KR100715294B1 - Flexible metal laminate and flexible printed board - Google Patents

Abstract

In a flexible metal laminate for use in compressing a projection such as a bump under high temperature conditions and a flexible printed circuit board using the same, a flexible metal laminate capable of solving a problem involving softening and shrinkage of the resin layer and a Provided is a flexible printed circuit board used.

A flexible metal laminate having a metal layer (10) and a resin layer (11), wherein the resin layer (11) is divided into two in portions having a thickness of 1/2, and the contact surface (13) side with the metal layer (10) is removed. When the first sample 11a and the remaining sample are the second sample 11b, the penetration displacement amount L1 of the first sample 11a from the contact surface 13 with the metal layer 10 is equal to the metal layer 10. A flexible metal laminate, which is smaller than the intrusion displacement amount (L2) of the second sample (11b) from the surface on the opposite side (12, outermost surface).

Metal laminates, printed circuit boards, penetration displacements, resin layers, metal layers,

Description

Flexible metal laminate and flexible printed board

1A is a cross-sectional view showing an example of the flexible metal laminate of the present invention,

1B to 1D are explanatory views showing the measurement procedure of the intrusion displacement amount.

2 is a cross-sectional view showing another example of the flexible metal laminate of the present invention.

3 is an explanatory view showing an example of a bonding method by a COF bonder.

** Explanation of Signs of Major Parts of Drawings **

10; Metal layer

11; Resin layer

11a; First sample

11b; Second sample

12; Surface opposite to metal layer (outermost)

13; Contact surface

14; First layer (layer adjacent to metal layer)

15; Second layer (outermost layer)

20; Probe

The present invention relates to a flexible metal laminate and a flexible printed circuit board.

Background Art [0002] Nowadays, the spread of mobile phones, liquid crystal monitors, and the like, electronic devices are required to be further downsized, thinned, and multifunctional. In order to realize this demand, miniaturization and high integration of electronic components are essential, but further, high-density packaging technology of electronic components is required.

Recently, with the demand for miniaturization of driving ICs for liquid crystal displays (LCDs) and multi-output ICs, flip chip bonding, particularly COF (Chip On Film), is used for bonding IC chips and flexible printed circuit boards. ) Implementation is adopted.

The conventional COF implementation remodels the ILB (Inner® Lead® Bonder) bonder used in the TCP (Tape® Carrier® Package) implementation.

In addition, in order to further reduce the size of the driving IC and to increase the output power of the IC, it is necessary to reduce the degree of imbalance between the bonding position between the IC chip and the flexible printed circuit board. In recent years, I began to recruit.

3 is an explanatory diagram showing an example of a bonding method by a COF bonder.

The COF bonder is schematically composed of a heating tool 3 and a stage 4 for press-contacting the IC chip 1 and the flexible printed circuit board 2.

The IC chip 1 has a plate-shaped main body 1a and a bump 1b made of gold or the like. In the bump 1b, for example, a plurality of plate-like protrusions are arranged at predetermined intervals on one surface of the main body 1a.

Moreover, the flexible printed circuit board 2 is provided with the plate-shaped insulating resin layer 2a and the metal wiring 2b provided in the one surface. The flexible printed circuit board 2 is produced by processing a flexible metal laminate. That is, the flexible metal laminate is obtained by laminating an insulating resin layer and a metal layer, and the flexible printed circuit board 2 can be obtained by processing the metal layer by plating or the like to form the wiring 2b.

When the IC chip 1 and the flexible printed circuit board 2 are press-contacted, the flexible printed circuit board 2 is disposed so that the surface on which the wiring 2b is provided on the stage 4 is upward. Then, the bump 1b side of the IC chip 1 is disposed so as to face the wiring 2b.

Next, when the heating tool 3 is pressed from the IC chip 1 and pressure is applied to the IC chip 1 and the flexible printed circuit board 2, the bump 1b and the wiring 2b are dissolved at high temperature and high pressure. By eutectic, the IC chip 1 and the flexible printed circuit board 2 are joined.

After the bonding is completed in this manner, an insulating resin called underfill is filled around the bump 1b and the wiring 2b between the IC chip 1 and the flexible printed circuit board 2.

Japanese Patent Laid-Open No. 2004-82719, Japanese Patent Laid-Open No. 2004-322636, and Japanese Patent Laid-Open No. 2004-230670 are flexible for producing a flexible printed circuit board 2 used for such a purpose. As a metal laminated body, the laminated body which laminated | stacked the non-thermoplastic polyimide layer and the metal foil which consists of copper foil, and provided the thermoplastic polyimide layer which has a glass transition point lower than a non-thermoplastic polyimide layer between these is proposed.

However, when the flexible printed circuit board 2 is obtained using the conventional flexible metal laminate and the obtained flexible printed circuit board 2 is bonded to the IC chip 1 as shown in Fig. 3, the bump 1b is connected to the wiring ( It is strongly pressed to the flexible printed circuit board resin layer 2a under 2b) under high temperature conditions. Therefore, there arises a problem that the resin layer 2a of the flexible printed circuit board 2 shrinks and deforms.

When the resin layer 2a shrinks and deforms, the position of the wiring 2b provided thereon and the bump 1b to be bonded thereto is shifted or the gap between the IC chip 1 and the flexible printed circuit board 2 becomes narrow. After bonding, the underfill cannot be filled between the IC chip 1 and the flexible printed circuit board 2.

Moreover, when the resin layer 2a shrinks and deforms, when the bump 1b and the wiring 2b are pointed and strongly crimped, the wiring 2b may be peeled from the resin layer 2a using these contacts as supporting points. have. And this peeled wiring 2b may contact with IC chip 1, and may short (so-called edge short).

Therefore, in the present invention, in the flexible metal laminate used for the crimping process of bumps such as bumps under high temperature conditions, and the flexible printed circuit board using the same, softening and shrinkage deformation of the resin layer (hereinafter referred to as deformation, etc.). It is an object of the present invention to provide a flexible metal laminate and a flexible printed circuit board using the same.

MEANS TO SOLVE THE PROBLEM This invention is a flexible metal laminated body which has a metal layer and a resin layer in order to solve the said subject, The said resin layer is divided into two in the part of thickness 1/2, and the contact surface side with the said metal layer is made into the 1st sample, and the remainder is made. When the second sample is used, the intrusion displacement amount L1 of the first sample from the contact surface with the metal layer is smaller than the intrusion displacement amount L2 of the second sample from the side opposite to the metal layer. Provide a sieve.

In the first flexible metal laminate, the absolute value dL of the difference between the penetration amount L1 and the penetration amount L2 is preferably 2 μm or more.

Moreover, it is also preferable that the penetration displacement amount L0 of the said resin layer is 10 micrometers or less from the contact surface with the said metal layer.

Moreover, it is preferable that the said resin layer becomes multiple layers.

Moreover, in order to solve the said subject, this invention is a flexible metal laminated body which has a metal layer and the resin layer which consists of two or more layers formed on it, and the moisture absorption expansion coefficient ( _CHO ) of the outermost layer of a resin layer is a metal layer of a resin layer. The second flexible metal laminate is smaller than the hygroscopic expansion coefficient (C _HM ) of the adjacent layer.

In the said 2nd flexible metal laminated body, it is preferable that the absolute value of the difference between the linear thermal expansion coefficient of a resin layer and the linear thermal expansion coefficient of a metal layer is less than ^10x10 <^-6> / degreeC.

It is a difference (C _HM -C _HO) with the moisture-absorbing expansion coefficient (C _HM) and the hygroscopic expansion coefficient (C _HO) less than 10 × 10 ^-6 /% RH is preferred.

Moreover, in the said 2nd flexible metal laminated body, it is preferable that ratio (T1) / (T0) of thickness T1 of outermost layer and thickness T0 of the whole resin layer is 35/100 or more and 95/100 or less. .

In the said 1st and 2nd flexible metal laminated body, it is preferable that the said resin layer has a storage modulus (E ') in 300 degreeC of 1 GPa or more, and has a glass transition point (Tg) of 300 degreeC or more.

It is preferable that the said resin layer contains the thermoplastic resin soluble in an organic solvent.

It is preferable that the said resin layer contains at least 1 sort (s) of resin chosen from the group which consists of polyimide resin, polyamideimide resin, polyetherimide resin, and polysiloxane imide resin.

It is preferable that the said metal layer is comprised from metal foil.

Moreover, it is preferable that the said metal foil is 1 or more types chosen from the group which consists of copper foil, stainless foil, aluminum foil, and nickel foil.

In another aspect, the present invention provides a flexible printed circuit board using the flexible metal laminate.

[1st flexible metal laminated body]

1: A is sectional drawing which shows an example of the structure of a flexible metal laminated body.

The flexible metal laminate of this example is composed of a metal layer 10 and a resin layer 11 laminated on one surface thereof.

Copper, stainless steel, aluminum, steel, etc. are mentioned as a metal which comprises the metal layer 10. FIG.

Especially, metal foil is very suitable. By using metal foil, generation | occurrence | production of a pinhole can be suppressed. Therefore, wiring defects can be reduced. Therefore, the effect of the improvement of manufacture yield and the improvement of electrical reliability can be acquired. Moreover, when metal foil is used, the outstanding effect which does not peel between a resin layer and a metal layer (wiring) can be acquired even if it heats continuously at high temperature continuously.

And it is preferable to use 1 or more types chosen from the group which consists of copper foil, stainless foil, aluminum foil, and steel foil also in metal foil.

More preferably, electrolytic copper foil which has favorable etching characteristics and corresponds to a fine pitch, rolled copper foil which can improve high bendability, and very thin copper foil which used the copper foil which can improve the process conveyance of copper foil as a carrier, etc. are mentioned. Can be.

The thickness of the metal layer is preferably 3 to 50 µm, more preferably 3 to 35 µm. Moreover, it is preferable to set it as 8-18 micrometers which can be conveyable with fine pitch formation correspondence or metal foil alone.

In the first flexible metal laminate of the present invention, the resin layer 11 is divided into two layers in a portion having a thickness of 1/2, as shown in FIGS. 1B to D, and the side of the contact surface 13 with the metal layer 10 is removed. When the first sample 11a and the remainder are the second samples 11b, the intrusion displacement amount L1 when the first sample 11a enters the first sample 11a from the contact surface 13 with the metal layer 10 is the metal layer 10. ) Is smaller than the intrusion displacement amount L2 at the time of invading the second sample 11b from the surface 12 (herein referred to as &quot; outermost surface &quot; for convenience).

In the present invention, the “intrusion displacement amount” refers to an intrusion probe having a tip of 1 mm × 1 mm angle using a TMA (Thermo Mechanical Analyzer). It is the displacement amount of the probe in 300 degreeC measured by the measurement conditions of mN and a temperature increase rate: 20 degree-C / min.

As TMA, the brand name of EXII6100TMA / SS made from SII Nanotechnologies Corporation is used suitably, for example.

In addition, the kind, load, temperature increase rate, measurement temperature, etc. of the probe were all determined in consideration of the conditions of the joining method by the COF bonder shown in FIG.

That is, the needle probe corresponds to the bump in the protruding state. By measuring the amount of intrusion displacement under such conditions, the resin layer state when the bump and the wiring are connected can be expressed numerically.

Specifically, it measures in the following procedure, for example.

