阅读说明：本技术 天线封装件 (Antenna package ) 是由 崔秉搢 朴东必 申胜玹 洪源斌 朴俊昊 于 2020-11-11 设计创作，主要内容包括：本发明提供了一种天线封装件,该天线封装件包括：基板；结合至基板的配线图案；第一有机绝缘膜,形成在基板上,同时密封所述配线图案；天线图案,形成在第一有机绝缘膜上；导电通孔,穿过第一有机绝缘膜以连接配线图案和天线图案；以及第二有机绝缘膜,形成在第一有机绝缘膜上,同时密封所述天线图案。(The present invention provides an antenna package, comprising: a substrate; a wiring pattern bonded to the substrate; a first organic insulating film formed on the substrate while sealing the wiring pattern; an antenna pattern formed on the first organic insulating film; a conductive via hole passing through the first organic insulating film to connect the wiring pattern and the antenna pattern; and a second organic insulating film formed on the first organic insulating film while sealing the antenna pattern.)

1. An antenna package, comprising:

a substrate;

a wiring pattern bonded to the substrate;

a first organic insulating film formed on the substrate while sealing the wiring pattern;

an antenna pattern formed on the first organic insulating film;

a conductive via hole passing through the first organic insulating film to connect the wiring pattern and the antenna pattern; and

a second organic insulating film formed on the first organic insulating film while sealing the antenna pattern.

2. The antenna package according to claim 1, wherein the first organic insulating film and the second organic insulating film are cured layers of a photosensitive resin composition containing an alkali-soluble resin, a photopolymerizable compound, a photopolymerization initiator, and a solvent.

3. The antenna package according to claim 1 or 2, wherein the first organic insulating film and the second organic insulating film each have a thickness of 0.1 to 2.5 μm.

4. The antenna package of claim 3, wherein the conductive via and the antenna pattern are the same electrode.

5. The antenna package of claim 1, wherein the substrate comprises an IC chip.

6. The antenna package of claim 1, wherein the conductive via has a tapered shape.

7. A method of manufacturing an antenna package, the method comprising:

forming a wiring pattern on a substrate;

forming a first organic insulating film sealing the wiring pattern on the substrate;

forming a contact hole for opening the wiring pattern in the first organic insulating film by photolithography;

forming a conductive via in the contact hole;

forming an antenna pattern connected to the conductive via on the first organic insulating film; and

forming a second organic insulating film sealing the antenna pattern on the first organic insulating film.

8. The manufacturing method of the antenna package according to claim 7, wherein the step of forming the conductive via and the step of forming the antenna pattern are a single process.

9. The manufacturing method of the antenna package according to claim 8, wherein the step of forming the first organic insulating film and the second organic insulating film includes: a photosensitive resin composition comprising an alkali-soluble resin, a photopolymerizable compound, a photopolymerization initiator and a solvent is coated and cured.

10. The manufacturing method of an antenna package according to any one of claims 7 to 9, wherein in the step of forming the first organic insulating film and the second organic insulating film, the first organic insulating film and the second organic insulating film each have a thickness of 0.1 to 2.5 μm.

Technical Field

The present invention relates to an antenna package. In particular, the present invention relates to an antenna package with improved flexibility by configuring a thin thickness.

Background

Ultra high frequencies (i.e., frequencies in the millimeter wave band) of 20GHz or higher are used as main frequency resources for next-generation information and communication services. By using the broadband characteristic, a frequency in the millimeter wave band can transmit a large amount of information at high speed.

In the millimeter wave band, the electrical connection distance between the antenna and the IC chip is very important. That is, since the loss increases with an increase in the distance between the antenna and the IC chip, it is preferable to electrically connect the antenna of the millimeter-wave band (particularly, 60GHz band) to the vicinity of the IC chip.

In korean patent laid-open publication No. 2014-: the semiconductor package includes a semiconductor chip, a package portion for packaging the semiconductor chip, a substrate portion including an upper substrate formed on an upper surface of the package portion and a lower substrate formed on a lower surface of the package portion, an antenna portion formed in the package portion or the substrate portion and electrically connected to the semiconductor chip, a through-hole connection portion formed through the package portion, and the like.

