Conveying tool and conveying method using same

Abstract

To provide a carrier and a carrier method having higher adhesive strength than conventional carriers by changing the surface irregularities. [Solution] A transport tool is used, which includes a plate-shaped substrate and a holding layer formed on one surface of the substrate from an elastic material to hold the transported item, the holding layer having a holding surface with a surface roughness Ssk of 0.1 or less. The transport method includes a fixing step of fixing the transported item on the transport tool, a first moving step of moving the transport tool after the fixing step, a processing step of processing the transported item after the moving step, a second moving step of moving the transport tool after the processing step, and a removal step of stopping the transport tool and removing the transported item from the transport tool after the second moving step.

Description

[Technical Field]

[0001] The present invention relates to a conveying tool for conveying substrates, electronic components, etc. during mounting processes, etc., and a conveying method using the same, and in particular to a conveying tool for positioning and holding circuit boards across an electronic component mounting line when mounting electronic components on flexible or rigid type circuit boards (thin glass epoxy boards that are difficult to transport by themselves). [Background technology]

[0002] There have been transport tools for transporting circuit boards and components in the past (Patent Document 1). There was a correlation between surface roughness (Ra) and adhesive strength. The greater the surface roughness, the lower the adhesive strength. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4144886 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when the surface roughness (Ra) increased, the adhesive strength became weaker than expected, making it impossible to transport the components. In other words, the conventional uneven surface structure was not sufficient. Therefore, an object of the present invention is to provide a conveying tool and a conveying method that change the surface unevenness and have higher adhesive strength than conventional tools. [Means for solving the problem]

[0005] In order to achieve the above object, the following invention is used. [Invention 1] a substrate formed in a plate shape; a holding layer formed of an elastic material on one surface of the substrate and configured to hold the article to be transported; a support surface having surface roughness is formed on the surface of the support layer; The carrier used has a surface roughness Ssk of 0.1 or less. The elastic body includes rubber, elastomer, and resin. [Invention 2] The conveying tool according to Invention 1, wherein the surface roughness Ssk is -0.80 or more and 0 or less. [Invention 3] Further, the conveying tool of the first aspect has a surface roughness Ssk of not less than -0.68 and not more than -0.19. [Invention 4] 2. The carrier according to claim 1, wherein the surface roughness Sa is 0.25 to 5 μm. [Invention 5] The adhesive strength of the retaining layer is 50 to 2000 g / cm 2 The carrier according to Invention 1. [Invention 6] 2. The carrier according to claim 1, wherein the elastic body is at least one of fluororubber, fluororesin, silicone rubber, silicone resin, acrylic rubber, and acrylic resin. [Invention 7] In addition, a conveying method is used that includes a fixing step of fixing the object to be conveyed on a conveying tool described in any one of Inventions 1 to 6 above, a first moving step of moving the conveying tool after the fixing step, a processing step of processing the object to be conveyed after the moving step, a second moving step of moving the conveying tool after the processing step, and a removing step of stopping the conveying tool and removing the object to be conveyed from the conveying tool after the second moving step. [Effects of the Invention]

[0006] The conveying tool and the conveying method using the same according to the present invention can provide a conveying tool and a conveying method with higher adhesive strength than conventional ones by changing the structure of the surface irregularities. [Brief explanation of the drawings]

[0007] [Figure 1] (a) is a side view of the carrier of the embodiment, (b) is a plan view of the carrier of the embodiment. [Figure 2] (a) is a cross-sectional view of a conventional carrier having surface irregularities, and (b) is a cross-sectional view of a carrier according to an embodiment of the present invention. [Figure 3] (a) Graph of Sa and adhesive strength for Examples and Comparative Examples when fluororubber is used for the retaining layer, (b) Graph of Ssk and adhesive strength for Examples and Comparative Examples when fluororubber is used for the retaining layer [Figure 4] (a) Graph of Sa and adhesive strength for Examples and Comparative Examples when silicone rubber is used for the retaining layer, (b) Graph of Ssk and adhesive strength for Examples and Comparative Examples when silicone rubber is used for the retaining layer [Figure 5] (a) Graph of Sa and adhesive strength for Examples and Comparative Examples when acrylic rubber is used for the retaining layer, (b) Graph of Ssk and adhesive strength for Examples and Comparative Examples when acrylic rubber is used for the retaining layer BEST MODE FOR CARRYING OUT THE INVENTION

