Test strip manufacturing method for simulating the peel strength under the inner layer substrate process flow

Abstract

The application discloses a kind of test strip manufacturing method for simulating peel strength under inner layer substrate process flow, it belongs to substrate test technical field, it solves the problem that the test strip of cutting in prior art cannot simulate the actual substrate condition.It mainly includes: sampling two carrier copper foils, double-sided copper foil substrate is formed by once pressing treatment;Copper foil substrate upper and lower surface is carried out electroplating or micro-etching operation;Copper foil substrate upper and lower surface is carried out roughening treatment;Two inner layer substrates are placed on the upper and lower sides of copper foil substrate, and an integrated body is formed by twice pressing treatment;After separating out test substrate, copper foil on test substrate is generated pattern;Finally, test substrate is cut into test strip.The application can realize all designs of inner layer pattern in reality, such as electroplating, micro-etching copper reduction and other actual scene simulation, and the test strip manufactured by the method of the application can verify the actual peel strength of the process flow in actual production.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of substrate testing, in particular, to a test strip manufacturing method for simulating the peeling strength under the process flow of inner-layer substrate. BACKGROUND

[0002] In PCB manufacturing, the bonding strength of copper foil and base material (such as PP resin) directly affects the reliability of the circuit board. The peeling strength is a key indicator for measuring the bonding performance of the two, which needs to be quantitatively evaluated through standardized test strips. The existing method needs to fix the copper foil on a substitute plate by using staples or other methods for flow roughening treatment process. After the flow is completed, the copper foil is removed and pressed according to the normal stacking method. After the pressing is completed, the conductor layer is electroplated to about 25um, and the next step of pattern formation is performed. After completion, the pattern is cut into sample strips for peeling strength test. However, the copper foil attached to the substitute plate is easily damaged during the liquid flow process. Moreover, the copper foil on the substitute plate cannot be electroplated, and only the condition after the direct roughening of the copper foil can be simulated. In reality, the inner-layer pattern needs to be electroplated and micro-etched to reduce the copper, which cannot be achieved. At present, there is a lack of a test strip manufacturing method that can simulate the actual inner-layer pattern conditions. SUMMARY

[0003] The purpose of the present application is to provide a test strip manufacturing method for simulating the peeling strength under the process flow of inner-layer substrate, to solve the problem that the cut test strip cannot simulate the actual substrate conditions in the prior art.

[0004] The present application is achieved by the following technical solutions:

[0005] A test strip manufacturing method for simulating the peeling strength under the process flow of inner-layer substrate, comprising the following steps:

[0006] Step S1, taking two carrier copper foils; the carrier copper foils are provided with a separation layer in the middle;

[0007] Step S2, the two carrier copper foils are clamped with a PP resin layer in the middle, and a double-sided copper foil substrate is formed by one-time pressing treatment;

[0008] Step S3, performing electroplating or micro-etching operation on the upper and lower surfaces of the copper foil substrate;

[0009] Step S4, roughening treatment is performed on the upper and lower surfaces of the copper foil substrate;

[0010] Step S5, placing two inner-layer substrates with PP resin layers on the upper and lower sides of the copper foil substrate, and forming an integral body by two-time pressing treatment;

[0011] Step S6, separating the two test substrates from the separation layer of the copper foil substrate after two-time pressing by a plate separating machine;

[0012] Step S7, generating a pattern on the copper foil on the test substrate in step S6;

[0013] Step S8, cutting the test substrate into test strips.

[0014] Further, the carrier copper foil comprises a peelable copper foil and a carrier, and the peelable copper foil and the carrier are connected by a separation layer.

[0015] Further, the separation layer is a chromium-zinc alloy layer or an organic silane coupling agent layer, and the thickness of the separation layer is 10-50nm.

[0016] Further, in step S2, the carriers of the two carrier copper foils are placed opposite to each other, and the two sides of the copper foil substrate are both peelable copper foils.

