KR102418506B1 - High damping Multi-layer Printed Circuit Board using Viscoelastic Tape and The Manufacturing Method thereof - Google Patents

Abstract

In the present embodiments, a circuit layer is formed on one surface of the insulating layer, and is laminated on the back surface of the substrate and the substrate for connecting circuits between a plurality of components through the circuit layer, and includes a reinforcing unit for damping vibration transmitted to the substrate; Boo proposes a high-damping laminated printed circuit board characterized by laminating a restraining layer made of the same material as the substrate and a damping layer forming viscoelastic properties.

Description

High damping multi-layer Printed Circuit Board using Viscoelastic Tape and The Manufacturing Method thereof

The present invention relates to a high damping laminated printed circuit board and a method for manufacturing the same, and more particularly to a high damping laminated printed circuit board using viscoelastic properties and a manufacturing method thereof.

The content described in this section merely provides background information for the present embodiment and does not constitute the prior art.

According to the recent trend of economical development and mass production of small satellites according to the new space paradigm, there is an increasing demand for the design of small, light and efficient structures for satellite-mounted electronics to realize a smaller/lighter satellite system.

Conventional electrical equipment uses a mechanical connection part called a wedge lock to mount the printed circuit board to the electronic mechanical structure (chassis), which reduces the ease of mounting/detaching of electronic equipment and the vibration transmitted to the inside of the printed circuit board. It is widely used for the purpose of reducing

If the dynamic displacement of the board to which the wedgelock is applied is expected to be excessive during mechanical design of the electronic device, a separate metal stiffener is applied to the board to reduce the displacement, which leads to an increase in the weight of the electronic device, and a large number of boards When mounted, an increase in the overall weight/volume of the electrical equipment is unavoidable. In addition, in order to manufacture a reinforcing material having a complex shape, there is a problem in that the processing process is complicated and the manufacturing cost is increased.

Embodiments of the present invention have been devised to solve the above problems, and by improving the damping ability of the printed circuit board without a separate metallic reinforcing material, damage to the printed circuit board due to environmental vibration input from the outside and solder (Solder) ) The main purpose of the invention is to solve the fatigue failure problem of the joint.

Other objects not specified in the present invention may be additionally considered within the scope that can be easily inferred from the following detailed description and effects thereof.

According to one aspect of this embodiment, in the present invention, a circuit layer is formed on one surface of an insulating layer, a substrate connecting circuits between a plurality of components through the circuit layer, and laminated on the back surface of the substrate, and transferred to the substrate A high-damping multilayer printed circuit board comprising a reinforcing unit for damping vibration, wherein the reinforcing unit stacks a restraining layer made of the same material as the substrate and a damping layer forming viscoelastic properties.

Preferably, the reinforcing part is characterized in that the damping layer and the constraining layer formed of a viscoelastic material are cross-stacked and fixed.

Preferably, the reinforcing unit comprises a first reinforcing line formed along an edge of the substrate on the rear surface of the substrate and a second reinforcing line formed by connecting opposite surfaces of the first reinforcing line, respectively, to the damping layer and The constraint layer is stacked, and the first reinforcing line and the second reinforcing line are formed to have a preset thickness.

Preferably, the substrate is characterized in that the damping performance is improved by adjusting the number of laminations of the constraint layer and the damping layer.

Preferably, the reinforcing part applies a uniform pressure when the constraining layer and the damping layer are laminated to enable uniform adhesion, and an arrangement between the substrate and the constraining layer, and the constraining layer and the constraining layer. Includes a guide hole formed for.

Preferably, the substrate is characterized in that it includes an interface hole for fastening to the device.

Preferably, a pair of the interface holes are provided at opposite edges of the substrate and do not come into contact with the reinforcing part.

According to another embodiment of the present invention, a circuit layer is formed on one surface of an insulating layer, preparing a substrate for connecting circuits between a plurality of components through the circuit layer, and the substrate on the back side of the substrate High-damping laminated type, comprising the step of seating a reinforcing unit for damping vibration transmitted to A method for manufacturing a printed circuit board is proposed.

Preferably, the step of seating the reinforcing part is characterized in that the damping layer formed of a viscoelastic material and the constraining layer are cross-stacked and fixed.

Preferably, the step of seating the reinforcing part is characterized in that the damping layer is implemented with a viscoelastic tape.

Preferably, the step of seating the reinforcing part is characterized in that the damping performance of the substrate is improved by adjusting the number of laminations of the constraining layer and the damping layer.

