Method for manufacturing processed article, method for manufacturing semiconductor device, and device for manufacturing processed article

Abstract

The method for manufacturing a processed article includes: a preparation step, preparing a workpiece (1) that includes at least a lead frame with a groove (5) pre-formed along the location to be cut; a surface removal step, partially removing the surface portion (3c) of the workpiece (1) with the groove (5) before cutting the workpiece (1); and a plating step, plating the workpiece (1) with the surface portion (3c) partially removed before cutting the workpiece (1), wherein, in the state before the surface removal step, the surface portion (3c) includes a cut area (3m) removed by cutting the workpiece (1) and a non-cut area (3n) located between the cut area (3m) and the opening end (5c) of the groove (5), and in the surface removal step, at least a portion of the non-cut area (3n) is removed. This provides a method for manufacturing a processed article that achieves higher connection reliability. This method for manufacturing a processed article comprises: a preparation step for preparing an object (1) to be processed that includes at least a lead frame in which a groove (5) is formed in advance along a position to be severed; an upper layer removing step for partially removing, before the object (1) to be processed is severed, an upper layer part (3c) of the object (1) to be processed forming the groove (5); and a plating step for performing, before the object (1) to be processed is severed, a plating process on the object (1) to be processed from which the upper layer part (3c) has been partly removed. In a state prior to the implementation of the upper layer removing step, the upper layer part (3c) includes a severed region (3m) that will be removed when the object (1) to be processed is severed, and a non-severed region (3n) that is positioned between the severed region (3m) and an opening end (5c) of the groove (5).In the upper layer removing step, at least a part of the non-severed region (3n) is removed. Thus, it is possible to obtain a method for manufacturing a processed article from which enhanced connection reliability can be obtained.

Description

[Technical Field]

[0001] This specification relates to a method for manufacturing a processed article, a method for manufacturing a semiconductor device, and an apparatus for manufacturing a processed article. [Previous Technology]

[0002] As disclosed in Japanese Patent Application Publication No. 2011-77278 (Patent Document 1), various processing treatments are performed on the lead frame and other workpieces individually, or on workpieces integrally formed with other components such as resin, thereby obtaining a processed product (e.g., a finished product). Regarding the workpiece (lead frame) disclosed in Patent Document 1, after undergoing prescribed steps, the surface of the workpiece is plated to form a single sheet, which is then encapsulated in a substrate or the like. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2011-77278 [Summary of the Invention]

[0004] [The problem that the invention aims to solve]

[0005] As disclosed in Patent Document 1, when preparing an object to be processed, sometimes a groove (recess) is pre-formed along the position where it will eventually be cut. Due to the presence of the groove, for example, the plating film provided on the inner surface of the groove presents an inwardly recessed space after the lead frame is cut (or, in Patent Document 1, after being monolithized). Solder or other bonding materials are guided into this recessed space. For example, when packaging a semiconductor device onto a substrate, the solder can be well bonded to both the lower surface and the side surface of the lead, thus improving the connection reliability.

[0006] Here, when the workpiece is prepared during the preparation stage, the inner surface of the groove may sometimes have a surface shape, for example, curved into a concave shape. When the workpiece is prepared during the preparation stage and remains unchanged, the inner surface of the groove may not have a surface shape suitable for subsequent processing steps such as guiding or joining solder. To improve the reliability of the connection when using solder, it is preferable, for example, to make the concave space wider, so that the inner surface of the groove has a wider joining area.

[0007] This specification is disclosed in view of the aforementioned actual situation, and its purpose is to disclose a method for manufacturing a processed article, a method for manufacturing a semiconductor device, and an apparatus for manufacturing a processed article, wherein, when manufacturing a processed article using a workpiece with a groove pre-formed along the location to be cut, higher connection reliability can be obtained compared to existing methods. [Means of Solving the Problem]

[0008] A method for manufacturing a processed article based on the present disclosure includes: a preparation step, preparing a workpiece including at least a lead frame having a groove pre-formed along the location to be cut; a surface removal step, partially removing a surface portion of the workpiece having the groove formed therein before cutting the workpiece; and a plating step, performing a plating treatment on the workpiece with the surface portion partially removed before cutting the workpiece, wherein, in the state before performing the surface removal step, the surface portion includes a cut area removed by cutting the workpiece and a non-cut area located between the cut area and the opening end of the groove, wherein, in the surface removal step, at least a portion of the non-cut area is removed.