[0017] Further, in step S3, the thickness of the peelable copper foil is electroplated to 20-30um.

[0018] Further, in step S6, the test substrate comprises an inner layer substrate, the inner layer substrate is provided with a PP resin layer, and the PP resin layer is provided with a peelable copper foil.

[0019] Further, in step S4, the roughening treatment uses an etching solution containing 50-80g / L sodium persulfate and 10-20ml / L sulfuric acid, the treatment temperature is 30-50℃, and the treatment time is 1-3 minutes.

[0020] Further, in step S6, the test substrate is FR-4 material, the thickness is 0.1-0.3mm, and the test substrate needs to be preheated at 80-100℃ for 20-40 minutes before secondary pressing.

[0021] Further, in step S8, the peel strength test value between the copper foil of the test strip and the PP resin layer is 0.7N / mm, the test environment temperature is 23±2℃, and the relative humidity is 50±5%.

[0022] Compared with the prior art, the beneficial effects of the present application are:

[0023] Compared with the traditional method which can only realize the scene of the surface of the raw material copper foil, the beneficial effects of the present application are that all design of the inner layer pattern in reality can be realized, such as electroplating, micro-etching and copper reduction, and the test strip manufactured by the method of the present application can verify the actual peel strength capability under the process flow in actual production. The present application can obtain two test substrates at the same time in one process, thereby improving the work efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a flowchart of the present application;

[0025] Figure 2 is a schematic diagram of the carrier copper foil of the present application;

[0026] Figure 3 is a schematic diagram of a substrate structure during a one-time lamination process of the present application;

[0027] Figure 4 is a schematic diagram of a test substrate structure of the present application;

[0028] Figure 5 is a schematic diagram of a substrate structure during a two-time lamination process of the present application;

[0029] Figure 6 is a schematic diagram of separation of a separation layer of the present application;

[0030] Figure 7 is a top view of a test strip of the present application;

[0031] Figure 8 is a sectional view of a test strip of the present application.

[0032] In the figure: 1, carrier; 2, peelable copper foil; 3, separation layer; 4, PP resin layer; 5, inner layer substrate. DETAILED DESCRIPTION

[0033] In order to make the technical solutions of the present application better understood by the people in the art, the technical solutions of the present application will be described clearly and completely below in combination with the drawings of the present application. Based on the embodiments in the present application, other similar embodiments obtained by the people in the art without making creative efforts should all belong to the scope of protection of the present application. In addition, the directional words mentioned in the following embodiments, such as “up”, “down”, “left”, “right”, etc. are only the directions of the drawings, therefore, the directional words used are used for illustration but not for limiting the present application.

[0034] The present application will be further described and explained below in combination with the drawings.

[0035] Embodiment 1, a test strip manufacturing method for simulating the peel strength in the process flow of an inner layer substrate, as shown in FIG. 1, comprising the following steps: Figure 1

[0036] Step S1, taking two carrier copper foils; the carrier copper foils are provided with a separation layer 3 in the middle;

[0037] Step S2, the two carrier copper foils are provided with a PP resin layer 4 in the middle, and through a one-time lamination process, a double-sided copper foil substrate is formed;

[0038] Step S3, performing electroplating or micro-etching operation on the upper and lower surfaces of the copper foil substrate;

[0039] Step S4, performing roughening treatment on the upper and lower surfaces of the copper foil substrate;

[0040] ​Step S5, placing two inner layer substrates 5 with PP resin layer 4 on the upper and lower sides of the copper foil substrate, and forming an integrated body by secondary pressing treatment;

[0041] Step S6, separating the copper foil substrate after secondary pressing from the separation layer 3 by a plate separator to obtain two test substrates, thereby improving work efficiency;

[0042] Step S7, generating a pattern on the copper foil of the test substrate in step S6;

[0043] Step S8, cutting the test substrate into a test strip.

