JP2012186240A - Protection tape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a protection tape which protects substrates passing through solder reflow process, does not increase the adhesion due to heat generated in the solder reflow process, and effectively maintains the ease of removal.SOLUTION: A protection tape has an adhesive layer which is adhered to a substrate, a metal layer, and a resin layer. At least the metal layer and the resin layer are provided on the adhesive layer.

Description

  The present invention relates to a protective tape for protecting a substrate flowing through a solder reflow process.

  Conventionally, when connecting electronic components such as resistors, capacitors, and ICs to a substrate, solder is first applied to the connecting portion on the substrate, and the corresponding electronic component is placed on the solder and reflowed. In the solder reflow process, the solder is melted by heat, and then the solder is cooled and solidified, whereby the connection portion on the substrate and the electronic component are connected.

  Here, when flowing a board | substrate in said solder reflow process, the melted solder may scatter. At this time, scattered solder tends to adhere to portions other than the connection portion to which the electronic component is connected on the substrate, particularly in the vicinity of the connection portion, which may cause an electrical failure or deteriorate in appearance. To do. Therefore, in order to prevent the scattered solder from adhering during the solder reflow process, a protective tape has been applied in the vicinity of the connection portion in advance. As a result, even if the solder scatters in the vicinity of the connection portion, it can be prevented from adhering to the vicinity of the connection portion located on the lower surface only by adhering to the surface of the protective tape.

  However, since the conventional protective tape has a structure in which a silicon-based resin or the like is laminated on polyimide (PI) as a heat-resistant adhesive layer, if the temperature of the protective tape rises due to heat during the solder reflow process, In some cases, the adhesive strength of the adhesive layer on the side adhered to the surface becomes stronger than the initial state. In such a case, it was difficult to peel off the protective tape from the substrate in the subsequent process, or the adhesive layer remained after the protective tape was peeled off. As a result, there has been a problem that workability is deteriorated, for example, it takes time to peel off the protective tape. Therefore, the protective tape that protects the substrate flowing through the solder reflow process is required to be easy to peel off without increasing the adhesive force even when heated.

  Further, in the case of the above-described conventional protective tape, the silicon resin as the adhesive layer may adversely affect the electronic component, and polyimide is expensive. Therefore, in practice, the conventional protective tape is not used, and the solder scattered after the solder reflow process is removed.

  Here, from the viewpoint of ease of peeling, Patent Document 1 discloses a pressure-sensitive adhesive tape that is thin but excellent in reworkability.

Japanese Patent No. 3902162

  However, the adhesive tape disclosed in Patent Document 1 is used by being attached between the LCD panel of the LCD module and the backlight housing, and has light reflectivity and light shielding properties with respect to light from the light source. It is an adhesive tape having both. Therefore, the use and use state are completely different from the protective tape for protecting the substrate flowing through the solder reflow process. Therefore, when the pressure-sensitive adhesive tape disclosed in Patent Document 1 is attached to a substrate and is passed through a solder reflow process, the pressure-sensitive adhesive tape deteriorates due to heat in the process, and it becomes difficult to peel off or a residue remains. A malfunction occurred.

  The present invention has been made in view of the above-mentioned problems, protects the substrate flowing through the solder reflow process, does not increase the adhesive force even with heat during the solder reflow process, and maintains good ease of peeling. An object of the present invention is to provide a protective tape that can be used.

  The protective tape of the present invention is a protective tape that is attached to a substrate flowing through a solder reflow process and protects at least a part of the substrate, and includes an adhesive layer, a metal layer, and a resin layer that are attached on the substrate. And at least the metal layer and the resin layer are provided on the adhesive layer.