However, in Korean patent laid-open No. 2014-0015607, an antenna portion is formed on an outer surface of an upper substrate. Further, the upper substrate is thick, and the upper substrate is composed of a multilayer substrate. As a result, the connection distance between the antenna portion and the semiconductor chip (IC chip) is long. However, there is a limitation in reducing their connection distance.

Disclosure of Invention

Technical problem

The present invention is directed to solving the problems of the prior art, and the antenna package of the present invention is directed to shortening the connection distance between an antenna and an IC chip by reducing the thickness of an antenna forming region.

Second, the antenna package of the present invention reduces the thickness of the antenna forming region. In this way, the flexibility of the antenna package is increased, and as a result, easy application to a foldable device or the like can be achieved.

Technical scheme

An antenna package of the present invention for achieving the above object may include a substrate, a wiring pattern, a first organic insulating film, an antenna pattern, a conductive via, a second organic insulating film, and the like.

The substrate may include IC chips, connection pads, and the like.

The wiring pattern is formed on the substrate, and may be bonded with a connection pad or the like.

The first organic insulating film may be formed on the substrate while sealing the wiring pattern.

An antenna pattern may be formed on the first organic insulating film.

The conductive via may pass through the first organic insulating film to connect the wiring pattern and the antenna pattern.

A second organic insulating film may be formed on the first organic insulating film while sealing the antenna pattern.

In the antenna package of the present invention, the first organic insulating film and the second organic insulating film may be cured layers of a photosensitive resin composition containing an alkali-soluble resin, a photopolymerizable compound, a photopolymerization initiator, and a solvent.

In the antenna package of the present invention, the first organic insulating film and the second organic insulating film may each have a thickness of 0.1 to 2.5 μm.

In the antenna package of the present invention, the conductive via and the antenna pattern may be the same electrode.

In the antenna package of the present invention, the substrate may include an IC chip.

In the antenna package of the present invention, the conductive via may have a tapered shape.

The manufacturing method of the antenna package according to the present invention includes the steps of: forming a wiring pattern on a substrate; forming a first organic insulating film sealing the wiring pattern on the substrate; forming a contact hole for opening the wiring pattern in the first organic insulating film by photolithography; forming a conductive via in the contact hole; forming an antenna pattern connected to the conductive via on the first organic insulating film; and forming a second organic insulating film on the first organic insulating film to seal the antenna pattern.

In the manufacturing method of the antenna package according to the present invention, the step of forming the conductive path and the step of forming the antenna pattern may be performed in a single process.

In the manufacturing method of the antenna package according to the present invention, the step of forming the first organic insulating film and the second organic insulating film may include: a photosensitive resin composition comprising an alkali-soluble resin, a photopolymerizable compound, a photopolymerization initiator and a solvent is coated and cured.

In the method of manufacturing an antenna package according to the present invention, in the step of forming the first organic insulating film and the second organic insulating film, the first organic insulating film and the second organic insulating film may be formed to have a thickness of 0.1 to 2.5 μm each.

Effects of the invention

In the antenna package of the present invention having such a configuration, the conductive through hole, the antenna pattern, and the like are formed by photolithography using the organic insulating film. As a result, the present invention can reduce the connection distance between the antenna pattern and the IC chip. In this way, the present invention can minimize signal loss in ultra high frequency communications.

Further, the antenna package of the present invention can reduce the overall thickness of the antenna package by thinning of the antenna forming region. As a result, the present invention can increase the flexibility of the antenna package. Furthermore, the present invention is easily applied to a foldable device.

Drawings

Fig. 1 is a cross-sectional view of an antenna package according to the present invention.

Fig. 2a to 2i are sectional views illustrating a method of manufacturing an antenna package according to the present invention.

Detailed Description

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Fig. 1 is a cross-sectional view of an antenna package according to the present invention.

Referring to fig. 1, the antenna package of the present invention includes a substrate 110, a wiring pattern 140, a first organic insulating film 121, an antenna pattern 130, a conductive via 150, a second organic insulating film 123, and the like.

The substrate 110 may be a flexible substrate. The substrate 110 may use a flexible substrate such as PI (polyimide), MPI (modified polyimide), LCP (liquid crystal polymer), COP (cyclic olefin polymer), TAC (cellulose triacetate), PET (polyethylene terephthalate), PC (polycarbonate), PCT (polycyclohexadienedimethylene terephthalate), and the like.