[0008] <Transportation equipment> First, a carrier 10 according to an embodiment will be described with reference to FIGS. 1(a) and 1(b). FIG. 1(a) shows a side view of a carrier 10 of this embodiment, and FIG. 1(b) shows a top view. The carrier 10 comprises a base material 13 and a holding layer 12 located on the upper surface of the base material 13. The holding layer 12 temporarily holds the article 11 to be carried.

[0009] The process is as follows. For example, the transported object 11 is a circuit board, which is held by a holding layer 12. The transport tool 10 secures the circuit board as the transported object 11 with the holding layer 12. The transport tool 10 is moved across an electronic component mounting line where electronic components are mounted on the circuit board. In the electronic component mounting line, the electronic components are mounted on the circuit board using cream solder. The circuit board, which is the transported object 11, is positioned and held by the holding layer 12. Circuit boards include FPC boards and thin glass epoxy boards that are difficult to transport on their own. The transport tool 10 has a rigid base material 13 and a holding layer 12 provided on one side of the base material 13. In addition to electronic component mounting lines, the transport tool 10 can also be used to transport components in vacuum equipment and wafers in semiconductor processes. Other examples of the transported object 11 include semiconductor chips, electronic components, flexible substrates, glass panels, etc. The transported object 11 is also used in processes other than electronic component mounting lines where the transported object 11 is transported and processed.

[0010] The substrate 13 is made of a mechanically rigid material, such as a metal plate (e.g., aluminum, copper, stainless steel, glass epoxy, magnesium board, carbon FRP, ceramic, phenol, polyimide, etc.), as long as it ensures flatness. The substrate 13 is provided with positioning holes as needed. The positioning holes can be used for positioning the workpiece 11 when fixing it to the substrate 13, and can also be used for rough positioning when processing the workpiece 11 or when mounting electronic components on the workpiece 11. The positioning holes can also be used to recognize the pattern position marks on the workpiece 11 with a recognition means, and can be used as a means for correcting positional variations when the workpiece 11 is fixed to the substrate 13.

[0011] The holding layer 12 is an adhesive layer made of an elastic material such as resin, elastomer, or rubber, and serves to adhesively hold (temporarily fix) the transported object 11 with a degree of adhesion according to the surface roughness of the surface. As shown in Figure 1(a), the holding layer 12 is fixed to one surface of the substrate 13. Various features can be added to the carrier 10. Positioning holes or position markers may be provided for alignment. Also, in order to remove the transported item 11 from the holding layer 12, a hole may be provided that penetrates the base material 13 and the holding layer 12, and the transported item 11 may be removed by a protrusion using the through hole.

[0012] <Adhesion and surface roughness> Here, adhesive strength and surface roughness Ra are proportional to each other. Surface roughness Ra can be set to achieve the desired adhesive strength. However, as the surface roughness Ra increases, adhesive strength becomes weaker than expected. The reason for this is explained below. The surface roughness in Patent Document 1 is evaluated by the surface roughness Ra.

[0013] Surface roughness Ra is the parameter most commonly used as an index of roughness. It refers to the average area of ​​unevenness obtained by adding the area of ​​the convex parts above the center line and the area of ​​the concave parts, and dividing by the reference length. It is easy to remember as rough average. Because it is an average value, it is said to be less susceptible to the influence of large scratches that occur suddenly. This evaluation (surface roughness Ra) does not adequately evaluate the shape of the convex parts. In fact, the ratio of the top of the convex parts is important for holding the adhesive object. Therefore, we thought of using skewness Ssk (degree of deviation) as a method of measuring surface roughness.