  According to said structure, the heat | fever in a solder reflow process can be reflected and thermally radiated outside by the metal layer which the protective tape which protects at least one part of a board | substrate has. As described above, the metal layer can make it difficult for heat to be transmitted to the adhesive layer attached to the substrate, so that the temperature rise of the adhesive layer can be reduced. Thereby, it becomes difficult to peel off from a board | substrate after a solder reflow process, or a residue remains after peeling, and workability deterioration can be prevented. Even when the protective tape is bent, the influence of the bending on the metal layer can be mitigated by the elasticity of the resin layer of the protective tape. Therefore, tearing of the metal layer when the protective tape is peeled from the substrate can be prevented by the resin layer.

  Moreover, the masking tape of this invention WHEREIN: The said resin layer and the said metal layer may be provided in order of the said resin layer and the said metal layer on the said adhesion layer.

  According to the above configuration, even when the resin layer and the metal layer are provided in this order on the adhesive layer, the metal layer can make it difficult to transfer heat to the adhesive layer attached to the substrate. The influence of the bending on the metal layer can be mitigated by the elasticity of the resin layer.

  Moreover, the masking tape of this invention WHEREIN: The said resin layer and the said metal layer may be provided in order of the said metal layer and the said resin layer on the said adhesion layer.

  According to the above configuration, even when the metal layer and the resin layer are provided in this order on the adhesive layer, the metal layer can make it difficult to transfer heat to the adhesive layer attached to the substrate. The influence of the bending on the metal layer can be mitigated by the elasticity of the resin layer.

  In the protective tape of the present invention, the metal layer may have a thickness of 6 μm to 30 μm.

  According to said structure, since the thickness of a metal layer becomes suitable, it becomes easy to reflect and dissipate heat effectively. Further, the protective tape does not become too hard due to the thickness of the metal layer and is difficult to peel off, and a large amount of material is required and the cost is not increased.

  Moreover, the masking tape of this invention WHEREIN: The said metal layer may be formed with aluminum.

  According to said structure, since a metal layer is formed with a suitable material, a heat | fever can be reflected and thermally radiated more effectively. Thereby, the temperature rise of an adhesion layer can be relieved further, it becomes easy to peel off a protective tape in peeling operation | work, and work efficiency can be improved.

  Moreover, the masking tape of this invention WHEREIN: The temperature in the said board | substrate may be 270 degreeC at the maximum during the said solder reflow process.

  According to said structure, even when the temperature in a board | substrate becomes 270 degreeC at the maximum in a solder reflow process, a protective tape is applicable.

  Moreover, the masking tape of this invention WHEREIN: The said solder reflow process is good also considering infrared rays as a heat source.

  According to said structure, the heat | fever in the solder reflow process which uses infrared rays as a heat source can be reflected and thermally radiated outside by a metal layer. Thus, the protective tape can be applied to the solder reflow process using infrared rays as a heat source.

  According to the protective tape of the present invention, the metal layer can make it difficult for heat to be transferred to the adhesive layer attached to the substrate, so that the temperature rise of the adhesive layer can be mitigated. Thereby, it becomes difficult to peel off from a board | substrate after a solder reflow process, or a residue remains after peeling, and workability deterioration can be prevented. Moreover, tearing of the metal layer when peeling the protective tape from the substrate can be prevented by the resin layer.

It is explanatory drawing which shows the external appearance and cross section of the protective tape which concerns on this embodiment. It is explanatory drawing which shows the state by which the protective tape which concerns on this embodiment was affixed on the board | substrate. It is explanatory drawing which shows the solder reflow process which concerns on this embodiment. It is explanatory drawing which shows the peeling test result using Example 1 and the comparative example 1 of the protective tape which concerns on this embodiment. It is explanatory drawing which shows the peeling test result using Examples 2-4 and the comparative example 2 of the protective tape which concerns on this embodiment.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