Preferably, the step of preparing the substrate includes forming an interface hole provided at the opposite edge of the substrate for fastening to the wedgelock, wherein the interface hole is formed so as not to come into contact with the reinforcing part characterized.

Preferably, the step of seating the reinforcing part includes forming a first reinforcing line along an edge of the substrate on the rear surface of the substrate, and connecting opposite surfaces of the first reinforcing line to form a second reinforcing line and the first reinforcing line and the second reinforcing line are formed to have a preset thickness.

As described above, according to the embodiments of the present invention, the present invention guarantees the fatigue life of the solder joint according to the reduction of the dynamic displacement of the substrate with the characteristics of the viscoelastic tape and the high damping characteristics realized by the friction between the thin plate and the tape. can have an effect.

Even if it is an effect not explicitly mentioned herein, the effects described in the following specification expected by the technical features of the present invention and their potential effects are treated as if they were described in the specification of the present invention.

1 to 3 are diagrams illustrating a high-damping multilayer printed circuit board using viscoelastic properties according to an embodiment of the present invention.
4 is a flowchart illustrating a method of manufacturing a high-damping multilayer printed circuit board using viscoelastic properties according to an embodiment of the present invention.
5 to 10 are diagrams showing test results according to the number of layers of reinforcing parts of a high-damping multilayer printed circuit board using viscoelastic properties according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Advantages and features of the present invention, and a method for achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments published below, but may be implemented in various different forms, and only these embodiments allow the publication of the present invention to be complete, and common knowledge in the technical field to which the present invention pertains It is provided to fully inform the possessor of the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

Unless otherwise defined, all terms (including technical and scientific terms) used herein may be used with the meaning commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in a commonly used dictionary are not to be interpreted ideally or excessively unless clearly defined in particular.

The terms used in this application are only used to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It should be understood that this does not preclude the existence or addition of numbers, steps, operations, components, parts, or combinations thereof.

Terms including an ordinal number such as second, first, etc. may be used to describe various elements, but the elements are not limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the second component may be referred to as the first component, and similarly, the first component may also be referred to as the second component. and/or includes a combination of a plurality of related listed items or any of a plurality of related listed items.

The present invention relates to a high-damping multilayer printed circuit board using viscoelastic properties and a method for manufacturing the same.

According to the recent trend of economical development and mass production of small satellites according to the New Space paradigm, there is a demand for the design of a small and light efficient structure for satellite-mounted electronics with excellent vibration reduction performance to realize a smaller/lighter satellite system. is increasing Conventional electrical equipment uses a mechanical connection part called a wedge lock to mount the printed circuit board to the electronic mechanical structure (chassis), which reduces the ease of mounting/detaching of electronic equipment and the vibration transmitted to the inside of the printed circuit board. It is widely used for the purpose of reducing If the dynamic displacement of the board to which the wedgelock is applied is expected to be excessive during mechanical design of conventional electronic devices, a separate metal stiffener is applied to the board to reduce the displacement, which leads to an increase in the weight of the electronic device and multiple boards When this is mounted, an increase in the overall weight/volume of the electrical equipment is unavoidable. In addition, in order to manufacture a reinforcing material having a complicated shape, a problem of a complicated machining process and an increase in manufacturing cost may also occur.

Therefore, in order to solve the above-mentioned problem, the high damping laminated printed circuit board 10 improves the damping ability of the electronic board without a separate metal material reinforcing material, thereby causing damage to the electronic board due to environmental vibration input from the outside and element solder joints It can solve the problem of shortening the fatigue life of Here, the device solder joint may refer to a portion where devices are soldered to connect the components.

The high-damping laminated printed circuit board 10 is a miniaturization/lightweight mechanical technology of electrical equipment using vibration reduction characteristics, and can be widely used in all fields of defense and civil affairs, such as aerospace, aviation, and electrical equipment for ground platforms. In particular, the high-damping laminated printed circuit board 10 is highly integrated by effectively reducing the external disturbance (vibration/shock) without increasing the weight and size by applying all electronic equipment using the printed circuit board (PCB). , it can be used to ensure the performance of expensive electronic components.

1 to 3 are diagrams illustrating a high-damping multilayer printed circuit board using viscoelastic properties according to an embodiment of the present invention.

1 to 3 , the high-damping laminated printed circuit board 10 includes the substrate 100 and the reinforcing part 200 . Here, the reinforcing part 200 includes a constraining layer 210 and a damping layer 220 . The high damping laminated printed circuit board 10 may omit some of the various components exemplarily illustrated in FIGS. 1 to 3 or additionally include other components.