The substrate 110 may include an IC chip 111, a connection pad 113, a package portion 115, and the like.

The IC chip 111 may perform wireless communication with the outside through electrical connection with the antenna pattern 130.

The connection pad 113 may be connected to the wiring pattern 140 to transmit a wireless signal, power, and the like between the IC chip 111 and the antenna pattern 130. The connection pad 113 may have a solder bump (solder bump) shape or the like in addition to the pad shape.

The package portion 115 can protect the IC chip 111 from external impact by internally incorporating the IC chip 111 and sealing it. The encapsulation portion 115 may be formed by a method such as molding. The package 115 may use an Epoxy Molding Compound (EMC) or the like.

As shown in fig. 1, the substrate 110 may be formed to have an IC chip 111 built therein. The substrate 110 may be formed by bonding an IC chip 111, a connection pad 113, and the like to a surface.

The wiring pattern 140 may be formed on the substrate 110 and the organic insulating film 120. The wiring pattern 140 may be combined with the connection pad 113, the antenna pattern 130, and the like. In addition, the wiring pattern 140 may be coupled to an external power source, an external device, or the like to transmit power, a data signal, or the like.

The first organic insulating film 121 may be formed on the substrate 110 while sealing the wiring pattern 140.

The first organic insulating film 121 may be formed of a material to which photolithography can be applied. The first organic insulating film 121 may be a cured layer of a photosensitive resin composition including an alkali-soluble resin, a photopolymerizable compound, a photopolymerization initiator, and a solvent.

Alkali soluble resins are generally reactive under the action of light or heat. The alkali-soluble resin is a component that imparts solubility to an alkali developer in a developing step when forming a pattern.

The alkali-soluble resin can be used by selecting a resin having an acid value of 10 to 200(KOH mg/g). The acid value is a value measured as the amount of potassium hydroxide (mg) required to neutralize 1 gram of polymer and is related to solubility. If the acid value of the alkali-soluble resin is less than the above range, it may be difficult to ensure a sufficient development speed. On the contrary, if the acid value of the alkali-soluble resin exceeds the above range, the adhesion with the substrate 110 is lowered and the pattern short-circuit is liable to occur. Further, if the acid value of the alkali-soluble resin exceeds the above range, the storage stability of the entire composition may decrease and the viscosity may increase.

Further, the weight average molecular weight of the alkali-soluble resin may be 3000 to 200000Da, preferably 5,000 to 100,000 Da. The alkali soluble resin may be directly polymerized or purchased and used so that the molecular weight distribution is in the range of 1.5 to 6.0, preferably in the range of 1.8 to 4.0. When the alkali soluble resin having a molecular weight and a molecular weight distribution within this range is used, hardness is improved, the residual film rate is high, solubility of an unexposed portion in a developer is excellent, and resolution can be improved.

The alkali-soluble resin may be prepared by copolymerizing a monomer having a carboxyl group and an unsaturated bond and a monomer having an unsaturated bond copolymerizable therewith.

The monomer having a carboxyl group and an unsaturated bond includes: monocarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, and the like; dicarboxylic acids such as fumaric acid, mesaconic acid, itaconic acid, and the like; anhydrides of these dicarboxylic acids; mono (meth) acrylates of polymers having carboxyl and hydroxyl groups at both ends, such as ω -carboxy polycaprolactone mono (meth) acrylate, and the like.

The monomer copolymerizable therewith may be one selected from the group consisting of: an aromatic vinyl compound, an unsaturated carboxylic acid ester compound, an unsaturated carboxylic acid aminoalkyl ester compound, an unsaturated carboxylic acid glycidyl ester compound, a carboxylic acid vinyl ester compound, an unsaturated ether compound, a vinyl cyanide compound, an unsaturated imide compound, an aliphatic conjugated diene compound, a macromonomer having a monoacryl group or a monomethacryl group at a molecular chain end, a bulky monomer, and a combination thereof.