[0009] The method for manufacturing a semiconductor device based on the present disclosure is a method for manufacturing the processed article, comprising: a resin sealing step, in which the lead frame and the semiconductor wafer are sealed with a resin material while the semiconductor wafer is bonded to the lead frame; a resin removal step, in which the resin material in the groove is removed; and a cutting step, in which the lead frame is cut along the groove. As a method for manufacturing the processed article, the surface removal step and the plating step are performed between the resin removal step and the cutting step, or the surface removal step and the plating step are performed at a stage before the resin sealing step, or the surface removal step is performed at a stage before the resin sealing step and the plating step is performed between the resin removal step and the cutting step.

[0010] A manufacturing apparatus for processed articles according to the present disclosure processes a workpiece including at least a lead frame with a groove pre-formed along a cut-off location. The apparatus includes: a surface removal unit that partially removes a surface portion of the workpiece having the groove formed therein while it is not cut; and a plating processing unit that performs a plating process on the workpiece after the surface portion has been partially removed while it is not cut, wherein, before the surface removal unit partially removes the surface portion, the surface portion includes a cut-off region removed by cutting the workpiece and a non-cut-off region located between the cut-off region and the opening end of the groove, and the surface removal unit removes at least a portion of the non-cut-off region. [Effects of the Invention]

[0011] By means of the above disclosure, a method for manufacturing a processed article, a method for manufacturing a semiconductor device, and an apparatus for manufacturing a processed article can be obtained, wherein, when manufacturing a processed article using a workpiece in which a groove is pre-formed along the position to be cut, higher connection reliability can be obtained compared with the prior art.

Implementation Method

[0013] Hereinafter, embodiments will be described with reference to the drawings. In the following description, the same reference numerals will sometimes be used to refer to the same parts and equivalent parts, and the description will not be repeated. Hereinafter, the structure of the workpiece manufacturing apparatus 20 and the lead frame 1 used in the workpiece manufacturing method (or semiconductor device manufacturing method) will be described first, and then the workpiece manufacturing method (or semiconductor device manufacturing method) will be described.

[0014] [Workpiece Manufacturing Apparatus 20] FIG1 is a diagram showing a workpiece manufacturing apparatus 20. The workpiece manufacturing apparatus 20 processes a workpiece 22 held on a stage 21. A groove is pre-formed on the workpiece 22 along the position where it is to be cut. Here, the groove is a bottomed groove portion, sometimes referred to as a bottomed groove. In the case where the workpiece 22 is a lead frame 1 described later, a groove 5 is formed on the lead frame 1 (see FIG5, etc.), and the workpiece manufacturing apparatus 20 can function as a semiconductor device manufacturing apparatus. In the following description, an example based on the case where the workpiece manufacturing apparatus 20 is a semiconductor device manufacturing apparatus will be described.

[0015] The manufacturing apparatus 20 for the processed product includes an injection unit 23, a scanning unit 24, a control unit 25, and a plating processing unit 26. The control unit 25 controls the injection unit 23 and the scanning unit 24 according to predetermined processing conditions. The injection unit 23 generates and emits laser light. The laser light emitted from the injection unit 23 is transmitted to the scanning unit 24, which uses, for example, a lens and a scanner mirror to irradiate the laser light L toward the workpiece 22. The scanning unit 24 scans the workpiece 22 along a predetermined scanning direction by changing the relative position of the workpiece 22 and the beam point of the laser light L. In this way, a portion of the workpiece 22 is removed.

[0016] Details will be described later. The injection unit 23, scanning unit 24 and control unit 25 can function as a "surface removal unit". The surface removal unit partially removes the surface portion (surface portion 3c in lead frame 1) of the workpiece 22 that has a groove (groove 5 in lead frame 1 (see Figure 4)) from the workpiece 22 before it is cut off.

[0017] Referring to FIG4, the surface portion 3c of the lead frame 1 is partially removed by laser light irradiation from the surface removal section. The plating processing section 26 performs plating processing on the workpiece 22 (lead frame 1) whose surface portion 3c has been partially removed while the workpiece 22 (lead frame 1) has not been cut.

[0018] [Method for Manufacturing a Semiconductor Device] FIG2 is a diagram illustrating a method for manufacturing a workpiece and a method for manufacturing a semiconductor device using the method for manufacturing a workpiece. The method for manufacturing a semiconductor device can be performed using the workpiece manufacturing apparatus 20 shown in FIG1. ​​The method for manufacturing a semiconductor device includes: a preparation step ST10, a resin sealing step ST12, a resin removal step ST13, a surface layer removal step ST14, a plating step ST15, and a cutting step ST16. The preparation step ST10 includes a trench forming step ST11.

[0019] (Method for manufacturing a processed article) The preparation step ST10, the surface layer removal step ST14, and the plating step ST15 constitute a method for manufacturing a processed article. That is, a method for manufacturing a semiconductor device may include a method for manufacturing a processed article. Hereinafter, each step will be described in turn.