1 is a perspective view and a partially enlarged view showing a high damping laminated printed circuit board using viscoelastic properties according to an embodiment of the present invention, and FIG. 2 is a high damping laminated printing using viscoelastic properties according to an embodiment of the present invention. It is a perspective view showing an exploded circuit board, and FIG. 3 is a plan view of a high-damping stacked printed circuit board using viscoelastic properties according to an embodiment of the present invention.

According to an embodiment of the present invention, the high damping laminated printed circuit board 10 has a constraint layer 210 made of the same material as the substrate 100 on the rear surface of the substrate 100 in order to improve the damping ability of the substrate 100 itself. A reinforcing part 200 in the form of being laminated with a viscoelastic tape was applied.

In addition, the high-damping laminated printed circuit board 10 has a vibration reduction performance superior to that of a conventional metal reinforcing material due to a simple manufacturing process and a low unit price, thereby reducing costs.

The substrate 100 has a circuit layer formed on one surface of the insulating layer, and circuits between the plurality of components 20 may be connected through the circuit layer.

The substrate 100 is a plate on which an electric circuit is knitted, and is wired with a copper foil on the surface, so that an electric component 20 such as an integrated circuit or a resistor can be installed and used. In general, the substrate 100 may be made of paper, glass fiber, glass cloth, Teflon, metal, epoxy, etc., and may be provided with a circuit printed on the surface. Preferably, the substrate 100 is preferably implemented with FR-4 of a material made of glass fiber and epoxy.

1 and 2 , the substrate 100 may be used in a form in which a plurality of components 20 are combined, and an electric circuit may be efficiently formed to connect the components 20 to each other.

The substrate 100 may improve damping performance by adjusting the number of stacking of the constraining layer 210 and the damping layer 220 .

According to an embodiment of the present invention, the number of stacking of the constraining layer 210 and the damping layer 220 may be changed according to the environment and necessity in which the high damping stacked printed circuit board 10 is used.

The constraint layer 210 and the damping layer 220 increase the rigidity and damping capacity of the substrate 100 according to the number of stacked layers, and the number of the constraint layer 210 and the damping layer 220 may be adjusted as needed. can

The substrate 100 may include an interface hole 110 for fastening to a device.

A pair of interface holes 110 may be provided at opposite edges of the substrate 100 and may be formed so as not to come into contact with the reinforcing part 200 provided on the rear surface.

According to an embodiment of the present invention, the interface hole 110 is fastened with a device through a wedge lock to reduce vibration transmitted to the inside of the substrate 100 . Here, the wedge lock is a mechanical connection component and may facilitate attachment/detachment of electronic equipment.

The substrate 100 connects circuits between the components 20 , and may be fastened to a device through the interface hole 110 . In addition, a high-damping laminated reinforcing unit 200 for damping vibration transmitted to the substrate 100 may be provided on the rear surface of the substrate 100 .

The reinforcing part 200 is laminated on the rear surface of the substrate 100 , and may attenuate vibration transmitted to the substrate 100 .

According to an embodiment of the present invention, the thickness of the laminated thin plates of the reinforcing part 200 is several mm or less, and the weight/volume increase can be minimized compared to the conventional metal reinforcement. can be implemented Here, the laminated thin plates are the constraint layer 210 and the damping layer 220 .

The constraint layer 210 may be made of the same material as the substrate 100 . As the substrate 100 and the constraining layer 210 are made of the same material, the properties of the vibration frequency transmitted to each are formed to be the same, thereby effectively damping vibration. Here, the substrate 100 can be inexpensively manufactured with a light and thin thickness, and the constraint layer 210 made of the same material as the substrate 100 can also be inexpensively manufactured with a light and thin thickness.

According to an embodiment of the present invention, the constraint layer 210 may be implemented with a material different from that of the substrate 100 , and the bending behavior of the substrate 100 may be sufficiently required to implement high damping. Accordingly, when the constraining layer 210 is made of a high-rigidity material, the effect may be extremely reduced.

The damping layer 220 may form viscoelastic properties. In addition, the damping layer 220 may be implemented as a viscoelastic tape.

According to an embodiment of the present invention, the high-damping laminated printed circuit board 10 has the characteristics of the viscoelastic tape and the high damping property realized by the friction between the substrate 100 and the viscoelastic tape to reduce the dynamic displacement of the substrate 100. It can be effective to guarantee the fatigue life of the solder joint according to the Here, the viscoelastic tape is the damping layer 220 and may represent a tape in which properties as a liquid and properties as a solid appear simultaneously when a force is applied to an object.