First, two flexible metal laminates of the structure shown in FIG. 1A are prepared.

Next, for the two flexible metal laminates, as shown in FIG. 1B, the metal layer 10 is removed to form only the resin layer 11. Chemical etching or the like can be applied to the removal of the metal layer 10. For example, when the metal layer 10 which consists of copper foil is used, it can remove by ferric chloride solution etc.

And the 1st sample 11a is obtained from one resin layer 11 as follows. That is, the film thickness T0 of the resin layer 11 is measured about the said resin layer 11 using a micrometer, and the film thickness T1 of 1/2 is computed.

And the resin layer 11 is polished until it becomes the film thickness T1 from the outermost surface 12 side by methods, such as mechanical polishing, measuring a film thickness with a micrometer.

Thereby, the 1st sample 11a by the side of the contact surface 13 with the metal layer 10 can be obtained.

And about the other resin layer 11, the 2nd sample 11b is obtained as follows.

That is, when the resin layer 11 is made to be the same as the procedure of obtaining the 1st sample 11a, and this time the resin layer 11 becomes the film thickness T1 from the contact surface 13 side with the metal layer 10 this time. Polish until Thereby, the 2nd sample 11b by the outermost surface 12 side on the opposite side to the metal layer 10 can be obtained.

After leaving the first sample 11a in a 23 ± 5 ° C. and 55 ± 5% relative humidity environment for 24 hours or more, as shown in FIG. 1C, the probe 20 is pressed from the contact surface 13 side. The penetration displacement is measured up to 400 ° C while the temperature is raised at 20 ° C / min. The intrusion displacement amount at the point of reaching 300 ° C is referred to as the intrusion displacement amount L1.

On the other hand, the second sample 11b is also left for 24 hours or more in a 23 ± 5 ° C and 55 ± 5% relative humidity environment, and as shown in FIG. 1D, the probe 20 is moved from the outermost surface 12 side. It presses and measures penetration amount to 400 degreeC, heating up at 20 degree-C / min. The intrusion displacement amount at the point of reaching 300 ° C is referred to as the intrusion displacement amount L2.

In the present invention, the intrusion displacement amount L1 is set to a value smaller than the intrusion displacement amount L2. That is, in the resin layer 11, the displacement amount when crimping the needle-shaped probe 20 from the contact surface 13 side is smaller than the displacement amount crimping the probe 20 from the outermost surface 12 side.

Therefore, when manufacturing a flexible printed circuit board using the said flexible metal laminated body, in the outermost surface 12 side, at the contact surface 13 side, maintaining the required flexibility (flexibility) as a flexible substrate, Even if the needle-like material such as the probe 20 is pressed, rather than the outer surface 12 side, the resin layer 11 is hardly deformed. Therefore, even if the bumps are strongly pressed against the resin layer 11 through the wiring formed of the metal layer 10 under high temperature conditions, deformation of the resin layer 11 and the like can be suppressed.

As a result, as described above, it is possible to prevent the problem that the wiring and the bumps are caught in the resin layer 11 or the underfill cannot be filled thereby. In addition, edge short circuits in which the wiring contacts the IC chip can be suppressed.

In addition, the separation of the outermost surface 12 side and the contact surface 13 side and measuring the intrusion displacement amount with respect to the first sample 11a and the second sample 11b, respectively, is the outermost surface 12 side and the contact surface 13. This is to accurately evaluate the characteristics of the side.

If the probe 20 is crimped from the outermost surface 12 side and the contact surface 13 side with respect to the whole resin layer 11 without measuring the resin layer 11, and the penetration displacement is measured, a 1st sample The portion corresponding to 11a and the portion corresponding to the second sample 11b are influenced by each other. Therefore, the characteristic of each of the outermost surface 12 side and the contact surface 13 side cannot be evaluated correctly.

The value of the intrusion displacement amount L1 and the intrusion displacement amount L2 is preferable although the absolute value dL therebetween is 2 m or more. Preferably it is 5 micrometers or more, More preferably, it is 10 micrometers or more. By setting it as this range, the function of the outermost surface 12 side and the function of the contact surface 13 side are exhibited effectively each, and very preferably the deformation | transformation of the resin layer 11 etc. under high temperature conditions with flexibility is carried out. The inhibitory effect can be improved.

Moreover, it is preferable that it is 0-6 micrometers, and, as for the value of the penetration displacement L1 in consideration of the characteristic of the outermost surface 12 side and the contact surface 13 side, it is more preferable that it is 0-3 micrometers especially.

In consideration of the characteristics of the outermost surface 12 side and the contact surface 13 side, the value of the intrusion displacement amount L2 is preferably 2 to 15 µm, more preferably 2 to 10 µm.

In addition, the thickness T0 of the resin layer 11 is preferably 12 to 75 µm, more preferably from the viewpoint of flexibility and flexibility (flexibility) from the viewpoints of bendability and tensile strength required for conveying the flexible metal laminate. Preferably it is 12-50 micrometers.

The resin layer 11 having the characteristic that the penetration displacement amount L1 is smaller than the penetration displacement amount L2 can be produced by laminating a plurality of different kinds of resins in some cases. For example, as shown in FIG. 2, the resin layer 11 is comprised by multiple layers like the 1st layer 14 and the 2nd layer 15. As shown in FIG.

Preferably, for example, one or both of the layer constituting the contact surface 13 and the layer adjacent thereto are constituted by a layer (hereinafter referred to as a "displacement prevention layer" for convenience) having an effect of reducing the amount of intrusion displacement. do. In addition, "displacement prevention layer" is set as the layer which does not comprise outermost surface 12. As shown in FIG.

The displacement preventing layer is made of a resin material having a high "glass potential point (Tg)". Or it consists of a resin material with large "storage modulus (E ') in dynamic viscoelasticity measurement." In particular, it is preferable to constitute a resin material having a high glass potential Tg and a large storage modulus E '.

The glass potential temperature (Tg) of the resin material constituting the displacement preventing layer is measured by the dynamic viscoelasticity as described below, and the peak temperature of the peak when the result is plotted as a graph of the relationship between the temperature and the loss factor (tanδ). Peak top temperature).

In practice, the peak top temperature is automatically detected by the measuring device.

That is, using a forced vibration non-resonant viscoelasticity meter (Orientech Co., Ltd., brand name: Leo Vibratorron), measurement conditions: vibration frequency 11 Hz, static tension 3.0 gf, sample size 0.5 mm (width). At a temperature of 30 mm (length) x 20 μm (thickness), the temperature is raised at a temperature rising rate of 10 deg.

In the resin material constituting each layer of the resin layer, for example, two or more peak top temperatures may exist when a resin having different mass average molecular weights is mixed. And it is preferable that at least one of peak top temperature is 300 degreeC or more.

The glass transition point (Tg) of the resin material which comprises a displacement prevention layer is so preferable that it is high, More preferably, glass transition point (Tg) of 330 degreeC or more exists. More preferably, the glass potential point (Tg) of 350 degreeC or more exists.

Moreover, when several glass potential points Tg exist, it is preferable that all the glass potential points Tg are 300 degreeC or more in the point which prevents deformation, etc. at the time of high temperature treatment.

The storage modulus (E ') of the resin material constituting the displacement preventing layer is a measured value at a temperature of 300 ° C. in the dynamic viscoelasticity measurement by a forced vibration non-resonant type viscoelasticity meter (Orientech Co., Ltd., brand name: Leo Vibrator Ron). to be.

The specific measurement conditions were the same as the glass potential point (Tg), and the excitation frequency was 11 Hz, the static tension was 3.0 gf, and the sample size was 0.5 mm (width) x 30 mm (length) x thickness 20 (μm) under normal temperature and humidity environment. The temperature increase rate is raised to 10 ℃ / min. And the measured value at 300 degreeC is calculated | required.

The storage modulus (E ') is preferably 1 GPa or more, more preferably 3 GPa or more. The upper limit is not particularly limited, but is substantially 10 GPa or less.

The storage modulus (E ′) and the glass potential point (Tg) can be adjusted by changing the type (chemical structure) and mass average molecular weight (Mw) of the resin, as the case may be.

It is preferable that it is 2-20 micrometers, for example, and, as for the thickness of a displacement prevention layer in adjusting the intrusion displacement amount L1 to an appropriate range, it is more preferable that it is 5-15 micrometers.

Moreover, it is preferable from a viewpoint of heat resistance improvement to make the layer adjacent to the layer which comprises the contact surface 13 into a displacement prevention layer.

In this case, the layer which comprises the contact surface 13 can be manufactured from resin which has the same characteristic as the material of layers other than the displacement prevention layer shown below.

At this time, the thickness of the layer constituting the contact surface 13 is preferably about 2 to 10 m from the viewpoint of exerting the effect of the displacement preventing layer provided adjacent thereto.

Similarly, when the resin layer 11 is constituted of a plurality of layers, it is easy to control the characteristics of the flexible metal laminate. Preferably, it is preferable to comprise the resin layer 11 by 2 to 5 layers, and when considering cost savings, such as a resin laminated product ratio, 2-3 layers are more preferable.

It is preferable that layers other than a displacement prevention layer are comparatively soft layers which exhibit flexibility.

For example, although the glass potential point (Tg) of the resin material which comprises layers other than a displacement prevention layer is preferable to some extent high, it is preferable that it is a range 300 degreeC or more.

Moreover, the storage modulus (E ') of the resin material which comprises layers other than a displacement prevention layer is 0.1-5 GPa, Preferably it is 0.5-3 GPa.

Moreover, in the whole resin layer 11, it is preferable from a viewpoint of heat resistance improvement to satisfy the following characteristics. That is, when the whole resin layer 11 is used as a measurement sample, the penetration displacement amount L0 from the contact surface 13 is preferably 10 μm or less, more preferably 8 μm or less, and even more preferably 5 μm or less. Do. Thereby, the deformation | transformation of the resin layer 11 at the time of high temperature, etc. can be suppressed more effectively.

Intrusion displacement amount L0 makes the resin layer 11 after removing metal layer 10 as the sample for (L0) measurement as demonstrated in the measuring method of intrusion displacement amount L1. And with respect to this sample, the probe 20 can be crimped and measured from the contact surface 13 side similarly to the above-mentioned 1st sample 11a.

Moreover, when the whole resin layer 11 is used as a measurement sample, the storage modulus (E ') at 300 degreeC becomes like this. Preferably it is 1 GPa or more, Especially preferably, it is 3 GPa or more. The upper limit is not particularly limited, but is substantially 10 GPa or less. If it is this range, especially the deformation of the resin layer 11 at the time of high temperature, etc. can be suppressed effectively.

The storage modulus (E ') at this time can be measured by the same measuring method for every resin material mentioned above using the same sample as the sample for (L0) measurement. In addition, although the thickness of a sample is prescribed | regulated by each measuring method of the above-mentioned resin material, when measuring with respect to the whole resin layer 11, it is not necessary to change the thickness of the resin layer 11 especially.

In addition, since the resin layer 11 is made by laminating a plurality of different types of resin materials, for example, when the entire resin layer 11 is measured as a measurement sample, a plurality of glass potential points Tg exist. There is. And when measuring with the whole resin layer 11, it is preferable that at least 1 point of the resin layer 11 has the glass potential point (Tg) of 300 degreeC or more. More preferably, there is a glass potential point (Tg) of 330 ° C. or more. In particular, it is preferable that the glass potential point (Tg) of 350 degreeC or more exists.

