Process for bonding a heat sink plate with a printed board film

Abstract

The present application relates to a kind of special-shaped structure heat dissipation plate and printed board film sticking process, S1 film sticking process formulation→S2 bonding tool design→S3 tool production→S4 film etching data processing→S5 film etching→S6 film punching→S7 cold sticking→S8 tool positioning→S9 preheating→S10 hot pressing→S11 cooling→S12 disassembly tool→S13 processing;The present application is prepared by parameter formulation technology, the force received by the process parameters prepared in combination with the stress area of special-shaped structure cold plate and the contact area with printed board when hot pressing can meet the film sticking pressure requirement, can ensure that bonding assembly is not damaged in hot pressing link and heat dissipation plate and printed board are bonded together, and meet the requirements of bonding peel strength.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of film bonding process, in particular to a film bonding process of a special-shaped structure heat dissipation plate and a printed board. BACKGROUND

[0002] At present, the integration degree of aerospace electronic equipment is higher and higher, and the energy density is larger and larger. One problem brought by miniaturization, integration and modularization is that a large number of surface mounted components and modules are integrated on the surface of the printed board, thereby causing a large heat flux of the printed board.

[0003] When the product is subjected to environmental stress screening, under high temperature conditions, the components are likely to fail due to heat dissipation problems, so it is very urgent to pursue a simple and effective heat dissipation method.

[0004] One of the common methods is to install a heat dissipation fin in the printed board. The commonly used heat dissipation fins are metal materials, and aluminum and copper are the most common. Non-metallic materials such as epoxy board, glass, ceramic and fluoroplastic. The circuit board assembled with the heat dissipation fin has greatly improved heat conductivity, dimensional stability, vibration resistance and appearance protection, and the thermal expansion and contraction of the components on the printed board is relieved, thereby improving the reliability and service life of the electronic equipment. Through the research of the present application, the process of bonding the special-shaped structure heat dissipation plate is improved, and the bonding efficiency and bonding quality are improved.

[0005] At present, in the prior art, the bonding method of the special-shaped structure heat dissipation plate on the market mostly adopts liquid adhesive bonding method. The anti-peeling strength and high temperature resistance of the assembly bonded by this bonding method are not as good as film bonding. SUMMARY

[0006] In view of the above-mentioned shortcomings in the prior art, the present application provides a film bonding process of a special-shaped structure heat dissipation plate and a printed board, thereby the special-shaped structure is analyzed in detail, the force-bearing area of the material is analyzed in the process development link, and the optimal film bonding process parameters are developed.

[0007] The technical scheme adopted by the present application is as follows:

[0008] A film bonding process of a special-shaped structure heat dissipation plate and a printed board, comprising the following operation process:

[0009] S1: film bonding process development;

[0010] The size of the special-shaped structure is researched, the positioning mode and tooling are developed, and the required pressure value is calculated according to the contact area of the special-shaped structure heat dissipation plate and the printed board, and the film bonding process parameters are developed;

[0011] S2: bonding tooling design;

[0012] Through the research on the structure of the heat dissipation plate and the size of the printed board, the basic structure of the bonding positioning tool is confirmed, and the tool with anti-static, anti-impact and fast positioning is considered;

[0013] S3: tool production;

[0014] According to the size of the designed tool and the production clamping process, the tool production raw materials are purchased, and the tool is produced;

[0015] S4: film engraving data processing;

[0016] The electronic file data produced by the cold plate is converted into a format that can be used by the film engraving machine, and is edited and typeset; S5: film engraving;

[0017] Cut the KAPTON adhesive film according to the required size, and adsorb the cut KAPTON adhesive film to the film engraving machine; load the corresponding data edited, and start the film engraving machine to engrave the film.

[0018] As a further improvement of the above technical solution:

[0019] Tear off the KAPTON adhesive film, clean the inside of the KAPTON adhesive film with a sharp cone; place the finished product film with paper to avoid direct contact between the finished product films;

[0020] S7: cold bonding;

[0021] The production personnel place the finished product film in the same position as the heat dissipation plate, use a syringe to inject a small amount of adhesive into the bonding surface, and until the cold plate and the adhesive film are completely bonded and flat;

[0022] S8: tool positioning;

[0023] Confirm the bonding surface of the printed board, take out the cold bonded heat dissipation plate, put the printed board and the heat dissipation plate into the tool, and ensure that the printed board and the heat dissipation plate are embedded in the tool;

[0024] S9: preheating;

[0025] Take a piece of kraft paper and a high-temperature-resistant film, fold them in half, and clamp the bonding assembly in the middle, with the cold plate facing up, and put it into a drying box for heating;

[0026] S10: hot pressing;

[0027] Put the preheated bonding assembly into the vulcanizing machine for heating and pressing;

[0028] S11: cooling;

[0029] After hot pressing, take the bonding assembly out of the vulcanizing machine and place it in the middle position between two steel plates for cooling.