The content of the alkali-soluble resin is not particularly limited, and may be 2 to 80% by weight, preferably 10 to 70% by weight, based on 100% by weight of the total solid content of the photosensitive resin composition. When the content of the alkali-soluble resin is within the above range, the pattern layer is easily formed. Further, when the content of the alkali-soluble resin is within the above range, the film of exposed portions at the time of development can be prevented from being reduced, and thus omission of unexposed portions can be increased.

The photopolymerizable compound may increase the crosslink density during the manufacturing process and enhance the mechanical properties of the photocurable film.

The photopolymerizable compound is a compound that can be polymerized by the action of light and a photopolymerization initiator described later, and includes a monofunctional monomer, a bifunctional monomer, other polyfunctional monomers, and the like.

As monofunctional monomers, nonylphenylcarbinol acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-ethylhexyl carbitol acrylate, 2-hydroxyethyl acrylate, N-vinylpyrrolidone and the like can be used.

As the bifunctional monomer, 1, 6-hexanediol di (meth) acrylate, ethylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, bis (acryloyl) ethoxy ether of bisphenol a, 3-methylpentanediol di (meth) acrylate, and the like can be used.

As the polyfunctional monomer, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and the like can be used.

The content of the photopolymerizable compound is not particularly limited, but may be contained in a range of 5 to 45 wt% with respect to 100 wt% of the total solid content in the photosensitive resin composition. When the photopolymerizable compound is contained in the above-mentioned content, durability is good and developability is improved.

A photopolymerization initiator may be used without any particular limitation on its kind as long as it can polymerize the photopolymerizable compound. From the viewpoint of polymerization properties, initiation efficiency, absorption wavelength, availability, price, and the like, the photopolymerization initiator may use one or more compounds selected from the group consisting of: acetophenone-based compounds, benzophenone-based compounds, triazine-based compounds, bisimidazole-based compounds, oxime-based compounds, and thioxanthone-based compounds.

In addition, the photopolymerization initiator may further include a photopolymerization initiation aid to improve the sensitivity of the photosensitive resin composition. The photosensitive resin composition contains a photopolymerization initiation aid, whereby the sensitivity is further improved and the productivity can be improved.

As the photopolymerization initiation aid, one or more compounds selected from the group consisting of: amine compounds, carboxylic acid compounds, and organic sulfur compounds having a thiol group.

The content of the photopolymerization initiator may be 0.1 to 40 parts by weight, preferably 1 to 30 parts by weight, relative to 100 parts by weight of the total amount of the alkali-soluble resin and the photopolymerizable compound. When the photopolymerization initiator is contained within the above range, since the photosensitive resin composition is highly sensitive, the exposure time is shortened, and as a result, productivity can be improved.

In addition, when a photopolymerization initiation aid is further used, the content of the photopolymerization initiation aid may be 0.1 to 40 parts by weight, preferably 1 to 30 parts by weight, relative to 100 parts by weight of the total amount of the alkali-soluble resin and the photopolymerizable compound. When the amount of the photopolymerization initiation aid is within the above range, the sensitivity of the photosensitive resin composition becomes high, and the productivity of the photocurable film can be improved.

The solvent is not particularly limited, and an organic solvent generally used in the art may be used. As the solvent, an ether, an aromatic hydrocarbon, a ketone, an alcohol, an ester, an amide, or the like can be used.

Among the above solvents, organic solvents having a boiling point of 100 to 200 ℃ are preferable in view of coating properties and drying properties. As the organic solvent, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, cyclohexanone, ethyl 3-ethoxypropionate, methyl 3-methoxypropionate, or the like can be used. These solvents may be used alone or in combination of two or more.

The content of the solvent may be 40 to 95% by weight, preferably 45 to 85% by weight, relative to 100% by weight of the entire photosensitive resin composition. In the case where the content of the solvent is within the above range, the coatability can be improved when coating is performed by a coating apparatus such as a roll coater, a spin coater, a slit coater (sometimes referred to as a die coater), or ink jet.

In the embodiment of the present invention, a polymer material may be used as the material of the first organic insulating film 121. The polymer material may use one or more substances selected from the group consisting of: polyacrylates, polymethacrylates (e.g., PMMA), polyimides, polyamides, polyvinyl alcohols, polyamic acids, polyolefins (e.g., PE, PP), polystyrenes, polynorbornenes, phenylmaleimide copolymers, polyazobenzenes, polyphthalamides, polyesters (e.g., PET, PBT), polyarylates, cinnamate polymers, coumarin polymers, phthalimide polymers, chalcone polymers, and aromatic acetylene polymers.