[0044] Compared with the conventional method which can only realize the surface scene of the raw material copper foil, the present application can realize all design of the inner layer pattern in reality, such as electroplating, micro-etching and copper reduction, and the actual scene simulation, and the method can verify the actual peeling strength under the process flow in actual production.

[0045] Embodiment 2, a test strip manufacturing method for simulating the peeling strength under the process flow of the inner layer substrate, as shown in Figure 2 The carrier copper foil includes a peelable copper foil 2 and a carrier 1, and the peelable copper foil 2 and the carrier 1 are connected by a separation layer 3. The separation layer 3 is a chromium-zinc alloy layer, the thickness of the separation layer 3 is 50 nm, the initial thickness of the peelable copper foil 2 is 12 μm, and the carrier 1 is an electrolytic copper foil with a thickness of 18 μm.

[0046] As shown in Figure 3 , the carriers 1 of the two carrier copper foils are placed opposite to each other, and the two sides of the copper foil substrate are both peelable copper foils 2. A PP resin layer 4 with a thickness of 80 μm is arranged in the middle. The temperature of the primary pressing treatment is 180°C, the pressure is 30 kg / cm², and the pressing time is 100 minutes.

[0047] After the pressing is completed, the peelable copper foil 2 is electroplated or micro-etched to reduce copper, and the actual scene simulation is completed.

[0048] After the electroplating or micro-etching and copper reduction is completed, the peelable copper foil 2 is subjected to roughening treatment. During the roughening treatment, an etching solution containing sodium persulfate 60 g / L and sulfuric acid 15 ml / L is used, the temperature is maintained at 45°C, and the treatment time is 2 minutes.

[0049] As shown in Figure 4 , the test substrate includes an inner layer substrate 5, the inner layer substrate 5 is provided with a PP resin layer 4, and the PP resin layer 4 is provided with a peelable copper foil 2; the upper and lower inner layer substrates 5 are made of FR-4 type plate material with a thickness of 0.2 mm. Two inner layer substrates 5 with PP resin layer 4 are placed opposite to each other on the upper and lower sides of the copper foil substrate, and the roughened copper foil substrate needs to be preheated at 100°C for 30 minutes before secondary pressing.

[0050] During the secondary lamination process, such as Figure 5 As shown, the pressing temperature was 170℃, the pressure was 30kg / cm², and the pressing time was 100 minutes.

[0051] like Figure 6 As shown, the PCB separator separates the substrates at separation layer 3 to obtain two test substrates; a 1mm wide strip pattern with a spacing of 2mm is formed on the copper foil by etching.

[0052] Finally, cut the test strips into 10mm × 100mm pieces, as follows: Figure 7 and Figure 8 As shown, the test environment temperature was set at 25℃ and the relative humidity at 50%; the measured peel strength was 0.75 N / mm.

[0053] Everything else is the same as in Example 1.

[0054] Example 3: A method for manufacturing a test strip to simulate peel strength under an inner layer substrate process flow. The carrier copper foil includes a peelable copper foil 2 and a carrier 1, connected by a separation layer 3. The separation layer 3 uses an organosilane coupling agent and has a thickness of 10 nm. The initial thickness of the peelable copper foil 2 is 12 μm, and the carrier 1 is an 18 μm electrolytic copper foil. The PP resin layer 4 has a thickness of 60 μm and a dielectric constant of 3.0. This improves the interface stability after high-frequency signal transmission.

[0055] During the first lamination, the two carrier copper foils (carrier 1) are placed facing each other, and both sides of the copper foil substrate are peelable copper foils (2). The PP resin layer (4) sandwiched in the middle has a thickness of 25 μm. The temperature of the first lamination process is 160℃, the pressure is 30 kg / cm², and the lamination time is 100 minutes.

[0056] After lamination, the peelable copper foil 2 is electroplated or micro-etched to reduce copper content, thus simulating the actual scenario.

