JP2011257259A - Evaluation method for junctional membrane and evaluation device for junctional membrane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an evaluation method for a junctional membrane and an evaluation device for the junctional membrane that easily and accurately evaluate an activated state of the junctional membrane.SOLUTION: The evaluation method for the junctional membrane is adapted to evaluate a state in which a base 1 with the junctional membrane which is formed by forming, on a base 2, a junctional membrane 3 including an atomic structure including a siloxane bond and a desorption group combined with the siloxane bond and comprising an organic group enters the activated state by imparting energy to the junctional membrane 3 to have adhesiveness. The evaluation method for the junctional membrane includes a water droplet sticking process of sticking a water droplet 10 on a surface of the junctional membrane 3 in the activated state, and a contact angle measurement process of measuring an angle θ of contact of the water droplet 10. The measured angle θ of contact correlates with the activated state of the junctional membrane 3 and can be thereby an index for evaluating the extent of the activated state, i.e., adhesiveness. Therefore, the angle θ of contact is measured to evaluate the activated state of the junctional membrane 3 even before actual joining.

Description

  The present invention relates to a method for evaluating a bonding film and an apparatus for evaluating a bonding film that exhibit adhesiveness by applying energy.

As a method for bonding (adhering) two members (base materials) to each other, Patent Literature 1 proposes a method for bonding members to each other via a bonding film formed by a plasma polymerization method.
In the above method, a plasma polymerized film is formed on the surface of each member, energy is applied to each plasma polymerized film to activate it, and then adhesion is developed, and then two plasma polymerized films are brought into close contact with each other. These are joined by overlapping the members.

However, if the plasma polymerized film that has been activated and exhibits adhesiveness is left in the atmosphere, the adhesiveness deteriorates over time. For this reason, after the plasma polymerization film is activated, the plasma polymerization must be brought into close contact with each other and bonded.
Because of such time constraints, for example, an activation process is performed on a plurality of plasma polymerized films together to secure a stock of plasma polymerized films in an activated state, and the subsequent bonding process is performed using this stocking process. Therefore, it is impossible to perform an efficient bonding process in which a necessary number of plasma polymerized films are taken out and performed when necessary. That is, it is necessary to perform an activation process immediately before the bonding process, and there are significant time constraints on the process. In addition, since the activation process and the subsequent joining process cannot be separated from each other for a long time, the location where each process is performed must be geographically close, and there are significant restrictions on the flow lines of the members. Accompanied by.

  Therefore, it is becoming necessary to maximize the time and geographical freedom of the process while ensuring the necessary and sufficient adhesiveness by determining the state of the plasma polymerized film in the activated state. . However, since there is no method for accurately evaluating the activation state of the plasma polymerized film, it is impossible to determine whether or not it has sufficient and sufficient adhesiveness for joining the members, and the efficiency of the joining process can be improved. It was a hindrance.

JP 2008-307873 A

  An object of the present invention is to provide a bonding film evaluation method and a bonding film evaluation apparatus capable of easily and accurately evaluating the activation state of the bonding film.

The above object is achieved by the present invention described below.
The bonding film evaluation method of the present invention includes an atomic structure including a siloxane bond and a leaving group formed of an organic group bonded to the siloxane bond, and is activated by applying energy, thereby exhibiting adhesiveness. A method for quantitatively evaluating the activation state of the bonding film,
The method includes a step of attaching a water droplet to the surface of the bonding film in the activated state and measuring a contact angle of the water droplet.
As a result, the activation state of the bonding film can be easily and accurately evaluated.

In the bonding film evaluation method of the present invention, it is preferable to further include a step of determining whether or not the measured contact angle of the water droplet is within a predetermined range.
Thereby, it can be determined whether or not the bonding film has a predetermined adhesion capability, and selection for surely obtaining a bonded body in a final bonded state can be performed.
In the bonding film evaluation method of the present invention, the step of measuring the contact angle of the water droplet is preferably performed in accordance with the sessile drop method defined in the wettability test method of JIS R 3257.
Thereby, the contact angle can be calculated geometrically easily and accurately.
In the bonding film evaluation method of the present invention, the step of measuring the contact angle of the water droplet is preferably performed in a state where the bonding film is placed in an inert gas.
As a result, the influence of the atmosphere on the measurement of the contact angle is minimized, so that more accurate measurement is possible.

In the bonding film evaluation method of the present invention, the bonding film is a test bonding film having the same manufacturing history and the same storage history as the bonding film for manufacturing a product,
It is preferable to include a step of regarding the contact angle of the water droplet measured for the test bonding film as the contact angle of the water droplet measured for the bonding film for manufacturing the product.
Thereby, while preventing the base material with a bonding film for products from contamination, the activated state of a bonding film can be accurately evaluated irrespective of the shape of the base material with a bonding film for products.

The bonding film evaluation apparatus of the present invention includes an atomic structure including a siloxane bond and a leaving group composed of an organic group bonded to the siloxane bond, and is activated by applying energy to exhibit adhesiveness. An apparatus for quantitatively evaluating the activated state of the bonding film
Water droplet preparation means for preparing water droplets and attaching the water droplets to the surface of the bonding film in the activated state;
Contact angle measuring means for measuring the contact angle of water droplets attached to the surface of the bonding film.
Thereby, a bonding film evaluation apparatus capable of easily and accurately evaluating the activation state of the bonding film is obtained.

In the bonding film evaluation apparatus of the present invention, the water droplet preparation means may include a storage unit that stores water, and a nozzle that supplies the water stored in the storage unit to the surface of the bonding film. preferable.
Thereby, the activated state of the bonding film can be easily evaluated using the water droplets discharged from the nozzle.

In the bonding film evaluation apparatus of the present invention, the contact angle measuring means analyzes a camera that shoots water droplets attached to the surface of the bonding film from the side, an image shot by the camera, and the contact angle. It is preferable to have an analysis unit that identifies
Thereby, the measurement value of a contact angle does not contain a measurement error (individual difference), and a highly reliable measurement value is obtained.

In the bonding film evaluation apparatus of the present invention, it is preferable that the apparatus has a sealed structure, the water droplet preparation means is housed therein, and a case capable of housing the bonding film.
Thereby, the influence which external factors (external air etc.) have on the measured value of a contact angle can be suppressed to the minimum.
In the bonding film evaluation apparatus of the present invention, it is preferable that the case has a gas supply unit for supplying an inert gas.
As a result, the influence of the atmosphere on the measurement of the contact angle is minimized, so that more accurate measurement is possible.

It is sectional drawing (including a partial enlarged view) which shows the state before energy provision of the joining film with which the base material with a joining film is provided. It is sectional drawing (including a partial enlarged view) which shows the state after energy provision of the joining film with which the base material with a joining film is provided. It is a figure for demonstrating the method to join a base material with a bonding film, and a to-be-adhered body. It is a figure (sectional drawing) for demonstrating the evaluation method of the bonding film of this invention. It is a figure (front view) which shows typically embodiment of the evaluation apparatus of the bonding film of this invention. In Example 1, it is a graph which shows the relationship of the joint strength with respect to the process time of an activation process, and a contact angle. In Example 2, it is a graph which shows the relationship of the joint strength with respect to the process time of an activation process, and a contact angle. In Example 1, it is a graph which shows transition of a contact angle and transition of joining strength when it leaves in air | atmosphere for predetermined time, after giving oxygen plasma processing to a joining film | membrane.