In the reinforcement part 200 , a plurality of constraint layers 210 and damping layers 220 may be stacked.

The reinforcing part 200 may be fixed by cross-stacking the damping layer 220 and the constraining layer 210 formed of a viscoelastic material.

According to an embodiment of the present invention, the reinforcing part 200 is formed by stacking a plurality of constraint layers 210 and damping layers 220 . The constraint layer 210 may be made of the same material as the substrate 100 , and the damping layer 220 may have viscoelastic properties.

The reinforcing part 200 has a high damping capability implemented with viscoelastic properties, and reduces the bending behavior of the substrate 100 in a satellite vibration environment, thereby limiting damage to the component 20 .

The reinforcing part 200 may be a structure made of various viscoelastic materials having a damping ability capable of dissipating vibrations transmitted to the substrate 100 . Here, damping is an ability to damp vibration, and vibration can be reduced by dissipating vibration energy transmitted to the substrate 100 through the mechanism.

Referring to the enlarged view of FIG. 1, the reinforcing part 200 is implemented with a viscoelastic tape having viscoelastic properties to maximize the friction of the damping layer 220 to damp vibrations, and a constraint layer made of the same material as the substrate 100 ( 210) may be a cross-stacked laminate.

The viscoelastic tape has a viscoelastic material, and may be a variety of materials capable of adhering the constraint layer 210 to be laminated. Preferably, the viscoelastic tape is implemented with 3M966, which is used for various materials requiring high adhesion, heat resistance, moisture resistance, solvent resistance, and the like. Here, the 3M966 tape satisfies the outgassing characteristic of the space application standard in addition to the above-mentioned properties, and as a product with a space mission application record (Space Heritage), it must satisfy the outgassing standard in order to be used for space. can

Accordingly, a plurality of high-damping laminated printed circuit boards 10 are laminated to connect the substrate 100 with a tape having a reinforcing part 200 having viscoelastic properties, and the vibration response in the form of bending behavior that appears when vibration is transmitted is viscoelastic on both sides. It can be effectively damped due to friction between the tape and the printed circuit board.

According to an embodiment of the present invention, in the high-damping laminated printed circuit board 10 , the damping performance of the electronic board is improved as the number of laminated layers of the reinforcing unit 200 increases, and the number of laminates can be adjusted as needed. have. The improvement of the performance of the electronic board according to the number of laminations of the reinforcing part 200 will be described in detail with reference to the free damping test and the vibration test of FIGS. 5 to 10 .

Referring to FIG. 2 , the reinforcing part 200 includes a first reinforcing line 202 formed along an edge of the substrate 100 on the rear surface of the substrate 100 and opposing surfaces of the first reinforcing line 202 , respectively. The damping layer 220 and the constraining layer 210 may be stacked along the second reinforcing line 204 formed by connecting them. Here, the first reinforcing line 202 and the second reinforcing line 204 may be formed to have a preset thickness.

It also includes a center hole 206 at the center of the second reinforcement line 204 .

The center hole 206 at the center of the second reinforcing line 204 may apply a uniform pressure to the lamination part during the lamination process to enable uniform adhesion. To this end, a separate interface for fastening M3 bolts can be provided at the center and outside of the jig for lamination work.

In addition, a guide hole 208 is included at the edge of the first reinforcing line 202 .

In FIG. 3 , the four guide holes 208 of the corners of the first reinforcement line 202 of the reinforcement unit 200 are formed between the substrate 100 - the constraining layer 210 and the constraining layer 210 - the constraining layer 210 . It may be provided for passing a guide pin for alignment.

According to an embodiment of the present invention, the reinforcing part 200 may be formed in a rectangular shape and may be formed in a shape connecting the middle of each side. Specifically, the reinforcing part 200 does not cover the entire substrate 100 , is provided with a predetermined thickness along the edge of the substrate 100 where the interface hole is not provided, and is provided with a predetermined thickness in the middle of each side facing each other. It may be formed in the form of connecting at the position. The shape of the reinforcing part 200 may be implemented as shown in FIG. 3 to ensure a fatigue life according to a reduction in dynamic displacement of the substrate with high damping characteristics implemented by friction, to alleviate vibration, and at the same time to minimize weight and volume. .

According to an embodiment of the present invention, the high damping laminated printed circuit board 10 may be fixed by connecting the substrate 100 and the reinforcing part 200 through the damping layer 220 , but is not limited thereto. .