In addition, when there are a plurality of glass potential points Tg, it is preferable that all the glass potential points Tg are 300 degreeC or more in the point which prevents deformation, etc. at the time of high temperature treatment.

The glass potential point Tg can be measured by the same measuring method for every resin material mentioned above using the same sample as the sample for (L0) measurement. In addition, although the thickness of a sample is prescribed | regulated by each measuring method of the above-mentioned resin material, when measuring with respect to the whole resin layer 11, it is not necessary to change the thickness of the resin layer 11 in particular.

The resin constituting the resin layer 11 does not need to be particularly limited as long as it can obtain the bendability and tensile strength necessary for conveying the flexible metal laminate and can provide flexibility. In this invention, a thermoplastic resin is used suitably from a viewpoint of workability and flexibility.

In addition, in manufacturing, since thermoplastic resin is easy to operate, it is preferable that a thermoplastic resin is soluble in an organic solvent. "Solubility" means here melt | dissolving 1 mass% or more in the organic solvent with respect to the temperature range of room temperature-100 degreeC.

Specifically, heat resistant thermoplastic resins, such as a polyimide resin, a polyamideimide resin, a polyether imide resin, a polysiloxane imide resin, a polyether ketone resin, and a polyether ether ketone resin, are mentioned, for example.

More preferably, the polyimide resin, the polyamideimide resin, the polyetherimide resin, the polysiloxane imide resin, the polyether ketone resin which is soluble with respect to the organic solvent, and the deshrinkment polymerization reaction, such as imidation reaction, was fully completed, Polyether ether ketone resins are preferred.

More preferably, it is a thermoplastic resin which consists of at least 1 sort (s) chosen from polyimide resin, polyamideimide resin, polyetherimide resin, and polysiloxane imide resin.

Moreover, resin which comprises the resin layer 11 can be used 1 type or in mixture of 2 or more types.

Moreover, the mass mean molecular weight of resin is chosen in the range of 20000-150000, for example.

Moreover, you may comprise one or more layers which comprise the resin layer 11 by the three-dimensional crosslinking type thermosetting resin in the range which does not lose the effect of this invention.

In that case, in order to promote the thermosetting of the three-dimensional crosslinking type thermosetting resin layer, a curing accelerator such as an organic peroxide or Lewis acid compound may be added.

In addition, a phosphate ester compound, a nitrogen ester compound, and a halogenated epoxy resin may be added to the resin layer 11 to impart flame retardancy.

Moreover, an organic filler, an inorganic filler, etc. can also be added for linear expansion control etc.

However, it is preferable to mix | blend an organic filler and an inorganic filler not with the contact surface 13 side but the layer of the outermost surface 12 side. Moreover, it is more preferable to add to the outermost layer which comprises the outermost surface 12. FIG. By mix | blending an organic filler and an inorganic filler, the conveyability at the time of the manufacturing process of a flexible printed circuit board can be improved.

As a filler, an inorganic filler is especially preferable, Especially preferably, it is colloidal silica, silicon nitride, talc, titanium oxide, calcium phosphate etc. of 0.005-5 micrometers of average particle diameters, More preferably, it is 0.005-2 micrometers.

The compounding quantity is made into 0.1-3 mass parts with respect to 100 mass parts of resin of the layer to add, for example.

[2nd flexible metal laminated body]

An example of a structure of the 2nd flexible metal laminated body of this invention is demonstrated using FIG. Similarly to the first flexible metal laminate, the second flexible metal laminate is also composed of the metal layer 10 and the resin layer 11 laminated on one surface thereof.

In this example, the resin layer 11 and the first layer (layer adjacent to the metal layer 10) 14 constituting the contact surface 13 with the metal layer 10 stacked on the metal layer 10. It has a two-layer structure which consists of the 2nd layer (outermost layer) 15 which comprises the outermost surface 12 laminated | stacked on it.

As a metal which comprises the metal layer 10, copper, stainless steel, aluminum, nickel, steel, etc. are mentioned similarly to the metal used for the said 1st flexible metal laminated body.

Especially, using metal foil is very suitable. By using metal foil, generation of a pinhole can be suppressed. Therefore, wiring defects can be reduced. Therefore, the effect of the product ratio improvement and the electrical reliability can be obtained. Moreover, when metal foil is used, the outstanding effect that it is hard to peel between a resin layer and a metal layer (wiring) can be acquired even if it heats continuously at high temperature continuously.

And it is preferable to use 1 or more types chosen from the group which consists of copper foil, stainless foil, aluminum foil, and nickel foil among metal foil.

More preferably, the electrolytic copper foil which can have a favorable etching characteristic and respond | corresponds to fine pitch, the rolled copper foil which can improve high bendability, the ultra-thin copper foil which makes copper foil which can improve the process conveyance of copper foil as a carrier, etc. Can be mentioned.

The thickness of a metal layer becomes like this. Preferably it is 3-50 micrometers, More preferably, it is 3-35 micrometers. Moreover, it is preferable to set it as 8-18 micrometers which can be conveyed by correspondence to a fine pitch and metal foil alone.

In the second flexible metal laminate of the present invention, the hygroscopic expansion coefficient C _HO of the outermost layer (second layer 15) of the resin layer 11 is adjacent to the metal layer 10 of the resin layer 11. It is characterized by being smaller than the hygroscopic expansion coefficient (C _HM ) of the layer (first layer 14).

Thereby, the reduced deformation of the resin layer 11 can be suppressed, and the problem accompanying this can be reduced.

The reason why such an effect can be acquired can be estimated as follows.

That is, the resin layer of the conventional flexible metal laminated body uses resin which is hygroscopic to some extent from the viewpoint of ensuring the flexibility (flexibility) as the flexible printed circuit board. Therefore, after manufacturing a flexible metal laminated body, it becomes a flexible printed circuit board, and a resin layer absorbs moisture until it processes, such as joining with an IC chip, and contains some moisture.

In the case where the flexible printed circuit board and the IC chip are bonded as described above, the reduced deformation of the resin layer when the bump or the like is pressed under high temperature under high temperature conditions is reduced in the resin layer of the flexible printed circuit board. This is due to the fact that the moisture present in the vicinity of the film is released from the resin layer to the outside when the bumps and the like are compressed at high pressure under high temperature conditions, thereby rapidly decreasing the vicinity of the wiring (metal layer) of the resin layer. It can be considered.

Therefore, as in the second flexible metal laminate of the present invention, the outermost layer opposite to the metal layer has a property that is hard to absorb moisture, whereby a portion adjacent to the metal layer is protected by the metal layer and the outermost layer. As a result, after the flexible metal laminate is manufactured, it can be stored in the vicinity of the resin layer in contact with the metal layer (wiring) until processing such as processing on a flexible printed circuit board and connecting with an IC chip. Reduce the amount of water

Therefore, even when the bumps and the like are compressed at a high pressure under high temperature conditions, the amount of water is originally reduced, so that the phenomenon of sudden release of water and shrinkage and deformation in the vicinity of contact with the metal layer (wiring) of the resin layer can be prevented. .

In the resin layer 11, the moisture absorption expansion coefficient C _HM of the layer (first layer 14) adjacent to the metal layer 10 and the outermost layer of the resin layer 11 (second layer 15) The difference (C _HM -C _HO ) from the hygroscopic expansion coefficient (C _HO ) is 10 × 10 ⁻⁶ /% RH or more, more preferably 15 × 10 ⁻⁶ /% RH or more, substantially 25 × 10 ^{−H 6} /% RH or less. By setting it as this range, the characteristic which prevents moisture absorption in the 2nd layer 15 is expressed, and the flexibility in the 1st layer 14 can be exhibited.

The value of the hygroscopic expansion coefficient (C _HO ) of the outermost layer (second layer 15) is preferably 5 × 10 ⁻⁶ /% RH to 35 × 10 ⁻⁶ /% RH from the viewpoint of the effect thereof. For example, 10 × 10 ^-6 /% RH to 25 × 10 ^-6 /% RH. By setting it as this range, moisture absorption can be suppressed effectively and the effect of this invention improves.

The hygroscopic expansion coefficient (C _HM ) of the layer (first layer 14) adjacent to the metal layer 10 is preferably 15 × 10 ⁻⁶ /% RH to 60 × 10 ⁻⁶ /% RH, more preferably Is ^15x10-6 /% RH to ^50x10-6 /% RH.

By setting it as this range, the flexibility (flexibility) required for a flexible printed circuit board can be maintained.

The moisture absorption expansion coefficient C _HM of the layer (first layer 14) adjacent to the metal layer 10 is measured as follows.

The first layer 14 is formed on the metal layer 10. Next, the metal layer 10 is removed and a sample for measurement composed of only the first layer 14 is obtained. The size of the sample for measurement shall be 70 mm long x 70 mm wide. The thickness is made the same as the thickness of the 1st layer 14 when it is set as a flexible metal laminated body.

Chemical etching or the like can be applied to the removal of the metal layer 10. For example, when the metal layer 10 made of copper foil is used, it can remove with a ferric chloride solution or the like.

Subsequently, one mark was made on the surface of the side which was not in contact with the metal layer 10 of the measurement sample in the MD direction (the direction in which the crystal is oriented), and the distance between the two points was 55 mm. Mark the point. Also in the TD direction (the direction orthogonal to the MD direction), marking is performed so that the distance between the two points is 55 mm.

Subsequently, the phosphorus pentaoxide powder was put into the desiccator, and it was made into 23 degreeC 0% relative humidity atmosphere state, the sample for measurement was put to stand for 72 hours, and the sample for measurement between two points marked in MD direction was left to stand. The distance is measured with a three-dimensional digital dimension meter. Let this measurement be (MD0).

Similarly, the distance between two points marked in the TD direction is measured with a three-dimensional digital dimension measuring instrument. Let this measurement be (TD0).

Subsequently, after the measurement, the measurement sample was placed in a constant temperature and humidity chamber under an atmosphere of 23 ° C. 80% relative humidity, and the humidity was adjusted for 72 hours. Similarly, the distance between the two points marked in the MD direction and the two points marked in the TD direction Measure The measured value of MD direction is set to (MD80). The measured value of TD direction is set to (TD80).

Then, the hygroscopic expansion coefficient (C _HM ) is obtained by the following equation.

C _HM = [(TD80)-(TD0)] / (TD0) ÷ 80 (× ^10-6 /% RH)

However, the measurement conditions were determined assuming that they were stored under severe conditions of high humidity.

The moisture absorption expansion coefficient C _HO of the outermost layer (2nd layer 15) of the resin layer 11 is measured as follows.

On the metal layer 10, the 2nd layer 15 is directly laminated | stacked, the metal layer 10 is removed similarly to the case of the 1st layer 14, and it is set as the sample for a measurement. The size of the sample for measurement shall be 70 mm long x 70 mm wide. The thickness is made the same as the thickness of the 2nd layer 15 when it is set as a flexible metal laminated body.

Hereinafter, the hygroscopic expansion coefficient C _HO is measured in the same manner as in the first layer 14.

In addition, in consideration of the bendability, tensile strength, and flexibility required at the time of conveyance of the flexible metal laminate, the thickness T0 of the resin layer 11 is preferably 12 to 75 µm, more preferably 12 to 50 µm. .