Hereinafter, a bonding film evaluation method and a bonding film evaluation apparatus according to the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.
The bonding film to be evaluated in the bonding film evaluation method of the present invention is activated and imparts adhesiveness by applying energy.
Since this adhesiveness is gradually lost over time, sufficient bonding strength may not be obtained depending on the elapsed time. For this reason, it is sufficient to bond (join) quickly after applying energy, but on the other hand, it involves time and geographical constraints of the joining process. For this reason, a method for evaluating the activation state of the bonding film from the viewpoint of maximizing the temporal and geographical freedom of the bonding process while taking into account a certain degree of decrease in adhesion (deterioration of the activated state). There was a request to establish and improve the efficiency of the bonding process.
In order to meet such demands, the present inventor has intensively studied, found a method for easily and accurately evaluating the activation state of the bonding film, and completed the present invention.

First, prior to the description of the method for evaluating a bonding film of the present invention, a bonding film to be evaluated and a base material with a bonding film comprising the bonding film on the base material will be described.
(Base material with bonding film)
FIG. 1 is a cross-sectional view (including a partially enlarged view) showing a state before energy application of a bonding film included in a substrate with a bonding film, and FIG. 2 shows a state after energy application of the bonding film included in the substrate with a bonding film. It is sectional drawing (a partial enlarged view is included) which shows. In the following description, the upper side in FIGS. 1 and 2 is referred to as “upper” and the lower side is referred to as “lower”.
A substrate 1 with a bonding film shown in FIG. 1 has a substrate 2 and a bonding film 3 formed on the substrate 2. Such a substrate 1 with a bonding film is bonded to a desired adherend using the adhesiveness developed in the bonding film 3. As a result, a bonded body obtained by bonding the base material 2 and the adherend through the bonding film 3 is obtained.

Hereinafter, the configuration of each part will be described in detail.
The base material 2 supports the bonding film 3, and the shape thereof is not particularly limited. For example, the base material 2 has a substrate shape (sheet shape).
Although it does not specifically limit as a constituent material of the base material 2, For example, various resin material, various metal materials, various silicon materials, various glass materials, various ceramic materials, various carbon materials, etc. are mentioned, A composite material combining two or more of these materials can also be used.
In addition, the base material 2 may have a peeling layer provided on the surface on the bonding film 3 side as necessary. This peeling layer can easily peel the bonding film 3 from the substrate 2, and after bonding the substrate 1 with bonding film to the adherend, the interface between the peeling layer and the bonding film 3 is peeled off. This makes it possible to transfer only the bonding film 3 to the adherend side.

As the release layer, for example, fluorine resin, olefin resin, styrene resin, acrylic resin, silicone resin, polyimide, polycarbonate, polyamide, polyethylene terephthalate, polyvinyl chloride, polyvinyl alcohol, ABS resin, polyphenylene sulfide resin, etc. And various resin materials.
Further, the release layer preferably has a surface energy (surface free energy) smaller than the surface energy of the adherend. As a result, the bonding film 3 adheres relatively firmly to the adherend, while preferentially peeling between the bonding film 3 and the peeling layer. As a result, the bonding film 3 can be reliably transferred to the adherend side.
The bonding film 3 transferred to the adherend side can be bonded to another adherend by applying energy to the peeled surface as described later. Therefore, an adherend and another adherend can be joined via the peeled bonding film 3 to obtain a joined body.

  As shown in FIG. 1, the bonding film 3 has a Si skeleton 301 including a siloxane (Si—O) bond 302 and a leaving group 303 bonded to the Si skeleton 301. Since such an atomic structure is random, such a bonding film 3 exhibits characteristics similar to those of amorphous, and is a strong film that is not easily deformed. This is presumably because defects such as dislocations and deviations in the crystal grain size are less likely to occur because the crystallinity of the atomic structure of the bonding film 3 is low (non-crystalline). For this reason, the bonding film 3 itself has high bonding strength, chemical resistance, light resistance and dimensional accuracy, and the finally obtained bonded body also has high bonding strength, chemical resistance, light resistance and dimensional accuracy. Is obtained.

When energy is applied to such a bonding film 3, the leaving group 303 is detached from the Si skeleton 301, and active hands 304 are generated on the surface and inside of the bonding film 3 as shown in FIG. 2. Thereby, adhesiveness is developed on the surface of the bonding film 3. The base material 1 with a bonding film and the adherend can be bonded using such adhesiveness.
Note that the bond energy between the leaving group 303 and the Si skeleton 301 is smaller than the bond energy of the siloxane bond 302 in the Si skeleton 301. This is because the bond energy of the siloxane bond 302 is about 430 kJ / mol, which is considerably larger than other bond types. Therefore, when energy is applied to the bonding film 3, the Si skeleton 301 is destroyed. While preventing this, the bond between the leaving group 303 and the Si skeleton 301 can be selectively cleaved to leave the leaving group 303.

In addition, such a bonding film 3 has a structure that is relatively close to an inorganic material, and thus is a solid that does not have fluidity. For this reason, the thickness and shape of the bonding film 3 hardly change, and the dimensional accuracy of the bonded body is remarkably higher than the conventional one.
In addition, since the bonding film 3 is solid, the substrate 1 with the bonding film has an advantage that it is easy to handle from the viewpoint of storage or distribution.

  Further, in the bonding film 3, among the atoms obtained by removing H atoms from all atoms constituting the bonding film 3, the total content of Si atoms and O atoms is 10 atomic% or more and 90 atomic% or less. Is preferably about 20 atomic% or more and 80 atomic% or less. If Si atoms and O atoms are contained in the above-mentioned range, the bonding film 3 forms a strong network between the Si atoms and the O atoms, and the bonding film 3 itself becomes strong. It shows particularly high bonding strength to the body.

The abundance ratio of Si atoms to O atoms in the bonding film 3 is preferably about 3: 7 to 7: 3, more preferably about 4: 6 to 6: 4. By setting the abundance ratio of Si atoms and O atoms to be in the above range, the stability of the bonding film 3 is increased, and the bonding can be more firmly bonded to the adherend.
In addition, the crystallinity of the Si skeleton 301 in the bonding film 3 is preferably 45% or less, and more preferably 40% or less. As a result, the Si skeleton 301 includes a sufficiently random atomic structure and exhibits more amorphous characteristics. For this reason, the characteristics of the Si skeleton 301 described above become obvious, and the dimensional accuracy and adhesiveness of the bonding film 3 become more excellent.

Note that the crystallinity of the Si skeleton 301 can be measured by a general crystallinity measurement method, and specifically, a method of measuring based on the intensity of scattered X-rays in a crystal portion (X-ray method). , The method of obtaining from the intensity of the crystallization band of infrared absorption (infrared method), the method of obtaining based on the area under the differential curve of nuclear magnetic resonance absorption (nuclear magnetic resonance absorption method), It can be measured by a chemical method utilizing the difficulty.
Among these, the X-ray method is preferably used from the viewpoint of convenience and the like.
Further, when the crystallinity of the Si skeleton 301 is measured, the above-described measurement method may be applied to the bonding film 3. A measurement result is obtained.