(Protective tape)
The outline | summary of the protective tape 1 which concerns on this embodiment is demonstrated using FIG. 1 and FIG. A protective tape 1 according to this embodiment is a protective tape that is attached to a substrate 30 that flows through a solder reflow process and protects at least a part of the substrate 30, and includes an adhesive layer 11 that is attached to the substrate 30, a metal It has a layer 14 and a resin layer 13, and at least a metal layer 14 and a resin layer 13 are provided on the adhesive layer 11. 1 and 2, the resin layer 13 and the metal layer 14 are provided on the adhesive layer 11 in the order of the resin layer 13 and the metal layer 14. In addition, the resin layer 13 and the metal layer 14 may be provided in this order on the adhesive layer 11 in the order of the metal layer 14 and the resin layer 13. Here, the temperature in the substrate 30 is 270 ° C. at the maximum during the solder reflow process according to the present embodiment.

  As shown in FIG. 1, the protective tape 1 is stored in a roll-like shape like a normal tape, and is rolled into a desired size when used by an operator's hand or the like. It can be cut. Further, the cut-off protective tape 1 is attached to a location on the substrate 30 to be protected with the adhesive layer 11 facing the surface of the substrate 30.

  The protective tape 1 is formed by sequentially laminating an adhesive layer 11, a resin layer 13, and a metal layer 14 from the side attached to the substrate 30. The metal layer 14 is attached on the resin layer 13 by the adhesive layer 12. In addition, the metal layer 14 located on the outermost layer of the protective tape 1 can reflect the heat 70 in the solder reflow process and dissipate the heat 70a applied to the metal layer 14 to the outside. Therefore, the protective tape 1 can make it difficult to transmit heat to the adhesive layer 11 located on the lower surface of the metal layer 14. Note that, even when the adhesive layer 11, the metal layer 14, and the resin layer 13 are sequentially laminated from the side to be attached to the substrate 30, the protective tape 1 has heat 70 that has passed through the resin layer 13 by the metal layer 14. And the applied heat 70a can be radiated to the outside.

(How to use the protective tape)
Specifically, a method of using the protective tape 1 will be described with reference to FIG. The substrate 30 according to the present embodiment uses what is called a flexible printed circuit board (FPC). This board | substrate 30 is arrange | positioned on the support plate 20 used in the solder reflow process of FIG. 3 mentioned later. In addition, connection portions 35 a and 35 b to which the electronic component 40 and the like are connected are provided on the substrate 30. In the case of FIG. 2, the electronic component 40 is connected to the connection part 35a via the solder 45, and the protective tape 1 is affixed to the connection part 35b. The protective tape 1 attached to the substrate 30 in this way is also attached to the surface of the support plate 20 at the same time, and the substrate 30 is fixed to the support plate 20 by the protective tape 1. As described above, the protective tape 1 is attached to the connection portion 35b to which the electronic component 40 is not connected, so that the solder 45 is melted in the solder reflow process, and the scattered solder 45 is prevented from adhering to the substrate 30. It is out. In addition, the protective tape 1 can be appropriately affixed not only to the connection portion 35 b of the substrate 30 but also to a portion to be protected on the substrate 30.

  Here, as described above, the flexible printed board such as the board 30 according to the present embodiment is often bent frequently during work. Accordingly, the protective tape 1 that protects the substrate 30 may be bent. In addition, since the protective tape 1 is bent when the protective tape 1 is peeled off from the substrate 30, the protective tape 1 is also considered to have flexibility and strength that are difficult to break even when bent, in addition to heat countermeasures by the solder reflow process. In addition, the material and thickness of each component are set.

  Each structure of the protective tape 1 which concerns on this embodiment is demonstrated.

(Metal layer)
First, the metal layer 14 of the protective tape 1 will be described. The metal layer 14 is affixed by the adhesive layer 12 on the resin layer 13 to be described later, and is disposed on the outermost layer of the protective tape 1. The metal layer 14 reflects and dissipates heat during the solder reflow process. Have Further, the thickness of the metal layer 14 is preferably 6 μm to 30 μm. This is because if the thickness of the metal layer 14 is less than 6 μm, the metal layer 14 is easily torn during the peeling operation or is difficult to dissipate heat. On the other hand, if the thickness of the metal layer 14 is larger than 30 μm, the protective tape 1 becomes too hard depending on the thickness, and it is difficult to peel off, or a large amount of material is required, resulting in high cost. Further, the metal layer 14 may be metal plating such as aluminum, silver, copper or the like, or may use a metal foil. Among these, it is better to use aluminum for the metal layer 14 because it reflects heat and easily dissipates heat during the solder reflow process.

