Coil component

Abstract

The technical problem of the present invention is to further improve the insulativity of a magnetic element body and a conductor pillar, and a terminal electrode, in a coil component having a structure in which a coil pattern and the conductor pillar are embedded in the magnetic element body. This coil component (1) is provided with: a magnetic element body (M) having a mounting surface (4); a coil pattern (130) embedded in the magnetic element body (M); a conductor pillar (P1) embedded in the magnetic element body (M), one end of the conductor pillar (P1) being connected to the coil pattern (130); a pillar protection film (15) provided between the conductor pillar (P1) and the magnetic element body (M); a cover insulating film (21) that covers the mounting surface (4) of the magnetic element body (M); and a terminal electrode (E1) provided on the cover insulating film (21) and connected to the other end of the conductor pillar (P1) via an opening (21a) of the cover insulating film (21). The pillar protection film (15) is made of an insulating material different from that of the cover insulating film (21).

Description

Technical Field

[0001] The present disclosure relates to a coil component, and more particularly to a coil component having a structure in which a coil pattern and conductor posts connected to both ends of the coil pattern are embedded in a magnetic body. Background Art

[0002] Patent Document 1 discloses a coil component having a structure in which a coil pattern and conductor posts connected to both ends of the coil pattern are embedded in a magnetic body. In Patent Document 1, an insulating film is provided between the conductor posts and the magnetic body, thereby ensuring insulation between the conductor posts and the magnetic body.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2020-155509 Summary of the invention

[0006] Problems to be solved by the invention

[0007] In the coil component described in Patent Document 1, the terminal electrodes connected to the conductor posts are in contact with the mounting surface of the magnetic body.

[0008] In the present disclosure, a technology for further improving the insulation between the conductor post and the terminal electrode and the magnetic body in a coil component having a structure in which a coil pattern and a conductor post are embedded in a magnetic body is described.

[0009] Technical solutions to solve problems

[0010] One aspect of the present disclosure provides a coil component comprising: a magnetic body having a mounting surface; a coil pattern embedded in the magnetic body; a conductor post embedded in the magnetic body and connected to the coil pattern at one end; a post protection film disposed between the conductor post and the magnetic body; a cover insulating film covering the mounting surface of the magnetic body; and a terminal electrode disposed on the cover insulating film and connected to the other end of the conductor post via an opening of the cover insulating film, wherein the post protection film is composed of an insulating material different from that of the cover insulating film.

[0011] According to the present disclosure, the insulation between the conductor post and the terminal electrode and the magnetic body is further improved.

[0012] In the present disclosure, the thermal expansion coefficient of the pillar protection film may be lower than that of the cover insulating film, and the Young's modulus of the cover insulating film may be lower than that of the pillar protection film. This further improves the reliability of the product.

[0013] In the present disclosure, the other end of the conductor post may be flush with the mounting surface of the magnetic body. This improves the flatness of the mounting surface of the magnetic body.

[0014] In the present disclosure, the pillar protection film may be thicker than the cover insulating film. This further improves the reliability of the product.

[0015] The coil component according to one aspect of the present disclosure may further include an interlayer insulating film provided between the coil pattern and the magnetic body, and the post protection film may be made of the same insulating material as the interlayer insulating film. This can reduce manufacturing costs.

[0016] In the present disclosure, the pillar protection film may have a tapered shape in which the film thickness decreases from one end toward the other end. This can suppress the generation of voids in the magnetic body.

[0017] In the present disclosure, the cover insulating film may include a magnetic filler. This can further increase the inductance.

[0018] The coil component according to one aspect of the present disclosure may further include: another cover insulating film covering the upper surface of the magnetic body located on the opposite side to the mounting surface. This further improves the reliability of the product.

[0019] Effects of the Invention

[0020] As described above, according to the present disclosure, a technology is provided for further improving the insulation between the conductor post and the terminal electrode and the magnetic body in a coil component having a structure in which the coil pattern and the conductor post are embedded in the magnetic body. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic perspective view for explaining the appearance of the coil component 1 according to the first embodiment of the present disclosure.

[0022] Figure 2A It is a schematic cross-sectional view of an example of the coil component 1 .

[0023] Figure 2B This is a schematic cross-sectional view of another example of the coil component 1 .