  The bonding film 3 preferably contains Si—H bonds in the structure. This Si-H bond is generated in the polymer when the silane undergoes a polymerization reaction by the plasma polymerization method. At this time, if the Si-H bond inhibits the regular formation of the siloxane bond, Conceivable. For this reason, the siloxane bond is formed so as to avoid the Si—H bond, and the regularity of the atomic structure of the Si skeleton 301 is lowered. Thus, according to the plasma polymerization method, the Si skeleton 301 having a low crystallinity can be efficiently formed.

  On the other hand, the greater the Si—H bond content in the bonding film 3, the lower the crystallinity. Specifically, in the infrared absorption spectrum of the bonding film 3, when the intensity of the peak attributed to the siloxane bond is 1, the intensity of the peak attributed to the Si—H bond is 0.001 or more and 0.2 or less. Is preferably about 0.002 to 0.05, more preferably about 0.005 to 0.02. When the ratio of the Si—H bond to the siloxane bond is within the above range, the atomic structure in the bonding film 3 is relatively random. For this reason, when the peak intensity of the Si—H bond is within the above range with respect to the peak intensity of the siloxane bond, the bonding film 3 is particularly excellent in bonding strength, chemical resistance, and dimensional accuracy.

Further, as described above, the leaving group 303 bonded to the Si skeleton 301 acts to generate an active hand in the bonding film 3 by detaching from the Si skeleton 301. Therefore, although the leaving group 303 is relatively easily and uniformly desorbed by being given energy, it is securely bonded to the Si skeleton 301 so as not to be desorbed when no energy is given. It needs to be a thing.
In the film formation by the plasma polymerization method, the component of the source gas is polymerized to generate a Si skeleton 301 containing a siloxane bond and a residue bonded thereto. For example, this residue is a leaving group. 303.

  From this point of view, the leaving group 303 includes an H atom, a B atom, a C atom, an N atom, an O atom, a P atom, an S atom, and a halogen atom, or each of these atoms. What consists of at least 1 sort (s) selected from the group which consists of an atomic group arrange | positioned so that it may couple | bond with frame | skeleton 301 is used preferably. Such a leaving group 303 is relatively excellent in bond / elimination selectivity by energy application. For this reason, such a leaving group 303 can sufficiently satisfy the above-described necessity, and the adhesiveness of the bonding film 3 can be made higher.

Examples of the atomic group (group) arranged so that each atom as described above is bonded to the Si skeleton 301 include, for example, an alkyl group such as a methyl group and an ethyl group, and an alkenyl group such as a vinyl group and an allyl group. Aldehyde group, ketone group, carboxyl group, amino group, amide group, nitro group, halogenated alkyl group, mercapto group, sulfonic acid group, cyano group, isocyanate group and the like.
Among these groups, the leaving group 303 is particularly preferably an organic group, and more preferably an alkyl group. Since the organic group and the alkyl group have high chemical stability, the bonding film 3 including the organic group and the alkyl group has excellent weather resistance and chemical resistance.

Here, when the leaving group 303 is a methyl group (—CH ₃ ) in particular, the preferred content is defined as follows from the peak intensity in the infrared light absorption spectrum.
That is, in the infrared absorption spectrum of the bonding film 3, when the intensity of the peak attributed to the siloxane bond is 1, the intensity of the peak attributed to the methyl group is about 0.05 to 0.45. Preferably, it is about 0.1 or more and 0.4 or less, more preferably about 0.2 or more and 0.3 or less. When the ratio of the peak intensity of the methyl group to the peak intensity of the siloxane bond is within the above range, it is necessary and sufficient in the bonding film 3 while preventing the methyl group from inhibiting the generation of the siloxane bond more than necessary. Since a number of active hands are generated, sufficient adhesiveness is generated in the bonding film 3. Further, the bonding film 3 exhibits sufficient weather resistance and chemical resistance due to the methyl group.

Examples of the constituent material of the bonding film 3 having such characteristics include a polymer containing a siloxane bond such as polyorganosiloxane and an organic group capable of forming a leaving group 303 bonded thereto.
The bonding film 3 made of polyorganosiloxane itself has excellent mechanical properties. In addition, it exhibits particularly excellent adhesion to many materials. Therefore, the bonding film 3 made of polyorganosiloxane adheres particularly firmly to the base material 2 and also exhibits a particularly strong adhesion force to the adherend. The bonded body can be firmly bonded.
Polyorganosiloxane usually exhibits water repellency (non-adhesiveness), but can easily desorb organic groups when given energy, changes to hydrophilicity, and exhibits adhesiveness. However, it has the advantage that control of this non-adhesiveness and adhesiveness can be performed easily and reliably.

  This water repellency (non-adhesiveness) is mainly an effect of organic groups (for example, alkyl groups) contained in the polyorganosiloxane. Therefore, the bonding film 3 made of polyorganosiloxane exhibits an adhesive property when energy is applied thereto, and also has an advantage that the action and effect of the organic group described above can be obtained in portions other than the surface. . Therefore, such a bonding film 3 has excellent weather resistance and chemical resistance, and is effectively used when assembling a member that is exposed to chemicals or the like for a long time.

  Further, among polyorganosiloxanes, those mainly composed of a polymer of octamethyltrisiloxane are preferred. The bonding film 3 mainly composed of a polymer of octamethyltrisiloxane is particularly excellent in adhesiveness. Moreover, since the raw material which has octamethyltrisiloxane as a main component is liquid at normal temperature and has an appropriate viscosity, there is also an advantage that it is easy to handle.

The average thickness of the bonding film 3 is preferably about 1 nm to 1000 nm, and more preferably about 2 nm to 800 nm. By setting the average thickness of the bonding film 3 within the above range, the base material 2 and the adherend can be bonded more firmly while preventing the dimensional accuracy of the bonded body from being significantly reduced.
That is, when the average thickness of the bonding film 3 is less than the lower limit, sufficient bonding strength may not be obtained. On the other hand, when the average thickness of the bonding film 3 exceeds the upper limit, the dimensional accuracy of the bonded body may be reduced.

Furthermore, if the average thickness of the bonding film 3 is within the above range, the shape of the bonding film 3 can be maintained to some extent. For this reason, for example, even when unevenness exists on the bonding surface of the substrate 2 (surface adjacent to the bonding film 3), the bonding film follows the shape of the unevenness depending on the height of the unevenness. 3 can be deposited. As a result, the bonding film 3 can absorb the unevenness, relieve the height of the unevenness generated on the surface, and improve the adhesion of the bonded body.
Note that the degree of the shape followability as described above becomes more significant as the thickness of the bonding film 3 increases. Therefore, the thickness of the bonding film 3 should be as large as possible in order to sufficiently ensure the shape following ability.

  Although the bonding film 3 has been described in detail above, such a bonding film 3 may be produced by any method, and various types such as a plasma polymerization method, a CVD method (particularly a plasma CVD method), and a PVD method. It can be produced by a vapor deposition method or various liquid deposition methods. Among these, according to the plasma polymerization method, the dense and homogeneous bonding film 3 can be efficiently produced. In addition, in the bonding film 3 manufactured by the plasma polymerization method, the activated state with the energy applied is maintained for a relatively long time.