  According to this configuration, since heat can be reflected and radiated more effectively to the outside, the temperature rise of the adhesive layer 11 can be mitigated, and the protective tape can be easily peeled off during the peeling operation, thereby improving the work efficiency. be able to.

  Moreover, since the thickness of the metal layer 14 is suitable, it becomes easy to effectively reflect and dissipate heat. Furthermore, the thickness of the metal layer 14 does not cause the protective tape 1 to be too hard and difficult to peel off, and does not require a large amount of material and increase the cost.

(Adhesive layer)
The adhesive layer 12 is interposed between the metal layer 14 and the resin layer 13 and has a role of attaching the metal layer 14 on the resin layer 13. The adhesive layer 12 is formed of a polyurethane adhesive or a polyester adhesive and has a thickness of 1 to 6 μm.

(Resin layer)
Next, the resin layer 13 of the protective tape 1 will be described. The resin layer 13 is provided on the adhesive layer 11 described later together with the metal layer 14 attached by the adhesive layer 12. In the case of FIG. 1, the resin layer 13 is interposed between the metal layer 14 and the adhesive layer 11, and is bonded to the metal layer 14 by the adhesive layer 12. The resin layer 13 prevents the metal layer 14 from being torn when the protective tape 1 is peeled off.

  The resin layer 13 is formed of a resin such as polyethylene terephthalate (PET), polyimide (PI), or epoxy. Among them, polyethylene terephthalate is preferably used because it prevents tearing of the metal layer 14 when the protective tape 1 is peeled off and costs are not so high. The thickness of the resin layer 13 is 6 μm to 50 μm. This is because if the thickness of the resin layer 13 is thinner than 6 μm, it is difficult to reduce the influence of the metal layer 14 on the bending. On the other hand, if the thickness of the resin layer 13 is larger than 50 μm, the protective tape 1 becomes too hard depending on the thickness, and it becomes difficult to peel off, or a large amount of material is required and the cost is increased. The polyethylene terephthalate used for the resin layer 13 turns yellow at a temperature of about 180 ° C., starts thermal deformation, and shrinks at a temperature of about 240 ° C. Therefore, the metal layer 14 according to the present embodiment reflects and dissipates heat so that the temperature of the resin layer 13 does not reach 180 ° C., which starts to change color.

  In the case of FIG. 1, the resin layer 13 is interposed between the metal layer 14 and the adhesive layer 11, but may be provided on the surface of the metal layer 14 (outermost layer of the protective tape 1). . In this case, the metal layer 14 has a role of mitigating the influence on the bending of the metal layer 14 and can also have a role of protecting the metal layer 14 from acidic chemicals.

  According to the configuration of the resin layer 13 as described above, even if the protective tape 1 is bent, the influence of the bending on the metal layer 14 can be mitigated by the elasticity of the resin layer 13. Therefore, the resin layer 13 can prevent the metal layer 14 from tearing when the protective tape 1 is peeled from the substrate 30.