[0024] Figure 3 It is a schematic plan view for explaining the pattern shape of the conductor layer C0.

[0025] Figure 4 It is a schematic plan view for explaining the pattern shape of the conductor layer C1.

[0026] Figure 5 It is a schematic plan view for explaining the pattern shape of the conductor layer C2.

[0027] Figure 6 It is a schematic plan view for explaining the pattern shape of the conductor layer C3.

[0028] Figure 7The following are process diagrams for explaining a method for manufacturing the coil component 1 .

[0029] Figure 8 The following are process diagrams for explaining a method for manufacturing the coil component 1 .

[0030] Fig. 9 The following are process diagrams for explaining a method for manufacturing the coil component 1 .

[0031] Fig.10 The following are process diagrams for explaining a method for manufacturing the coil component 1 .

[0032] Fig.11 The following are process diagrams for explaining a method for manufacturing the coil component 1 .

[0033] Fig.12 The following are process diagrams for explaining a method for manufacturing the coil component 1 .

[0034] Fig.13 The following are process diagrams for explaining a method for manufacturing the coil component 1 .

[0035] Fig.14 The following are process diagrams for explaining a method for manufacturing the coil component 1 .

[0036] Fig.15 The following are process diagrams for explaining a method for manufacturing the coil component 1 .

[0037] Fig.16 is a schematic cross-sectional view of the pillar protection film 15 having a tapered shape.

[0038] Fig.17 2 is a schematic cross-sectional view of a coil component 2 according to a second embodiment of the present disclosure. DETAILED DESCRIPTION

[0039] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0040] Figure 1 It is a schematic perspective view for explaining the appearance of the coil component 1 according to the first embodiment of the present disclosure.

[0041] like Figure 1 As shown, the coil component 1 of the first embodiment is a chip-type coil component having a structure in which a coil portion 3 with the Z direction as the coil axis is embedded in a magnetic body M. The magnetic body M has a mounting surface 4 and an upper surface 5 that are orthogonal to the coil axis and constitute an XY plane. The mounting surface 4 and the upper surface 5 are located on opposite sides of each other. Terminal electrodes E1 and E2 are provided on the mounting surface 4. During installation, the terminal electrodes E1 and E2 are soldered and mounted on the circuit substrate in a manner that the mounting surface 4 faces the circuit substrate. That is, Figure 1 The upper and lower directions of the coil component 1 shown are different by 180° from those when installed.

[0042] Figure 2A 2 is a schematic cross-sectional view of the coil component 1 according to the present embodiment.

[0043] like Figure 2A As shown, the coil component 1 of the first embodiment has: a coil portion 3 composed of interlayer insulating films 10 to 14 and conductor layers C0 to C3 alternately stacked along the coil axial direction (Z direction). The conductor layers C0 to C3 are composed of Cu or the like. The magnetic body M is composed of magnetic resin layers M1 and M2. Among them, the magnetic resin layer M1 is arranged in the inner diameter area of ​​the coil portion 3, the outer area in the radial direction of the coil portion 3, and one side of the coil axial direction of the coil portion 3. The magnetic resin layer M2 is arranged on the other side of the coil axial direction of the coil portion 3. The magnetic resin layers M1 and M2 are composed of a composite magnetic material containing a magnetic filler and a binder resin. The composite magnetic material constituting the magnetic resin layer M1 and the composite magnetic material constituting the magnetic resin layer M2 can be the same material as each other, or different materials. As a magnetic filler, a metal magnetic material such as iron (Fe) or a Permalloy material can be used. As a binder resin, an epoxy resin can be used. In addition, the boundary between the magnetic resin layer M1 and the magnetic resin layer M2 does not need to be clear. In the case where the magnetic resin layer M1 and the magnetic resin layer M2 are composed of the same material as each other, for example, Figure 2B As shown, the two can also be integrated so that there is no clear boundary between them.