Here, a method for manufacturing the bonding film 3 by the plasma polymerization method will be described.
The plasma polymerization method is a film forming method in which a mixed gas of a raw material gas and a carrier gas is supplied in a strong electric field to polymerize molecules in the raw material gas by the action of plasma and deposit a polymer on the substrate 2. It is. According to this method, since the surface of the substrate 2 is activated and cleaned by the action of plasma, the bonding film 3 having high adhesion to the substrate 2 can be formed regardless of the type of the substrate 2. . That is, by using the bonding film 3 formed by the plasma polymerization method, it is possible to finally obtain a strongly bonded bonded body.

Examples of the source gas include organosiloxanes such as methylsiloxane, octamethyltrisiloxane, decamethyltetrasiloxane, decamethylcyclopentasiloxane, octamethylcyclotetrasiloxane, and methylphenylsiloxane.
On the other hand, for example, helium gas, argon gas, nitrogen gas or the like is used as the carrier gas.

The strong electric field is formed by applying a high frequency voltage to the electrode, and the output density of the high frequency voltage is preferably about 0.01 W / cm ² or more and 100 W / cm ² or less.
Further, the deposition is carried out under reduced pressure, the pressure is preferably about 133.3 × ¹⁰ -5 Pa or more 1333Pa less (1 × ¹⁰ -5 Torr or 10Torr or less), 133.3 × 10 ^- More preferably, it is about ⁴ Pa or more and 133.3 Pa or less (1 × 10 ⁻⁴ Torr or more and 1 Torr or less).
The bonding film 3 can be obtained as described above.

(Joining method)
Next, a method for obtaining the joined body by joining the base material 1 with the joining film as described above to the adherend 4 will be described.
FIG. 3 is a diagram for explaining a method of bonding a base material with a bonding film and an adherend. In the following description, the upper side in FIG. 3 is referred to as “upper” and the lower side is referred to as “lower”.
In this bonding method, energy is applied to the bonding film 3 of the substrate 1 with bonding film to activate the surface of the bonding film 3, and the bonding film 3 is attached so that the bonding film 3 and the adherend 4 are in close contact with each other. A step of superposing the substrate 1 and the adherend 4 to obtain a bonded body 5. Hereinafter, each process will be described sequentially.
<1> First, the base material 1 with the bonding film and the adherend 4 are prepared (see FIG. 3A). The bonding surface of the adherend 4 may be subjected in advance to a base treatment such as plasma treatment or ultraviolet irradiation treatment (see FIG. 3B).

  <2> Next, energy is applied to the bonding film 3 (see FIG. 3B). As the method, for example, a method of irradiating energy rays, a method of heating, a method of applying compressive force (physical energy), a method of exposing to plasma (applying plasma energy), or exposing to ozone gas (chemical energy is applied) A method of irradiating with energy rays and a method of exposing to plasma are particularly preferable.

Examples of energy rays include electromagnetic waves such as ultraviolet rays and X-rays, particle beams such as electron beams and ion beams, and the like.
Among these, it is preferable to irradiate ultraviolet rays having a wavelength of 126 nm to 300 nm. According to such ultraviolet rays, adhesiveness can be expressed in a shorter time while preventing a significant deterioration in the properties of the bonding film 3.
The time for irradiation with ultraviolet rays is not particularly limited, but is preferably 0.5 minutes or more and 30 minutes or less, and more preferably 1 minute or more and 10 minutes or less.
On the other hand, the plasma exposure treatment is useful in that the vicinity of the surface of the bonding film 3 can be activated locally. That is, there is little possibility that the substrate 2 is deteriorated by the activation treatment.

In this way, dangling bonds are generated on the surface of the bonding film 3 to which energy has been applied and activated, and active hands such as hydroxyl groups (OH groups) are introduced. In addition, the above-mentioned “activate” means a state where dangling bonds are generated, a state where hydroxyl groups are bonded, or a state where these are mixed.
In such an activated state, for example, a hydroxyl group exposed on the surface of the bonding film 3 and a hydroxyl group exposed on the surface of the adherend are attracted to each other by hydrogen bonding, and an attractive force is generated between the hydroxyl groups.

In addition, hydroxyl groups that are attracted to each other by hydrogen bonding are dehydrated and condensed depending on temperature conditions and the like. As a result, the hydrogen bond changes to a covalent bond via an oxygen atom, leading to a stronger bond.
In addition, since hydroxyl groups are naturally introduced into the surface of a metal material, a ceramic material, or the like due to the influence of moisture in the air, bonding can be performed using this. Moreover, the surface of the adherend 4 can be activated and the active hands can be exposed by the base treatment as described above.

In the present embodiment, the case where the bonding film 3 is provided on the substrate 2 side has been described. However, the bonding film 3 may also be formed on the adherend 4 side. That is, bonding may be performed so that the bonding films 3 are in close contact with each other.
In this case, active hands are introduced at a higher density in the bonding interface, so that stronger bonding is possible.
As will be described later, the bonding film evaluation method and the bonding film evaluation apparatus according to the present invention quantitatively evaluate the activation state of the bonding film 3 to quantitatively determine the adhesiveness of the bonding film 3. It is intended to lead to evaluation.

<3> Next, as shown in FIG. 3C, the base member 1 with the bonding film 1 and the adherend 4 are overlapped so that the bonding film 3 and the adherend 4 are in close contact with each other. Thereby, the joined body 5 shown in FIG.
Thereafter, the bonding strength of the bonded body 5 can be further increased by performing treatment such as heating and compression on the bonded body 5 as necessary.

(Evaluation method of bonding film)
Here, the evaluation method of the bonding film of the present invention will be described.
The bonding film evaluation method of the present invention is a method for quantitatively evaluating the activation state of the bonding film 3 as described above.
FIG. 4 is a view (cross-sectional view) for explaining the bonding film evaluation method of the present invention.
The evaluation method of the bonding film of the present invention includes a water droplet adhesion process for attaching water droplets to the surface of the bonding film 3 in an activated state, and a contact angle measurement process for measuring the contact angle of the water droplets adhered to the surface of the bonding film 3. And a determination step of determining whether or not the measured contact angle is within a predetermined range. Hereinafter, each process will be described sequentially.

[1] First, prior to the water droplet adhesion step, energy is applied to the bonding film 3 as described above (activation process). As a result, the bonding film 3 enters the activated state described above.
When the bonding film 3 in the activated state is left in the atmosphere, the activated state deteriorates (relaxes) with time, and finally the activated state is lost. If it becomes like this, since the bonding film 3 loses its adhesiveness, it cannot be used for bonding to the adherend 4.

The bonding film 3 is thus very rapidly degraded in the activated state, and the rate of degradation depends on the surrounding environment. Therefore, it is required to accurately evaluate the activated state.
Further, since the adhesiveness of the bonding film 3 cannot be evaluated until it is bonded, there is a problem that a large work load is involved in determining how much activation treatment is performed.

  [2] Therefore, in the present invention, water droplets are attached to the surface of the bonding film 3 in the activated state (water droplet attachment step). Thereafter, the contact angle of the water droplet is measured by a contact angle measurement step to be described later, whereby the measured contact angle can be used as an index for quantitatively evaluating the activated state. Thereby, even if it does not actually join, the activation state of the joining film | membrane 3 can be evaluated easily and correctly.

