diff --git a/app/controllers/admin/patents_controller.rb b/app/controllers/admin/patents_controller.rb
index 42d7ea2..731f8fa 100644
--- a/app/controllers/admin/patents_controller.rb
+++ b/app/controllers/admin/patents_controller.rb
@@ -26,7 +26,7 @@ class Admin::PatentsController < OrbitMemberController
     redirect_to :action=> 'index'
   end
   def merge
-    @patents=Patent.order_by(:year=>'desc').map{|value| value}.group_by{|v| [v[:patent_title],v[:patent_no]]}
+    @patents=Patent.sort_year_date.map{|value| value}.group_by{|v| [v[:patent_title],v[:patent_no]]}
     @patents.each do |key,value|
       if value.length<=1
         @patents.delete key
@@ -49,7 +49,7 @@ class Admin::PatentsController < OrbitMemberController
   end
 
   def index
-    @patents = Patent.order_by(:year=>'desc').page(params[:page]).per(10)
+    @patents = Patent.sort_year_date.page(params[:page]).per(10)
   end
 
   def new
diff --git a/app/controllers/personal_patents_controller.rb b/app/controllers/personal_patents_controller.rb
index 565c4d1..af58c96 100644
--- a/app/controllers/personal_patents_controller.rb
+++ b/app/controllers/personal_patents_controller.rb
@@ -3,7 +3,7 @@ class PersonalPatentsController < ApplicationController
   def index
     params = OrbitHelper.params
     page_data_count = OrbitHelper.page_data_count
-    patents = Patent.where(is_hidden: false).sort_for_frontend.page(OrbitHelper.params[:page_no]).per(page_data_count)
+    patents = Patent.sort_for_frontend.page(OrbitHelper.params[:page_no]).per(page_data_count)
     fields_to_show = Page.where(page_id: params[:page_id]).first.custom_array_field rescue []
     if fields_to_show.blank?
       fields_to_show = %w[
diff --git a/app/models/patent.rb b/app/models/patent.rb
index 28cce00..0593686 100644
--- a/app/models/patent.rb
+++ b/app/models/patent.rb
@@ -34,7 +34,9 @@ class Patent
 
   before_validation :add_http
 
-  scope :sort_for_frontend, ->{ where(:is_hidden=>false).order_by(:year => "desc", :application_date => "desc", :publish_date => "desc") }
+  index({year: -1, application_date: -1, publish_date: -1, _id: -1}, { unique: false, background: false })
+  scope :sort_year_date, ->{ order_by(:year => "desc", :application_date => "desc", :publish_date => "desc", :id => "desc") }
+  scope :sort_for_frontend, ->{ where(:is_hidden=>false).order_by(:year => "desc", :application_date => "desc", :publish_date => "desc", :id => "desc") }
 
   def member_profile()
     (super || MemberProfile.find(self.member_profile_id)) rescue nil
diff --git a/app/views/plugin/personal_patent/_profile.html.erb b/app/views/plugin/personal_patent/_profile.html.erb
index e3f50c5..006271b 100644
--- a/app/views/plugin/personal_patent/_profile.html.erb
+++ b/app/views/plugin/personal_patent/_profile.html.erb
@@ -7,9 +7,9 @@
 
 <%
   if has_access?
-    @patents = Patent.where(member_profile_id: @member.id).desc(:year).page(params[:page]).per(10)
+    @patents = Patent.where(member_profile_id: @member.id).sort_year_date.page(params[:page]).per(10)
   else
-    @patents = Patent.where(is_hidden: false, member_profile_id: @member.id).desc(:year).page(params[:page]).per(10)
+    @patents = Patent.where(is_hidden: false, member_profile_id: @member.id).sort_year_date.page(params[:page]).per(10)
   end
 %>