plurality of terminal portions 21a to which bonding wires 22 are attached. The semiconductor element 21 is fixed to the surface of the die pad 11 with an adhesive 24 such as a die bonding paste.

  Each bonding wire 22 is made of a material having good conductivity such as gold. Each bonding wire 22 has one end connected to the terminal portion 21 a of the semiconductor element 21 and the other end connected to the electrical connection region 15 of each lead portion 12 via the Ag forming portion 16.

  As the sealing resin 23, a thermosetting resin such as a silicone resin or an epoxy resin, or a thermoplastic resin such as a PPS resin can be used. The total thickness of the sealing resin 23 can be about 100 μm to 1500 μm. In FIG. 3, the display of the sealing resin 23 provided on the surface side of the die pad 11 and the lead portion 12 is omitted.

Manufacturing Method of Lead Frame Next, with respect to the manufacturing method of the lead frame 10 shown in FIGS. 1 and 2, FIGS. 5 (a)-(e), FIGS. 6 (a)-(d), FIGS. 7 and 8 are used. I will explain.

  First, as shown in FIG. 5A, a flat metal substrate 31 is prepared. As the metal substrate 31, a substrate made of a metal such as copper, a copper alloy, or a 42 alloy (Ni 42% Fe alloy) can be used. In addition, it is preferable to use what the metal substrate 31 performed the degreasing | defatting etc. to the both surfaces, and performed the washing process.

  Next, photosensitive resists 32a and 33a are applied to the entire front and back surfaces of the metal substrate 31, respectively, and dried (FIG. 5B). As the photosensitive resists 32a and 33a, conventionally known resists can be used.

  Subsequently, the metal substrate 31 is exposed through a photomask and developed to form etching resist layers 32 and 33 having desired openings 32b and 33b (FIG. 5C).

  Next, the etching resist layers 32 and 33 are used as an anticorrosion film, and the metal substrate 31 is etched with an etching solution (FIG. 5D). Thereby, the outer shape of the die pad 11 and the plurality of lead portions 12 is formed. The corrosive liquid can be appropriately selected according to the material of the metal substrate 31 to be used. For example, when copper is used as the metal substrate 31, an aqueous ferric chloride solution is usually used and sprayed from both surfaces of the metal substrate 31. It can be performed by etching. At this time, electrical connection regions 15 are formed at the inner end portions 12b of the lead portions 12, respectively.

  Next, the resist layers 32 and 33 for etching are peeled and removed to have the outer shape of the die pad 11 and the lead portion 12, and the electrical connection region 15 is provided at a predetermined position (inner end portion 12 b) of the lead portion 12. The obtained lead frame base material 30 is obtained (FIG. 5E).

  Next, a resist layer 35 is formed along the periphery of the electrical connection region 15 of the lead frame substrate 30 to prevent the outflow of Ag nano paste 16a described later.

  In this case, for example, using an inkjet device 60 shown in FIG. 7, a resist material is applied and cured along a part of the periphery of the electrical connection region 15 of the lead frame base material 30. Thereby, the resist layer 35 is formed along a part of the periphery of the electrical connection region 15 (FIG. 6A). When applied, the temperature of the resist material can be in the range of 70 ° C. to 150 ° C., for example.

  The resist material preferably includes a hot melt type resist. The hot melt type resist preferably contains an olefinic thermoplastic resin such as ethylene vinyl acetate (EVA). When using a hot-melt type resist as the resist material, especially an olefin-based thermoplastic resin, it is easily peeled off with cold water after printing, and the resist after peeling can be recovered and reused by filtration without dissolving, The effect that the cost can be reduced is obtained.

  Next, using the inkjet device 60 (FIG. 7), Ag nano paste 16a is printed and applied to the electrical connection region 15 defined by the resist layer 35 in the lead portion 12 by the inkjet method (FIG. 6B). .

  As the Ag nanopaste 16a, for example, a mixture of Ag (silver) nanoparticles, an acrylic resin-based dispersant covering the particles, and a solvent (for example, tetradecane, water, or ethylene glycol) is used. it can.

  In this way, a resist layer 35 that prevents the outflow of the Ag nanopaste 16a is formed along the periphery of the electrical connection region 15 of the lead portion 12, and an ink jet is formed on the electrical connection region 15 defined by the resist layer 35. The lead frame base material 30 to which the Ag nano paste 16a is applied is obtained using the method (FIG. 6B and FIG. 8). In the present embodiment, such a lead frame substrate 30 is also provided.