[0057] After electroplating or micro-etching to reduce copper content, the peelable copper foil 2 is subjected to a roughening treatment. During the roughening treatment, the etching solution is adjusted to 50g / L sodium persulfate and 10ml / L sulfuric acid, the temperature is maintained at 30℃, and the treatment time is 3 minutes to avoid excessive roughening affecting high-frequency loss.

[0058] During the secondary lamination process, the lamination temperature was 160℃, the pressure was 30kg / cm², and the lamination time was 100 minutes. The depaneling machine separated the substrates at point 3 of the separation layer, obtaining two test substrates. A 1mm wide strip pattern with a spacing of 2mm was formed on the copper foil by etching.

[0059] Finally, cut into 10mm x 100mm test strips, the test ambient temperature is normal temperature 25℃, relative humidity 50%; the measured peel strength is 0.72N / mm. The test data fluctuation under high frequency environment (10GHz) is less than 5%.

[0060] The other is the same as example 2.

[0061] The application has been described in detail above, the above is only the preferred embodiment of the application, which cannot limit the scope of the application, that is, all equivalent changes and modifications made according to the scope of the application should still fall within the scope of the application.

Claims

1. A method of manufacturing a test strip to simulate the peel strength under a process flow of an inner layer substrate, the method comprising: It comprises the following steps: ​ Step S1, sampling two carrier copper foils; a separation layer (3) is arranged in the middle of the carrier copper foils; the carrier copper foils comprise a peelable copper foil (2) and a carrier (1), and the peelable copper foil (2) and the carrier (1) are connected by the separation layer (3); Step S2, a PP resin layer (4) is arranged in the middle of the two carrier copper foils, and a double-sided copper foil substrate is formed through one-time pressing; the carriers (1) of the two carrier copper foils are placed in opposition, and both sides of the copper foil substrate are peelable copper foils (2); Step S3, electroplating or micro-etching is performed on the upper and lower surfaces of the copper foil substrate; Step S4, roughening treatment is performed on the upper and lower surfaces of the copper foil substrate; Step S5, two inner layer substrates (5) are placed on the upper and lower sides of the copper foil substrate, and an integrated body is formed through two-time pressing; Step S6, the copper foil substrate is separated into two test substrates at the separation layer (3) through a plate separating machine; the test substrate comprises an inner layer substrate (5), the inner layer substrate (5) is provided with a PP resin layer (4), and the PP resin layer (4) is provided with a peelable copper foil (2); Step S7, the copper foil on the test substrate in step S6 is patterned; Step S8, the test substrate is cut into a test strip.

2. The method of claim 1, wherein the test strip is manufactured by a process flow of simulating the release strength of the inner layer substrate, the process flow comprising: The separation layer (3) is a chromium-zinc alloy layer or an organosilane coupling agent layer, and the thickness of the separation layer (3) is 10-50 nm. ​ 3. The method of claim 1, wherein the test strip is manufactured by a process flow of simulating the release strength of the inner substrate, the process flow comprising: In step S3, the thickness of the peelable copper foil (2) is electroplated to 20-30 um. ​ 4. The method for manufacturing a test strip for peel strength under simulated inner layer substrate process flow according to claim 1, characterized in that: In step S4, the roughening treatment adopts an etching solution containing 50-80 g / L of sodium persulfate and 10-20 ml / L of sulfuric acid, the treatment temperature is 30-50 ℃, and the treatment time is 1-3 minutes.

5. The method for manufacturing a test strip for peel strength under simulated inner layer substrate process flow according to claim 1, characterized in that: In step S6, the test substrate is made of FR-4 material, the thickness is 0.1-0.3 mm, and the test substrate needs to be preheated at 80-100 ℃ for 20-40 minutes before two-time pressing.

6. The method for manufacturing a test strip for peel strength under simulated inner layer substrate process flow according to claim 1, characterized in that: In step S8, the peelable strength test value between the copper foil of the test strip and the PP resin layer (4) is 0.7 N / mm or more, the test environment temperature is 23±2 ℃, and the relative humidity is 50±5%.

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