(Adhesive layer)
Next, the adhesive layer 11 of the protective tape 1 will be described. The adhesive layer 11 is disposed on the side in contact with the substrate 30, is laminated on the resin layer 13 laminated on the metal layer 14, and is attached to the substrate 30. The adhesive layer 11 is made of a resin such as acrylic, rubber, silicon, or urethane. Among these, in consideration of transparency, stability of adhesive strength, and the like, the adhesive layer 11 is preferably formed using an acrylic resin. Moreover, the thickness of the adhesion layer 11 is 5 micrometers-20 micrometers. This is because when the thickness of the adhesive layer 11 is less than 5 μm, it is difficult to stick to the substrate 30, and when it is thicker than 20 μm, a residue is easily generated when the protective tape 1 is peeled off. In the case of the pressure-sensitive adhesive layer 11 formed of an acrylic resin, since the deterioration starts when heat of 250 ° C. or higher is applied, the temperature of the heat applied to the pressure-sensitive adhesive layer 11 needs to be at least 250 ° C. or lower.

(substrate)
Next, the substrate 30 to which the protective tape 1 having the above configuration is attached will be described. The substrate 30 according to the present embodiment is a flexible printed circuit board (FPC). The substrate 30 is provided with a plurality of wiring patterns such as a signal wiring pattern and a ground wiring pattern (not shown) on a base member made of polyimide, and the surface thereof is covered with an insulating layer or the like. . The substrate 30 having such a configuration is provided with a connection portion 35a and a connection portion 35b, and the connection terminal arranged in the connection portion 35a and the connection terminal arranged in the electronic component 40 are bonded by the solder 45. Both are connected electrically. The substrate 30 made of polyimide can withstand heat of 300 ° C. or higher. Further, as shown in FIG. 2, the protective tape 1 is attached to the connection portion 35 b of the substrate 30 to which the electronic component 40 is not connected, and the solder 45 scattered in the solder reflow process adheres to the substrate 30. To prevent that. In the present embodiment, a flexible printed circuit board (FPC) is used for the substrate 30, but other types of substrates may be used.

(Solder reflow process)
Next, the solder reflow process according to the present embodiment will be described with reference to FIG. First, the solder reflow device 50 used in the solder reflow process will be described. The solder reflow device 50 includes a base part 51, a belt conveyor 52, and a heating furnace part 55. The base portion 51 has a long casing and serves as a base for the solder reflow device 50. The belt conveyor 52 is installed on the base 51, and a plurality of rollers 53 arranged in parallel in the same direction at a constant distance are installed inside so as to cover the upper and lower surfaces of each roller 53. The belt is erected. The rollers 53 have a long and narrow cylindrical shape with a circular cross section, and the belts of the belt conveyor 52 move in the left-right direction as the rollers 53 rotate around the center of the circle. The heating furnace 55 has a total length of 2 m, and an infrared irradiation unit 56 is provided therein, so that infrared rays can be irradiated onto the belt conveyor 52. Moreover, the infrared irradiation part 56 is installed with a certain gap between the belt conveyor 52. Thereby, the infrared rays can be irradiated from the infrared irradiation unit 56 to the substrate 30 flowing on the belt conveyor 52.

  Here, before the solder reflow process, the plurality of substrates 30 are arranged on the support plate 20, and the protective tape 1 is attached to the connection portion 35b to which the electronic component 40 is not connected. At this time, the protective tape 1 is simultaneously attached to the support plate 20 so as to fix the substrate 30 to the support plate 20. The protective tape 1 is attached so that the adhesive layer 11 of the protective tape 1 is in contact with the substrate 30. And cream solder is apply | coated to the connection part 35a of the board | substrate 30, and the electronic component 40 is set | placed on it and it prepares for solder reflow.