[0020] [Lead Frame 1 (Preparation Step ST10)] Figure 3 is a plan view showing the structure of the lead frame 1 prepared in the preparation step as viewed from the back side 1b. Figure 4 is an arrow view along line IV-IV in Figure 3. Figure 5 is a perspective view showing a portion (lead part 3, tie rod 4, and groove part 5) of the lead frame 1 prepared in the preparation step as viewed from the back side 1b.

[0021] Figure 3 does not show a cross-sectional structure of the lead frame 1, but for ease of illustration, the parts constituting the lead frame 1 are given a shaded line extending in the inclined direction. Two types of shaded lines are used here, and their differences will be described later. In Figures 3 to 5, for ease of explanation, the length direction S, the width direction W, and the height direction H are illustrated, and these directions should be referred to in the following description. These directions are also suitable for illustration in the diagrams from Figure 6 onwards.

[0022] As shown in FIG3, the lead frame 1 has a generally plate-like shape extending along both the length direction S and the width direction W. The lead frame 1 has a surface 1a on one side where the semiconductor wafer 6 (FIG. 6) is mounted, and a back surface 1b on the opposite side of the surface 1a, and contains a metal such as copper. The lead frame 1 includes a plurality of die pads 2, a plurality of lead portions 3, and a plurality of tie rods 4.

[0023] (Dice pads 2, lead portions 3, tie rods 4) Multiple die pads 2 are arranged at intervals along both the length direction S and the width direction W. A semiconductor wafer 6 is mounted on the surface 1a of the lead frame 1 (see Figure 6). Multiple lead portions 3 are arranged in a rectangular shape around each of the multiple die pads 2. Multiple tie rods 4 are arranged in a grid pattern to surround each of the multiple die pads 2. Multiple lead portions 3 are provided on both sides of a tie rod 4, and the multiple lead portions 3 are arranged at intervals along the extension direction of the tie rod 4. Each of the multiple lead portions 3 has a thick-walled portion 3a and a thin-walled portion 3b (Figures 3 and 5). In the lead portion 3, the thick-walled portion 3a is connected to the tie rod 4 via the thin-walled portion 3b. In the height direction H, the die pads 2 and the thick-walled portion 3a have a larger height dimension (i.e., thickness) than the thin-walled portion 3b.

[0024] The grain pad 2 and the thick-walled portion 3a are given a shaded line extending from the upper right side of the paper in FIG3 toward the lower left side. The thin-walled portion 3b of the lead portion 3 and the tie rod 4 are given a shaded line extending from the upper left side of the paper in FIG3 toward the lower right side.

[0025] (Slot 5) Referring to FIG5, regarding the tie rod 4, the thick-walled portion 3a and the thin-walled portion 3b of the lead wire portion 3, if we focus on the surfaces located on the "negative side of the height direction H" as shown in FIG5, the height positions of these surfaces are the same. On the other hand, if we focus on the surfaces located on the "positive side of the height direction H" as shown in FIG5, the height position of the surface of the thick-walled portion 3a of the lead wire portion 3 is higher than the height position of the surface of the tie rod 4 and the height position of the surface of the thin-walled portion 3b of the lead wire portion 3.

[0026] That is, the surface of the front side of the tie rod 4 and the surface of the front side of the thin wall portion 3b of the lead wire portion 3 present a shape that is recessed relative to the surface of the front side of the thick wall portion 3a of the lead wire portion 3. With this structure, in the lead wire frame 1, a grid-like groove 5 is formed on the back side 1b (Fig. 3) of the tie rod 4, extending along the height direction H and the width direction W, and extending along the height direction H and the length direction S.

[0027] The groove 5 does not penetrate the lead frame 1 in the height direction H. For example, it has a groove depth of half that of the lead frame 1 (thick-walled portion 3a) and can be formed by etching (wet etching) the lead frame 1. The groove width is, for example, 0.30 mm to 0.50 mm. The groove width and groove depth can be set by taking into account the strength to ensure that no defects such as deformation occur in subsequent steps, the ability to perform good appearance inspection in subsequent steps, and the good packaging strength of the finished semiconductor device.

[0028] As shown in Figure 4, the groove 5 is a space defined by the bottom 5a of the groove 5, the side portion 5b of the groove 5, and the open end 5c of the groove 5. The open end 5c of the groove 5 is the inner edge portion of the groove 5 formed in the back surface 1b of the lead frame 1, and extends in a straight line (Figure 5). The bottom 5a of the groove 5 has a generally flat surface shape. The side portion 5b of the groove 5 is curved such that it is located closer to the center in the width direction than the open end 5c of the groove 5, the closer it is to the bottom 5a of the groove 5.