And ratio (T1) / (T0) of thickness T1 of outermost layer (2nd layer 15) and thickness T0 of the whole resin layer 11 is 35/100 or more and 95/100 or less, Preferably Preferably it is 5/100 or more and 75/100 or less. By making thickness of outermost layer (2nd layer 15) into this range, the effect by outermost layer (2nd layer 15) improves. In addition, it is easy to ensure appropriate flexibility by the layer (first layer 14) adjacent to the metal layer 10.

In order to effectively prevent moisture absorption by the outermost layer (second layer 15), the thickness T1 of the outermost layer (second layer 15) is preferably 4 to 70 µm, more preferably 6 to 50 µm. .

In addition, the resin layer 11 is not limited to a two-layer structure, For example, it is preferable to comprise two to five layers, and 2-3 layers are more preferable from a cost point of view, such as a product ratio of a laminated structure.

In the case of three or more layers, the moisture absorption expansion coefficient C _HM of the layer adjacent to the metal layer 10 (the layer constituting the contact surface 13) and the moisture absorption expansion coefficient of the outermost layer constituting the outermost surface 12 on the opposite side thereof. As long as the relationship with (C _HO ) satisfies the conditions of the present invention.

In the case of a three-layer structure or more, the characteristics of the layer to be interposed between the layer (first layer 14) and the outermost layer (second layer 15) adjacent to the metal layer 10 are not particularly limited. For example, it can be set as the same characteristic as the 1st layer 14 which ensures flexibility, and can also be made into the same characteristic as the 2nd layer 15 which suppresses moisture absorption. However, it is preferable to provide a layer having a moisture absorption expansion coefficient smaller than that of the first layer 14 in that the effect of the present invention is improved and the degree of dimension is improved.

Moreover, in this invention, the absolute value which is a difference between the linear thermal expansion coefficient and the linear thermal expansion coefficient of the metal layer 10 when using the whole resin layer 11 as a sample for a measurement is less than ^10x10 <^-6> / degreeC, especially preferable. Preferably it is 5x10 <^-6> / degrees C or less.

As described above, when the difference in the coefficient of linear expansion between the resin layer 11 and the metal layer 10 is small, there is a problem that the resin layer 11 is greatly deformed under high temperature conditions and the relative positional relationship with the metal layer 10 is shifted. It can be suppressed. As a result, the effect of the present invention can be improved.

The linear expansion coefficient of the whole resin layer 11 is measured as follows.

A flexible metal laminate in which the metal layer 10 and the resin layer 11 are laminated is prepared. Then, as in the measurement of the hygroscopic expansion coefficient, the metal layer 10 is removed and only the resin layer 11 is used as a sample for measurement.

The size of the sample for measurement shall be 70 mm long x 70 mm wide.

And this measurement sample is measured according to the average linear expansion rate calculation method in JISKK7197.

Specifically, the TMA tensile measurement was performed by a thermomechanical analyzer (TMA) (trade name: TMA7 manufactured by Shinkuriko Co., Ltd.), and the average linear expansion coefficient at 50 ° C to 250 ° C was used as the coefficient of linear thermal expansion.

The measurement conditions are as follows.

Sample shape: 5 mm width x 15 mm length, initial length: 15 mm, load: 9.8 mN, temperature increase rate: 10 deg. C / min, measurement environmental conditions: The temperature is raised in a normal temperature and humidity environment.

In addition, the measurement conditions were determined in consideration of the conditions etc. at the time of bonding with an IC chip.

The linear expansion coefficient of the metal layer 10 is measured similarly to the measuring method of the said resin layer 11 whole. The sample for a measurement uses the metal foil which comprises the metal layer 10, for example. The size of the sample for measurement shall be 70 mm long x 70 mm wide.

In the case of using a sample for measurement other than the metal foil, the resin layer 11 is dissolved from the flexible metal laminate by immersing the flexible metal laminate in an alkaline solution such as an aqueous 10% by weight sodium hydroxide solution to dissolve the resin layer 11. Remove 11) to make a sample for measurement.

Adjusting the hygroscopic expansion coefficient C _HO of the outermost layer (second layer 15) to a value smaller than the hygroscopic expansion coefficient (C _HM ) of the layer (first layer 14) in contact with the metal layer 10. For example, the outermost layer (second layer 15) is made of a resin material having a high "glass transition point (Tg)". Or it consists of a resin material with large "storage modulus (E ') in dynamic viscoelasticity measurement." In particular, it is preferable to comprise a resin material having a high glass transition point (Tg) and a large storage modulus (E ').

When the glass transition point (Tg) of the resin material constituting the outermost layer (second layer 15) is subjected to dynamic viscoelasticity measurement as follows, the result is a graph of the relationship between the temperature and the loss factor (tanδ). Is the peak temperature (peak top temperature) of the peak. In practice, the peak top temperature is automatically detected by the measuring device.

That is, using a forced vibration non-resonant viscoelasticity measuring instrument (Orientech Co., Ltd., brand name: Leo Vibrator Ron), measurement conditions: vibration frequency 11 Hz, static tension 3.0 gf, sample size 0.5 mm (width) x 30 mm ( Length) x thickness 20 (μm), the temperature is raised at a temperature rising rate of 10 deg.

In the resin material which comprises each layer of a resin layer, two or more peak top temperatures may exist, for example when mixing resin with a different mass mean molecular weight. And it is preferable that at least 1 point is 300 degreeC or more.

The higher the glass transition point (Tg) of the resin material constituting the outermost layer (second layer 15) is, the more preferable, and more preferably, a glass transition point (Tg) of 330 ° C or more is present, particularly 350 ° C. It is preferable that the above glass transition point (Tg) exists.

Moreover, when a some glass transition point Tg exists, it is preferable that all the glass transition points Tg are 300 degreeC or more from a viewpoint of prevention of shrinkage deformation at the time of high temperature processing.

The storage modulus (E ') of the resin material constituting the outermost layer (second layer 15) is determined by dynamic viscoelasticity measurement by a forced vibration non-resonant viscoelasticity meter (Orientech Co., Ltd., brand name: Leo Vibrator Ron). It is a measured value of the temperature of 300 degreeC.

The specific measurement conditions are the same as those of the glass transition point (Tg), and the vibration frequency is 11 Hz, the static tension is 3.0 gf, and the sample size is 0.5 mm (width) x 30 mm (length) x thickness 20 (μm) under normal temperature and humidity environment. The temperature is increased at a temperature increase rate of 10 deg. And the measured value at 300 degreeC is calculated | required.

The storage modulus (E ') is preferably 1 GPa or more, particularly preferably 3 GPa or more. Although the upper limit is not particularly limited, it is substantially 10 GPa or less.

Storage modulus (E ') and glass transition point (Tg) can be adjusted by changing the kind (chemical structure) and mass average molecular weight (Mw) of resin, for example.

On the other hand, in the 1st layer 14 which contact | connects the metal layer 10, although the glass transition point Tg of the resin material which comprises the 1st layer 14 is preferable to some extent high, it is 300 It is preferable that it is the range of ° C or higher.

Moreover, the storage modulus (E ') of the resin material which comprises the 1st layer 14 becomes like this. Preferably it is 0.1-5 GPa, It is preferable that it is 0.5-3 GPa especially.

Moreover, in the whole resin layer 11, it is preferable from a viewpoint of heat resistance improvement to satisfy the following characteristics.

When the whole resin layer 11 is made into the sample for a measurement, the storage modulus (E ') at 300 degreeC becomes like this. Preferably it is 1 GPa or more, More preferably, it is 3 GPa or more. Although the upper limit is not particularly limited, it is substantially 10 GPa or less. If it is this range, especially the shrinkage distortion of the resin layer 11 at the time of high temperature can be suppressed effectively.

The storage modulus (E ') at this time can be measured by the same measuring method for every resin material using the measurement sample which removed the metal layer 10 in the flexible metal laminated body. In addition, although the thickness of a sample is prescribed | regulated by each measuring method of the above-mentioned resin material, when measuring with respect to the whole resin layer 11, it is not necessary to change the thickness of the resin layer 11 specially.

In addition, since the resin layer 11 is laminated | stacked the resin material of a different kind from multiple layers, for example, when the whole resin layer 11 is measured as a sample for a measurement, a plurality of glass transition points Tg exist. There is a case. And when measuring as the whole resin layer 11, it is preferable that the resin layer 11 has a glass transition point (Tg) of at least 1 point or more and 300 degreeC or more. More preferably, the glass transition point (Tg) of 330 degreeC or more exists. In particular, it is preferable that the glass transition point (Tg) of 350 degreeC or more exists.

Moreover, when a some glass transition point Tg exists, it is preferable that all the glass transition points Tg are 300 degreeC or more from a viewpoint of prevention of shrinkage deformation at the time of high temperature processing.

The glass transition point Tg can be measured similarly to the measuring method for every resin layer using the measurement sample which removed the metal layer 10 in the flexible metal laminated body. However, although the thickness of the measurement sample is prescribed | regulated by each measuring method of the above-mentioned resin material, when measuring with respect to the whole resin layer 11, it is not necessary to change the thickness of the resin layer 11 specially.

The resin constituting the resin layer 11 need not be particularly limited as long as it can obtain the bendability and tensile strength necessary for conveyance of the flexible metal laminate and can provide flexibility. In this invention, a thermoplastic resin is used suitably from a point of workability and flexibility.

In addition, since the operation | movement, such as coating at the time of manufacture is easy, it is preferable that a thermoplastic resin is soluble in an organic solvent. "Solubility" means here melt | dissolving 1 mass% or more in the organic solvent with respect to the temperature range of room temperature-100 degreeC.

Specifically, heat resistant thermoplastic resins, such as a polyimide resin, a polyamideimide resin, a polyether imide resin, a polysiloxane imide resin, a polyether ketone resin, and a polyether ether ketone resin, are mentioned, for example.

More preferably, the polyimide resin, the polyamideimide resin, the polyetherimide resin, the polysiloxane imide resin, the polyether ketone resin, which is soluble with respect to the organic solvent, and the deshrinkable polymerization reaction, such as imidation reaction, was fully completed, Polyether ether ketone resins are preferred.

More preferably, it is a thermoplastic resin which consists of at least 1 sort (s) chosen from polyimide resin, polyamideimide resin, polyetherimide resin, and polysiloxane imide resin.

Moreover, resin which comprises the resin layer 11 can be used 1 type or in mixture of 2 or more types.

Moreover, the mass mean molecular weight of resin is chosen in the range of 20000-150000, for example.

Moreover, you may comprise one or more layers which comprise the resin layer 11 by the three-dimensional crosslinking type thermosetting resin in the range which does not lose the effect of this invention.

In that case, in order to promote the thermosetting of the three-dimensional crosslinking type thermosetting resin layer, a curing accelerator such as an organic peroxide or Lewis acid compound may be added.

In addition, a phosphate ester compound, a nitrogen ester compound, and a halogenated epoxy resin may be added to the resin layer 11 to impart flame retardancy.

Moreover, an organic filler, an inorganic filler, etc. can also be added for linear expansion control etc.