[0014] Surface roughness Ssk is defined in ISO 25178 and quantifies the skewness (degree of deviation) of unevenness. The case where Ssk is small is shown in Fig. 2(a), and the case where Ssk is large is shown in Fig. 2(b), which are schematic cross-sectional views. Fig. 2(a) shows a conventional uneven structure, and Fig. 2(b) shows the uneven structure of the embodiment. A small Ssk means that the proportion of the surface (top, apex) of the convex portion is large, that is, the proportion of the apex side is large. Since the transported object 11 is held at the apex, it is preferable that the proportion of the apex is large, and it is preferable that Ssk is small. A large Ssk means that the proportion of the surface (top) of the convex portion is small, that is, the proportion of the top side is small. The magnitudes of Ra and Ssk in Figures 2(a) and 2(b) are shown in Table 1.

[0015] The Ra in Figure 2(a) and Figure 2(b) are the same, but the Ssk is different. Figure 2(a) has a higher Ssk than Figure 2(b). Ssk reflects the proportion of the peaks of the convex parts. The smaller the value, the greater the proportion of peaks. The greater the proportion of peaks, the more firmly the transported product 11 held by the peaks is held. In other words, the adhesive force is greater.

[0016] [Table 1]

[0017] As a result, the conventional Ra could not accurately evaluate the state of the convex parts of the unevenness, and the adhesive strength was not accurately reflected. On the other hand, Ssk can evaluate the state of the convex parts more accurately than Ra. To further increase the adhesive strength, it is better to use the uneven structure shown in Figure 2(b) rather than the uneven structure shown in Figure 2(a).

[0018] The manufacturing method is described below. One method for forming the irregularities is to form the retaining layer 12 on the substrate 13 using a mold with irregularities. As a result, irregularities can be formed on the surface of the retaining layer 12. In other words, the irregularities of the retaining layer 12 can be formed by transferring the irregularities of the mold. The same shape as the irregularities of the mold is transferred.

[0019] The unevenness is formed on the mold by blasting. When blasting is simply performed under one condition (conventional), the shape shown in Figure 2(a) is obtained. To achieve the structure shown in FIG. 2(b) of this embodiment, for example, two blasting conditions are used. The blasting conditions can be changed. For example, by changing the particles used (using multiple types of particles), shifting the blasting position and blasting multiple times, or polishing after blasting, the top can be flattened as shown in FIG. 2(b). Conventionally, the structure shown in FIG. 2(a) was achieved by simply forming unevenness.

[0020] <Method for manufacturing retention layer 3> By press molding using a mold, the retaining layer 12 according to this embodiment can be formed on one surface of the substrate 13. If the mold is processed so that the surface side of the retaining layer 12 has a surface roughness corresponding to the desired adhesiveness, the surface roughness of the mold is transferred to the surface of the retaining layer 12 during press molding. Known techniques such as shot blasting, etching, polishing, and cutting can be used to finish the surface of the mold to the desired surface roughness.

[0021] Furthermore, depending on the position of the retaining layer 12, different transported articles 12 may be held, and different adhesive strengths may be required. In such cases, the mold may be machined to have different surface roughnesses depending on the location of the retaining layer 12. In this way, by press molding using a mold with the desired surface roughness, a conveying tool 10 having a retaining layer 12 with different required adhesive strengths in different locations can be easily produced.

[0022] In addition to molding using a mold, it is also possible to form the support layer 12 by screen printing or the like, and then additionally process the surface so that it has a desired surface roughness.

[0023] <Material> The fluororubber (resin) used to form the retaining layer 12 in the carrier 10 will be described. As described above, the fluororubber used in this embodiment can be one having a peroxide cross-linked structure, one having a polyol cross-linked structure, or one having a diamine cross-linked structure. The retaining layer 12 may be formed from one of these three types of fluororubber (peroxide cross-linked structure, polyol cross-linked structure, and diamine cross-linked structure), or may be formed from a combination of these. Another fluororubber may also be used. Materials other than fluororubber are also possible, as will be described below.