[0029] As shown in Figures 4 and 5 (especially Figure 4), the lead frame 1 has a surface portion 3c with a groove 5 formed thereon. In Figure 4, the surface portion 3c is represented by a dashed line. The surface portion 3c of the lead frame 1 is the portion of the lead frame 1 defined from the outer surface of the lead frame 1 to a predetermined depth, and is the portion that forms the groove 5. The surface shape of the surface portion 3c forms (divides) the groove 5 as a space. As shown in the cross-sectional shape of Figure 4, the surface portion 3c has a predetermined thickness, and here it extends in a U-shape or C-shape. Furthermore, the "range up to a predetermined depth" and "predetermined thickness" mentioned here are not limited to a structure in which the surface portion 3c has a certain (uniform) thickness in the width direction W. As long as the groove 5 is formed, the surface portion 3c can have any thickness in the width direction W, or it can have different thicknesses in the width direction W.

[0030] Details will be described later. The lead frame 1 is monolithized by performing the cutting step ST16 (see Figure 14). The surface portion 3c includes a cut area 3m that is removed by cutting the lead frame 1, and a non-cut area 3n located between the cut area 3m and the opening end 5c of the groove 5. In Figure 4, the blade 12 used by the cutting step ST16 is illustrated imaginarily using a two-point chain line.

[0031] The cutting area 3m is located inside the frame representing the two-point chain line of the blade 12, and the non-cutting area 3n is located outside the frame representing the two-point chain line of the blade 12. The surface portion 3c includes a boundary portion 3t between the cutting area 3m and the non-cutting area 3n. The surface 3q of the boundary portion 3t is located on the two-point chain line representing the blade 12. Furthermore, the width and position of the frame representing the two-point chain line are shown schematically, and the actual area removed by cutting is wider than the width of the blade 12.

[0032] The surface shape 3p of the cut-off region 3m corresponds to the bottom 5a of the groove 5. The surface shape 3r of the non-cut-off region 3n corresponds to the side 5b of the groove 5. The upper portion 3s of the surface shape 3r of the non-cut-off region 3n corresponds to the opening end 5c of the groove 5. In the example shown in FIG4, the entire side 5b of the groove 5 is included in the surface shape 3r of the non-cut-off region 3n. Alternatively, the bottom 5a (flat surface) of the groove 5 may be included in the lower portion of the surface shape 3r of the non-cut-off region 3n (in other words, a portion of the bottom 5a of the groove 5 may also be included in the non-cut-off region 3n).

[0033] (Resin sealing step) Figure 6 is a cross-sectional view showing the state in which a semiconductor wafer 6 is bonded to the lead frame 1 (die pad 2) prepared in the preparation step. As shown in Figure 6, multiple electrodes provided on each semiconductor wafer 6 are electrically connected to the lead portion 3 (thick-walled portion 3a) via bonding lines 7.

[0034] Figure 7 is a cross-sectional view showing the state after the resin sealing step. In the resin sealing step, with the semiconductor wafer 6 bonded, the lead frame 1 and the semiconductor wafer 6 are sealed using resin material 9. Before the resin sealing step, a protective film 8 (e.g., polyimide resin tape) can be attached to the side of the groove 5 of the lead frame 1, and the resin sealing can be performed after the protective film 8 is attached.

[0035] The method for manufacturing a semiconductor device may further include, at some point between the resin sealing step and the cutting step described later, the following step: performing laser marking on the surface 9a (FIG. 7) opposite to the groove 5 of the lead frame 1 by irradiating with laser light L1. By using a pulsed laser and scanning with a scanning optical system, it is possible to print any information such as model number or serial number.

[0036] As shown in FIG8, the protective film 8 is peeled off from the lead frame 1 before performing the resin removal step described below. By removing the protective film 8, the resin material 9 (9b) formed in the groove 5 of the lead frame 1 is exposed. Furthermore, the protective film 8 can also be peeled off from the lead frame 1 before performing the laser marking step described with reference to FIG7.

[0037] (Resin Removal Step) Figure 9 is a cross-sectional view showing the state of the resin removal step. In the resin removal step, laser light L2 is irradiated onto the resin material 9 (9b) in the tank 5, and the laser light L2 is scanned along the length direction S. Thereby, the resin material in the tank 5 is removed. The laser light L2 can be in the form of a pulsed laser, such as an infrared laser, a green laser, or an ultraviolet laser.

[0038] Regarding the pulse width, a laser capable of generating pulse widths such as nanoseconds or picoseconds can be used. Furthermore, by controlling the emission section 23 and the scanning section 24 using the control unit 25 (Fig. 1), the processing conditions based on the laser light L2 can be varied. Depending on the material or dimensions of the resin material 9 (9b) (such as the groove width of the groove 5), the wavelength, output, laser focusing diameter, and irradiation time of the laser light L2 are optimized to efficiently remove the resin material 9 (9b).