FIG. 4A shows a state in which water droplets 10 are attached to the surface of the bonding film 3 included in the substrate 1 with the bonding film.
Here, the surface of the bonding film 3 has different wettability depending on its activated state, and thus the shape of the water droplet 10 is different. In general, the cross-sectional shape of the water droplet 10 is a semicircular shape, but the angle formed by the semicircular arc and the surface of the bonding film 3 (the angle formed inside the water droplet 10) is the contact angle. In the present invention, the contact angle is used as an index of the activated state by utilizing the fact that this contact angle is correlated with the activated state (hydrophilicity) of the bonding film 3.

  Note that this correlation is specifically a negative correlation between the contact angle and the hydrophilicity of the surface of the bonding film 3, and the hydrophilicity of the surface of the bonding film 3 and the activity of the bonding film 3. It is a positive correlation between the formation state (adhesiveness). In other words, if the contact angle is small, it can be said that the hydrophilicity is large and the adhesiveness is large. Conversely, if the contact angle is large, the hydrophilicity is small and the adhesiveness is also small. One of the reasons why such a correlation occurs is that a hydrophobic leaving group (for example, an organic group) is detached from the bonding film 3 by the activation process, and in response, hydrophilicity and adhesiveness are expressed. Therefore, inevitably, there is a correlation between the contact angle, the activated state (hydrophilicity), and the adhesiveness.

By the way, at the time of this process, the base material 1 with a bonding film is hold | maintained so that the surface of the bonding film 3 may become as horizontal as possible.
Further, the volume of the water droplet 10 attached to the surface of the bonding film 3 is preferably 1 μL or more and 4 μL or less. As the water used for forming the water droplet 10, for example, tap water, distilled water, ion exchange water, RO water, pure water, ultrapure water, or the like can be used, but distilled water is preferably used.
When the water droplet 10 is formed, the water droplet 10 is formed by gently placing water on the surface of the bonding film 3.

In addition, the environment for performing this step is preferably a room temperature of 20 ° C. to 30 ° C. and a relative humidity of 40% to 60%. Furthermore, examples of the atmosphere include an air atmosphere, an inert gas atmosphere, a reducing gas atmosphere, and the like. Although not particularly limited, an inert gas atmosphere such as a nitrogen gas atmosphere or an argon gas atmosphere is preferably used.
The water droplets 10 are preferably formed at five or more locations with respect to the surface of one bonding film 3. By measuring the contact angle of many water droplets 10 and calculating the average value and the standard deviation value, it is possible to suppress variations in measurement values and measurement errors, and to increase the reliability of the measured contact angle.
In addition, it is preferable that the water droplets 10 are similarly formed on the three or more bonding films 3. Thereby, the further improvement of the reliability of a measured value is achieved.

  In addition, the base material 1 with a bonding film is usually bonded to the adherend 4 to become a bonded body 5, and the bonded body 5 is used as various products or various parts. Therefore, the bonding film 3 included in the substrate with bonding film 1 constitutes a part of a product or a part, and even if it is for evaluating the activation state, from the viewpoint of preventing contamination, etc. There is also a demand to avoid forming water droplets 10 on the surface of the bonding film 3.

  Therefore, when performing this process, a substrate with a bonding film for testing having the same manufacturing history and the same storage history is prepared separately from the substrate with bonding film 1 used as a part of the product or part. The water droplet 10 as described above may be formed on the base material with the bonding film for use. By using a base material with a bonding film for testing as an alternative to the base material with bonding film 1 for products, it is not necessary to form water droplets 10 on the base material 1 with bonding film for products. And if the base material with a bonding film for a test has the same history as the base material with a bonding film for a product 1, the measured value of the base material with a bonding film for testing is the It can be regarded as a measured value.

  Moreover, depending on the shape of the base material 2 of the base material 1 with a bonding film used for products or parts, the surface of the bonding film 3 may not be a smooth surface or a horizontal surface. Further, the shape of the substrate 2 affects the measured value of the contact angle, and there is a possibility that an accurate measured value reflecting only the activated state of the bonding film 3 cannot be obtained. Even in such a case, the activation state of the bonding film 3 included in the substrate 1 with the bonding film for products can be accurately determined by using the substrate with the bonding film for testing having the bonding film with a smooth and horizontal surface. Can be evaluated.

The base material with a bonding film for testing has the same configuration as the base material 1 with a bonding film for products described above. Specifically, the base material is equivalent to the base material 2 and formed thereon. It has a bonding film equivalent to the formed bonding film 3. And energy is provided on the same conditions as the base material 1 with a bonding film for products, and the bonding film is in an activated state.
Further, as described above, in order to accurately evaluate the activation state of the bonding film 3, the surface of the bonding film provided in the base material with the bonding film for testing is preferably a smooth surface and a horizontal surface. . Thereby, the activated state of the bonding film 3 can be accurately evaluated regardless of the shape of the substrate 1 with the bonding film for products.

[3] Next, the contact angle of the water droplet 10 attached to the surface of the bonding film 3 is measured (contact angle measurement step).
The contact angle may be measured by any method as long as the angle formed by the water droplet 10 and the surface of the bonding film 3 can be measured. In general, the water droplet 10 is observed from the side, A method of geometrically obtaining the angle for the observed image is used.
Specifically, the sessile drop method defined in the wettability test method of JIS R 3257 is preferably used. In the sessile drop method, with respect to the lateral observation image of the water droplet 10, the upper arc is regarded as a part of a sphere, whereby the contact angle can be calculated geometrically easily and accurately.

FIG. 4B is a diagram for explaining a method of calculating a contact angle of a water droplet by a sessile drop method.
When the upper arc of the water droplet 10 is a part of a sphere (perfect circle), the contact angle θ is calculated from the radius r of the water droplet 10 and the height h of the water droplet 10 from the surface of the bonding film 3.
θ = 2 tan ⁻¹ (h / r)
Can be calculated.

The environment for performing this step is preferably an environment equivalent to the water droplet adhesion step described above, specifically, room temperature of 20 ° C. to 30 ° C., and relative humidity of 40% to 60%. Furthermore, examples of the atmosphere include an air atmosphere, an inert gas atmosphere, a reducing gas atmosphere, and the like. Although not particularly limited, an inert gas atmosphere such as a nitrogen gas atmosphere or an argon gas atmosphere is preferably used. As a result, the influence of the atmosphere on the measurement of the contact angle θ can be minimized, so that more accurate measurement can be performed. Also, the atmospheric pressure is not particularly limited and is, for example, about atmospheric pressure.
Moreover, it is preferable not to give time as much as possible between the said water droplet adhesion process and this process, for example, it is made within 1 minute.

  The contact angle measured in this way is to evaluate the activation state of the bonding film 3 by comparing with the contact angle found based on the correlation with various activation states of the bonding film 3 in advance. Can do. For example, if the contact angle θ is about the same as the contact angle corresponding to the case where the degree of activation of the bonding film is large (adhesion is high), the bonding film to be measured potentially has a higher bonding strength. It is evaluated as having. On the other hand, if the contact angle θ is about the same as the contact angle corresponding to the case where the degree of activation of the bonding film is small (adhesion is small), the bonding film to be measured has high bonding strength adhesiveness. It is evaluated that it cannot be expressed. In this case, it can be known before the manufacture of the bonded body 5 that it is not suitable for an application that must be bonded with a large bonding strength.