[0024] <Adhesion measurement> Using a dedicated adhesiveness measuring device, a measuring probe is pressed against the retaining layer 12 with a predetermined load to adhere it, and then the measuring probe is pulled up at a constant speed. The load applied when the measuring probe separates from the retaining layer 12 is recorded as the adhesiveness (g / cm 2 The experimental temperature was 25°C.

[0025] <Surface roughness measurement> The surface roughness of the retention layer 12 was measured using a three-dimensional optical profiler (Zygo NewView8300). The measurement conditions were vertical scanning low-coherence interferometry, vertical resolution 0.1 nm, spatial resolution 0.52 μm, objective lens 10X, zoom lens 1.0X, and long wavelength cutoff 250 μm. Ssk and Sa were obtained. Sa is calculated from Ra in a two-dimensional area (surface area, Ra is measured in a line).

[0026] <Examples and Comparative Examples> A: When fluororubber is used as the retaining layer 12 A-5052 was used as the substrate 11. 100 parts by weight of fluororubber (VDF / PAVA / TFE copolymer; trade name Viton (registered trademark) GLT-200S; manufactured by DuPont Elastomers Co., Ltd.) were used as the material for the support layer 12, 3 parts by weight of a vulcanizing agent (2,5-dimethyl-2,5-bis(t-butylperoxy)hexane; trade name Perhexa 25B; manufactured by NOF Corporation), and 3 parts by weight of a co-crosslinking agent (triallyl isocyanurate; trade name TAIC; manufactured by Nippon Kasei Chemical Co., Ltd.) were used. These were mixed and kneaded using a test roll with a roll diameter of 8 inches and a roll length in the horizontal direction of 20 inches to produce a kneaded product.

[0027] <Combine> The substrate 13 was set in a mold, and a predetermined amount of the kneaded material was added and press-molded (primary vulcanization) at a predetermined temperature (160°C to 190°C) and for a predetermined time (6 to 10 minutes) suitable for each formulation. Then, secondary vulcanization was performed in an oven at 232°C for 10 hours. The temperature was around 220 to 240°C, depending on the crosslinking agent and crosslinking aid.

[0028] The adhesiveness and surface roughness of the carrier 10 prepared above were measured. Table 2 shows the surface irregularities and adhesive strength of the examples and comparative examples.

[0029] [Table 2]

[0030] In the comparative examples, shot blasting was performed under one condition to finish the surface roughness of the mold. The shot blasting conditions were changed for each comparative example to form various surface irregularities. In the examples, shot blasting was performed under two conditions to finish the surface roughness of the mold. The two conditions were either different particles used or different shot blasting conditions (number of shots, amount of shots, shot speed, processing time, etc.). For each example, the particles and shot blasting conditions were changed to form various surface irregularities. The surface roughness of the mold was transferred to the irregularities on the surface of the support layer 12 .

[0031] Figure 3(a) is a graph showing the relationship between Sa and adhesive strength for an example and a comparative example in which a fluororesin is used for the retaining layer 12, and Figure 3(b) is a graph showing the relationship between Ssk and adhesive strength for an example and a comparative example in which a fluororesin is used for the retaining layer 12. In Figure 3(a), there is no difference in Sa between the comparative example and the example, but there is a difference in adhesive strength. This is thought to be due to surface irregularities that cannot be evaluated by Sa, as explained above. In Figure 3(b), there is a difference in Ssk between the comparative example and the working example. There is also a difference in adhesive strength. As a result, it can be considered that the surface irregularities can be evaluated using Ssk. That is, the adhesive strength is high in the example because Ssk is small and the ratio of the peaks of the convex portions is high (FIG. 2(b)). On the other hand, in the comparative example, the ratio of the peaks of the convex portions is small (few), and the adhesive strength is low (weak).