[0030] Push out the adhesive assembly from the hollow part of the tooling;

[0031] S13: processing;

[0032] The production personnel use a blade or a sharp cone to clean the excess glue on the edge part, and use anhydrous ethanol to clean the surface.

[0033] Further technical solutions thereof are:

[0034] In S2, the tooling precision is controlled within ±0.05mm.

[0035] In S3, when the production process is replaced, a quick positioning and clamping tooling needs to be designed to ensure that the adhesive tooling can be quickly produced to ensure the overall progress of the adhesive.

[0036] In S9, the high-temperature-resistant film is inside and ensures that there is no foreign matter inside the kraft paper and the high-temperature-resistant film.

[0037] In S9, the film sticking preheating temperature is 123℃, and the preheating time is 5min.

[0038] In S10, the film sticking hot pressing temperature is 135℃, the pressure is 0.5-1MPA, and the hot pressing time is 15min.

[0039] In S11, the cooling time is 5min.

[0040] The beneficial effects of the present application are as follows:

[0041] The present application determines the process parameters by parameter determination technology, which can meet the film sticking pressure requirements by combining the force received by the stress area of the special-shaped structure cold plate and the contact area with the printed board during hot pressing, can ensure that the adhesive assembly will not be damaged during hot pressing and the heat dissipation plate and the printed board are bonded together, and can meet the adhesive peel strength requirements.

[0042] The present application effectively solves the problems that the conventional film sticking process parameters may cause excessive or insufficient stress on the special-shaped structure heat dissipation plate due to structural characteristics during the bonding process, resulting in bonding quality problems; by analyzing the special-shaped structure heat dissipation plate, a set of special process parameter conversion method is mastered, so that the bonded assembly produced will not damage the bonded plate, and the bonding strength can be guaranteed, and the bonding quality is obviously improved compared with the conventional process. DETAILED DESCRIPTION

[0043] The specific embodiments of the present application will be described below.

[0044] The film sticking process of the special-shaped structure heat dissipation plate and the printed board of the present embodiment includes the following operation process:

[0045] S1: film sticking process determination;

[0046] The size of the special-shaped structure is studied, the positioning method and tooling are formulated, and the required pressing value is calculated according to the contact area of the special-shaped structure heat sink and the printed board, and the film sticking process parameters are formulated;

[0047] S2: bonding tool design;

[0048] By studying the structure of the heat sink and the size of the printed board, the basic structure of the bonding positioning tool is confirmed, and the tooling with anti-static, anti-impact and fast positioning is considered;

[0049] S3: tooling production;

[0050] According to the design tooling size combined with the production clamping process, the tooling production raw materials are purchased, and the tooling is produced;

[0051] S4: film engraving data processing;

[0052] Convert the electronic file data of the cold plate production into a format that can be used by the film engraving machine, and edit and typeset it; S5: film engraving;

[0053] Cut the KAPTON adhesive film according to the required size, and adsorb the cut KAPTON adhesive film to the film engraving machine; load the corresponding data edited into the film engraving machine, and start the film engraving machine to engrave the film.

[0054] Tear off the KAPTON adhesive film according to the shape, and use a sharp cone to clean the internal residual slices of the KAPTON adhesive film; place the cleaned finished film with paper to avoid direct contact between the finished films;

[0055] S7: cold bonding;

[0056] The production personnel place the finished film and the heat sink bonding surface in coincidence, use a syringe to inject a small amount of adhesive into the bonding surface, and until the cold plate and the adhesive film are completely bonded and flat;

[0057] S8: tool positioning;

[0058] Confirm the bonding surface of the printed board, take out the cold bonded heat sink, and place the printed board and the heat sink into the tooling to ensure that the printed board and the heat sink are embedded in the tooling on all four sides;

[0059] S9: preheating;

[0060] Take a piece of kraft paper and a high-temperature-resistant film, fold them in half, and clamp the bonding assembly in the middle, with the cold plate facing up, and place it in a drying oven for heating;

[0061] S10: hot pressing;

[0062] Place the preheated bonding assembly into the vulcanizing machine for heating and pressing;

[0063] S11: cooling;

[0064] After hot pressing, the bonded assembly is taken out of the vulcanizing machine and placed in the middle position between two steel plates for cooling.