  Next, as shown in FIG. 3A, the support plate 20 on which the substrates 30 prepared as described above are arranged is placed on a belt conveyor 52. As the rollers 53 of the belt conveyor 52 rotate, the belt conveyor 52 moves to the right in the figure, and the support plate 20 on which the substrates 30 are arranged is also moved. As shown in FIG. 3B, the substrate 30 moved rightward by the belt conveyor 52 eventually reaches a lower position of the heating furnace 55, and infrared rays are irradiated onto the substrate 30 from the infrared irradiation unit 56. At this time, the substrate 30 moving below the furnace 55 moves in the furnace 2 55 having a total length of 2 m over 3 minutes. During the movement, the temperature on the substrate 30 gradually rises from the initial position of the thermal furnace section 55, eventually reaches a maximum of 270 ° C., and moves to the final position of the thermal furnace section 55. The temperature gradually decreases. The solder 45 applied to the connection portion 35a is melted by the heat at this temperature (270 ° C.), and the connection portion 35a and the connection terminal disposed on the electronic component 40 are bonded together by the solder 45, so that both are electrically connected. Connected. In addition, as shown in FIG.3 (b), the heat added to the protective tape 1 is transmitted by the metal layer 14 to the location where the temperature on the support plate 20 is low. As described above, the temperature of the adhesive layer 11 of the protective tape 1 is at least 250 ° C. or less because the infrared rays are reflected to the outside by the metal layer 14 and the heat generated by the infrared rays is dissipated. ing. In FIG. 3, the solder reflow process according to the present embodiment uses infrared rays as a heat source, but is not necessarily limited to this. For example, it may be a step of soldering by blowing hot air. Any means may be used as long as heat can be reflected and dissipated by the metal layer 14 of the protective tape 1.

  As described above, the metal layer 14 included in the protective tape 1 that protects at least a part of the substrate 30 can reflect and dissipate heat to the outside during the solder reflow process. As described above, the metal layer 14 can make it difficult for heat to be transmitted to the adhesive layer 11 attached on the substrate 30, so that the temperature increase of the adhesive layer 11 can be reduced. Thereby, it becomes difficult to peel off from the board | substrate 30 after a solder reflow process, or the residue remains after peeling, and workability | operativity deterioration can be prevented.

  Further, heat during the solder reflow process using infrared rays as a heat source can be reflected and radiated to the outside by the metal layer 14. Thus, the protective tape 1 can be applied also to the solder reflow process using infrared as a heat source.

  Further, in the solder reflow process, the protective tape 1 according to the present embodiment can be applied even when the temperature in the substrate 30 is 270 ° C. at the maximum.

(Example 1 and Comparative Example 1)
Next, the present invention will be specifically described using Example 1 and Comparative Example 1 of the protective tape 1 according to the present embodiment.

  In Example 1, the protective tape 1 according to the present embodiment shown in FIG. Specifically, the metal layer 14 is formed from an aluminum (Al) foil and has a thickness of 9 μm. The resin layer 13 is made of polyethylene terephthalate (PET) and has a thickness of 12 μm. Furthermore, the adhesive layer 11 is made of an acrylic resin and has a thickness of 10 μm. On the other hand, as a comparative example, an experiment was first performed using only the resin layer 13 made of polyethylene terephthalate (PET) and the adhesive layer 11 made of an acrylic resin without using the metal layer 14, but the protective tape contracted. It became impossible to measure. Therefore, in the comparative example 1, the structure of only the resin layer 13 which consists of an epoxy resin, and the adhesion layer 11 which consists of acrylic resin was used.

  Next, as an evaluation method, a peel test using an adhesive tape / adhesive sheet test method specified in JIS Z 0237 was performed. Specifically, the protective tape 1 having a width of 10 mm and cut to a length of 100 mm is attached to a test plate made of stainless steel, and the tensile force when the protective tape 1 is peeled off from the test plate in the 180 ° direction by a tensile tester. The force was measured.

  The peel test as described above was performed before and after the solder reflow process shown in FIG. That is, the peeling test was performed before the solder reflow process in which the temperature on the substrate 30 becomes 270 ° C. with infrared rays, after the first solder reflow process, and after the third solder reflow process. In the test, four test samples were prepared for both Example 1 and Comparative Example 1, and the tensile force was measured. The result is shown in FIG.