  As shown in FIG. 8, in the lead frame base material 30, the resist layer 35 is provided so as to cross the longitudinal direction of each lead portion 12. The resist layer 35 is disposed in parallel to each side of the die pad 11. Further, the resist layer 35 is provided only on the peripheral edge located on the opposite side of the die pad 11 in the electrical connection region 15.

  The width of the resist layer 35 may be, for example, 30 μm to 300 μm. Moreover, the thickness of the resist layer 35 is good also as 0.3 micrometer-10 micrometers, for example. In order to prevent the outflow of the Ag nanopaste 16a with certainty, the thickness of the resist layer 35 is preferably made thicker than the coating thickness of the Ag nanopaste 16a.

  By the way, generally, a low viscosity is used as the Ag nano paste 16a. For this reason, it is conceivable that after the Ag nano paste 16 a is applied to the electrical connection region 15, the Ag nano paste 16 a flows on the lead portion 12 and spreads to the outside of the electrical connection region 15.

  On the other hand, according to the present embodiment, the resist layer 35 that prevents the outflow of the Ag nano paste 16 a is formed along the periphery of the electrical connection region 15. Thereby, the flow of the applied Ag nano paste 16 a is stopped at the side wall of the resist layer 35. Therefore, there is no possibility that the Ag nano paste 16a spreads around the electrical connection region 15. Note that the Ag nano paste 16 a does not flow out of the electrical connection region 15 due to the surface tension of the Ag nano paste 16 a at the periphery of the electrical connection region 15 where the resist layer 35 is not provided.

  Next, referring to FIG. 7, the specific action when applying the resist material and the Ag nano paste 16 a to the lead frame base material 30 using the ink jet device 60 will be further described.

  In FIG. 7, an inkjet apparatus 60 includes a casing 61, a table 62 that is disposed in the casing 61 and on which the lead frame base material 30 is placed, a rotating shaft 63 that rotates the table 62, a table 62, and a rotation It has a table scanning unit 64 that moves the shaft 63 in a straight line. In addition, inkjet heads (application heads) 65 and 66 for applying the Ag nano paste 16a and the resist material to the lead frame base material 30 are provided above the lead frame base material 30, respectively. Further, the inkjet heads 65 and 66 are held by a head carriage unit 68. The head carriage unit 68 can be moved linearly by the transport unit 69. Further, outside the housing 61, a control device 70 that controls the ink jet device 60, an ink supply unit 71 that houses the Ag nano paste 16a and supplies the Ag nano paste 16a to the ink jet head 65, and a resist material And a resist material supply unit 72 for supplying a resist material to the inkjet head 66 is disposed.

  In this case, the lead frame base material 30 is first placed on the table 62 of the inkjet device 60. In that case, the table 62 may be heated at 35 to 60 degreeC, for example. Thereafter, the table 62 and the lead frame base material 30 are moved by the table scanning unit 64, and a resist material (ink) is discharged from the inkjet head 66 above the lead frame base material 30. A resist material is applied along the periphery of the connection region 15. This resist material is naturally cooled and solidified on the lead frame base material 30 to form a resist layer 35.

  Next, the Ag nano paste 16a (ink) is ejected from the inkjet head 65 above the lead frame base material 30, and thereby the Ag nano paste 16a is applied to each electrical connection region 15 of the lead frame base material 30. .

  The control device 70 of the inkjet device 60 is programmed in advance to apply a resist material and Ag nano paste 16a in accordance with the shape of each electrical connection region 15. Then, the control device 70 controls the table scanning unit 64 and the inkjet heads 66 and 65 to apply the resist material and the Ag nano paste 16a in accordance with the position and shape of each electrical connection region 15 of the lead frame base material 30. It has become so.

  As described above, the resist material and the Ag nano paste 16a are applied from different inkjet heads 66 and 65 of one inkjet apparatus 60. Thereby, the operation | work which apply | coats a resist material and Ag nanopaste 16a can be performed efficiently. In addition, since it is not necessary to position the lead frame base material 30 in the ink jet device 60 after applying the resist material, there is no possibility that the position of the Ag nano paste 16a is shifted with respect to the resist layer 35.