Table 1 below shows the results of the flexibility test according to the thickness of the first organic insulating film 121. In the deflection test, it was examined whether cracks occurred when bent 100000 times at each radius of curvature. If cracking occurred, the mark was X (bad), and if no cracking occurred, the mark was O (normal).

[ TABLE 1 ]

As can be seen from table 1 above, when the thickness of the first organic insulating film 121 is 2.7 μm or less, it passes the 3R curvature test. When the thickness of the first organic insulating film 121 is 2.5 μm or less, it passes the 2R curvature test. On the other hand, when the first organic insulating film 121 is formed to be less than 0.1 μm, difficulty occurs in sealing the wiring pattern 140 and the antenna pattern 130 and the like due to the thicknesses of the wiring pattern 140 and the first antenna pattern 131.

In view of the above experimental results and difficulty in realizing products, it is preferable to configure the thickness of the first organic insulating film 121 in the range of 0.1 to 2.7 μm. In view of the future market of 2R curvature products, it may be desirable to configure the first organic insulating film 121 to have a thickness of 0.1 to 2.5 μm.

The first antenna pattern 131 may be formed on the first organic insulating film 121. The first antenna pattern 131 may include a microstrip antenna, a patch antenna, a dipole, a monopole, a loop antenna, and the like as a radiator. The first antenna pattern 131 may have various shapes such as a line shape, a polygon shape, a circle shape, and the like.

The conductive via 150 may penetrate the first organic insulating film 121 to connect the wiring pattern 140 and the first antenna pattern 131, and may connect the wiring pattern 140 and the wiring pattern 140 separately arranged up and down. The conductive via 150 may have a tapered shape. The tapered shape may be a forward/reverse tapered shape, but a forward tapered shape may be more preferable. The tapered shape can stably connect the circuit connected to the conductive via 150 without short-circuiting. The tapered shape may enable a circuit against electrostatic discharge (ESD). The taper angle is preferably 5 to 70 °, more preferably 15 to 50 °.

The second organic insulating film 123 may be formed on the first organic insulating film 121 while sealing the first antenna pattern 131, the wiring pattern 140, and the like formed on the first organic insulating film 121.

The second organic insulating film 123 may be composed of a cured layer of a photosensitive resin composition containing an alkali-soluble resin, a photopolymerizable compound, a photopolymerization initiator, and a solvent, or may be composed of a polymer material, similar to the first organic insulating film 121.

Table 2 below shows the results of the flexure test according to the thickness in the case where the first organic insulating film 121 and the second organic insulating film 123 have the same thickness. In the deflection test, similarly to the deflection test of the first organic insulating film 121, when bent 100000 times at each radius of curvature, it is checked whether or not a crack occurs. If cracking occurred, the mark was X (bad), and if no cracking occurred, the mark was O (normal).

[ TABLE 2 ]

Thickness \ test curvature of each organic insulating film	2R	3R	5R
				3.5μm	X	X	○
3.0μm	X	X	○
				2.8μm	X	X	○
2.7μm	X	X	○
				2.6μm	X	X	○
2.5μm	X	○	○
				2.4μm	X	○	○
2.3μm	X	○	○
				2.2μm	○	○	○

As can be seen from table 2 above, when the thicknesses of the first organic insulating film 121 and the second organic insulating film 123 are 2.5 μm or less, respectively, they pass the 3R curvature test. When the thicknesses of the first organic insulating film 121 and the second organic insulating film 123 are 2.2 μm or less, respectively, they pass the 2R curvature test. Therefore, when the organic insulating films are stacked in two layers, the thicknesses of the first organic insulating film 121 and the second organic insulating film 123 are preferably set in the range of 0.1 to 2.5 μm, respectively. In view of the future market of 2R curvature products, the thicknesses of the first organic insulating film 121 and the second organic insulating film 123 are preferably 0.1 to 2.2 μm, respectively.

In fig. 1, the antenna pattern 130 and the conductive through hole 150 may be separately formed through separate processes, or may be simultaneously formed through the same process to form an integral type electrode, i.e., a common electrode.