4 is a flowchart illustrating a method of manufacturing a high-damping multilayer printed circuit board using viscoelastic properties according to an embodiment of the present invention. The manufacturing method of the high damping laminated type printed circuit board is performed to manufacture the high damping laminated type printed circuit board, and a detailed description and overlapping description of the high damping laminated type printed circuit board will be omitted.

A method of manufacturing a high-damping laminated printed circuit board using viscoelastic properties includes the steps of preparing a substrate for connecting a circuit between a plurality of components through a circuit layer in which a circuit layer is formed on one surface of an insulating layer (S410) and on the rear surface of the substrate and seating (S420) a reinforcing part for damping vibration transmitted to the substrate.

In the step (S420) of seating the reinforcing unit for damping vibration transmitted to the substrate on the rear surface of the substrate, a restraining layer made of the same material as the substrate and a damping layer forming viscoelastic properties may be laminated.

In the step (S420) of seating the reinforcing unit for damping the vibration transmitted to the substrate on the rear surface of the substrate, the damping layer and the constraining layer formed of a viscoelastic material may be cross-stacked and fixed.

In the step (S420) of seating the reinforcing part for damping the vibration transmitted to the substrate on the rear surface of the substrate, the damping layer may be implemented with a viscoelastic tape.

In the step (S420) of seating the reinforcing part for damping the vibration transmitted to the substrate on the rear surface of the substrate, the damping performance of the substrate is improved by adjusting the number of laminations of the constraining layer and the damping layer, and the number of laminations may be formed to be several mm or less. can

A circuit layer is formed on one surface of the insulating layer, and the step of preparing a substrate for connecting a circuit between a plurality of components through the circuit layer (S410) is a step of forming an interface hole provided at the opposite edge of the substrate for fastening to the device includes Here, the interface hole may be formed so as not to contact the reinforcing part.

Although it is interposed as sequentially executing each process in FIG. 4, this is merely illustrative, and those skilled in the art change the order described in FIG. 4 within the range that does not depart from the essential characteristics of the embodiment of the present invention. Alternatively, various modifications and variations may be applied by executing one or more processes in parallel or adding other processes.

5 to 10 are diagrams showing test results according to the number of layers of reinforcing parts of a high-damping multilayer printed circuit board using viscoelastic properties according to an embodiment of the present invention.

The high damping laminated printed circuit board used in the test of FIGS. 5 to 10 uses the first printed circuit board, the second printed circuit board, and the third printed circuit board.

According to an embodiment of the present invention, the first printed circuit board, the second printed circuit board and the third printed circuit board form a printed circuit board (PCB, Printed Circuit Board) material of FR-4 (PCB/Layer) and , forming the dimensions of 243 X 160 X 2.4.

According to an embodiment of the present invention, the first printed circuit board represents layer 0, forms a viscoelastic layer, and forms a mass of 196 (grams). Here, the first printed circuit board may mean a pure printed circuit board to which the reinforcement part is not applied.

According to an embodiment of the present invention, the second printed circuit board represents three layers, and a pure printed circuit board (2.4 mm) forming a viscoelastic layer and a reinforcing part (1.5 mm) are combined. A substrate is formed and a mass of 214 (grams) is formed.

According to an embodiment of the present invention, the third printed circuit board represents five layers, and a pure printed circuit board (2.4 mm) forming a viscoelastic layer and a reinforcing part (2.5 mm) are combined. A substrate is formed and a mass of 224 (grams) is formed.

In the graphs of FIGS. 5 to 10 , Case 1 represents a first printed circuit board, Case 2 represents a second printed circuit board, and Case 3 represents a third printed circuit board.

5 is a graph showing the free attenuation history of the substrate for each case according to the number of laminations of the reinforcing parts of the high damping multilayer printed circuit board using the viscoelastic properties according to an embodiment of the present invention.

In order to understand the basic characteristics of high-damping multilayer printed circuit boards, a free attenuation test is performed for each case. Here, a clamped-clamped condition of a high-damping multilayer printed circuit board can be implemented by using a bracket instead of an actual wedgelock, and the test can be performed at room temperature of 20°C.

In the free attenuation test result according to the first printed circuit board, the first natural frequency (1st Eigenfrequency) is 120.7 (Hz), and the damping ratio is 0.013.

In the free attenuation test result according to the second printed circuit board, the first natural frequency (1st Eigenfrequency) is 134.2 (Hz), and the damping ratio is 0.034.