[0032] B: When silicone rubber is used as the retaining layer 12 As the substrate 11, A-5052 was used. The support layer 12 was made of silicone rubber (SR-60PO vulcanized, manufactured by Takehara Rubber Processing Co., Ltd.). The substrate 13 was set in a mold, a predetermined amount of silicone rubber was poured in, and press molding was carried out under suitable conditions of a predetermined temperature (150°C to 180°C) and a predetermined time (6 minutes to 15 minutes). The adhesiveness and surface roughness of the support layer 12 of the carrier 10 prepared above were measured. The roughness (surface roughness) of the molds of the comparative example and the example is the same as that of A. The results are shown in Table 3.

[0033] [Table 3]

[0034] Fig. 4(a) is a graph showing the relationship between Sa and adhesive strength for an example and a comparative example when silicone rubber is used for the retaining layer 12, and Fig. 4(b) is a graph showing the relationship between Ssk and adhesive strength for an example and a comparative example when silicone rubber is used for the retaining layer. The results are similar to those in case A.

[0035] C: When acrylic rubber is used as the retaining layer 12 As the substrate 11, A-5052 was used. Acrylic rubber (AR-60 epoxy heat-resistant -10L manufactured by Takehara Rubber Processing Co., Ltd.) was used as the material for the retaining layer 12. The substrate 13 was set in a mold, and a predetermined amount of the above kneaded material was added, followed by press molding under conditions of a predetermined temperature (150°C to 180°C) and a predetermined time (6 minutes to 15 minutes) suitable for each formulation.

[0036] The adhesiveness and surface roughness of the carrier 10 prepared above were measured. The roughness of the mold was the same as that of A. The results are shown in Table 4.

[0037] [Table 4]

[0038] The roughness of the molds of the comparative example and the example is the same as that of A. Fig. 5(a) is a graph showing the relationship between Sa and adhesive strength for an example and a comparative example when acrylic rubber is used for the retaining layer 12, and Fig. 5(b) is a graph showing the relationship between Ssk and adhesive strength for an example and a comparative example when acrylic rubber is used for the retaining layer. The results are similar to those in case A.

[0039] From the above three examples, it can be seen that the adhesive strength of the support layer 12 of the conveyance tool 10 is best evaluated by the surface roughness Ssk. The surface roughness Ssk of the support layer 12 of the example has a structure different from that of conventional support layers. The surface roughness Ssk is preferably 0.1 or less. The surface roughness Ssk is more preferably −0.68 or more and −0.19 or less. The surface roughness Ssk is more preferably −5 or more, and even more preferably −1 or more. The surface roughness Ssk does not depend on the material (resin) of the support layer 12. It is likely that similar results would be obtained if other resin materials were used. Although there are differences in adhesive strength between the resins used, when comparing the same materials, the retention layer 12 with this structure has stronger adhesive strength than conventional retention layers.

[0040] <Effects> The carrier 10 of the example has stronger adhesive strength than the carrier of the comparative example, which is due to the difference in Ssk of the surface irregularities of the support layer 12. Regardless of the composition (material) of the support layer 12, the adhesive strength can be improved.

[0041] <Adhesive strength> The adhesive strength of the carrier 10 of the embodiment is not particularly limited, and the present embodiment is applicable. 2 In particular, adhesive strength of 150 to 1500 g / cm 2 This is effective when making products with a density of 150 to 1000 g / cm. This cannot be made using conventional methods. 2 , B silicone rubber: 100~400g / cm 2 , C acrylic rubber: 250~1500g / cm 2 This is particularly effective when producing the above-mentioned items.

[0042] <sa> Although the embodiment is not limited to the range of the surface roughness Sa, it is particularly effective when the surface roughness Sa is 0.5 μm or more and 1.6 μm or less. Conventional methods cannot produce products with high adhesive strength. It is particularly effective to produce a surface roughness of 0.6 μm or more and 1.6 μm or less for fluororubber type A, 0.6 μm or more and 1.5 μm or less for silicone rubber type B, and 0.5 μm or more and 1.3 μm or less for acrylic rubber type C. Sa is at least 0.25 μm or more and 5 μm or less.