[0039] (Surface Removal Step) Figure 10 is a cross-sectional view showing the state of the surface removal step. Figure 11 is a plan view illustrating the scope of the surface removal step. In the surface removal step, before cutting the lead frame 1 (in other words, before the cutting step), the surface portion 3c of the lead frame 1 with the groove 5 is partially removed. The surface removal step is performed, for example, using a laser. In order to efficiently process the material (copper, etc.) of the lead frame 1 and suppress the thermal effects, a short-pulse (less than picosecond) oscillator can be used. The surface removal step can also be performed by other grinding or polishing parts.

[0040] Referring to FIG10, in the state before the surface removal step, the surface portion 3c of the lead frame 1 includes: a cut area 3m that is removed by cutting the lead frame 1, and a non-cut area 3n located between the cut area 3m and the opening end 5c of the groove 5. In the state before the surface removal step, the surface shape 3r of the non-cut area 3n is curved such that it is located closer to the bottom 5a of the groove 5 and closer to the center of the groove width direction than the opening end 5c of the groove 5. Furthermore, in FIG10, the sidewall portion of the blade 12 used in the cutting step ST16 is only schematically illustrated using two-point chain lines.

[0041] In the surface removal step, laser light L3 is irradiated at least toward the non-cut area 3n, and the laser light L3 is scanned along the length direction S (see Figure 11). Thereby, at least a portion of the non-cut area 3n is removed. For example, an amount with a depth of 30 μm to 40 μm can be removed from the surface portion 3c. As the laser light L3, a short-pulse laser such as a picosecond pulse laser can be used, for example.

[0042] FIG12 is an enlarged cross-sectional view of a portion of FIG10, showing the state after the surface removal step. In the example shown in FIG10 and FIG12, the portion of the central part in the height direction of the non-cut area 3n, slightly lower (closer to the bottom 5a of the groove 5), is removed. Furthermore, the two sides of the cut area 3m in the width direction are also slightly removed. That is, in the surface removal step here, in addition to removing at least a portion of the non-cut area 3n, the portion of the cut area 3m close to the non-cut area 3n is also removed.

[0043] After the surface removal step is performed and before the lead frame 1 is cut, the surface portion 3c of the lead frame 1 includes a boundary portion 3t between the cut region 3m and the non-cut region 3n. When the position of the surface of the surface portion 3c in the depth direction of the groove 5 is defined as "height", after the surface removal step is performed and before the lead frame 1 is cut, the height H1 of the surface of the cut region 3m is equal to the height H2 of the surface 3q of the boundary portion 3t, or the height H1 of at least a portion of the surface of the cut region 3m is higher than the height H2 of the surface 3q of the boundary portion 3t (the height position of the surface 3q of the boundary portion 3t is located at a lower height position than the surface of at least a portion of the cut region 3m).

[0044] (Platinum Plating Step) Figure 13 is a cross-sectional view showing the state after the plating step. After the surface removal step and before cutting the lead frame 1, the lead frame 1, whose surface portion 3c has been partially removed, is plated. A plating layer 10 is formed on the surface of the die pad 2 of the lead frame 1, the surface of the tie rod 4 of the lead frame 1, the surface of the thin-walled portion 3b of the lead portion 3, and the surface in the surface portion 3c where the surface removal step was performed. By forming the plating layer 10, the manufacturing method of the processed article is completed, and the lead frame 1 with the plating layer 10 formed at this time constitutes a "processed article".

[0045] As the material for the plating layer 10, a material with good solder wettability can be selected according to the solder material used in the package. For example, when using Sn (tin) based solder, tin (Sn), tin-copper alloy (Sn-Cu), tin-silver alloy (Sn-Ag), tin-bismuth (Sn-Bi), etc. can be used.

[0046] In the plating step, the plating process can be performed after the lead frame 1 has undergone a prescribed cleaning process. The surface treatment of the lead frame 1, as a pretreatment for the plating step, can include cleaning, oxide film removal, surface activation, and other treatments. The resin material 9 in the tank 5 is sometimes modified (e.g., carbonized) by laser irradiation. Even if a small amount of resin material 9 remains, the modified resin material 9 can be removed from the tank 5 through surface treatments such as cleaning before the plating process.

[0047] (Cutting Step) As shown in FIG14, the plated lead frame 1 is cut along the groove 5. In this cutting step, the total thickness of the lead frame 1 and the resin material 9 is cut off using a blade 12. By performing the cutting step, multiple semiconductor devices 11 as unit resin molded articles can be obtained. As shown in FIG15, the semiconductor device 11 is a leadless article of the Quad Flat Non-leaded Package (QFN) type, in which the leads for electrical connection do not protrude outwards when viewed from above.