[0065] The bonded assembly is pushed out from the hollow part of the tooling;

[0066] S13: processing;

[0067] The production personnel use a blade or a sharp cone to clean the excess glue on the edge part, and use anhydrous ethanol to clean the surface.

[0068] In S2, the tooling precision is controlled within ±0.05mm.

[0069] In S3, when the production process is replaced, a quick positioning and clamping tooling needs to be designed to ensure that the bonding tooling can be quickly produced to ensure the overall progress of the bonding.

[0070] In S9, the high-temperature-resistant film is inside and ensures that there is no foreign matter inside the kraft paper and the high-temperature-resistant film.

[0071] In S9, the film sticking preheating temperature is 123℃, and the preheating time is 5min.

[0072] In S10, the film sticking hot pressing temperature is 135℃, the pressure is 0.5-1MPA, and the hot pressing time is 15min.

[0073] In S11, the cooling time is 5min.

[0074] The film sticking process of the special-shaped structure heat dissipation plate and the printed board according to the present application has the following process route:

[0075] S1 film sticking process development→S2 bonding tooling design→S3 tooling production→S4 film etching data processing→S5 film etching→S6 film punching→S7 cold sticking→S8 tooling positioning→S9 preheating→S10 hot pressing→S11 cooling→S12 disassembly tooling→S13 processing.

[0076] Specifically:

[0077] Film sticking process development: After receiving the to-be-bonded plate, the process personnel research its structure and size, develop a suitable positioning method and tooling according to the uneven stress characteristics of the special-shaped structure heat dissipation plate, calculate the required pressure value according to the contact area between the special-shaped structure heat dissipation plate and the printed board, and develop the film sticking process parameters.

[0078] Bonding tooling design: Through research on the structure of the heat dissipation plate and the size of the printed board, the basic structure of the bonding positioning tooling is confirmed, and the tooling that can realize quick positioning with anti-static and anti-impact functions is considered, and the tooling precision is controlled within ±0.05mm.

[0079] Tool production: according to the design of the tool shape size combined with production clamping process, the tool production raw materials are purchased, and when the process is replaced during production, the quick positioning and clamping tool is designed to ensure that the bonding tool can be quickly produced to ensure the overall progress of the bonding.

[0080] Data processing: convert the electronic file data produced by the cold plate into a format that can be used by the film engraving machine, and edit and layout.

[0081] Film engraving: cut KAPTON adhesive film according to the required size, and adsorb the cut KAPTON adhesive film to the film engraving machine; load the corresponding edited data, and start the film engraving machine to engrave the film.

[0082] Film punching: take the engraved KAPTON adhesive film from the film engraving machine, tear the KAPTON adhesive film along the shape, and use a sharp cone to clean the internal residual slices of the KAPTON adhesive film; the finished product film is placed separately with paper to avoid direct contact between the finished product films.

[0083] Cold bonding: the production personnel place the finished product film and the heat dissipation plate with the bonding surface coinciding, use a syringe to inject a small amount of adhesive into the bonding surface until the cold plate and the adhesive film are completely bonded and flat.

[0084] Tool positioning: confirm the bonding surface of the printed board, take out the cold bonded heat dissipation plate, and place the printed board and the heat dissipation plate into the tool to ensure that the printed board and the heat dissipation plate are embedded in the tool on all four sides.

[0085] Preheating: take a piece of kraft paper and a high-temperature-resistant film, fold them in half (the high-temperature-resistant film is inside and ensure that there are no foreign objects in the kraft paper and high-temperature-resistant film), clamp the bonding assembly in the middle, and place the cold plate face up into the drying oven for heating; the preheating temperature of the conventional film bonding is 123℃, and the preheating time is 5min.

[0086] Hot pressing: place the preheated bonding assembly into the vulcanizing machine for heating and pressing; the hot pressing temperature of the conventional film bonding is 135℃, the pressure is 0.5-1MPA, and the hot pressing time is 15min.