[0044] Conductor posts P1 and P2 are embedded in the magnetic resin layer M1. The conductor posts P1 and P2 are made of Cu or the like and are columnar conductors extending in the Z direction. One end of the conductor post P1, i.e., the lower surface B, is connected to one end of the coil formed by the conductor layers C0 to C3, and one end of the conductor post P2, i.e., the lower surface B, is connected to the other end of the coil formed by the conductor layers C0 to C3. On the other hand, the other ends of the conductor posts P1 and P2, i.e., the upper surfaces T, are exposed from the mounting surface 4 in a manner that forms the same plane as the mounting surface 4, and are connected to the terminal electrodes E1 and E2, respectively. The side surfaces S (surfaces along the Z direction) of the conductor posts P1 and P2 are covered by a post protective film 15. Thus, since the post protective film 15 is interposed between the conductor posts P1 and P2 and the magnetic body M, contact between the conductor posts P1 and P2 and the magnetic body M is prevented, thereby ensuring insulation between the two. Furthermore, when the coil component 1 of the present embodiment having the conductor posts P1 and P2 is mounted on a circuit board or the like, stress is relieved by the conductor posts P1 and P2, and damage to the coil portion 3 is reduced. Therefore, the mounting reliability of the coil component 1 is also improved.

[0045] The mounting surface 4 and the upper surface 5 of the magnetic body M are covered by cover insulating films 21 and 22, respectively. The cover insulating film 22 covers substantially the entire upper surface 5, and openings 21a and 21b are provided at positions where the cover insulating film 21 overlaps with the conductor posts P1 and P2, respectively. Thus, the upper surfaces T (XY plane) of the conductor posts P1 and P2 are exposed from the openings 21a and 21b of the cover insulating film 21, respectively. The terminal electrodes E1 and E2 are provided on the cover insulating film 21. The terminal electrodes E1 and E2 are formed by, for example, a resin electrode 31 containing metal powder composed of Ag or the like and a binder resin, and a Ni film 32 and a Sn film 33 formed on the surface of the resin electrode 31. The terminal electrodes E1 and E2 are connected to the upper surfaces T of the conductor posts P1 and P2, respectively, via the openings 21a and 21b of the cover insulating film 21. It is not essential that the upper surface 5 of the magnetic body M is covered with the cover insulating film 22 . However, by providing the cover insulating film 22 , reliability can be improved and a directional mark or the like can be provided on the upper surface 5 .

[0046] Figure 3 to Figure 6 Each of them is a schematic plan view for explaining the pattern shape of the conductor layers C0 to C3.

[0047] like Figure 3 As shown, the conductor layer C0 is provided with a coil pattern 100. The coil pattern 100 is a pattern that is wound around approximately one turn, and both ends thereof are connected to the conductor layer C1 via through holes 11a and 11b provided in the interlayer insulating film 11.

[0048] like Figure 4 As shown, a coil pattern 110 and a connection pattern 111 are provided on the conductor layer C1. The coil pattern 110 is a pattern that is wound around about one turn, and one end of the coil pattern 100 of the conductor layer C0 is connected to the other end via a through hole 11b provided in the interlayer insulating film 11, and the other end of the coil pattern 110 is connected to the conductor layer C2 via a through hole 12b provided in the interlayer insulating film 12. The connection pattern 111 is provided at a position overlapping with one end of the coil pattern 100 provided on the conductor layer C0, and is connected to one end of the coil pattern 100 of the conductor layer C0 via a through hole 11a provided in the interlayer insulating film 11, and is connected to the conductor layer C2 via a through hole 12a provided in the interlayer insulating film 12.

[0049] like Figure 5As shown, a coil pattern 120 and a connection pattern 121 are provided on the conductor layer C2. The coil pattern 120 is a pattern that is wound around about one turn, one end of which is connected to the other end of the coil pattern 110 of the conductor layer C1 via a through hole 12b provided in the interlayer insulating film 12, and the other end of which is connected to the conductor layer C3 via a through hole 13b provided in the interlayer insulating film 13. The connection pattern 121 is provided at a position overlapping with the connection pattern 111 provided on the conductor layer C1, is connected to the connection pattern 111 of the conductor layer C1 via a through hole 12a provided in the interlayer insulating film 12, and is connected to the conductor layer C3 via a through hole 13a provided in the interlayer insulating film 13.