[0048] FIG16 is a cross-sectional view showing the packaged state of the semiconductor device 11. As shown in FIG16, in the semiconductor device 11, a step is formed on the side (single side) of each lead portion 3, and no plating layer 10 is formed on the side 3d of the lead portion 3, leaving the original metal exposed. The semiconductor device 11 is packaged on a printed circuit board, for example, with the side of the resin material 9 facing up and the side of the lead portion 3 facing down. On the printed circuit board, pads 13 are formed at positions corresponding to the lead portions 3, and the lead portions 3 are connected to the pads 13 via solder 14.

[0049] At this time, since solder 14 accumulates on the inner side (recess) of the portion in the surface portion 3c (FIG. 12) of the lead frame 1 where the surface removal step has been performed, the wettability of the solder 14 is improved, and a better solder joint structure can be obtained. By performing the surface removal step, the joint area (surface area) of the recessed portion becomes larger, and consequently, the volume of the recessed portion that can guide the solder 14 also becomes larger.

[0050] Figure 17 is a cross-sectional view showing the packaged state of a semiconductor device obtained by the manufacturing method of the comparative example. In the case of the comparative example, since the surface removal step is not performed, the bonding area (surface area) and volume of the portion corresponding to the recess are both small. In contrast, according to the embodiment described above (Figure 16), when manufacturing a workpiece using a workpiece with a groove pre-formed along the cut-off position, higher connection reliability can be obtained compared to the existing method. In addition, by performing the surface removal step, the height HS of the recessed portion can be further increased, and inspection using an automatic inspection machine for inspecting the solder 14 becomes easier and results with higher accuracy can be obtained.

[0051] When the groove 5 of the lead frame 1 is formed by wet etching, the surface shape 3r of the non-cut area 3n tends to bend closer to the bottom 5a of the groove 5 and more towards the center in the groove width direction than the opening end 5c of the groove 5. This effect can be obtained by performing a surface removal step on the surface shape 3r of the non-cut area 3n during wet etching.

[0052] As shown in FIG18, in the embodiment described above, when the position of the surface of the surface portion 3c in the depth direction of the groove 5 is defined as "height", after the surface removal step and before cutting the lead frame 1, the height H1 of the surface of the cutting area 3m is equal to the height H2 of the surface 3q of the boundary portion 3t, or the height H1 of at least a portion of the surface of the cutting area 3m is higher than the height H2 of the surface 3q of the boundary portion 3t. In the latter case, the height position of the surface 3q of the boundary portion 3t is located at a height position lower than that of at least a portion of the surface of the cutting area 3m. With this structure, when cutting with the blade 12, the blade 12 first contacts the portion of the cutting area 3m with height H1. At this time point, a gap 3w is formed below both sides of the blade 12 in the width direction (FIG. 18). Then, the blade 12 contacts the portion of the boundary portion 3t with height H2 (the surface 3q of the boundary portion 3t). Thus, since the thickness of the lead frame 1 becomes thinner at both ends of the blade 12, the occurrence of burrs in the boundary portion 3t can be reduced.

[0053] [First Modification] FIG19 corresponds to FIG12 and is a cross-sectional view illustrating the surface removal step related to the first modification of the embodiment. In the example (FIG. 18, etc.), in addition to removing at least a portion of the non-cut region 3n, the end of the cut region 3m (corresponding to the portion of the gap 3w shown in FIG. 18) is also removed. This structure is not necessary. As shown in FIG19, if the cut region 3m is flat and the side portion 5b of the groove 5 is not included in the cut region 3m, the cut region 3m may not be removed in the surface removal step. By performing the surface removal step only on the non-cut region 3n and not on the cut region 3m, the purpose of forming the recess that facilitates the guidance or bonding of solder can also be achieved. Corresponding to not performing the surface removal step on the cut region 3m, the manufacturing time is shortened.

[0054] [Second Modification] FIG20 corresponds to FIG12 and is a cross-sectional view illustrating the surface removal step related to the second modification of the embodiment. After the surface removal step is performed and before the lead frame 1 is cut, the portion where the surface of the cut area 3m and the surface of the non-cut area 3n intersect (i.e., the surface of the boundary portion 3t) can be flat, and the flat surface can be approximately orthogonal to the depth direction of the groove 5 (the direction orthogonal to the back surface 1b). According to this structure, the occurrence of burrs in the boundary portion 3t can also be reduced.