  According to the test results shown in FIG. 4, the measured values before the solder reflow process were the same as 0.27 N in the average value of the tensile force in both Example 1 and Comparative Example 1, and there was no difference. Next, when the test was conducted after passing through the solder reflow process once, the average value of the tensile force of Example 1 was 0.30 N, the average value of the tensile force of Comparative Example 1 was 0.61 N, and both tensile forces were The difference came out. When the test was conducted after passing through the solder reflow process three times, the average value of the tensile force of Example 1 was 0.33N, whereas the average value of the tensile force of Comparative Example 1 was 1.04N. There is a big difference in power. In Example 1, when the solder reflow process was passed once, the tensile force was 1.1 times, and when the solder reflow process was passed 3 times, it was 1.22 times that of the comparative example. In No. 1, it was found that when the solder reflow process was passed once, the tensile force was greatly increased by 2.25 times, and when the solder reflow process was passed 3 times, it was greatly increased by 3.85 times. This is presumably because, in the case of Comparative Example 1, the metal layer 14 was not provided, so that heat could not be reflected and dissipated, and the temperature of the adhesive layer 11 on the lower surface was raised. That is, the temperature of the adhesive layer 11 rises to 250 ° C. or more at which the adhesive layer 11 starts to deteriorate due to the heat of the solder reflow process, and the material of the adhesive layer 11 is decomposed to increase the adhesive force. It is thought that the tensile force at the time of peeling from 60 became large. On the other hand, in the case of Example 1, since the outermost layer is the metal layer 14, heat is reflected and dissipated by the metal layer 14, heat is hardly transmitted to the adhesive layer 11, and the temperature of the adhesive layer 11 rises to 250 ° C or higher. There is nothing to do. Therefore, the adhesive force of the adhesive layer 11 remains the same, the tensile force when peeling the protective tape 1 from the substrate 30 does not change much, and the adhesive layer 11 remains when peeled from the test plate 60. There is nothing. From the above, it was possible to obtain a comprehensive evaluation in which Example 1 was “◯” in all the test products and “×” was in the comparative example.

(Examples 2 to 4 and Comparative Example 2)
Next, the present invention will be specifically described using Examples 2 to 4 and Comparative Example 2 of the protective tape 1 according to the present embodiment.

  Examples 2, 3 and Comparative Example 2 both have the same configuration as that of the protective tape 1 according to this embodiment, but only the thickness of the metal layer 14 is different. Specifically, the thickness of the metal layer 14 in Example 2 is 6 μm, the thickness of the metal layer 14 in Example 3 is 9 μm, and the thickness of the metal layer 14 in Comparative Example 2 is 0.1 μm. Other thicknesses are the same as those of the first embodiment shown in FIG. In Example 4, a metal layer 14 having a thickness of 9 μm is provided on the adhesive layer 11, and a resin layer 13 made of 12 μm polyimide (PI) is further laminated on the metal layer 14. In the case of Example 4, the resin layer 13 made of polyimide (PI) prevents the metal layer 14 from being torn when the protective tape 1 is peeled from the substrate. Furthermore, since the resin layer 13 made of polyimide (PI) is located in the outermost layer of the protective tape 1, the metal layer 14 can be protected from acidic chemicals.

  Using Examples 2 to 4 and Comparative Example 2 having the above-described configuration, before the solder reflow process, after the first solder reflow process, and after the third solder reflow process, respectively. The aforementioned peel test was performed. Moreover, the protective tapes of Examples 2 to 4 and Comparative Example 2 were put into a hot air dryer having different temperatures for 3 minutes, and then a peel test was performed. In addition, in the test of a hot air dryer, the test heated for 3 minutes at the temperature of 200 degreeC and the test heated for 3 minutes at the temperature of 270 degreeC were implemented, respectively. The result is shown in FIG.