In the free attenuation test result according to the third printed circuit board, the first natural frequency (1st Eigenfrequency) is 143.3 (Hz), and the damping ratio is 0.048.

Referring to the test results, the damping ratio was improved by 2.6 times and the first natural frequency by 1.1 times according to the second printed circuit board stacked in three layers based on the first printed circuit board stacked in 0 layers, and the third printed circuit board stacked in five layers was improved by 2.6 times. It can be seen that the damping ratio according to the printed circuit board is improved by 3.7 times and the first natural frequency by 1.2 times.

Therefore, it can be confirmed from the test results that the damping performance and rigidity of the substrate are improved as the number of stacks increases. In particular, it can be seen that the damping ratio is improved by about 3.7 times in the third printed circuit board in which the five layers are stacked.

6 is a graph showing changes in the natural frequency and damping ratio of the substrate according to the number of layers of reinforcement parts of the high-damping multilayer printed circuit board using viscoelastic properties according to an embodiment of the present invention.

The influence of the characteristics of the high damping laminated printed circuit board according to the temperature condition was studied, and the experiment was conducted at -20°C to 60°C.

Since the viscoelastic tape is sensitive to temperature changes due to the characteristics of the material, it is possible to examine the influence of the stiffness and damping properties of the laminate substrate through the free damping test according to the temperature conditions.

Although the characteristic change of the substrate and the viscoelastic tape according to the temperature condition is somewhat observed, it can be confirmed that the damping ratio, which is the most important for ensuring the fatigue life, is about twice as high as that of Case1 in which Case2 and Case3 are laminated with 0 layers. Therefore, it is possible to ensure the improvement of fatigue life in the general operating temperature range of electrical equipment.

7 is a configuration showing a firing motion test of a high-damping laminated printed circuit board using viscoelastic properties according to an embodiment of the present invention.

The firing motion test can be performed to prove the effect of increasing the high damping performance and fatigue life of the proposed board concept, and to prove the structural integrity of the laminated part peeling due to fatigue accumulation. Here, the laminated part is a reinforcing part, and it may represent that the restraining layer and the damping layer of the reinforcement part are laminated|stacked.

Solder joint lifetime evaluation based on daisy-chain resistance measurement was performed.

Referring to FIG. 7 , the third printed circuit board 12 of Case 3 was used, and both sides of the third printed circuit board 12 were fixed with a test jig 300 .

A daisy chain 330 may be formed on the upper surface of the third printed circuit board 12 . The daisy chain 330 means that all internal circuits of the device are continuously connected, and in this study, it can be used to measure the time of fatigue failure of the solder part under a vibration environment. Although the internal circuits of each of U1 to U4 devices are all connected, the circuits between the devices are all separated, so that the time of fatigue failure of each solder joint can be measured. Each of the separated circuits may be respectively connected to the cable 330 of FIG. 7 , and may refer to U2, U1, U3, and U4 from the left.

The upper surface of the third printed circuit board 12 may include an accelerometer 320 for input control and an accelerometer 310 for output measurement.

The standard of the firing motion test using the third printed circuit board 12 of Case 3 is that the frequency is 20 Hz and the acceleration power spectrum density (PSD) is 0.026 g ² /Hz, and the frequency is the acceleration at 50 Hz. The power spectrum density is 0.160 g ² /Hz, the acceleration power spectrum density is 0.160 g ² /Hz at the frequency of 800 Hz, and the acceleration power spectrum density is 0.026 g ² /Hz at the frequency of 2000 Hz. Here, the standard deviation value of the acceleration according to each frequency is 14.14 (grms), which is the same. Grms is a value representing the average acceleration when the acceleration changes with respect to time.

Referring to FIG. 7 , the printed circuit board includes solder joints of U1, U2, U3, and U4.

Therefore, it is formed like the third printed circuit board 12 of Case 3 of FIG. 7 to perform a vibration test through the first printed circuit board, the second printed circuit board, and the third printed circuit board, and the results are shown in FIG. It can be confirmed through 8 to 10.

8 is a graph showing result 1 according to the firing motion test through the printed circuit board according to an embodiment of the present invention.

8 shows the response characteristics according to the application of the lamination part.

In response characteristics according to the application of the stacked part of the first printed circuit board, the effective acceleration value (RMS Acceleration, Root Mean Square Acceleration) is 42.64 (grms), and the maximum displacement is 0.99 (mm).