  After the Ag nano paste 16a is applied to the electrical connection region 15 in this way, the resist layer 35 on the lead frame base material 30 is removed (FIG. 6C). In this case, the resist layer 35 may be peeled off with a strong alkaline aqueous solution such as sodium hydroxide, or may be peeled off with cold water of about 0 ° C. to 10 ° C. At this time, a part of the solvent in the Ag nano paste 16a has already been removed by the pre-heated table 62, and the Ag particles are solidified to some extent. Therefore, when the resist layer 35 is peeled off, the Ag nano paste is removed. There is no possibility that 16a will be peeled off together.

  Thereafter, the lead frame base material 30 is moved to, for example, a plasma apparatus and baked in the plasma apparatus. As a result, the solvent in the Ag nanopaste 16 a is volatilized and removed, and the Ag particles are solidified, whereby the Ag forming portion 16 is formed in the electrical connection region 15. Specifically, the Ag nano paste 16a may be heated to a temperature of 50 ° C. to 100 ° C., for example, in a mixed gas of helium / 3% hydrogen in a plasma apparatus, and may be treated at an output of 500 to 1000 W for 4 minutes. . Alternatively, in the oven, the Ag nanopaste 16a is heated from room temperature to 300 ° C. in 10 minutes in a nitrogen / 3% hydrogen mixed gas in 10 minutes, and then held at 300 ° C. for 30 minutes, and then cooled by the mixed gas flow. The Ag nano paste 16a may be baked by performing the treatment so as to be divided.

  In this way, the lead frame 10 shown in FIGS. 1 and 2 is obtained (FIG. 6D).

Manufacturing Method of Semiconductor Device Next, a manufacturing method of the semiconductor device 20 shown in FIGS. 3 and 4 will be described with reference to FIGS.

  First, the lead frame 10 is manufactured by the method shown in FIGS. 5A to 5E and FIGS. 6A to 6D (FIG. 9A).

  Next, the semiconductor element 21 is mounted on the die pad 11 of the lead frame 10. In this case, the semiconductor element 21 is placed and fixed on the die pad 11 using, for example, an adhesive 24 such as a die bonding paste (die attaching step) (FIG. 9B).

  Next, each terminal portion 21a of the semiconductor element 21 and the Ag forming portion 16 provided on the electrical connection region 15 of each lead portion 12 are electrically connected to each other by a bonding wire 22 (wire bonding step) ( FIG. 9 (c)). In this case, since the Ag forming portion 16 is provided on the electrical connection region 15, the bonding wire 22 can be firmly connected to the lead portion 12.

  Next, the sealing resin 23 is formed by injection molding or transfer molding of a thermosetting resin or a thermoplastic resin to the lead frame 10 (FIG. 9D). As a result, the lead frame 10, the semiconductor element 21, and the bonding wire 22 are sealed.

  Next, the lead frame 10 is separated for each semiconductor element 21 by dicing the sealing resin 23 between the semiconductor elements 21. At this time, the lead frame 10 and the sealing resin 23 between the semiconductor elements 21 may be cut while rotating a blade (not shown) made of, for example, a diamond grindstone.

  In this way, the semiconductor device 20 shown in FIGS. 3 and 4 is obtained (FIG. 9E).

  As described above, according to the present embodiment, the Ag forming portion 16 is formed by applying and baking the Ag nano paste 16a to the electrical connection region 15 using the inkjet method. This eliminates the need to prepare a jig in advance (in the case of a jig plating method) or a photomask (in the case of a plate making plating method) as compared with the case of using a plating method. For this reason, while reducing the manufacturing cost of the lead frame 10, the preparation time required for manufacture can be shortened.

  Further, as described above, since the resist layer 35 that prevents the outflow of the Ag nano paste 16a is formed around the electrical connection region 15, the problem that the Ag nano paste 16a wets and spreads on the lead frame 10 is prevented. Can do. Thereby, it is possible to prevent the adhesion between the lead frame 10 and the sealing resin 23 from being deteriorated and the moisture absorption reliability from being lowered. Furthermore, the Ag nanopaste 16a wets and spreads on the back surface of the lead frame 10, so that a problem that Ag dendrite occurs after the semiconductor device 20 is mounted on the board can be prevented.

Modified Examples Next, various modified examples of the present invention will be described with reference to FIGS. 10 and 11 are diagrams showing various modifications of the present invention. 10 and 11 are different in the configuration of the resist layer 35, and other configurations are substantially the same as those in the above-described embodiment. 10 and 11, the same parts as those in the embodiment shown in FIGS. 1 to 9 are denoted by the same reference numerals, and detailed description thereof will be omitted.

  FIG. 10 is a partially enlarged plan view showing a modification of the present invention, and corresponds to FIG. 8 described above.