However, it is preferable to mix | blend an organic filler and an inorganic filler not with the contact surface 13 side but the layer of the outermost surface 12 side. Moreover, it is more preferable to add to the outermost layer (2nd layer 15) which comprises the outermost surface 12. FIG. By mix | blending an organic filler and an inorganic filler, the conveyability at the time of the manufacturing process of a flexible printed circuit board can be improved.

As the filler, inorganic fillers are preferred, and particularly preferably colloidal silica, silicon nitride, talc, titanium oxide, calcium phosphate, or the like having an average particle size of 0.005 to 5 µm, more preferably 0.005 to 2 µm.

The compounding quantity is made into 0.1-3 mass parts with respect to 100 mass parts of resin of the layer to add, for example.

[Manufacturing method of a 1st and 2nd flexible metal laminated body]

As a method of manufacturing a 1st and 2nd flexible metal laminated body, the following methods are mentioned, for example.

A resin solution dissolved in an organic solvent on a metal layer such as copper foil is applied by casting, dip, spraying or the like, and the organic solvent is dried to form one layer. In particular, it is preferable to apply | coat by casting in order to make thickness uniform.

The organic solvent may be any organic solvent in which resin can be soluble, and only one kind of solvent may be used, or may be suitably used in two or more kinds of mixed solvents.

For example, pyrrolidone solvents such as N-methyl-2-pyrrolidone and N-vinyl-2-pyrrolidone, acetamides such as N, N-dimethylacetamide, N, and N-diethylacetamide Polar solvents, such as foam amide type solvents, such as a type | system | group solvent, N, N- dimethyl formamide, N, N- diethyl formamide, and a slewoxy seed type solvent, such as dimethyl thrukiside and diethyl thrucoxide, are mentioned. have. In addition to these relatively high boiling point solvents, ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone and cyclohexanone, toluene and xylene aromatic solvents, tetrahydro, and the like, have no problem in solubility of the coating resin. Ether-based solvents such as franc, dioxane, diclime, and triglyceride can also be used as a mixed solvent.

Hereinafter, the above application and drying operations are repeated to form a resin layer 11 having a plurality of layers. Moreover, it can apply continuously so that it may not mix between multiple layers.

The coating machine is not limited as long as it can be applied at a desired thickness of the resin layer. As an example, the coating machine which can apply | coat a dam coater, a die coater, a reversor coater, a lip coater, a gravure coater, a comma coater etc. to a thickness of a desired resin layer individually or in combination with each coating head is mentioned.

Moreover, in application | coating, you may use two or more coating heads.

In a more preferable method, after apply | coating a resin solution on the metal layer 10, the operation of initial drying is repeated until the surface of the layer has no turbidity, and after forming the resin layer 11 which consists of multiple layers, In order to control the heat resistance of the resin and the bending recovery property of the flexible metal laminate, the organic solvent is removed at a temperature at which the organic solvent can be completely removed under reduced pressure or an oxygen-free atmosphere.

[Flexible printed board]

The flexible printed circuit board of the present invention uses the first or second flexible metal laminate of the present invention. For example, in the configuration shown in FIG. 1, the metal layer 10 is processed by plating treatment or the like to form wiring. You can get it.

As described above, in the present invention, in a flexible metal laminate used for the application of pressing projections such as bumps under high temperature conditions and a flexible printed circuit board using the same, problems associated with deformation of the resin layer and the like can be solved. A flexible metal laminate and a flexible printed circuit board using the same can be provided.

That is, in the case of a flip chip bonding method, in particular, in a high temperature condition such as a COF mounting, when a bump-like projection is used in a process of strongly compressing the resin layer through a metal layer or a metal wiring formed of the metal layer, Problems such as deformation can be solved. Therefore, the inconvenience of filling of underfill and the problem of an edge short can also be suppressed.

EXAMPLE

EXAMPLES Hereinafter, although an Example is shown concretely, this invention is not limited to these.

<Polyimide resin solution: A>

Polyimide resin (product of PI R & D Corporation, brand name: Q-VR-FP007, glass transition point 330 ° C) is dissolved in N-methyl-2-pyrrolidone so as to have a solid content concentration of 12% by mass, and a polyimide resin solution ( Hereinafter, "resin solution A" was obtained.

<Polyimide resin solution: B>

Polyamideimide resin (product of Toyo Boseki Co., Ltd., brand name: Viromax HR16NN, glass transition point 320 degreeC) is melt | dissolved in N-methyl- 2-pyrrolidone so that solid content concentration may be 12 mass%, and the polyamideimide resin solution ( Hereinafter, "resin solution B" was obtained.

<Polyimide resin solution: C>

A polyamideimide resin (manufactured by Toyo Boseki Co., Ltd., product name: Viromax N003TM, glass transition point 370 ° C.) was dissolved in N-methyl-2-pyrrolidone so as to have a solid content concentration of 12% by mass, and a polyamideimide resin solution ( Hereinafter, "resin solution C" was obtained.

<Polyimide resin solution: D>

100 g of the polyimide resin solution A300 and the polyamideimide resin solution C were mixed and stirred to obtain a polyimide resin solution (hereinafter referred to as "resin solution D").

<Polyimide resin solution: E>

200 g of the said polyimide resin solution A200 and the said polyamide-imide resin solution C were mixed and stirred, and the polyimide resin solution (henceforth "resin solution E") was obtained.

<Polyimide resin solution: F>

A polyamideimide resin (manufactured by Toyo Boseki Co., Ltd., product name: Viromax NN95TM, glass transition point 290 ° C) is dissolved in N-methyl-2-pyrrolidone so as to have a solid content concentration of 12% by mass, and a solution of polyamideimide resin (Hereinafter, referred to as "resin solution F").

Next, using the resin solution produced above, a flexible metal laminate was produced according to the following procedure.

In addition, in the following description, the resin layers manufactured using resin solutions A-F are called resin layers A-F, respectively.

Example 1

After the final heat treatment of the resin solution C, the electrolytic copper foil (trade name; USLP, manufactured by Nippon Denkai Co., Ltd., thickness: 9 μm) was coated to a thickness of 10 μm after the final heat treatment, followed by heating and drying at 100 ° C. for 10 minutes. Resin layer C was obtained. Next, the resin solution A was apply | coated on the resin C layer, it heat-dried at 120 degreeC for 5 minutes, and it applied over twice so that it might become a thickness of 30 micrometers after drying, and obtained the resin layer A. And heat-processing for 18 hours and 280 degreeC for 10 hours, raising temperature from 30 degreeC to 280 degreeC under nitrogen atmosphere, the flexible metal laminated body of which the total thickness of all the resin layers is 40 micrometers was obtained.

Example 2

After the final heat treatment of the resin solution E, the resin solution E was applied to a thickness of 20 μm on a fire-treated surface of an electrolytic copper foil (trade name; USLP, manufactured by Nippon Denkai Co., Ltd., thickness: 9 μm), heated to dry at 120 ° C. for 10 minutes, and the resin layer E was applied. Got it. Next, after drying the resin solution A on the resin layer E, it applied so that it might become 20 micrometers in thickness, and heat-dried at 120 degreeC for 10 minutes, and obtained the resin layer A. FIG. And it heat-processed at 300 degreeC for 18 hours, raising temperature from 30 degreeC to 300 degreeC under nitrogen atmosphere, and obtained the flexible metal laminated body whose total thickness of all the resin layers is 40 micrometers.

Example 3

The resin solution D was applied to a fire extinguishing surface of an electrolytic copper foil (trade name; USLP, manufactured by Nippon Denkai Co., Ltd., thickness: 9 μm) so as to have a thickness of 5 μm, and dried by heating at 120 ° C. for 5 minutes to obtain a resin layer D. Next, after drying the resin solution E on the resin layer D, it applied so that it might become thickness of 15 micrometers, and it heated and dried at 120 degreeC for 10 minutes, and obtained the resin layer E. And after drying resin solution B on resin layer E so that it might become 20 micrometers in thickness, it heat-dried at 130 degreeC for 10 minutes. It heat-processed at 300 degreeC for 20 hours, raising temperature from 30 degreeC to 300 degreeC in nitrogen atmosphere, and obtained the flexible metal laminated body whose total thickness of all the resin layers is 40 micrometers.

Example 4

Resin solution D was apply | coated so that it might become thickness of 8 micrometers after drying on the fire-extinguishing surface of electrolytic copper foil (brand name; USLP, Nippon Denkai Co., thickness: 9 micrometers), and it dried by heating at 120 degreeC for 5 minutes, and obtained the resin layer D. Next, after drying the resin solution E on the resin layer D, it was apply | coated so that it might become thickness of 13 micrometers, and it heat-dried at 120 degreeC for 5 minutes. And after drying resin solution B on resin layer E so that it might become thickness of 19 micrometers, it heat-dried at 130 degreeC for 10 minutes. It heat-processed at 300 degreeC for 20 hours, raising temperature from 30 degreeC to 300 degreeC in nitrogen atmosphere, and obtained the flexible metal laminated body whose total thickness of all the resin layers is 40 micrometers.

Comparative Example 1

After the final heat treatment of the resin solution B, the resin solution B was applied to a thickness of 30 μm after the final heat treatment of the electrolytic copper foil (brand name; F0-WS, manufactured by Furukawa Circuit Wheel Co., Ltd., thickness: 9 μm). B was obtained. Subsequently, the resin solution C was repeatedly applied on the resin layer B, heated and dried at 120 ° C. for 5 minutes, and dried to obtain a thickness of 10 μm, thereby obtaining a resin layer C. And it heat-processed at 280 degreeC for 10 hours, raising temperature from 30 degreeC to 280 degreeC in nitrogen atmosphere for 18 hours, and obtained the flexible metal laminated body whose total thickness of all the resin layers is 40 micrometers.

Comparative Example 2

Resin solution D was apply | coated so that it might become thickness of 18 micrometers after drying on the fire-extinguishing surface of electrolytic copper foil (brand name; USLP, Nippon Denkai Co., thickness: 9 micrometers), and it heat-dried at 130 degreeC for 10 minutes, and obtained the resin layer D. Next, after drying the resin solution E on the resin layer D, it applied so that it might become thickness of 14 micrometers, and it heat-dried at 120 degreeC for 5 minutes. And after drying the resin solution B on the resin layer E so that it might become thickness of 8 micrometers, it heat-dried at 120 degreeC for 5 minutes. It heat-treated at 300 degreeC for 20 hours, raising temperature from 30 degreeC to 300 degreeC in nitrogen atmosphere, and obtained the flexible metal laminated body whose total thickness of all the resin layers is 40 micrometers.

In Table 1, the structure of the resin layer of the flexible metal laminated body of an Example and a comparative example was put together and shown. However, the numerical value in a table | surface is a film thickness (unit: micrometer).

Moreover, the kind of the resin layer was shown as the 1st layer, the 2nd layer, and the 3rd layer from the metal foil side for convenience.

Type of resin layer Example Comparative example One 2 3 4 One 2 First layer Resin Layer A Resin Layer B 30 Resin Layer C 10 Resin Layer D 5 8 18 Resin Layer E 20 Second layer Resin Layer A 20 Resin Layer B 30 Resin Layer C 10 Resin Layer E 15 13 14 Third layer Resin Layer A Resin Layer B 20 19 8

Thus, the physical-value measurement and evaluation of the flexible metal laminated body of the Example and comparative example obtained were performed as follows.