In fig. 1, on the second organic insulating film 123, the second antenna pattern 133, the conductive via 150, and the third organic insulating film 125 may be formed to have two or more antenna patterns, similar to the combined structure of the first antenna pattern 131, the conductive via 150, and the second organic insulating film 123 described above. With such a stacked structure, a multi-channel antenna package can be configured.

Fig. 2a to 2i are sectional views illustrating a method of manufacturing an antenna package according to the present invention.

In the manufacturing method of the antenna package according to the present invention, first in a first step, for example, as shown in fig. 2a, a substrate 110 in which an IC chip 111 is sealed to an encapsulation portion 115 and a portion of a connection pad 113 is exposed may be prepared.

In the second step, as shown in fig. 2b, a wiring pattern 140 may be formed on the substrate 110. The wiring patterns 140 may be connected to the connection pads 113.

In the third step, as shown in fig. 2c, a first organic insulating film 121 may be formed while sealing the wiring pattern 140 on the substrate 110. The first organic insulating film 121 may be formed by coating and curing a photosensitive resin composition by a method such as coating. The coating step may include pre-drying the coated photosensitive resin composition. This enables a smooth coating film to be obtained by removing volatile components such as a solvent. At this time, the thickness of the coating film may be 0.1 to 2.5 μm. Curing may be performed using a UV light source or a heat source, etc.

In the fourth step, as shown in fig. 2d, the first contact hole CH1 for forming the conductive via 150 may be formed by selectively exposing and developing a partial region of the photosensitive resin composition.

In the exposure step, a pattern mask, an ultraviolet irradiator, or the like may be used.

In the developing step, the first contact hole CH1 may be formed by bringing an aqueous alkali solution as a developer into contact with the cured coating film by ultraviolet irradiation to dissolve and remove the unexposed region. After the development, drying may be carried out after drying at 150 to 230 ℃ for 10 to 60 minutes, if necessary.

In the fifth step, as shown in fig. 2e, the conductive via hole 150, the first antenna pattern 131, the wiring pattern 140, and the like may be formed by depositing a conductive material on the top surfaces of the first contact hole CH1 and the first organic insulating film 121. In this step, the conductive via 150, the first antenna pattern 131, and the wiring pattern 140 formed in the same layer as the first antenna pattern 131 may be simultaneously formed by the same process. The conductive via 150 may be formed through a separation process, and then the first antenna pattern 131 or the wiring pattern 140 formed at the same layer as the first antenna pattern 131 may be sequentially formed.

In the sixth step, as shown in fig. 2f, a second organic insulating film 123 may be formed which seals the first antenna pattern 131 and the wiring pattern 140 and the like on the first organic insulating film 121 at the same time. The second organic insulating film 123 may be formed by coating and curing a photosensitive resin composition by a method such as coating, similar to the first organic insulating film 121. The second organic insulating film 123 may be formed to a thickness of 0.1 to 2.5 μm.

Meanwhile, a multi-layer (multi-channel) antenna structure may be formed by additionally forming a second antenna pattern 133 on the second organic insulating film 123. In this case, as shown in fig. 2g to 2i, the following steps may be additionally performed: forming a second contact hole CH2 in the second organic insulating film 123; forming the second antenna pattern 133, the wiring pattern 140, and the like; a third organic insulating film 125 is formed on the second organic insulating film 123 while sealing the second antenna pattern 133. Since the steps of fig. 2g to 2i are the same as those of fig. 2d to 2f described above, the detailed description of the steps of fig. 2g to 2i will be replaced with the description related to fig. 2d to 2 f.

The present invention has been described above by way of examples, which are intended to illustrate the present invention. Those of ordinary skill in the art will be able to alter or modify these embodiments in other ways. However, since the scope of the present invention is defined by the appended claims, these modifications may be construed as being included in the scope of the present invention.

[ description of reference ]

110: substrate 111: IC chip

113: connection pad 115: packaging part

120: organic insulating films 121, 123, 125: first to third organic insulating films

130: antenna patterns 131, 133: first and second antenna patterns

140: wiring pattern 150: conductive vias

CH1, CH 2: and (6) contacting the holes.