  In the lead frame base material 30 </ b> A shown in FIG. 10, an electrical connection region 15 is provided at the inner end portion 12 b of each lead portion 12. In this case, the resist layer 35 that prevents the outflow of the Ag nano paste 16 a is provided over the entire periphery of the electrical connection region 15. That is, in the step of forming the resist layer 35 (FIG. 6A), a resist material is applied and cured along the entire periphery of the electrical connection region 15 of the lead frame base material 30. With such a configuration, it is possible to more reliably prevent a problem that the Ag nano paste 16a wets and spreads on the back surface of the lead portion 12.

  FIG. 11 is a partially enlarged plan view showing another modified example of the present invention, and corresponds to FIG. 8 described above.

  In the lead frame substrate 30B shown in FIG. 11, electrical connection regions 15A are provided at four locations in the vicinity of the suspension lead 14 in the die pad 11, respectively. Each electrical connection region 15 </ b> A is a region electrically connected to the terminal portion 21 a of the semiconductor element 21 through the bonding wire 22.

  In this case, the resist layer 35 for preventing the outflow of the Ag nano paste 16a is provided over the entire periphery of the electrical connection region 15A of the die pad 11. That is, in the step of forming the resist layer 35 (FIG. 6A), a resist material is applied and cured along the entire periphery of the electrical connection region 15A of the lead frame substrate 30. Thereby, it is possible to prevent the Ag nanopaste 16a from spreading on the die pad 11. In addition, since the resist layer 35 is provided over the entire periphery of the electrical connection region 15A, it is possible to reliably prevent a problem that the Ag nano paste 16a wets and spreads in each direction on the surface of the die pad 11.

  A plurality of constituent elements disclosed in the above-described embodiment can be appropriately combined as necessary. Or you may delete a some component from all the components shown by the said embodiment. For example, the embodiment shown in FIG. 11 is combined with each embodiment shown in FIGS. 1 to 10, and the resist layer 35 is applied to both the electrical connection region 15 of the lead portion 12 and the electrical connection region 15 A of the die pad 11. May be provided.

DESCRIPTION OF SYMBOLS 10 Lead frame 11 Die pad 12 Lead part 13 Outer frame 14 Hanging lead 15 Electrical connection area 16 Ag formation part 16a Ag nanopaste 17 Outer lead part 20 Semiconductor device 21 Semiconductor element 22 Bonding wire 23 Sealing resin 24 Adhesive 30, 30A, 30B Lead frame substrate 35 Resist layer 60 Inkjet device 65, 66 Inkjet head

Claims (8)

In the lead frame manufacturing method,
A step of preparing a lead frame substrate having a die pad on which a semiconductor element is mounted and a lead portion provided around the die pad, and having an electrical connection region provided in a predetermined position of the die pad or the lead portion;
Forming a resist layer that prevents the outflow of Ag nanopaste along the periphery of the electrical connection region of the lead frame base material by applying and curing the resist material using an inkjet method;
Applying an Ag nano paste on the electrical connection region defined by the resist layer using an inkjet method;
Removing the resist layer from the lead frame substrate;
And a step of firing the Ag nanopaste on the electrical connection region.   2. The method of manufacturing a lead frame according to claim 1, wherein the resist material and the Ag nano paste are applied from different application heads of the same ink jet apparatus.   3. The method of manufacturing a lead frame according to claim 1, wherein the electrical connection region is provided at a tip of the lead part of the lead frame base material, and the resist layer is provided across the lead part.   The lead frame manufacturing method according to claim 1, wherein the resist layer is provided over the entire periphery of the electrical connection region.   The lead frame manufacturing method according to claim 1, wherein the resist material includes a hot-melt type resist.   6. The lead frame manufacturing method according to claim 5, wherein the hot melt type resist contains an olefin-based thermoplastic resin.   7. The method of manufacturing a lead frame according to claim 1, wherein in the step of removing the resist layer from the lead frame base material, the resist layer is removed with an alkaline aqueous solution or water. In a method for manufacturing a semiconductor device,
A step of manufacturing a lead frame by the method of manufacturing a lead frame according to claim 1;
Mounting a semiconductor element on the die pad of the lead frame;
Electrically connecting the semiconductor element and the electrical connection region of the lead frame with a connection portion;
A method of manufacturing a semiconductor device, comprising: sealing a die pad, a lead portion, a semiconductor element, and a connection portion with a sealing resin.

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