[0050] like Figure 6 As shown, the conductor layer C3 is provided with a coil pattern 130 and a connection pattern 131. The coil pattern 130 is a pattern that is wound around about 0.5 turns, one end of which is connected to the other end of the coil pattern 120 of the conductor layer C2 via a through hole 13b provided in the interlayer insulating film 13, and the other end of which is connected to the conductor post P2 via a through hole 14b provided in the interlayer insulating film 14. The connection pattern 131 is provided at a position overlapping with the connection pattern 121 provided in the conductor layer C2, is connected to the connection pattern 121 of the conductor layer C2 via a through hole 13a provided in the interlayer insulating film 13, and is connected to the conductor post P1 via a through hole 14a provided in the interlayer insulating film 14.

[0051] Thus, coil patterns 100, 110, 120, and 130 are connected in series between the terminal electrodes E1 and E2, forming a coil with a total of about 3.5 turns. The coil component 1 of the present embodiment is an embedded type coil component having a structure in which the coil portion 3 is embedded in a magnetic body M, with interlayer insulating films 10 to 14 and conductor layers C0 to C3 alternately stacked. The structure is different from that of a stacked type coil component in which magnetic sheets and coil patterns made of ceramics or the like are alternately stacked. For example, in a stacked type coil component, a magnetic sheet is interposed between coil patterns adjacent in the stacking direction, but in the coil component 1 of the present embodiment, coil patterns adjacent in the stacking direction are insulated by an interlayer insulating film, and no magnetic body M is interposed between the two. In addition, the structure is also different from a sheet coil in which a coil pattern is formed on a printed circuit board.

[0052] Furthermore, in the present embodiment, the coil patterns 100, 110, 120, 130 or the connection patterns 111, 121, 131 constituting the coil portion 3 are insulated from the magnetic body M by the interlayer insulating films 10 to 14, the conductor posts P1 and P2 are insulated from the magnetic body M by the post protection film 15, and the terminal electrodes E1 and E2 are insulated from the magnetic body M by the cover insulating film 21. Thus, all the conductor patterns are insulated from the magnetic body M, and thus high insulation characteristics can be obtained.

[0053] Here, the specific materials constituting the interlayer insulating films 10 to 14, the post protection film 15, and the cover insulating films 21 and 22 are not particularly limited, but in the present embodiment, the post protection film 15 and the cover insulating films 21 and 22 are composed of different insulating materials. This is because the post protection film 15 is embedded in the magnetic body M and is in contact with the conductor posts P1 and P2, while the cover insulating films 21 and 22 constitute the outermost layer of the coil component 1, and therefore have different characteristics for improving the reliability of the product.

[0054] Specifically, the column protection film 15 can reduce the difference in thermal expansion coefficient with Cu, the material of the conductor columns P1 and P2, by selecting an insulating material with a low thermal expansion coefficient containing a filler made of an inorganic material such as silicon dioxide. In contrast, the cover insulating films 21 and 22 improve the physical protection characteristics of the magnetic body M on the mounting surface 4 and the upper surface 5 by using a photosensitive resin material with a low Young's modulus, and the formation of the openings 21a and 21b becomes easy. Therefore, as the column protection film 15, an insulating material with a lower thermal expansion coefficient than the cover insulating films 21 and 22 is selected, and the cover insulating films 21 and 22 are selected. An insulating material with a lower Young's modulus than the column protection film 15 is selected. In addition, if a magnetic filler is added to the insulating material constituting the cover insulating films 21 and 22, the inductance can be further increased.

[0055] The interlayer insulating films 10 to 14 bury the magnetic body M and are in contact with the coil patterns 100, 110, 120, 130 or the connection patterns 111, 121, 131, and therefore can use the same insulating material as the pillar protection film 15. If the interlayer insulating films 10 to 14 and the pillar protection film 15 use the same insulating material, the material cost can be reduced.

[0056] Next, a method for manufacturing the coil component 1 according to the present embodiment will be described.

[0057] Figure 7 to Figure 15 1 is a process diagram for explaining a method for manufacturing the coil component 1 according to the present embodiment. Figure 7 to Figure 15 Only one portion corresponding to the coil component 1 is shown, but in reality, a plurality of coil components 1 are manufactured simultaneously using an aggregate substrate.

[0058] First, prepare a support substrate 40 ( Figure 7 ), interlayer insulating films 10 to 14 and conductor layers C0 to C3 are alternately formed on the surface thereof, thereby forming the coil portion 3, and then through holes 14a and 14b are formed in the interlayer insulating film 14, thereby forming conductor posts P1 and P2 ( Figure 8 The conductor layers C0 to C3 and the conductor posts P1 and P2 can be formed by electroplating. The conductor layers C0 to C3 include a sacrificial pattern 41 located in the inner diameter region of the coil portion 3 and the outer region of the coil portion 3 .