[0087] Cooling: after hot pressing, take the bonding assembly out of the vulcanizing machine and place it in the middle position between two steel plates for cooling for 5 minutes.

[0088] Disassembly tool: take out the cooled bonding assembly and push it out from the reverse side of the tool.

[0089] Treatment: production personnel use a blade or a sharp cone to clean the excess glue on the edge; use anhydrous ethanol to clean the surface.

[0090] Through the above process, the optimal film bonding process parameters can be easily determined.

[0091] The above description is an explanation of the present application, not a limitation of the application, the scope of the present application is defined by the claims, within the scope of the present application, any form of modification can be made.

Claims

1. A film bonding process between an irregularly shaped heat sink and a printed circuit board, characterized in that: The following operational procedures are included: S1: Membrane bonding process design; The dimensions of the irregular structure are studied, the positioning method and tooling are determined, and the required pressure value is calculated based on the contact area between the heat sink and the printed circuit board of the irregular structure, and the membrane bonding process parameters are determined. S2: Adhesive tooling design; By studying the structure of the heat sink and the external dimensions of the printed circuit board, the basic structure of the bonding and positioning fixture was confirmed, and a fixture with anti-static, anti-impact and rapid positioning functions was comprehensively considered. S3: Tooling production; Based on the external dimensions of the designed tooling and the production clamping process, purchase the raw materials for tooling production and produce the tooling. S4: Membrane data processing; Convert the electronic data produced by the cold plate into a format usable by the engraving machine, and then edit and format it. S5: Engraving; Cut the KAPTON film to the required size, and attach the cut KAPTON film to the etching machine; load the corresponding data that has been edited, and start the etching machine to perform etching; S6: Stamping membrane; Remove the etched KAPTON film from the etcher, peel it off along its shape, and use a sharp awl to clean any remaining chips inside the KAPTON film. Separate the cleaned finished films with paper to prevent direct contact between them. S7: Cold bonding; Production staff place the finished film and the bonding surface of the heat sink plate on the same side, insert a syringe into the bonding surface and inject a small amount of adhesive until the cold plate and the film are completely bonded and flat. S8: Tooling positioning; Confirm the bonding surface of the printed circuit board, remove the cold-bonded heat sink, and place the printed circuit board and heat sink into the fixture, ensuring that all four sides of the printed circuit board and heat sink are embedded in the fixture; S9: Preheating; Take a piece of kraft paper and a high-temperature resistant film, fold them in half, sandwich the adhesive components in the middle, with the cold plate side facing up, and put them in a drying oven to heat; S10: Hot pressing; The preheated bonding components are placed in a vulcanizing machine for heating and pressurization; S11: Cooling; After hot pressing, remove the bonding components from the vulcanizing machine and place them between two steel plates to cool. S12: Disassembly of tooling; Remove the cooled adhesive component and push it out from the cutout on the reverse side of the fixture; S13: Processing; Production staff use blades or sharp awls to clean up any excess glue from the edges and then clean the surface with anhydrous ethanol.

2. The film bonding process between the irregularly shaped heat sink and the printed circuit board as described in claim 1, characterized in that: In S2, the tooling accuracy is controlled within ±0.05mm.

3. The film bonding process between the irregularly shaped heat sink and the printed circuit board as described in claim 1, characterized in that: In S3, when the production process involves process changes, a quick-positioning and clamping fixture needs to be designed to ensure that the bonding fixture can be produced quickly, thereby guaranteeing the overall progress of the bonding process.

4. The film bonding process between the irregularly shaped heat sink and the printed circuit board as described in claim 1, characterized in that: In S9, the high-temperature resistant film is inside, and it is ensured that there are no foreign objects inside the kraft paper and the high-temperature resistant film.

5. The film bonding process between the irregularly shaped heat sink and the printed circuit board as described in claim 1, characterized in that: In S9, the membrane adhesion preheating temperature is 123℃ and the preheating time is 5min.

6. The film bonding process between the irregularly shaped heat sink and the printed circuit board as described in claim 1, characterized in that: In S10, the membrane adhesion hot-pressing temperature is 135℃, the pressure is 0.5-1MPa, and the hot-pressing time is 15min.

7. The film bonding process between the irregularly shaped heat sink and the printed circuit board as described in claim 1, characterized in that: In S11, the cooling time is 5 minutes.