  According to the test results shown in FIG. 5, the measured values before the solder reflow process are 0.38N in Example 2, 0.45N in Example 3, 0.32N in Example 4, and 0.17N in Comparative Example 2. there were. Next, when the test was conducted after passing through the solder reflow process once, Example 2 was 0.43N, Example 3 was 0.51N, Example 4 was 0.39N, and Comparative Example 2 was 0.52N. It was. Further, when the test was conducted after passing through the solder reflow process three times, Example 2 was 0.49N, Example 3 was 0.55N, Example 4 was 0.36N, and Comparative Example 2 was 0.62N. . Thus, the difference in the thickness of the metal layer 14 and the presence or absence of the resin layer 13 on the metal layer 14 were not so different in tensile force even if the solder reflow process was performed three times.

  Moreover, in the test of the hot air dryer heated for 3 minutes at the temperature of 200 degreeC, Example 2 is 0.44N, Example 3 is 0.48N, Example 4 is 0.35N, Comparative example 2 is 0.34N. Met. However, in a test of a hot air dryer heated at 270 ° C. for 3 minutes, Example 2 was 0.41N, Example 3 was 0.38N, and Example 4 was 0.37N, which was 3 at 200 ° C. In the case of Comparative Example 2, the protective tape contracted and became impossible to measure, while there was not much change from the test of the hot air dryer heated for a minute. In the case of Comparative Example 2, it is considered that the metal layer 14 could not withstand the hot air dryer test at a temperature of 270 ° C. because the thickness of the metal layer 14 was thin. From this result, when the thickness of at least the metal layer 14 is 6 μm or more, even after the solder reflow process is performed three times or even after being put into a hot air dryer heated at 270 ° C. for 3 minutes, the adhesive layer 11 It was found that the adhesive strength of was not improved so much.

  Thus, according to the test using an Example and a comparative example, the heat | fever in a solder reflow process can be reflected and thermally radiated by the metal layer 14 which the protective tape 1 has. As described above, the metal layer 14 can make it difficult for heat to be transmitted to the adhesive layer 11 attached on the substrate 30, so that the temperature increase of the adhesive layer 11 can be reduced. Thereby, it becomes difficult to peel off from the board | substrate 30 after a solder reflow process, or the residue remains after peeling, and workability | operativity deterioration can be prevented.

  Moreover, since the thickness of the metal layer 14 becomes suitable as the thickness of the metal layer 14 is 6 μm or more, it becomes easy to effectively reflect and dissipate heat.

  Further, in the solder reflow process, the protective tape 1 according to the present embodiment can be applied even when the temperature in the substrate 30 is 270 ° C. at the maximum.

  The embodiments of the present invention have been described above, but only specific examples have been illustrated, and the present invention is not particularly limited. Specific configurations and the like can be appropriately changed in design. Further, the actions and effects described in the embodiments of the present invention only list the most preferable actions and effects resulting from the present invention, and the actions and effects according to the present invention are described in the embodiments of the present invention. It is not limited to things.

  The present invention can be applied to a protective tape for protecting a substrate flowing through a solder reflow process.

1 protective tape 11 adhesive layer 13 resin layer 14 metal layer 70 heat

Claims (7)

A protective tape that is attached to a substrate flowing through a solder reflow process and protects at least a part of the substrate,
An adhesive layer attached to the substrate, a metal layer, and a resin layer;
Have
On the said adhesion layer, the said metal layer and the said resin layer are provided at least, The protective tape characterized by the above-mentioned.   The said resin layer and the said metal layer are provided in order of the said resin layer and the said metal layer on the said adhesion layer, The protective tape of Claim 1 characterized by the above-mentioned.   The protective tape according to claim 1, wherein the resin layer and the metal layer are provided on the adhesive layer in the order of the metal layer and the resin layer.   4. The protective tape according to claim 1, wherein the metal layer has a thickness of 6 μm to 30 μm.   The protective tape according to claim 1, wherein the metal layer is made of aluminum.   The protective tape according to any one of claims 1 to 5, wherein a temperature of the substrate reaches a maximum of 270 ° C during the solder reflow process.   The protective tape according to any one of claims 1 to 6, wherein the solder reflow step uses infrared rays as a heat source.

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