<Evaluation of the Flexible Metal Laminate>

1.Intrusion displacement

The flexible metal laminated body of each of the said Example and the comparative example was prepared in multiple numbers, and the sample of the resin layer used for the measurement was produced as follows.

(L0) Sample for measurement

After the copper foil layer was removed from the flexible metal laminate with a ferric chloride solution, the resin thickness was measured and confirmed with a micrometer, and a sample for measuring the penetration displacement L0 from the water surface adjacent to the metal layer was prepared.

(L1) Sample for measurement

In the same manner, the resin layer from which the copper foil layer was removed from the flexible metal laminate was polished from the outermost side while measuring the resin thickness with a micrometer with a Tegra series polishing machine manufactured by Marumoto STORAS, Inc. to obtain a sample having a film thickness of 20 μm. .

(L2) Sample for measurement

A sample for measurement was prepared in the same manner as that for the sample for measurement (L1) except for polishing from the contact surface side with the metal layer (L2).

The three samples were allowed to stand for 24 hours or longer in a 23 ± 5 ° C and 55 ± 5% relative humidity environment, respectively, and then the temperature was raised to measure the penetration displacement at 300 ° C.

In the (L0) measurement sample and the (L1) measurement sample, the probe was crimped and measured from the contact surface side with a metal layer, respectively. (L2) In the measurement sample, the probe was crimped and measured from the outermost surface side.

In addition, measurement conditions are as follows.

Measuring apparatus: SII Nanotechnology Co., Ltd. Product name: EXSTAR6100TMA / SS, tip using 1 mm x 1 mm intrusion probe, load: 300 mN, heating rate: 20 ° C / min.

The results are shown in Table 2.

Example Comparative example One 2 3 4 One 2 Intrusion Displacement (μm) (L1) 2 2 3 6 8 10 (L2) 8 7 9 8 2 5 (dL) 6 5 6 2 6 5 (L0) 4 5 6 9 11 16

2. Storage modulus (E (), glass transition point (Tg)

(L0) The same thing as the sample for measurement is prepared, About this sample, it uses the forced vibration non resonance type viscoelasticity measuring instrument (Orientech company brand name: Leo Vibrator Ron) at 300 degreeC on condition of the following. The storage modulus (E ＇) was measured.

Measurement conditions: Vibration frequency: 11 Hz, Static tension: 3.0 gf, Sample size: 0.5 mm (width) x 30 mm (length), Temperature increase rate: 10 ° C / min, Measurement environment conditions: Normal temperature and humidity environment.

In the same manner, the peak top of the loss factor tan δ was detected to determine the glass transition point Tg. The results are shown in Table 3.

Example Comparative example One 2 3 4 One 2 Storage modulus (E ') (GPa) 1.1 1.2 1.2 1.1 1.1 1.2 Peak Top Temperature (Tg) (℃) 320 330 320 320 320 320 370 370 330 330 370 330 370 370 370

3. Coefficient of Thermal Expansion of Resin Layer

(L0) The same thing as the sample for a measurement was prepared, TMA tension measurement by a thermomechanical analyzer (trade name: TMA7 by Shinkuriko Co., Ltd.) was performed, and the average linear expansion rate in 50-250 degreeC was measured by JISKK7197. It was measured by the method of calculating the average linear expansion rate of.

The measurement conditions are as follows. Sample shape: 0.5cm (width) * 1.5cm (length), measurement temperature range: 30 → 400 degreeC, load: 9.8 mN, temperature increase rate: 10 degreeC / min, measurement initial environmental conditions: normal temperature and humidity environment.

The results are shown in Table 4.

4 curl

The flexible metal laminate of Examples and Comparative Examples was cut into 70 mm (width) x 50 mm.

Next, these cut samples were smoothed with a metal layer face up with a curl amount of 72 hours in a constant temperature and humidity chamber adjusted to a 23 ± 5 ° C and 55 ± 5% (humidity) environment as the curl amount of the state. The height from the glass surface of the sample which left still on a phase and curled in circular arc shape was measured.

The flexible metal laminate was placed in a constant temperature oven at 150 ° C. for 24 hours in air, and then the temperature was controlled at 150 ° C. for 72 hours in a constant temperature and humidity chamber adjusted to 23 ± 5 ° C. and 55 ± 5% (humidity) environment. It was set as the curl amount after leaving for 24 hours.

Each result is shown in Table 4.

5.Flip Chip Bonding (Inner Lead (ILB))

The circuit pattern for flip chip bonding was formed in the metal layer in the flexible metal laminated body of an Example and a comparative example by the photoresist method of photoresist application | coating, pattern exposure, image development, etching, solder register application, and tin plating. After leaving the flexible printed circuit board on which the circuit pattern was formed for 72 hours at 23 ° C. and 55% Rh, the circuit pattern for flip chip bonding and the IC bump were bonded with a flip chip bonder (manufactured by Shibuya Industrial Co., Ltd.).

In addition, the temperature, the joining time, and the joining pressure at the time of joining were implemented on condition of the following.

Circuit board side stage temperature: 100 degrees Celsius

Chip side tool temperature ： 450 ° C

Joining time 2.5 ： 2.5 seconds

Joining pressure ： 200mN / mm ²

And the external appearance change of the resin layer and the cross-sectional observation of the junction part were implemented by the following evaluation criteria.

The results are shown in Table 4.

<Evaluation Criteria>

(Circle): There was no external problem, and the remarkable deformation | transformation and peeling of the junction part did not arise.

(Triangle | delta): Although there was no external problem, resin pressurization a little generate | occur | produced in the joint part, but the edge short and lead detachment did not generate | occur | produce.

X: There was a problem on the appearance, and significant resin crushing, edge shorting, or lead detachment occurred at the joint.

Example Comparative example One 2 3 4 One 2 Coefficient of Linear Expansion of Resin Layer (× 10 ^-6 / ℃) 18 19 21 21 23 21 Curling volume (μm) condition 1.3 1.0 1.1 0.5 1.0 1.4 After 150/24 hours 1.3 1.1 1.1 0.4 1.0 1.4 Flip chip adhesion ○ ○ ○ ○ × △

As apparent from the results shown in Tables 2 to 4, the flexible metal laminates of Examples 1 to 4, in which the intrusion displacement level satisfies the conditions of the present invention, showed good results in flip chip bonding property (inner lead (ILB property)). Could get On the other hand, in the flexible metal laminates of Comparative Examples 1 and 2, the conditions of the penetration displacement amount were not satisfied, and flip chip bonding property (inner lead (ILB property)) was poor.

Example 5

Preparation of flexible metal laminate

After the final heat treatment of the resin solution A on the fire-treated surface of the electrolytic copper foil (trade name; USLP, manufactured by Nippon Denkai Co., Ltd., thickness: 9 μm), the resin solution A was applied to a thickness of 8 μm, and dried at 110 ° C. for 5 minutes to dry the resin layer A. Got it.

Next, the resin solution B was apply | coated on this resin layer A, it heat-dried at 120 degreeC for 5 minutes, and the resin layer B whose thickness after drying was 32 micrometers was obtained.

And it heat-processed at 300 degreeC for 18 hours, raising temperature from 30 degreeC to 300 degreeC in nitrogen atmosphere, and obtained the flexible metal laminated body whose total thickness of all the resin layers is 40 micrometers.

Preparation of sample for measurement of hygroscopic expansion coefficient (C _HM )

Resin solution A was applied to the fire-treated surface of the electrolytic copper foil (trade name; USLP, manufactured by Nippon Denkai Co., Ltd., thickness: 9 μm) so as to have a thickness of 8 μm after the final heat treatment, and dried at 110 ° C. for 5 minutes to obtain a resin layer A. . And heat-processing was carried out at 300 degreeC for 18 hours, and raising temperature from 30 degreeC to 300 degreeC under nitrogen atmosphere for 1 hour.

Next, the electrolytic copper foil (metal layer) was removed by the chemical etching process using the ferric chloride solution, and the sample for a measurement was obtained. The size of the sample for a measurement was 70 mm length x 70 mm width.

Preparation of sample for measurement of hygroscopic expansion coefficient (C _HO )

The resin solution B was applied to the fire-treated surface of the electrolytic copper foil (trade name; USLP, manufactured by Nippon Denkai Co., Ltd., thickness: 9 μm), heated and dried at 120 ° C. for 5 minutes, and dried to apply a thickness of 32 μm, thereby coating the resin layer B. Got it. And heat-processing was carried out at 300 degreeC for 18 hours, and raising temperature from 30 degreeC to 300 degreeC under nitrogen atmosphere for 1 hour.

Then, the electrolytic copper foil (metal layer) was removed by the same chemical etching process as the above, and the sample for a measurement was obtained. The size of the sample for measurement was 70 mm long x 70 mm wide.

Preparation of samples for measurement of the entire resin layer

The metal layer was removed from the said flexible metal laminated body by the said chemical etching, and the sample for a measurement was produced.

Example 6

Fabrication of Flexible Metal Laminates

Resin solution B was apply | coated so that it might become thickness of 10 micrometers after final heat processing on the fire-extinguishing surface of electrolytic copper foil (brand name; USLP, Nippon Denkai Co., thickness: 9 micrometers), and it heat-dried at 120 degreeC for 5 minutes, and obtained the resin layer B. .

Next, after drying the resin solution F on this resin layer B, it applied so that it might become thickness of 30 micrometers, and it heat-dried at 130 degreeC for 10 minutes, and obtained the resin layer F.

And it heat-processed at 300 degreeC for 18 hours, raising temperature from 30 degreeC to 300 in nitrogen atmosphere, and obtained the flexible metal laminated body whose total thickness of all the resin layers is 40 micrometers.

Preparation of sample for measurement of hygroscopic expansion coefficient (C _HM )

Resin solution B was apply | coated so that it might become thickness of 10 micrometers after final heat processing on the fire-extinguishing surface of electrolytic copper foil (brand name; USLP, Nippon Denkai Co., thickness: 9 micrometers), and it heat-dried at 120 degreeC for 5 minutes, and obtained the resin layer B. . And heat-processing was carried out at 300 degreeC for 18 hours, raising temperature from 30 degreeC to 300 degreeC in nitrogen atmosphere for 3 hours.

Next, the electrolytic copper foil (metal layer) was removed by the above chemical etching process, and the sample for a measurement was obtained. The size of the sample for measurement was 70 mm long x 70 mm wide.

Preparation of sample for measurement of hygroscopic expansion coefficient (C _HO )

Resin solution F was apply | coated to the fire-extinguishing process surface of electrolytic copper foil (brand name; USLP, Nippon Denkai Co., thickness: 9 micrometers), it heat-dried at 130 degreeC for 10 minutes, and it applied so that it might become 30 micrometers thickness after drying, and the resin layer F was applied. Got it. And heat-processing was carried out at 300 degreeC for 18 hours, raising temperature from 30 degreeC to 300 degreeC in nitrogen atmosphere for 3 hours.

Then, the electrolytic copper foil (metal layer) was removed by the above chemical etching process, and the sample for a measurement was obtained. The size of the sample for a measurement was 70 mm length x 70 mm width.

Preparation of samples for measurement of the entire resin layer

The metal layer was removed by the said chemical etching from the said flexible metal laminated body, and the sample for a measurement was produced.