[0059] Next, a post protection film 15 ( Fig. 9 The entire exposed surface of the conductor posts P1 and P2 refers to the side surface S along the Z direction and the upper surface T constituting the XY plane. The thickness of the post protection film 15 can be as follows: Fig. 9 is shown as constant, or as Fig.16 As shown, the conductor posts P1 and P2 have a tapered shape in which the film thickness gradually decreases from the lower surface B toward the upper surface T, that is, from one end toward the other end of the conductor posts P1 and P2. Fig.16 The tapered shape shown in the figure makes it difficult to generate voids when embedding the magnetic resin layer M1 described later. Here, the film thickness of the post protection film 15 refers to the film thickness in the direction perpendicular to the surfaces of the conductor posts P1 and P2.

[0060] Next, wet etching is performed in this state to remove the sacrificial pattern 41 ( Fig.10 ). The conductor pattern constituting the coil portion 3 is covered by the interlayer insulating films 10 to 14 and is therefore not etched. The conductor posts P1 and P2 are also covered by the post protection film 15 and are therefore not etched. Thus, a space 42 is formed in the inner diameter region and the outer region of the coil portion 3.

[0061] Next, the space 42 formed by removing the sacrificial pattern 41 is filled with the magnetic resin layer M1 ( Fig.11 Then, the surface of the magnetic resin layer M1 is polished until the conductor posts P1 and P2 are exposed ( Fig.12 ). Through this process, the mounting surface 4 of the magnetic resin layer M1 and the upper surfaces T of the conductor posts P1 and P2 become the same plane. In addition, the flatness of the mounting surface 4 side of the magnetic resin layer M1 is greatly improved compared to before grinding.

[0062] Next, the support substrate 40 is removed, and then a magnetic resin layer M2 is formed on the lower surface side of the magnetic resin layer M1 so as to cover the interlayer insulating film 10 ( Fig.13 ). After that, the upper surface 5 may be smoothed by grinding the surface of the magnetic resin layer M2. Next, after the cover insulating films 21 and 22 are formed on the mounting surface 4 and the upper surface 5 of the magnetic body M, respectively, openings 21a and 21b are formed in the cover insulating film 21 so that a part of the upper surface T of the conductor posts P1 and P2 is exposed. Fig.14 ). As described above, the flatness of the mounting surface 4 side of the magnetic resin layer M1 is greatly improved by grinding, so the thickness of the cover insulating film 21 can be thin. As a result, the thickness of the coil component 1 as a whole can be reduced. In contrast, the column protection film 15 is Fig.10 The post protection film 15 functions as an etching resist for protecting the conductor posts P1 and P2 during the removal of the sacrificial pattern 41 , and therefore needs to have a predetermined thickness. Therefore, the thickness of the post protection film 15 may be thicker than the thickness of the cover insulating film 21 .

[0063] Next, terminal electrodes E1 and E2 are formed on the cover insulating film 21 so as to be connected to the conductor posts P1 and P2, respectively. Fig.15 ) Then, when the individual pieces are cut by dicing, the coil component 1 of the present embodiment is completed.

[0064] Thus, in this embodiment, the magnetic resin layer M1 is embedded while the post protection film 15 covering the conductor posts P1 and P2 is left when the sacrificial pattern 41 is removed, so that the contact between the conductor posts P1 and P2 and the magnetic body M can be prevented without increasing the number of steps. Furthermore, the terminal electrodes E1 and E2 are not directly formed on the mounting surface 4 but are formed via the cover insulating film 21, so that the contact between the terminal electrodes E1 and E2 and the magnetic body M can also be prevented.

[0065] Fig.17 2 is a schematic cross-sectional view of a coil component 2 according to a second embodiment of the present disclosure.