[0043] <Elastic body material> Although the above example shows rubber as the elastic body of the retaining layer 12, it is not limited to rubber and any elastic resin or elastomer can be used. If the elastic material has adhesive properties, the same effect can be achieved when the above-mentioned unevenness is formed.

[0044] When no low-molecular-weight component remains and high-temperature stability is required, examples of the fluororubber (fluororesin) include those having a peroxide crosslinking structure, those having a polyol crosslinking structure, and those having a diamine crosslinking structure. Note that the support layer 12 may be formed from one of these three types of fluororesin (peroxide crosslinking structure, polyol crosslinking structure, and diamine crosslinking structure), or may be formed from a combination of these.

[0045] In the above examples, the results were obtained using one example of fluororubber, silicone rubber, and acrylic rubber, but similar effects can be obtained with other types of fluororubber, silicone rubber, and acrylic rubber. In addition to fluororubber, silicone rubber, and acrylic rubber, natural rubber, polyurethane rubber, polyimide silicone rubber, cyclopentadiene rubber, elastomer natural rubber, styrene-butadiene rubber, nitrile rubber, ethylene-propylene rubber, butyl rubber, chloroprene rubber, chlorosulfonated polyethylene, urethane rubber, etc. may also be used, and further, elastomers and resins thereof may also be used. The additives such as vulcanizing agents and curing agents and their amounts are selected according to the main component rubber (resin, elastomer). The elastic modulus (Young's modulus) at room temperature is preferably about 1 to 10 MPa.

[0046] <Transportation method> The conveying method using the conveying tool 10 of this embodiment is as follows. a fixing step of fixing the object 11 to be transported on the transport tool 10; a first moving step of moving the carrier 10 after the fixing step; a processing step of processing the transported object 11 after the moving step; a second moving step of moving the carrier 10 after the processing step; This is a conveying method including a removing step of stopping the conveying tool 10 after the second moving step and removing the conveyed object 11 from the conveying tool 10. <Overall> There are various methods for forming the unevenness of the support layer 12, and methods other than those described above are also acceptable. Any method may be used as long as the Ssk value falls within the above range. The unevenness can be regular and spaced at regular intervals, as shown in Figure 2(b), but a random distribution is better. In the above example, the unevenness is random because it was created using two shot blasting conditions. The randomness refers to the spacing between the convex parts or the height of the convex parts. [Industrial Applicability]

[0047] The transport tool 10 according to the present invention can transport the transported object 11 on a mounting line or the like, and can process the transported object 11. [Explanation of symbols]

[0048] 10. Transport equipment 11 Items to be transported 12 Retention layer 13 Base material< / sa>

Claims

1. a substrate formed in a plate shape; a holding layer formed of an elastic material on one surface of the substrate and configured to hold the article to be transported; a support surface having surface roughness is formed on the surface of the support layer; A conveying tool having a surface roughness Ssk of 0 or less.

2. 2. The transport tool according to claim 1, wherein the surface roughness Ssk is not less than -0.80 and not more than 0.

3. 2. The transport tool according to claim 1, wherein the surface roughness Ssk is not less than −0.68 and not more than −0.

19.

4. A conveying device as described in claim 1, wherein the surface roughness Sa is 0.25 μm or more and 5 μm or less.

5. 2. The carrier according to claim 1, wherein the adhesive strength of the support layer is 50 to 2000 g / cm<2>.

6. 2. The carrier according to claim 1, wherein the elastic body is made of at least one of fluororubber, fluororesin, silicone rubber, silicone resin, acrylic rubber, and acrylic resin.

7. a fixing step of fixing an object to be transported on the transport tool according to any one of claims 1 to 6; a first moving step of moving the carrier after the fixing step; a processing step of performing processing on the transported object after the first moving step; a second moving step of moving the carrier after the processing step; a removing step of stopping the transporting tool after the second moving step and removing the transported object from the transporting tool.

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