In response characteristics according to the application of the stacked part of the second printed circuit board, the effective acceleration value (RMS Acceleration, Root Mean Square Acceleration) is 32.41 (grms), and the maximum displacement is 0.48 (mm).

In response characteristics according to the application of the stacked part of the third printed circuit board, the effective acceleration value (RMS Acceleration, Root Mean Square Acceleration) is 25.87 (grms), and the maximum displacement is 0.27 (mm).

Referring to test result 1, grms was 1.31 times and displacement decreased by 2.06 times according to the second printed circuit board stacked in three layers based on the first printed circuit board stacked in 0 layers, and the third printed circuit stacked in five layers It can be seen that grms according to the substrate are reduced by 1.65 times and displacement by 3.67 times.

Accordingly, it can be confirmed that the displacement of the third printed circuit board of Case 3 is reduced by a maximum of 3.67 times with high damping performance compared to the non-stacked first printed circuit board of Case 1 .

9 is a graph showing result 2 according to the firing motion test through the third printed circuit board according to an embodiment of the present invention.

9 shows the result of measuring the daisy chain resistance value for the purpose of measuring the fatigue life of each element of the first printed circuit board, and when fatigue failure occurs, a vertical line may be generated as shown in U1 of FIG. 9 .

9 shows the solder joint fatigue life, and only the fatigue life of the first printed circuit board can be shown.

Fail occurs at the solder joint of the U1 package of the first printed circuit board of Case 1 and the second printed circuit board specimen of Case 2, whereas no failure occurs in the third printed circuit board of Case 3 even after excitation for 38 hours. Here, Fail may indicate that the lifespan has expired, and No Fail may indicate that the lifespan has not expired.

In the fatigue life of the solder joint according to the lamination part application of the first printed circuit board, the exposure time is 20 (hr), and the time to failure of U1 is 4.63 (hr). Here, the time to break may represent a lifetime.

In the fatigue life of the solder joint of the second printed circuit board, the exposure time is 20 (hr), and the rupture time of U1 is 6.19 (hr).

In the case of the third printed circuit board, although it was exposed to a vibration environment for 38 (hr), fracture did not occur in the solder joint, so the fracture time could not be measured.

Referring to test result 2, the rupture time according to the second printed circuit board stacked in three layers increased by 1.3 times based on the first printed circuit board stacked in 0 layers, and the breakage time according to the third printed circuit board stacked in five layers was increased by 1.3 times. It can be seen that the time increases by more than 8.2 times.

Therefore, it can be confirmed that the fatigue life of the electronic package can be expected at least 8.2 times higher than that of the first printed circuit board of Case 1, which is not laminated.

10 is a graph showing the result 3 according to the firing motion test through the third printed circuit board according to an embodiment of the present invention.

10 shows the structural integrity of the laminate. From the comparison of the natural frequencies of the laminated substrate before and after the test and the comparison of the laminate using an optical microscope, it can be confirmed that delamination does not occur.

Figure 10 (a) shows that the delamination does not appear before and after the test on the second printed circuit board of Case 2, and (b) of Figure 10 shows the before and after test of the third printed circuit board of Case 3 It shows that delamination does not appear.

The test duration (Test Duration) for the second printed circuit board in Case 2 is 20 (hr), and the frequency before and after the test is the same at 130 (Hz).

It can be seen that the test duration (Test Duration) for the third printed circuit board in Case 3 is 38 (hr), and the frequency before and after the test is almost unchanged from 135 (Hz) to 132.5 (Hz).

Therefore, it can be confirmed that there is no change in the dynamic properties of the substrate through the frequency change before and after the test. Here, the dynamic characteristic represents an operation characteristic when a time change of an input affects an output in the operation of a component, a circuit, a device, or the like.

A printed circuit board may undergo repetitive bending behavior in a vibrating environment. Fatigue is accumulated in the solder joint due to the bending behavior, and eventually, there may be a problem in that damage due to the accumulation of fatigue occurs. Conventionally, the rigidity of the substrate was increased by applying a metal reinforcing material to ensure fatigue life, but it resulted in an unavoidable increase in volume/weight. Therefore, the present invention proposes a high-damping-based electrical component design technique, rather than a conventional rigidity-based design, to reduce bending behavior. The proposed high-damping laminated printed circuit board can be advantageous in reducing the risk of damage to the board due to dynamic displacement in the firing motion environment and guaranteeing the fatigue life of the solder joint with only a small volume/weight compared to the existing metal reinforcement.