Example 7

Fabrication of Flexible Metal Laminates

Resin solution B was apply | coated so that it might become thickness of 20 micrometers after drying on the fire-extinguishing process surface of electrolytic copper foil (brand name; USLP, Nippon Denkai Co., thickness: 9 micrometers), and it heat-dried at 120 degreeC for 10 minutes.

Next, after drying the resin solution F on the obtained resin layer B, it applied so that it might become 20 micrometers in thickness, and heat-dried at 130 degreeC for 10 minutes, and obtained the resin layer F. FIG.

And it heat-processed at 300 degreeC for 18 hours, raising temperature from 30 degreeC to 300 degreeC in nitrogen atmosphere, and obtained the flexible metal laminated body whose total thickness of all the resin layers is 40 micrometers.

Preparation of sample for measurement of hygroscopic expansion coefficient (C _HM )

Resin solution B was apply | coated to the thickness of 20 micrometers after final heat processing on the fire-extinguishing surface of electrolytic copper foil (brand name; USLP, Nippon Denkai Co., thickness: 9 micrometers), and it heated and dried at 120 degreeC for 10 minutes, and obtained the resin layer B. . And heat-processing was carried out at 300 degreeC for 18 hours, raising temperature from 30 degreeC to 300 degreeC in nitrogen atmosphere for 3 hours.

Then, the electrolytic copper foil (metal layer) was removed by the above chemical etching process, and the sample for a measurement was obtained. The size of the sample for a measurement was 70 mm length x 70 mm width.

Preparation of sample for measurement of hygroscopic expansion coefficient (C _HO )

Resin solution F was applied to the fire-extinguishing surface of the electrolytic copper foil (trade name; USLP, manufactured by Nippon Denkai Co., Ltd., thickness: 9 μm), heated and dried at 130 ° C. for 10 minutes, and applied so as to have a thickness of 20 μm after drying. Got it. And heat-processing was carried out at 300 degreeC for 18 hours, raising temperature from 30 degreeC to 300 degreeC in nitrogen atmosphere for 3 hours. This will be referred to as sample C of _HO.

Then, the electrolytic copper foil (metal layer) was removed by the above chemical etching process, and the sample for a measurement was obtained. The size of the sample for a measurement was 70 mm length x 70 mm width.

Preparation of samples for measurement of the entire resin layer

In the flexible metal laminate, a metal layer was removed by the chemical etching to prepare a sample for measurement.

Example 8

Fabrication of Flexible Metal Laminates

The resin solution C was applied to a fire extinguishing surface of an electrolytic copper foil (trade name; USLP, manufactured by Nippon Denkai Co., Ltd., thickness: 9 μm) so as to have a thickness of 8 μm, and dried at 110 ° C. for 5 minutes to obtain a resin layer C.

Next, after drying the resin solution B on the resin layer C, it was apply | coated so that it might become thickness of 18 micrometers, and it heat-dried at 120 degreeC for 10 minutes, and obtained the resin layer B.

And after drying resin solution F on resin B layer so that it might become thickness of 14 micrometers, it heated and dried at 120 degreeC for 10 minutes, and obtained resin layer F.

It heat-processed at 300 degreeC for 18 hours, raising temperature from 30 degreeC to 300 degreeC in nitrogen atmosphere, and obtained the flexible metal laminated body whose total thickness of all the resin layers is 40 micrometers.

Preparation of sample for measurement of hygroscopic expansion coefficient (C _HM )

Resin solution C was apply | coated so that it might become thickness of 8 micrometers after final heat processing on the fire-extinguishing surface of electrolytic copper foil (brand name; USLP, Nippon Denkai Co., thickness: 9 micrometers), and it heat-dried at 110 degreeC for 5 minutes, and obtained the resin layer. And heat-processing was carried out at 300 degreeC for 18 hours, raising temperature from 30 degreeC to 300 degreeC in nitrogen atmosphere for 3 hours.

Then, the electrolytic copper foil (metal layer) was removed by the above chemical etching process, and the sample for a measurement was obtained. The size of the sample for measurement was 70 mm long x 70 mm wide.

Preparation of sample for measurement of hygroscopic expansion coefficient (C _HO )

Resin solution F was apply | coated to the fire-extinguishing process surface of electrolytic copper foil (brand name; USLP, Nippon Denkai Co., thickness: 9 micrometers), it heat-dried at 120 degreeC for 10 minutes, and it applied so that it might become 14 micrometers thickness after drying, and the resin layer F was applied. Got it. And heat-processing was carried out at 300 degreeC for 18 hours, raising temperature from 30 degreeC to 300 degreeC in nitrogen atmosphere for 3 hours.

Next, the electrolytic copper foil (metal layer) was removed by the above chemical etching process, and the sample for a measurement was obtained. The size of the sample for a measurement was made into 70 mm x 70 mm in width.

Preparation of samples for measurement of the entire resin layer

In the flexible metal laminate, a metal layer was removed by the chemical etching to prepare a sample for measurement.

Comparative Example 3

Fabrication of Flexible Metal Laminates

Resin solution A is applied twice to the thickness of 40 micrometers after the final heat treatment to the fire-extinguishing surface of electrolytic copper foil (brand name; USLP, Nippon Denkai Co., thickness: 9 micrometers), heat-dried at 130 degreeC for 10 minutes, and Strata A was obtained.

And it heat-processed at 300 degreeC for 18 hours, raising temperature from 30 degreeC to 300 degreeC in nitrogen atmosphere, and obtained the flexible metal laminated body whose total thickness of all the resin layers is 40 micrometers.

Preparation of sample for measurement of moisture absorption coefficient (C _HM ), sample for measurement of moisture absorption coefficient (C _HO )

The metal layer was removed like the preparation of the measurement sample of the whole resin layer as follows, and it was set as the measurement sample. The size of the sample for measurement was 70 mm long x 70 mm wide.

In the case where the resin layer is composed of one type of layer, both the hygroscopic expansion coefficient (C _HM ) and the hygroscopic expansion coefficient (C _HO ) were set to the same value. That is, the sample for measurement of a moisture absorption expansion coefficient (C _HM ) and a moisture absorption expansion coefficient ( _CHO ) was common.

Preparation of samples for measurement of the entire resin layer

In the flexible metal laminate, a metal layer was removed by the chemical etching to prepare a sample for measurement.

Comparative Example 4

Fabrication of Flexible Metal Laminates

The resin solution B was applied twice to a thickness of 40 μm after the final heat treatment to the fire-extinguishing surface of the electrolytic copper foil (trade name; USLP, manufactured by Nippon Denkai Co., Ltd., thickness: 9 μm), and dried by heating at 130 ° C. for 10 minutes. Strata B was obtained.

And it heat-processed at 300 degreeC for 18 hours, raising temperature from 30 degreeC to 300 degreeC in nitrogen atmosphere, and obtained the flexible metal laminated body whose total thickness of all the resin layers is 40 micrometers.

Preparation of sample for measurement of moisture absorption coefficient (C _HM ), sample for measurement of moisture absorption coefficient (C _HO )

The metal layer was removed like the preparation of the measurement sample of the whole following resin layer, and it was set as the measurement sample. The size of the sample for measurement was 70 mm long x 70 mm wide.

In the case where the resin layer is formed of one type of layer, both the hygroscopic expansion coefficient (C _HM ) and the hygroscopic expansion coefficient (C _HO ) were set to the same value. That is, the sample for measurement of a moisture absorption expansion coefficient (C _HM ) and a moisture absorption expansion coefficient ( _CHO ) was common.

Preparation of samples for measurement of the entire resin layer

In the flexible metal laminate, a metal layer was removed by the chemical etching to prepare a sample for measurement.

Comparative Example 5

Fabrication of Flexible Metal Laminates

Resin solution C was applied twice to a thickness of 15 μm after the final heat treatment on the fire-treated surface of the electrolytic copper foil (trade name; USLP, manufactured by Nippon Denkai Co., Ltd., thickness: 9 μm), heated at 130 ° C. for 10 minutes, and dried. Strata C was obtained.

Furthermore, it heat-processed at 300 degreeC for 18 hours, raising temperature from 30 degreeC to 300 degreeC in nitrogen atmosphere, and obtained the flexible metal laminated body of 15 micrometers in total thickness of all the resin layers.

Preparation of sample for measurement of moisture absorption coefficient (C _HM ), sample for measurement of moisture absorption coefficient (C _HO )

The metal layer was removed like the preparation of the measurement sample of the whole following resin layer, and it was set as the measurement sample. The size of the sample for a measurement was 70 mm length x 70 mm width.

In the case where the resin layer is formed of one type of layer, both the hygroscopic expansion coefficient (C _HM ) and the hygroscopic expansion coefficient (C _HO ) were set to the same value. That is, the sample for measurement of a moisture absorption expansion coefficient (C _HM ) and a moisture absorption expansion coefficient ( _CHO ) was common.

Preparation of samples for measurement of the entire resin layer

In the flexible metal laminate, a metal layer was removed by the chemical etching to prepare a sample for measurement.

Comparative Example 6

Fabrication of Flexible Metal Laminates

The resin solution F was applied twice to a thickness of 40 μm after the final heat treatment to the fire-extinguishing surface of the electrolytic copper foil (trade name; USLP, manufactured by Nippon Denkai Co., Ltd., thickness: 9 μm), heated at 130 ° C. for 10 minutes, and dried. Strata F was obtained.

And it heat-processed at 300 degreeC for 18 hours, raising temperature from 30 degreeC to 300 degreeC in nitrogen atmosphere, and obtained the flexible metal laminated body whose total thickness of all the resin layers is 40 micrometers.

Preparation of sample for measurement of moisture absorption coefficient (C _HM ), sample for measurement of moisture absorption coefficient (C _HO )

It carried out similarly to manufacture of the sample for a measurement of the whole resin layer below, and removed the metal layer to make a sample for a measurement. The size of the sample for measurement was 70 mm long x 70 mm wide.

In the case where the resin layer is formed of one type of layer, both the hygroscopic expansion coefficient (C _HM ) and the hygroscopic expansion coefficient (C _HO ) were set to the same value. That is, the sample for measurement of a moisture absorption expansion coefficient (C _HM ) and a moisture absorption expansion coefficient ( _CHO ) was common.

Preparation of samples for measurement of the entire resin layer

In the flexible metal laminate, a metal layer was removed by the chemical etching to prepare a sample for measurement.

Comparative Example 7

Fabrication of Flexible Metal Laminates

Resin solution A was apply | coated so that it might become thickness of 30 micrometers after final heat processing on the fire-extinguishing surface of electrolytic copper foil (brand name; USLP, Nippon Denkai Co., thickness: 9 micrometers), and it heated and dried at 130 degreeC for 10 minutes, and obtained the resin layer A. .

And resin solution F was apply | coated so that it might become thickness of 10 micrometers after final heat processing on resin layer A, and it heat-dried at 120 degreeC for 5 minutes, and obtained resin layer F.

And it heat-processed at 300 degreeC for 18 hours, raising temperature from 30 degreeC to 300 degreeC in nitrogen atmosphere, and obtained the flexible metal laminated body whose total thickness of all the resin layers is 40 micrometers.