[0055] FIG21 corresponds to FIG12 and is a cross-sectional view for explaining the surface removal step related to the third variation of the embodiment. As shown in FIG21, after the surface removal step is performed and before the lead frame 1 is cut, the surface shape 3r of the non-cut area 3n (i.e., the side portion 5b of the groove 5) can extend in a manner substantially parallel to the depth direction of the groove 5 (the direction orthogonal to the back surface 1b). By performing the surface removal step up to the extent shown in FIG21, a recess that facilitates solder guidance or bonding can be sufficiently formed. In addition, by making the recess deeper, the solder wetting height on the package side is ensured during the packaging of the semiconductor device, making inspection using an automatic inspection machine easier.

[0056] Furthermore, similar to the case described with reference to FIG20, as shown in FIG21, the portion where the surface of the cut region 3m and the surface of the non-cut region 3n intersect (i.e., the surface of the boundary portion 3t) is flat, and this flat surface is approximately orthogonal to the depth direction of the groove 5 (the direction orthogonal to the back surface 1b). In the structure shown in FIG21, the surface shape 3r of the non-cut region 3n (i.e., the side portion 5b of the groove 5) and the surface shape 3p of the cut region 3m (i.e., the bottom portion 5a of the groove 5) are orthogonal to each other. Even with this structure, the occurrence of burrs at the boundary portion 3t can be reduced.

[0057] [Fourth Modification] As described above, the method for manufacturing a processed article can be composed of a preparation step ST10, a surface removal step ST14, and a plating step ST15. In the case of the embodiment described above (Fig. 2), the surface removal step ST14 and the plating step ST15 are performed between the resin removal step ST13 and the cutting step ST16.

[0058] FIG22 is a diagram illustrating a method for manufacturing a processed article related to the fourth variation of the embodiment, and a method for manufacturing a semiconductor device using the method for manufacturing the processed article. As shown in FIG22, the resin sealing step ST12, resin removal step ST13, and cutting step ST16 may be performed after the various steps (preparation step ST10, surface removal step ST14, and plating step ST15) related to the method for manufacturing the processed article are performed. In the example shown in FIG22, the surface removal step ST14 and the plating step ST15 are performed before the resin sealing step ST12. In the plating step in this case, for example, pre-plated palladium plating (e.g., Ni / Pd / Au plating) or full-surface Pd plating may be used.

[0059] As the implementing entity, for example, the lead frame manufacturer can proceed up to the plating step ST15, and the semiconductor device manufacturer can perform all steps after the resin sealing step ST12. Alternatively, the lead frame manufacturer can proceed up to the surface removal step ST14, and the steps after the plating step ST15 can be performed by the semiconductor device manufacturer.

[0060] [Fifth Modification] FIG23 is a diagram showing a method for manufacturing a processed article related to the fifth modification of the embodiment, and a method for manufacturing a semiconductor device using the method for manufacturing the processed article. As shown in FIG23, the steps related to the method for manufacturing the processed article may be performed discontinuously. Alternatively, after performing the preparation step ST10, the surface removal step ST14, the resin sealing step ST12, the resin removal step ST13, the plating step ST15, and the cutting step ST16 may be performed sequentially. In the example shown in FIG23, the surface removal step ST14 is performed before the resin sealing step ST12, and the plating step ST15 is performed between the resin removal step ST13 and the cutting step ST16.

[0061] As the implementing entity, for example, the lead frame manufacturer can proceed up to the preparation step ST10, and the semiconductor device manufacturer can perform all steps after the surface removal step ST14. Alternatively, the lead frame manufacturer can proceed up to the surface removal step ST14, and the subsequent steps can be performed by the semiconductor device manufacturer.

[0062] The embodiments have been described above, but the disclosure is illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims. [Simplified Explanation of the Diagram]