As described above, according to the present invention, by evaluating the potential adhesion capability of the bonding film 3 before manufacturing the bonded body 5, the bonded body 5 that does not satisfy the specifications required for products and parts can be reluctantly used. Production can be avoided in advance. As a result, the manufacturing yield of the bonded body 5 can be increased and the reliability of the bonded body 5 can be increased.
Hereinafter, a specific example of the evaluation of the bonding film 3 will be described.

[4] Here, an example of determining whether or not the measured contact angle θ is within a predetermined range will be described (determination step).
The predetermined range of the contact angle θ is a range found in advance based on the correlation between the contact angle θ and the activation state of the bonding film 3, and is a range of the contact angle corresponding to the target activation state. . That is, when the measured contact angle θ is within the predetermined range, the bonded body 5 in the target bonded state is finally obtained. In this step, the bonded body 5 is obtained with certainty. Can be selected.

For example, in order to maximize the bonding ability of the bonding film 3, the contact angle θ is preferably 80 ° or less, more preferably 70 ° or less, and even more preferably 50 ° or less. .
On the other hand, the lower limit value of the contact angle θ in this case may not be set, but is, for example, 5 ° or more, preferably 10 ° or more.

The contact angle range is slightly different depending on the energy application method applied to the bonding film 3, and is found for each energy application method.
For example, when energy is activated in the bonding film 3 by exposure to oxygen plasma, the contact angle θ is preferably 60 ° or less in order to maximize the bonding ability of the bonding film 3. More preferably, it is 5 ° or more and 55 ° or less.
On the other hand, when energy is activated in the bonding film 3 by exposure to nitrogen plasma, the contact angle θ is preferably 80 ° or less in order to maximize the bonding ability of the bonding film 3. More preferably, the angle is 10 ° or more and 75 ° or less.

About the base material 1 with the bonding film provided with the bonding film 3 having the contact angle θ within the above range, the bonded body 5 having high bonding strength can be obtained by being bonded to the adherend 4 by the bonding method described above. .
On the other hand, the contact angle θ is preferably more than 80 ° and more than 70 ° in order to draw out in a state where the bonding capability of the bonding film 3 is suppressed to some extent (for example, 50% or less of the maximum strength). Is more preferable, and it is more preferable that it is more than 50 °.

Further, as described above, the contact angle θ in the activated bonding film 3 is activated in addition to the determination of the adhesion ability described above using the contact angle θ in the activated bonding film 3 as an index. The bonding ability may be determined using the difference from the contact angle θ ′ in the bonding film 3 (bonding film 3 not in the activated state) before the measurement as an index. In the case of the former determination method, the measurement value slightly varies depending on the measurement condition of the contact angle θ, while in the latter determination method, external factors such as the measurement condition are offset from the measurement value. Thus, a measurement value almost reflecting only the influence of the activation state is obtained.
Note that the above-described evaluation method of the bonding film can be easily confirmed by, for example, performing the bonding film 3 while the bonding film 3 in the activated state is being stored.

By maintaining the bonding film 3 in the activated state in a non-oxidizing gas atmosphere, deterioration of the activated state can be suppressed and the bonding ability of the bonding film 3 can be maintained over a long period of time.
The non-oxidizing gas atmosphere is not particularly limited as long as it is a non-oxidizing atmosphere. For example, an inert gas atmosphere such as an argon gas atmosphere, a rare gas atmosphere such as a helium gas atmosphere, a nitrogen gas atmosphere, hydrogen, A reducing gas atmosphere such as carbon monoxide is exemplified. Among these, an inert gas atmosphere is preferably used, and among these, at least one of a nitrogen gas atmosphere and a rare gas atmosphere is more preferably used. These are useful as non-oxidizing gases used for storage of the bonding film 3 because they can more reliably suppress deterioration of the activation state of the bonding film 3 despite being easily available and safe. It is.

  In addition, in the non-oxidizing gas atmosphere, inevitable mixing of oxidizing gases such as oxygen and ozone in addition to the non-oxidizing gases described above is allowed, but the allowable concentration is preferably 10% by volume or less. Yes, more preferably 5% by volume or less. In other words, the concentration of the non-oxidizing gas in the non-oxidizing gas atmosphere is preferably 90% by volume or more, and more preferably 95% by volume or more.

The dew point of the non-oxidizing gas atmosphere is preferably as low as possible, but is preferably 0 ° C. or lower, more preferably −10 ° C. or lower. Thereby, deterioration of the activation state of the bonding film 3 due to the influence of water vapor can also be suppressed.
Further, the temperature of the non-oxidizing gas atmosphere is preferably −20 ° C. or higher and 30 ° C. or lower, more preferably 0 ° C. or higher and 20 ° C. or lower. By maintaining the temperature of the non-oxidizing gas atmosphere in this range, the deterioration / deterioration of the bonding film 3 can be more reliably suppressed.

Although the temperature of the non-oxidizing gas atmosphere may be lower than the lower limit value, not only the deterioration / deterioration of the bonding film 3 can be further suppressed, but there is a possibility that a large amount of energy is required to maintain the temperature.
Further, the total pressure of such a non-oxidizing gas atmosphere is preferably equal to or higher than atmospheric pressure. As a result, there is no possibility that the external air flows into the periphery of the bonding film 3, so that the periphery of the bonding film 3 can always be maintained in a non-oxidizing gas atmosphere.

  According to the method as described above, the bonding film 3 in the activated state can be stored for a long period of time, but conventionally there has been no method for evaluating the deterioration of the activated state, and thus the bonding film 3 in the activated state. It was not possible to determine whether or not was properly stored. For this reason, even when the storage environment is not appropriate, it cannot be noticed, and the manufacturing yield may be significantly reduced.

  Therefore, the storage state of the bonding film 3 can be easily evaluated by applying the above-described bonding film evaluation method to the bonding film 3 being stored. Moreover, as described above, the bonding film 3 can be stored in a non-oxidizing gas atmosphere for a long time. However, the bonding film evaluation method of the present invention can be performed in such an atmosphere. It can be evaluated without loss.

(Bonding film evaluation device)
Next, the bonding film evaluation apparatus of the present invention will be described.
The bonding film evaluation apparatus of the present invention is an apparatus that quantitatively evaluates the activation state of the bonding film 3.
FIG. 5 is a diagram (front view) schematically showing an embodiment of the bonding film evaluation apparatus of the present invention.
An evaluation apparatus 100 shown in FIG. 5 includes a case 110 having a sealed structure, a gas supply unit 120 that supplies an inert gas into the case 110, a water droplet preparation unit 150 that attaches the water droplet 10 to the surface of the bonding film 3, Contact angle measuring means 160 for measuring the contact angle of the water droplet 10. Hereinafter, each part will be described in detail.