Even if all the components constituting the embodiment of the present invention described above are described as being combined or operated in combination, the present invention is not necessarily limited to this embodiment. That is, within the scope of the object of the present invention, all the components may operate by selectively combining one or more.

The above description is merely illustrative of the technical idea of the present invention, and those of ordinary skill in the art to which the present invention pertains may make various modifications, changes and substitutions within the scope without departing from the essential characteristics of the present invention. will be. Accordingly, the embodiments disclosed in the present invention and the accompanying drawings are intended to explain, not to limit the technical spirit of the present invention, and the scope of the technical spirit of the present invention is not limited by these embodiments and the accompanying drawings . The protection scope of the present invention should be construed by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

10: high damping laminated printed circuit board
100: substrate
200: reinforcement
210: constraint layer
220: damping layer

Claims (13)

a substrate having a circuit layer formed on one surface of the insulating layer and connecting circuits between a plurality of components through the circuit layer; and
It is laminated on the rear surface of the substrate, and includes a reinforcing unit for damping vibration transmitted to the substrate,
The reinforcing part includes a restraining layer made of the same material as the substrate and a damping layer forming viscoelastic properties,
The reinforcement portion may include: a first reinforcement line formed along an edge of the substrate on the rear surface of the substrate and including a guide hole formed in the edge; and a second reinforcing line formed to connect opposite surfaces of the first reinforcing line, respectively, and including a central hole formed in the center;
The reinforcing part is uniformly adhered by applying a uniform pressure when the constraining layer and the damping layer are laminated through the center hole, and a guide pin is applied to the guide hole to laminate the substrate, the constraint layer, and the constraint layer A high-damping laminated printed circuit board, characterized in that it aligns an arrangement between the constraining layers to be formed. According to claim 1,
The reinforcement part,
A high-damping laminated printed circuit board, characterized in that a plurality of damping layers formed of a viscoelastic material and the constraining layers are cross-stacked and fixed. 3. The method of claim 2,
The first reinforcing line and the second reinforcing line are formed to have a predetermined thickness. 3. The method of claim 2,
The substrate is
A high-damping laminated printed circuit board, characterized in that the damping performance is improved by adjusting the number of laminations of the constraining layer and the damping layer. delete According to claim 1,
The substrate is
A high-damping laminated printed circuit board comprising an interface hole for fastening to the wedge lock. 7. The method of claim 6,
The interface hole is
A high-damping laminated printed circuit board, wherein a pair is provided at opposite edges of the board and does not come into contact with the reinforcing part. preparing a substrate having a circuit layer formed on one surface of the insulating layer and connecting circuits between a plurality of components through the circuit layer; and
Comprising the step of seating the reinforcing part for damping the vibration transmitted to the substrate on the rear surface of the substrate,
In the step of seating the reinforcing part, a restraining layer made of the same material as the substrate and a damping layer forming viscoelastic properties are laminated,
The step of seating the reinforcement part is formed along the edge of the substrate on the rear surface of the substrate, and is formed to connect a first reinforcement line including a guide hole formed at the edge and opposite surfaces of the first reinforcement line, respectively, , A plurality of the damping layer and the constraining layer are cross-stacked along a second reinforcing line including a central hole formed in the center,
In the step of seating the reinforcing part, a uniform pressure is applied during lamination of the constraining layer and the damping layer through the center hole so that they are uniformly adhered, and a guide pin is applied to the guide hole to apply a guide pin to the substrate, the constraining layer, and the A method of manufacturing a high-damping laminated printed circuit board, characterized in that the arrangement is arranged between the constraint layer and the constraint layer to be laminated. 9. The method of claim 8,
The step of seating the reinforcing part is
A method of manufacturing a high-damping laminated printed circuit board, characterized in that the damping layer formed of a viscoelastic material and the constraining layer are cross-stacked and fixed. 10. The method of claim 9,
The step of seating the reinforcing part is
The method of manufacturing a high-damping laminated printed circuit board, characterized in that the damping layer implemented as a viscoelastic tape laminates the constraining layer. 9. The method of claim 8,
The step of seating the reinforcing part is
A method of manufacturing a high-damping laminated printed circuit board, characterized in that the damping performance of the substrate is improved by adjusting the number of laminations of the constraint layer and the damping layer. 10. The method of claim 9,
The step of preparing the substrate,
Comprising the step of forming an interface hole provided on the opposite edge of the substrate to be fastened to the appliance,
The interface hole is formed so as not to come into contact with the reinforcing part to attenuate vibration transmitted to the inside of the substrate. delete

Images