[0066] like Fig.17 As shown, the coil component 2 of the second embodiment is different from the coil component 1 of the first embodiment in that a portion of the upper surface T of the conductor posts P1 and P2 is covered by the post protection film 15 and the magnetic body M, and the terminal electrodes E1 and E2 penetrate the magnetic body M and the post protection film 15 and are connected to the conductor posts P1 and P2 respectively. The other basic structures are the same as the coil component 1 of the first embodiment, so the same elements are marked with the same reference numerals and repeated descriptions are omitted.

[0067] As shown in the coil component 2 of the second embodiment, it is not necessary that the upper surface T of the conductor posts P1 and P2 and the mounting surface 4 of the magnetic body M form the same plane, and a part of the upper surface T of the conductor posts P1 and P2 may be covered by the post protection film 15 and the magnetic body M. This structure is obtained as follows: Fig.11 After the steps shown, the support substrate 40 is peeled off and the cover insulating films 21 and 22 are formed without polishing. When the openings 21a and 21b are formed in the cover insulating film 21, through holes penetrating the magnetic body M and the column protection film 15 are formed to expose a part of the conductor columns P1 and P2.

[0068] As described above, the embodiments of the technology of the present disclosure are described, but the technology of the present disclosure is not limited to the above-mentioned embodiments, and various modifications can be made without departing from the gist of the invention, and these modifications are naturally included in the technical scope of the present disclosure.

[0069] For example, in the above embodiment, the coil portion 3 is composed of four conductor layers C0 to C3, but the number of conductor layers included in the coil portion is not particularly limited. In addition, in the above embodiment, the number of turns of the coil patterns 100, 110, and 120 provided in each conductor layer C0 to C2 is approximately one turn, but the number of turns of the coil pattern provided in each conductor layer is not particularly limited.

[0070] This application claims the benefit of Japanese Patent Application No. 2022-135660 filed on August 29, 2022, the disclosure of which is incorporated into this specification by reference.

[0071] Description of Reference Numerals

[0072] 1.2 Coil components

[0073] 3 Coil part

[0074] 4 Mounting surface

[0075] 5 Upper surface

[0076] 10~14 interlayer insulation film

[0077] 11a, 11b, 12a, 12b, 13a, 13b, 14a, 14b through holes

[0078] 15 Column protective film

[0079] 21, 22 Cover insulation film

[0080] 21a, 21b opening

[0081] 31. Resin electrode

[0082] 32 Ni film

[0083] 33 Sn film

[0084] 40 Support base plate

[0085] 41 Sacrifice Pattern

[0086] 42 Space

[0087] 100, 110, 120, 130 coil patterns

[0088] 111, 121, 131 connection pattern

[0089] B The lower surface of the conductor column

[0090] C0~C3 conductor layer

[0091] E1, E2 terminal electrodes

[0092] M Magnetic Body

[0093] M1, M2 magnetic resin layer

[0094] P1, P2 conductor column

[0095] S Side of the conductor column

[0096] T The upper surface of the conductor post.

Claims

1. A coil component, wherein: have: A magnetic body having a mounting surface; A coil pattern embedded in the magnetic body; A conductor post, which is embedded in the magnetic body and has one end connected to the coil pattern; A column protection film, which is disposed between the conductor column and the magnetic body; a cover insulating film covering the mounting surface of the magnetic body; as well as a terminal electrode provided on the cover insulating film and connected to the other end of the conductor post through an opening of the cover insulating film, The pillar protection film is made of an insulating material different from that of the cover insulating film.

2. The coil component according to claim 1, wherein The thermal expansion coefficient of the pillar protection film is lower than the thermal expansion coefficient of the cover insulation film, The cover insulating film has a Young's modulus lower than that of the post protection film.

3. The coil component according to claim 1, wherein The other end of the conductor post forms a flush plane with the mounting surface of the magnetic body.

4. The coil component according to claim 3, wherein: The pillar protection film is thicker than the cover insulating film.

5. The coil component according to claim 1, wherein It also includes: an interlayer insulating film provided between the coil pattern and the magnetic body; The pillar protection film is made of the same insulating material as the interlayer insulating film.

6. The coil component according to claim 1, wherein The pillar protection film has a tapered shape in which the film thickness gradually decreases from the one end toward the other end.

7. The coil component according to claim 1, wherein The cover insulating film contains a magnetic filler.

8. The coil component according to claim 1, wherein The invention further includes another cover insulating film covering an upper surface of the magnetic body located on the opposite side to the mounting surface.

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