  The case 110 may be any container as long as it has a sealed structure and can store the base material 1 with the bonding film. By housing the water droplet preparation means 150 and the contact angle measurement means 160 in the case 110, the influence of external factors (outside air or the like) on the contact angle measurement value can be minimized. Examples of the constituent material of the case 110 include various resin materials, various metal materials, and various glass materials. Among these, a transparent material is useful because it can visually recognize the inside of the case 110 from the outside, confirm the presence / absence of the substrate 1 with the bonding film, the state of the bonding film 3, and measure the contact angle. It is.

The sealed structure of the case 110 may have a high degree of airtightness like a vacuum chamber, but may not have such a high degree of airtightness. Specifically, the airtightness of the degree obtained by bonding members together with an adhesive may be used.
The case 110 is provided with an openable / closable door 111. The substrate 1 with the bonding film can be easily put in and out through the opening / closing door 111.

The gas supply unit 120 includes a gas cylinder 121 that stores an inert gas, a pipe 122 that feeds the inert gas from the gas cylinder 121 into the case 110, and a valve 123 provided in the middle of the pipe 122. .
The gas cylinder 121 supplies an inert gas into the case 110. The gas cylinder 121 may be replaced with a gas generator that generates an inert gas by causing a chemical reaction therein.
The valve 123 may be a manual valve, but an electromagnetic valve, a mass flow controller, or the like is preferably used. Thereby, the flow volume of the inert gas which passes the piping 122 can be electrically controlled from the outside.

Furthermore, the case 110 shown in FIG. 5 is provided with a gas detector 130 for detecting the internal gas.
The gas detection unit 130 is a sensor that measures the concentration of the inert gas in the case 110 and the total pressure in the case 110, and includes, for example, a combination of a concentration sensor that measures the concentration and a pressure sensor that measures the total pressure. Is done.

The concentration sensor may be an inert gas sensor that directly measures the concentration of the inert gas. The concentration of the inert gas is measured by the inert gas sensor that measures the concentration of the inert gas, and the measured value is used. You may obtain | require by calculating back the density | concentration of an inert gas. As the concentration sensor, any system such as a semiconductor system or a hot-wire semiconductor system may be used.
On the other hand, a pressure sensor such as a ceramic piezoelectric type, a thin film type, a piezoresistive type, or a semiconductor piezoresistive type can be used as the pressure sensor.

Further, the evaluation apparatus 100 illustrated in FIG. 5 includes a control unit 140 that controls the operation of each unit.
The control unit 140 is electrically connected to the gas supply unit 120 and the gas detection unit 130, acquires a measurement value by the gas detection unit 130, and controls the operation of the gas supply unit 120 based on the measurement value.

Specifically, the control unit 140 acquires a measurement value of the concentration of the inert gas measured by the gas detection unit 130 or a measurement value of the total pressure in the case 110. Then, the concentration and the total pressure are compared with preset threshold values, and when either the concentration or the total pressure falls below the threshold value, the supply of the inert gas into the case 110 is started. The operation of the gas supply unit 120 is controlled so that the supply amount increases. The control unit 140 controls, for example, the opening / closing amount of the valve 123.
By performing the control as described above, both the concentration of the inert gas and the total pressure of the atmosphere are maintained under the optimum conditions for measuring the contact angle θ around the substrate 1 with the bonding film.

The measurement value is acquired by the control unit 140 periodically, for example, every minute, every hour, every other day. Thereby, the conditions in the case 110 are periodically checked, and the inert gas is added based on the conditions. As a result, the concentration and total pressure can always be controlled to be constant with predetermined values. Since the temperature and relative humidity can be controlled by adding an inert gas, the operation of the gas supply unit 120 may be controlled while monitoring the temperature and relative humidity.
The measurement value acquisition interval may be appropriately set according to the airtightness of the airtight structure of the case 110.

Moreover, the gas supply unit 120, the gas detection unit 130, and the control unit 140 may be each driven by a portable power source. Thereby, since the whole evaluation apparatus 100 becomes movable, the activation state of the bonding film 3 can be evaluated at an arbitrary place. As a result, the geographical restriction in the manufacturing process of the joined body 5 can be solved.
Examples of portable power sources include various primary batteries, various secondary batteries, solar cells, and the like.
For the control unit 140, for example, an LSI, a personal computer, or the like can be used. The control unit 140 may store a reference value for controlling the concentration, total pressure, temperature, relative humidity, and the like in advance, and may be configured so that the reference value is input each time by an input unit. .

In the case 110 shown in FIG. 5, a water droplet preparation means 150 is provided. The water droplet preparation means 150 includes a water storage tank (storage part) 151 that stores water, and a nozzle 152 that supplies the water stored in the water storage tank 151 to the surface of the bonding film 3.
The water storage tank 151 is a container for storing water, and is configured such that internal water is supplied to the nozzle 152 by its own weight or various pumps.

The nozzle 152 can discharge the water stored in the water storage tank 151 as droplets. The nozzle 152 moves as necessary, and can be arranged quietly without dropping the water droplet 10 on the surface of the bonding film 3.
The temperature of the water stored in the water storage tank 151 is not particularly limited, but is preferably about the same as the temperature of the atmosphere.
The evaluation apparatus 100 further includes a contact angle measurement unit 160. The contact angle measuring means 160 is provided in the case 110, analyzes the water droplet 10 attached to the surface of the bonding film 3 from the side, and the image captured by the camera 161, and calculates the contact angle θ. And an analyzing unit 162 to be identified.

The camera 161 is composed of various cameras such as a still camera and a video camera, various imaging elements such as a CCD, a CMOS, an imaging plate, and an imaging tube. The captured image is generally a still image, but may be a moving image as necessary. The camera 161 may have various filters provided between the water droplet 10 and the camera 161, various light sources provided on the opposite side of the camera 161 with respect to the water droplet 10, and the like.
Further, the camera 161 is disposed at a position where its optical axis is located on the extended surface of the surface of the bonding film 3 and passes through the water droplet 10.

The analysis unit 162 is configured by, for example, an LSI, a personal computer, or the like, and is configured to specify the contact angle θ of the water droplet 10 by performing various processes on the captured image.
Further, when a plurality of water droplets 10 are formed on one bonding film 3, the analysis unit 162 calculates an average value and a standard deviation value of the contact angle θ measured for each water droplet 10.
According to such an evaluation apparatus 100, the measurement value of the contact angle θ does not include a measurement error (individual difference), and a highly reliable measurement value can be obtained.

As described above, the bonding film evaluation method and the bonding film evaluation apparatus of the present invention have been described based on the illustrated embodiments, but the present invention is not limited thereto.
For example, in the evaluation method of the bonding film of the present invention, the process is not limited to the configuration of the above embodiment, and one or two or more processes for an arbitrary purpose may be added.
In the bonding film evaluation apparatus of the present invention, the configuration of each part can be replaced with an arbitrary configuration that exhibits the same function, and an arbitrary configuration can be added.
Further, energy may be applied to the bonding film 3 in the case 110.

  Furthermore, the bonding film evaluation apparatus of the present invention can also be used as a storage apparatus that can store the bonding film 3 in an activated state while maintaining the activated state. This is because the bonding film 3 in the activated state can be stored for a long time by being held in the non-oxidizing gas atmosphere. In addition, since this evaluation apparatus 100 is provided with the water droplet preparation means 150 and the contact angle measurement means 160, by measuring the contact angle of the preserved bonding film 3 periodically or intermittently, This is useful in that the storage state (the degree of deterioration of the activated state) can be easily evaluated.