[0012] Figure 1 is a diagram showing the manufacturing apparatus 20 for the processed article. Figure 2 is a diagram showing the manufacturing method of the processed article and the manufacturing method of a semiconductor device using the manufacturing method of the processed article. Figure 3 is a plan view showing the structure of the lead frame 1 prepared in the preparation step as seen from the back side 1b. Figure 4 is a cross-sectional view along line IV-IV in Figure 3. Figure 5 is a perspective view showing the structure of a part (lead portion 3, tie rod 4, and groove portion 5) of the lead frame 1 prepared in the preparation step as seen from the back side 1b. Figure 6 is a cross-sectional view showing the state in which the semiconductor wafer 6 is bonded to the lead frame 1 (die pad 2) prepared in the preparation step. Figure 7 is a cross-sectional view showing the state in which the resin sealing step has been performed. Figure 8 is a cross-sectional view showing the state in which the protective film has been removed before the resin removal step. Figure 9 is a cross-sectional view showing the state in which the resin removal step has been performed. Figure 10 is a cross-sectional view showing the state in which the surface removal step has been performed. Figure 11 is a plan view for explaining the scope of the surface removal step. Figure 12 is an enlarged cross-sectional view of a portion of Figure 10, showing the state after the surface removal step. Figure 13 is a cross-sectional view showing the state after the plating step. Figure 14 is a cross-sectional view showing the state after the cutting step. Figure 15 is a perspective view showing a semiconductor device obtained by the manufacturing method of the embodiment. Figure 16 is a cross-sectional view showing the packaged state of the semiconductor device obtained by the manufacturing method of the embodiment. Figure 17 is a cross-sectional view showing the packaged state of the semiconductor device obtained by the manufacturing method of the comparative example. Figure 18 corresponds to Figure 12 and is a cross-sectional view for explaining the effects and functions related to the embodiment. Figure 19 corresponds to Figure 12 and is a cross-sectional view for explaining the surface removal step related to the first modification of the embodiment. Figure 20 corresponds to Figure 12 and is a cross-sectional view for explaining the surface removal step related to the second modification of the embodiment. Figure 21 corresponds to Figure 12 and is a cross-sectional view for explaining the surface removal step related to the third modification of the embodiment. Figure 22 is a diagram illustrating a method for manufacturing a processed article related to the fourth modification of the embodiment, and a method for manufacturing a semiconductor device using the method for manufacturing the processed article. Figure 23 is a diagram illustrating a method for manufacturing a processed article related to the fifth modification of the embodiment, and a method for manufacturing a semiconductor device using the method for manufacturing the processed article.

Claims

1. A method for manufacturing a processed article, comprising: Preparation steps include preparing a workpiece that includes at least a lead frame with grooves pre-formed along the cut-off points; The surface removal step involves partially removing the surface portion of the workpiece in which the groove is formed before cutting it off; and the plating step involves plating the workpiece in which the surface portion has been partially removed before cutting it off, wherein, prior to the surface removal step, the surface portion includes a cut area removed by cutting the workpiece off and a non-cut area located between the cut area and the opening end of the groove, and in the surface removal step, at least a portion of the non-cut area is removed.

2. The method of manufacturing a processed article as claimed in claim 1, wherein in the surface removal step, in addition to removing the at least portion of the non-cut region, the portion of the cut region adjacent to the non-cut region is also removed.

3. A method for manufacturing a processed article as claimed in claim 1 or claim 2, wherein, in the state prior to performing the surface removal step, the surface shape of the non-cut area is curved such that it is located closer to the center of the groove width direction than the opening end of the groove, closer to the bottom of the groove.

4. A method for manufacturing a processed article as claimed in any one of claims 1 to 3, wherein, in a state after the surface removal step and before the workpiece is cut off, the surface portion includes a boundary portion between the cut-off region and the non-cut-off region, and when the position of the surface of the surface portion in the depth direction of the groove is defined as height, in a state after the surface removal step and before the workpiece is cut off, the height of at least a portion of the surface in the cut-off region is higher than the height of the surface of the boundary portion.

5. A method for manufacturing a processed article as claimed in any one of claims 1 to 4, wherein, after the surface removal step is performed and before the processed object is cut off, the portion where the surface of the cut area and the surface of the non-cut area are connected is a flat surface, the flat surface being substantially orthogonal to the depth direction of the groove.

6. A method for manufacturing a processed article as described in any one of claims 1 to 5, wherein the surface removal step is performed using a laser.

7. A method for manufacturing a processed article as claimed in any one of claims 1 to 6, wherein the processed object prepared in the preparation step has the groove formed by wet etching.

8. A method for manufacturing a semiconductor device, using a method for manufacturing an article of any one of claims 1 to 7, the method for manufacturing the semiconductor device comprising: The resin sealing step involves sealing the lead frame and the semiconductor wafer with resin material while the semiconductor wafer is bonded to the lead frame; the resin removal step involves removing the resin material from the groove. The method of manufacturing the processed article includes a cutting step, cutting the lead frame along the groove, and the surface removal step and the plating step are performed between the resin removal step and the cutting step, or the surface removal step and the plating step are performed at a stage before the resin sealing step, or the surface removal step is performed at a stage before the resin sealing step, and the plating step is performed between the resin removal step and the cutting step.

9. An apparatus for manufacturing a workpiece, comprising processing a workpiece including at least a lead frame with grooves pre-formed along the cut-off points, the apparatus comprising: The surface removal section partially removes the surface portion of the workpiece in which the groove is formed, while the workpiece is not cut off. And a plating processing unit, which performs plating processing on the workpiece in a state where the workpiece has not been cut, wherein the surface layer portion has been partially removed, and in a state before the surface layer removal unit partially removes the surface layer portion, the surface layer portion includes a cut area that is removed by cutting the workpiece and a non-cut area located between the cut area and the opening end of the groove portion, wherein the surface layer removal unit removes at least a portion of the non-cut area.

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