Preparation of sample for measurement of hygroscopic expansion coefficient (C _HM )

The resin solution A was apply | coated so that it might become thickness of 30 micrometers after final heat processing on the fire-extinguishing surface of electrolytic copper foil (brand name: USLP, Nippon Denkai Co., thickness: 9 micrometers), and it heated and dried at 130 degreeC for 10 minutes, and obtained the resin layer. And heat-processing was carried out at 300 degreeC for 18 hours, and raising temperature from 30 degreeC to 300 degreeC under nitrogen atmosphere for 1 hour.

Then, the electrolytic copper foil (metal layer) was removed by the above chemical etching process, and the sample for a measurement was obtained. The size of the sample for a measurement was 70 mm length x 70 mm width.

Preparation of sample for measurement of hygroscopic expansion coefficient (C _HO )

Resin solution F was apply | coated to the fire-extinguishing surface of electrolytic copper foil (brand name: USLP, Nippon Denkai Co., thickness: 9 micrometers), it heat-dried at 120 degreeC for 5 minutes, and it applied so that it might become 10 micrometers thickness after drying, and obtained the resin layer. . And heat-processing was carried out at 300 degreeC for 18 hours, and raising temperature from 30 degreeC to 300 degreeC under nitrogen atmosphere for 1 hour. This will be referred to as sample C of _HO.

Then, the electrolytic copper foil (metal layer) was removed by the same chemical etching process as the above, and the sample for a measurement was obtained. The size of the sample for measurement was 70 mm long x 70 mm wide.

Preparation of samples for measurement of the entire resin layer

In the flexible metal laminate, a metal layer was removed by the chemical etching to prepare a sample for measurement.

In Table 5, the structure of the resin layer of the flexible metal laminated body of Examples 5-8 and Comparative Examples 3-7 is shown collectively.

Moreover, the kind of the resin layer was shown by the 1st layer, the 2nd layer, and the 3rd layer from the metal layer side for convenience.

Moreover, the film thickness T0 and the film thickness T1 are also shown in Table 1 at the same time. However, in the case of having a one-layer structure, the film thickness (T0) = film thickness (T1) was represented.

In addition, the numerical value in a table | surface is a film thickness (unit: micrometer).

Type of resin layer Example Comparative example 5 6 7 8 3 4 5 6 7 First layer Resin Layer A 8 40 30 Resin Layer B 10 20 40 Resin Layer C 8 15 Resin Layer F 40 Second layer Resin Layer A Resin Layer B 32 18 Resin Layer F 30 20 10 Third layer Resin Layer B Resin Layer F 14 Thickness of the whole resin layer (T0) 40 40 40 40 40 40 15 40 40 Thickness of outermost layer (T1) 32 30 20 14 40 40 15 40 10 Ratio of outermost layer / resin layer (T1 / T0) 80/100 75/100 50/100 35/100 100/100 100/100 100/100 100/100 25/100

Thus, the physical-value measurement and evaluation of the Example 5-8 and the flexible metal laminated body of Comparative Examples 3-7 which were obtained were performed as follows.

<Evaluation of the Flexible Metal Laminate>

1.Coefficient of thermal expansion of resin layer and metal layer

About the sample for the measurement of the whole resin layer, it measured in accordance with the average linear expansion rate calculation method to JISKK7197.

Specifically, TMA tensile measurement was performed by a thermomechanical analyzer (TMA) (trade name: manufactured by Shinkuriko Co., Ltd .: TMA7), and the average linear expansion coefficient at 50 ° C to 250 ° C was defined as the linear thermal expansion coefficient.

The measurement conditions were as follows.

Sample shape: 5 mm width x 15 mm length, initial length: 15 mm, load: 9.8 mN, temperature increase rate: 10 deg. C / min, measurement environmental conditions: The temperature is raised in a normal temperature and humidity environment.

The size of the sample for a measurement was 70 mm length x 70 mm width.

In addition, also in the metal foil which comprises a metal layer, the linear expansion coefficient was measured similarly.

The size of the sample for a measurement was 70 mm length x 70 mm width. The results are shown in Table 6.

2. Hygroscopic expansion coefficient

By the method described above, the moisture absorption expansion coefficient (C _HM ) and the moisture absorption expansion coefficient (C _HO ) were measured. The results are shown in Table 6.

Example Comparative example 5 6 7 8 3 4 5 6 7 Coefficient of Thermal Expansion (× 10 ^-6 / ℃) Resin layer 22 22 21 20 19 22 14 23 20 Metal layer 18 18 18 18 18 18 18 18 18 Difference in Coefficient of Thermal Expansion between Resin Layer and Metal Layer 4 4 3 2 One 4 -4 5 2 Hygroscopic expansion coefficient of resin layer (× 10 ^-6 /% RH) (C _HO ) 35 20 20 20 45 35 35 20 45 (C _HM ) 45 35 35 35 45 35 35 20 35 (C _HM -C _HO ) 10 15 15 15 0 0 0 0 -10

3. Storage modulus of resin layer (E ＇), glass transition point (Tg)

About the sample for the measurement of the whole resin layer, the storage elastic modulus (E ＇) in 300 degreeC is changed on condition of the following conditions using the forced vibration non-resonance type viscoelasticity meter (Orientech Co., Ltd. brand name: Leo Vibrator Ron). Measured.

Measurement conditions: Vibration frequency: 11 Hz, Static tension: 3.0 gf, Sample size for measurement: 0.5 mm (width) x 30 mm (length), Temperature increase rate: 10 ° C / min, Measurement environment conditions: Normal temperature and humidity environment.

Similarly, the peak top of the loss coefficient tan-delta was detected and glass transition point Tg was calculated | required. The results are shown in Table 7.

Example Comparative example 5 6 7 8 3 4 5 6 7 Dynamic viscoelasticity Storage modulus at 300 ° C (GPa) 1.1 1.1 1.0 2.0 1.1 1.1 4.0 0.7 1.1 Glass transition point (Tg) (peak top temperature) (° C) 320 290 290 290 330 320 370 290 320 330 320 320 320 330 370

4 curl

The flexible metal laminate was cut to 70 mm width x 50 mm.

Subsequently, these cut samples were placed on a smooth glass plate with the metal layer face up, with the amount of curl in a state of 72 hours humidity control in a constant temperature and humidity chamber adjusted to 23 ± 5 ° C./20±5% (humidity) environment. The height from the glass surface of the sample which left still and curled in the arc shape was measured.

The flexible metal laminate was then left in air in a constant temperature oven for 24 hours at 150 ° C. and then left for 24 hours in a constant temperature and humidity bath adjusted to 23 ± 5 ° C./80±5% (humidity) environment for 24 hours. It was set as the amount of curl later.

In addition, the difference in curl amounts between the former and the latter was determined. The results are shown in Table 8.

5.Flip Chip Bonding (Inner Lead (ILB))

The metal layer in the flexible metal laminate was subjected to photoresist coating, pattern exposure, development, etching, solder resist coating and tin plating to form a circuit pattern for flip chip bonding by the photoresist method. After leaving the flexible printed circuit board on which this circuit pattern was formed for 72 hours at 23 ° C. and 55% Rh, bonding of the circuit pattern for flip chip bonding to the bumps of the IC was performed by a flip chip bonder (manufactured by Shibuya Industrial Co., Ltd.).

In addition, the temperature at the time of joining, joining time, and joining pressure were made into the following conditions.

Circuit board side stage temperature ： 100 ℃

Chip side tool temperature ： 350 ° C

Joining time 2.5 ： 2.5 seconds

Joining pressure: 150 mN / mm ²

And the external appearance change of the resin layer and the cross-sectional observation of the junction part were implemented by the following evaluation criteria. The results are shown in Table 8.

<Evaluation Criteria>

(Circle): There was no external problem, and the remarkable deformation | transformation and peeling of the junction part did not arise.

(Triangle | delta): There was no external problem. In addition, the resin crushing phenomenon occurred slightly at the joint, but no edge short or lead detachment occurred.

X: There was a problem in appearance, and a significant resin crushing phenomenon, edge shorting, or lead detachment occurred at the joint.

Example Comparative example 5 6 7 8 3 4 5 6 7 Curling volume (μm) 23 ℃ / 20% RH 2 One 2 One 8 4 4 2 7 23 ℃ / 80% RH -2 -2 -2 -2 -9 -4 -3 -2 -6 Difference 4 3 4 3 17 8 7 4 13 Flip Chip Bonding (Inner Lead (ILB)) ○ ○ ○ ○ △ △ ○ × △

As apparent from the above results, the flexible metal laminates of Examples 5 to 8 related to the present invention had less curl amount than the flexible metal laminates of Comparative Examples 3 to 7, and flip chip bonding properties (inner lead (ILB properties)). Good results were obtained with respect to. In contrast, in the comparative example, flip chip bonding property (inner lead (ILB property)) was poor.

The present invention provides a flexible metal laminate that is used for compressing a protrusion such as a bump under high temperature conditions, and a flexible metal laminate that can solve a problem involving shrinkage deformation of a resin layer in a flexible printed circuit board using the same. A sieve and a flexible printed circuit board using the same are provided.

Claims (14)

As a flexible metal laminate having a metal layer and a resin layer, Intrusion displacement amount (L1) of the said 1st sample from the contact surface with a metal layer, when the said resin layer is divided into two in the part of thickness 1/2, and the contact surface side with a said metal layer is made into a 1st sample, and the remainder is a 2nd sample. Silver is smaller than the intrusion displacement amount (L2) of the said 2nd sample from the surface on the opposite side to a metal layer, The flexible metal laminated body characterized by the above-mentioned. delete The method of claim 1, The penetration metal displacement L0 of the said resin layer from the contact surface with the said metal layer is 10 micrometers or less, The flexible metal laminated body characterized by the above-mentioned. The method of claim 1, The said resin layer is comprised from multiple layers, The flexible metal laminated body characterized by the above-mentioned. A flexible metal laminate having a metal layer and a resin layer formed of two or more layers formed thereon, The moisture absorption expansion coefficient (C _HO ) of the outermost layer of the resin layer is smaller than the moisture absorption expansion coefficient (C _HM ) of the layer adjacent to the metal layer of the resin layer. The method of claim 5, An absolute value which is a difference between the linear thermal expansion coefficient of the resin layer and the linear thermal expansion coefficient of the metal layer is less than 10 × 10 ⁻⁶ / ° C. A flexible metal laminate. delete The method of claim 5, The ratio (T1) / (T0) of the thickness T1 of an outermost layer and the thickness T0 of the whole resin layer is 35/100 or more and 95/100 or less, The flexible metal laminated body characterized by the above-mentioned. delete The method according to claim 1 or 5, The said resin layer contains the thermoplastic resin soluble in the organic solvent, The flexible metal laminated body characterized by the above-mentioned. The method according to claim 1 or 5, The said resin layer contains at least 1 sort (s) of resin chosen from the group which consists of polyimide resin, polyamideimide resin, polyetherimide resin, and polysiloxane imide resin. The method according to claim 1 or 5, Said metal layer is comprised from metal foil, The flexible metal laminated body characterized by the above-mentioned. The method of claim 12, The said metal foil is 1 or more types chosen from the group which consists of copper foil, stainless foil, aluminum foil, and nickel foil, The flexible metal laminated body characterized by the above-mentioned. A flexible printed circuit board comprising the flexible metal laminate according to claim 1 or 5.

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