Next, specific examples of the present invention will be described.
1. Evaluation of activation state of bonding film (Example 1)
<1> First, a 20 mm square silicon substrate (base material) was prepared, and the surface was subjected to surface treatment with oxygen plasma.
Next, the silicon substrate was placed in a vacuum chamber of a plasma polymerization apparatus, and a plasma polymerization film having an average thickness of 150 nm was formed. As a result, a plurality of substrates with bonding films formed by forming a plasma polymerization film on a silicon substrate were obtained. The film forming conditions are as shown below.

<Film formation conditions>
-Source gas composition: Octamethyltrisiloxane-Source gas flow rate: 50 sccm
Carrier gas composition: Argon Carrier gas flow rate: 100 sccm
・ High frequency power output: 100W
・ High frequency output density: 25 W / cm ²
-Chamber pressure: 1 Pa (low vacuum)
・ Processing time: 15 minutes ・ Substrate temperature: 20 ° C.
As a result, a bonding film was formed.

<2> Next, the obtained bonding film was subjected to oxygen plasma treatment to activate the bonding film.
In the activation, the oxygen plasma treatment time is different from 0 hours, 0.5 hours, 1 hour, 1.5 hours, 2 hours, 2.5 hours, and 3 hours. Each bonding film was subjected to oxygen plasma treatment.

<3> Next, the plurality of bonding film-attached substrates subjected to the activation treatment were quickly placed in the case of the bonding film evaluation apparatus shown in FIG.
Next, nitrogen gas was supplied into the case, and the following conditions were maintained.
<Condition in case>
・ Atmosphere: Nitrogen gas atmosphere (nitrogen concentration: 99.9% by volume)
・ Temperature: 20 ℃
・ Relative humidity: 50%
-Pressure: Atmospheric pressure <4> Next, with respect to one of the two substrates with the bonding film, 4 μL of water droplets were attached to the surface of the bonding film at five locations. In addition, distilled water was used for preparation of water droplets.
<5> Next, the contact angles of the five water droplets attached to the surfaces of the bonding films having different activation treatment times were measured, and the average value was taken as the contact angle in each bonding film.

(Example 2)
A substrate with a bonding film is obtained in the same manner as in Example 1 except that nitrogen plasma processing is performed instead of oxygen plasma processing on the bonding film, and the contact angle of water droplets attached to the surface of the bonding film is obtained. Was measured.
In activation, the time for performing the nitrogen plasma treatment is different from 0 hours, 0.5 hours, 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours, and 4 hours. Then, nitrogen plasma treatment was performed on two bonding films for each treatment time.

2. Evaluation of Bonding Strength of Bonding Film In each Example, among the substrates with bonding films prepared for each treatment time, those having no water droplets attached thereto were bonded to a separately prepared silicon substrate (20 mm square). . Thereby, a joined body was obtained.
Subsequently, the load [unit: kgf] required for each peeling was measured for the obtained bonded body, and the maximum value of the measured load was defined as the bonding strength. And the processing time of the activation process was taken on the horizontal axis | shaft of the graph, the joint strength and the contact angle were taken on the vertical axis | shaft, and the measured value in each joined body was plotted on the graph. The obtained graphs are shown in FIGS. 6 shows the first embodiment, and FIG. 7 shows the second embodiment.

As is apparent from FIGS. 6 and 7, it is recognized that the bonding strength is large when the contact angle is small, and the bonding strength is small when the contact angle is large. From this tendency, it is recognized that the activation state and the potential adhesiveness of the bonding film can be evaluated by measuring the contact angle.
On the other hand, in Example 1, the transition of the contact angle and the transition of the bonding strength when the bonding film is left in the atmosphere for a predetermined time after the oxygen plasma treatment is performed are shown in FIG.

As can be seen from FIG. 8, when the bonding film 3 in the activated state is left in the atmosphere, the contact angle tends to increase with time. Moreover, the tendency for the bonding strength of the bonding film 3 to gradually decrease with time was also observed.
As described above, according to the present invention, it was recognized that the activation state and the potential adhesiveness of the bonding film can be quantitatively evaluated using the contact angle of the water droplet on the surface of the bonding film as an index.

  DESCRIPTION OF SYMBOLS 1 ... Base material with bonding film 10 ... Water droplet 2 ... Base material 3 ... Bonding film 301 ... Si skeleton 302 ... Siloxane bond 303 ... Leaving group 304 ... Active hand 4 ... Substrate 5 ··················································································································································································································· Control units 150 …… Water drop preparation means 151 …… Water storage tank (storage part) 152 …… Nozzle 160 …… Contact angle measurement means 161 …… Camera 162 …… Analysis part

Claims (10)

A bonding film that includes an atomic structure including a siloxane bond and a leaving group that is bonded to the siloxane bond and includes an organic group, is activated by applying energy, and has an activated state for a bonding film that exhibits adhesiveness. A method for quantitative evaluation,
A method for evaluating a bonding film, comprising a step of attaching a water droplet to a surface of the bonding film in the activated state and measuring a contact angle of the water droplet.   The bonding film evaluation method according to claim 1, further comprising a step of determining whether or not the measured contact angle of the water droplet is within a predetermined range.   The method for evaluating a bonding film according to claim 1 or 2, wherein the step of measuring the contact angle of the water droplet is performed according to a sessile drop method defined in a wettability test method of JIS R 3257.   The method for evaluating a bonding film according to claim 1, wherein the step of measuring the contact angle of the water droplet is performed in a state where the bonding film is placed in an inert gas. The bonding film is a test bonding film having the same manufacturing history and the same storage history as a bonding film for manufacturing a product,
5. The bonding film according to claim 1, further comprising a step of regarding a contact angle of the water droplet measured for the test bonding film as a contact angle of the water droplet measured for the bonding film for manufacturing the product. Evaluation method. A bonding film that includes an atomic structure including a siloxane bond and a leaving group that is bonded to the siloxane bond and includes an organic group, is activated by applying energy, and has an activated state for a bonding film that exhibits adhesiveness. A device for quantitative evaluation,
Water droplet preparation means for preparing water droplets and attaching the water droplets to the surface of the bonding film in the activated state;
An apparatus for evaluating a bonding film, comprising: a contact angle measuring unit that measures a contact angle of a water droplet adhered to the surface of the bonding film.   The bonding film evaluation device according to claim 6, wherein the water droplet preparation unit includes a storage unit that stores water and a nozzle that supplies the water stored in the storage unit to the surface of the bonding film.   The contact angle measurement means includes a camera that photographs a water droplet attached to the surface of the bonding film from a side, and an analysis unit that analyzes an image photographed by the camera and identifies the contact angle. The bonding film evaluation apparatus according to claim 6 or 7.   The bonding film evaluation apparatus according to claim 6, further comprising a case that has a sealed structure, houses the water droplet preparation means therein, and can accommodate the bonding film.   The bonding film evaluation apparatus according to claim 9, further comprising a gas supply unit configured to supply an inert gas in the case.

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